ENGINEERING ACOUSTIC SYSTEM by Bash Sound Acoustics

WE ARE ENVIRONMENTALLY-FRIENDLY

We are increasingly concerned about using recyclable and environmentally-friendly raw materials. The recyclable materials used in our manufacturing processes come from plastic, cotton, artificial wood and glass fiber reinforced materials. The recyclable materials of our products consist of wood from self-sustainable forests, fabric, ceramics and chipboards.

Engineering Acoustic System

Recycling is the process of converting waste materials into new materials and objects.

Our painting method uses ecological paints with environmentally harmless dyes and components with no active solvents. Recycling offers an indeterminate number of advantages. It prevents soil and water contamination, reduces the volume of waste that goes to the sanitary landfills, generates jobs for many people and saves natural resources. In the course of the years, Bash Sound Acoustics has become aware of the need to reduce waste that pollute the planet. This is an issue that concerns us all, especially in the industrial world. https://bashsoundinc.com

Product Catalogue Engineering Acoustic System

info@bashsoundinc.com

All products and pictures related to the scheme are attributable to Bash Sound Acoustics Unauthorized tampering with the content, unauthorized diversion, counterfeiting will be held legally accountable.

201901

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ABOUT US

CATALOGUE

T50/100/150

Ceiling absorber

About Bash Sound Acoustics

Sound Absorption Coefficient

Bash Sound Acoustics is a company located in Dubai that specializes in

When a sound wave comes in contact with building surfaces i.e. walls,

the research, development and manufacturing of acoustic products. In

ceiling and floor, the incident wave will be partially absorbed by the wall

CT30/60/120

pursuit of technical innovation, we have been producing acoustic

surfaces which possesses a certain level of robustness and rigidity,

CT60-400R/800R/1200R

products with excellent acoustic performance, suitable for various

which exhibit certain sound absorption capability. The ratio of the

MT320K/S/B

environments.

energy absorbed by the surfaces and the incident energy is termed as

MD48-300/600/1200

We provide a wide range of products for designers to choose from. With

the Sound Absorption Coefficient. The Sound Absorption Coefficient is

CM30/60/120

a perfect combination of absorption and diffusion, the products are

the fraction of sound energy absorbed by a material. Expressed as a

suitable for different areas.

value between 1.0 (Perfect absorption, no reflection) and 0 (Zero

The three series; Easy Acoustic System, Engineering Acoustic System

absorption, total reflection). The value varies with frequency and angle

and OFF® - Sound Insulation Damping System, we satisfy the different

of incidence, determined experimentally. Metric unit is Sabin per square

requirements for fixed and portable acoustic treatment as well as

meter. It is a quotient of Sabine absorption of a surface by area of the

soundproofing and vibration control. It is our passion to provide

surface and is also known as the Sabine sound absorption coefficient.

professional, affordable and convenient acoustic solutions to ser ve the

With αi as the Sabine absorption coefficient of the i-th surface whose

acoustic industr y with our experience and Know-how.

area is Si, the Sabine absorption attributed to the surface is Ai = Siαi.

T50X/100X/150X

end audio equipment is needed for good sounding hall. This lack in acoustic knowledge is the reason why most halls are hard to hear in. As a

Column ceiling absorber

Column ceiling absorber Magic block acoustic panel

Fabric acoustic panel

5 6 7 8 9

Special Pattern Fabric Acoustic Panel

CM30E/60E/120E

Fabric acoustic panel (Environmental Friendly)

CQ30/60/120

Special Pattern Fabric acoustic panel

SR25/50/25B Energy

Acoustic reflection board

SD-A/B/C/D/E/F/G Energy MLS800

In large halls, there is a misconception that simple acoustics and high-

Ceiling absorber

CQ30E/60E/120E

DIY300

Architectural Acoustics and Electroacoustics

Mesh ceiling absorber

Acoustic diffusion panel

Acoustic diffuser unit Original wood sound diffuser unit

13 14 17 18

Original wood sound diffuser unit

Eco wood sound diffuser unit

D8S

Aq3500

Movable Sound Reflection Baffle

Aq4000

Sound Diffusion Stand

Grooved acoustic panel

Solid wood grooved acoustic panel

CK-1

Perforated acoustic panel

discipline that cannot be learnt without effort and experience. People

CK-2

Perforated acoustic matrix panel

are always misled by the idea that the so-called acoustic design is merely

CK-3

Perforated acoustic nest panel

a connection of equipment to give out sound. However, specialized skills

CK-16

result, the expected sound effects pitifully cannot be realized, despite a large amount of investment. In fact, acoustic design for halls along with corresponding treatment measures has long been a highly specialized

Jumboard perforated acoustic panel

and rich engineering experience are required to ensure reliability, MG48-50/50T

Yellow acoustic wool

system design, to achieve uniformity between the cultural and regional

ME48-50/50T

White acoustic wool

background of the equipment. The business targets need to realize

MP24-20

Byer acoustic fiber panel

practicality, maintainability, coordinated product mix and ingenious

proper sound field distribution, control of electroacoustic technical National standard references

Application reference for stadium

to relevant national standards, architectural acoustics and

Application reference for classroom

electroacoustic design must be simulated for the halls with

Application reference for church and mosque

electroacoustic equipment.

Application reference for music hall

Application reference for multi-functional hall

Application reference for cinema

indicators, reliable construction arrangement and noise control, as well as interaction between building acoustics and hall aesthetics. According

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CEILING ABSORBER

Name: Ceiling Absorber

Name: Mesh Ceiling Absorber

Model No.: T50 / 100 / 150

Model No.: T50X / 100X / 150X

Installation method: Horizontal, vertical

Installation method: Horizontal, vertical Color : White/Beige/black non-inflammable acoustic fiberglass cloth

Color: Beige/black non-inflammable acoustic fiberglass cloth 2

Weight: 5.5kg/m /11.5kg/m / 13.5kg/m

Weight: 7kg/m 2 /13kg/m 2 / 15kg/m 2

Consumption: Refer to acoustic design

Structure: Surrounding aluminum alloy frame; Owens Corning sound

absorption wool; Airtight sound absorption felt; Non-inflammable,

water proof, sound absorption fabric.

water proof, sound absorption fabric. Wrapping stretch resistant, blow

Fire protection performance: Grade A

out proof protective aluminum mesh

Environmental protection: Formaldehyde emission≤0.4mg/L,

Fire protection performance: Grade A

meeting requirement in Indoor Decorating and Refurbishing

Environmental protection: Formaldehyde emission≤0.4mg/L, meeting

Materials-Limit of Formaldehyde Emission of Wood-based Panels

requirement in Indoor Decorating and Refurbishing Materials-Limit of

and Finishing Products (GB18580-2001); better than the national

Non-inflammable acoustic fiberglass cloth

E1 standard requirement, i.e. 0.15mg/m standard limit Beige

Black

Emission of fiberglass particles within 24 hours 1.7mg/m

Formaldehyde Emission of Wood-based Panels and Finishing Products

Non-inflammable acoustic fiberglass cloth

Beige

White

(GB18580-2001); better than the national E1 standard requirement, i.e.

Black

0.15mg/m 3 standard limit

Emission of fiberglass particles within 24 hours 1.7mg/m 3

Common specification: ≤W600 * L4000 * D50/100/150mm Lifting hole Aluminum frame Glass wool Fiberglass cloth Safety hole

multi-functional halls to control the reverberation time.

Structure detail drawing

Ceiling installation example

1.1

1.1 1.0

0.9

multi-functional halls to control the reverberation time

Horizontal installation

0.5 0.4 0.3

Frequency (Hz)

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0.5 0.4 0.3 T150X T100X T50X

0.2

3150

2500

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1600

1250

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1000

630

500

400

315

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160

0.0

100

0.1 125

3150

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125

0.1

4000

T150 T100 T50

0.2

0.6

5000

0.6

0.7

4000

Absorption Coefficient

0.8

0.7

5000

Absorption Coefficient

0.8

Scope of application: Large venue, e.g. Gymnasiums and

Structure detail drawing

1.0

0.0

Common specification: ≤W600 * L4000 * D50/100/150mm

Lifting hole Aluminum frame Glass wool Fiberglass cloth Safety hole Aluminum mesh

Scope of application: Large venue, e.g. Gymnasiums and

Frequency (Hz)

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CEILING ABSORBER

Name: Ceiling Absorber

Name: Column Ceiling Absorber

Model No.: CT30 /60 / 120

Model No.: CT 60-400R / 800R / 1200R

Installation method: Horizontal, vertical

Installation method: Horizontal, vertical, Configuration

Color: White/Beige/black non-inflammable acoustic fiberglass cloth

Color : White/Beige/black non-inflammable acoustic fiberglass cloth

Weight: 4kg/m / 7kg/m / 12.5kg/m

Weight: 7kg/m 2

Consumption: Refer to acoustic design

Structure: Surrounding aluminum alloy frame;

Airtight sound absorption felt; Non-inflammable, water proof,

Airtight sound absorption felt; Non-inflammable, water proof, sound absorption fabric.

sound absorption fabric. Non-inflammable acoustic fiberglass cloth

Fire protection performance: Grade A

Fire protection performance: Grade A/B1 White

Environmental protection: Zero formaldehyde emission, meeting

Beige

Black

Environmental protection: Zero formaldehyde emission, meeting requirement in Indoor Decorating and Refurbishing Materials-Limit of

requirement in Indoor Decorating and Refurbishing Materials-Limit Non-inflammable acoustic fiberglass cloth Black

1.1

Formaldehyde Emission of Wood-based Panels and Finishing Products

Products (GB18580-2001); better than the national E1 standard

1.0

(GB18580-2001); better than the national E1 standard requirement,

0.9

i.e. 0.15 mg/m 3 standard limit;

requirement, i.e. 0.15mg/m standard limit Emission of fiberglass particles within 24 hours 1.2mg/m 3

Lifting hole Aluminum frame Glass wool Fiberglass cloth Safety hole

Common specification: â&#x2030;¤W600 * L4000 * D30/60/120mm Scope of application: Large venue, e.g. Gymnasiums and multi-functional halls to control the reverberation time

0.8 Absorption Coefficient

Beige

White

of Formaldehyde Emission of Wood-based Panels and Finishing

Emission of fiberglass particles within 24 hours 1.2mg/m 3

0.7 0.6

Common specification: R400/800/1200 * D60mm

0.5

Scope of application: Large venue, e.g. Gymnasiums and multi-functional

0.4

halls to control the reverberation time

0.3 0.2 CT60

0.1

Structure detail drawing 45Â°suspension installation

5000

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0.0

Frequency (Hz) 1.1 1.0 Ceiling installation example

0.9

Absorption Coefficient

0.8 0.7 0.6 0.5 0.4 0.3 CT120 CT60 CT30

0.2 0.1

5000

3150

4000

2500

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1250

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630

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0.0

Frequency (Hz)

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CEILING ABSORBER

Name: Column Ceiling Absorber

Name: Magic Block Acoustic Panel

Model No.: MT320S / 320K / 320B

Model No.: MD48-300/600/1200

Installation method: Horizontal and vertical

Location of suspension: Attached to the ceiling or wall surfaces

Installation location: Ceiling rack

Color : Black, white, beige

Consumption: Refer to acoustic design

Weight: 1.5kg/m 2

Weight: MT320K 7.6kg /pcs; MT320S 7.2kg /pcs; MT320B 6.2kg /pcs

Consumption: 60% of Ceiling area

Fire protection performance: Base material Grade A

Fireproof performance: Non-inflammable grade A

Structure: MT320K / 320S:Perforation rate 11-28% cylindrical alloy;

Structure: Inner fit with broad band green sound absorptive wool, Airtight sound absorption felt; Non-inflammable, water proof, sound absorption fabric.

MT320B: cylindrical fabric

MT320K

MT320S

MT320B

Filled with capacious sound absorption fiber wool to form a broadband

Accessories: Ceiling pins

frequencies absorber.

Common specification: L1200 / 600 * W600 / 300 * D60mm

Accessories: Bolt rings

Scope of application: Bars; Games center, Machiner y room, Production line

Specification: White

Light Green

Green

Light Yellow

320 * 1000mm

Scope of application: Gymnasiums, airports and bus stations, etc. to control

Orange

the reverberation time Light Brown Dark Brown Light Grey Dark Grey

Non-inflammable acoustic fiberglass cloth

Beige

White

Black

1.1 1.0

Absorption Coefficient

0.9

Installation

0.8 0.7 0.6 0.5 0.4 0.3 0.2

MD48

0.1

1.1

4000

5000

2500

3150

1600

2000

1000

1250

630

800

400

500

315

200

250

125

100

0.9

160

0.0

1.0

Frequency (Hz)

Absorption Coefficient

0.8 0.7 Installation 0.6 0.5 0.4 0.3

Ceiling

MT320B MT320S MT320K

0.2 0.1

Magic sound absorption block Ceiling pin 5000

4000

3150

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1000

630

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0.0

Frequency (Hz)

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FABRIC ACOUSTIC PANEL

Name: Fabric Acoustic Panel

Name: Special Pattern Fabric Acoustic Panel

Model No.: CM30E/60E/120E

Model No.: CQ30E/CQ60E

Base material: 80kg/m high structure micropore fiber glass wool

Base material: 80kg/m 3 high structure micropore fiber glass wool

Fireproof grade: Base material grade A ; cloth grade B / C flame retardant

Fireproof grade: Base material grade A ; finishing cloth optional for grade B / C flame retardant

Frame: Light high - strength metal frame

Frame: Light high - strength aluminum frame

Finish: Acoustic cloth(Grade A/B/C)/Imagine Spray painting

Main features: Patented easily mounting solution; Zero formaldehyde emission meets

Main features: Easy installation; Zero formaldehyde emission meets International E0 standard;

International E0 standard; This new design functions much better than the older type

This new design functions much better than the older type by the more precise frame,

by the more precise frame, Eco-friendly, flame retardant and moisture proofing.

Eco-friendly, flame retardant and moisture proofing. .

M-softpack solves the older type whose sound absorbing function is sacrificed at

Size: External diameter ≤1200 * 2400mm. Thickness 30 / 60 mm

least 10% because of the resin solidified frame.

Scope of application: office, meeting room, classroom, canteen, café, etc. .

Size: Each edge ≥300mm ≤2400mm Thickness30 / 60 / 120mm Scope of application: Conference rooms, recording rooms, studios, multi-functional halls, and large auditoriums, etc. 1.1

Right angle

45 beveling metal frame Zero formaldehyde emission white fiber Fiberglass enclosure layer

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3150

2000

2500

1600

1000

Frequency (Hz)

1250

630

800

400

500

250

315

160

200

100

125

45 o beveling metal frame Zero formaldehyde emission white fiber Fiberglass enclosure layer

3150

2500

1600

2000

1000

1250

800

500

630

315

0.0

400

Acoustic cloth finish Fiberglass enclosure layer

CQ60E CQ30E

0.1

250

0.1

5000

0.2

0.0

Chamfer

CM120E CM60E CM30E

0.3 0.2

160

0.3

200

0.4

0.5 0.4

100

0.5

0.6

125

0.7 0.6

0.8 0.7

5000

4000

Absorption Coefficient

0.8

0.9

4000

Acoustic cloth finish Fiberglass enclosure layer

1.0 0.9

1.0

Absorption Coefficient

1.1

Frequency (Hz)

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FABRIC ACOUSTIC PANEL

Name: Fabric Acoustic Panel

Name: Special Pattern Fabric Acoustic Panel

Model no.: CM30/60/120

Model no.: CQ30/60

Base material: 80kg/m high structure micropore fiber glass wool

Base material: 80kg/m3 high structure micropore fiber glass wool

Fireproof grade: Base material grade A; cloth grade B / C flame retardant

Frame: Light high - strength metal frame

Finish: Acoustic cloth(Grade A/B/C)/Imagine Spray painting

Main features: patented easily installed solution; Up to International E0 standard; This new

design functions much better than the old softpack with more standard frame, Eco-friendly,

flame retardant and moisture proofing. In this design, M-softpack performs much better in

flame retardant and moisture proofing.

sound absorption than the older one whose sound absorbing function is sacrificed at least

Size: External Diameter ≤2400mm Thickness30 / 60 mm

10% because of the resin solidified frame.

Scope of application: office, meeting room, classroom, canteen, café, etc. .

Size: Each edge ≥300mm ≤2400mm Thickness30 / 60 / 120mm Scope of application: Conference rooms, recording rooms, studios, multi-functional halls, and large auditoriums, etc. Right angle Acoustic cloth finish Fiberglass enclosure layer 45 o beveling metal frame 80kg/m 3 Glass wool Fiberglass enclosure layer

0.3 0.2

5000

2500

3150

1600

2000

1250

800

1000

500

0.0

4000

CQ60 CQ30

0.1

630

3150

2500

2000

1600

45 o beveling metal frame 80kg/m 3 Glass wool Fiberglass enclosure layer

315

Frequency (Hz)

1250

800

1000

630

500

400

315

250

200

160

125

100

0.1 0.0

0.5 0.4

400

0.2

5000

CM120 CM60 CM30

0.6

200

Acoustic cloth finish Fiberglass enclosure layer

250

Chamfer

0.3

0.8 0.7

125

0.5 0.4

0.9

160

0.6

1.1 1.0

Absorption Coefficient

0.8 0.7

4000

Absorption Coefficient

0.9

100

1.1 1.0

Frequency (Hz)

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DIFFUSER

Name: Acoustic Reflection Board

Name: Acoustic Diffusion Panel

Model No.: SR25/SR50/SR25B

Model No: SD25A/B/C/D/E/F/G

Base material: High density calcium silicate board/high density flame retardant board

Base material: Rubber wood/ HDF(Flame retardant)

Fire protection performance: Grade A/B

Finish: Wood veneer/HPL/PU matte paint

Environmental protection: Tested and found totally in accordance with the national

Main features: The energy acoustic diffuser is mainly used for the proscenium of the halls and

environmental protection E1 standard

the box boom at two sides with the purpose to reflect the sound wave to the auditorium in the

Finish: Solid wood/veneer fully matte open type NC paint, with moisture proof and mould

halls to prevent acoustic coloration, sound focusing and standing wave to make the sound

proof treatment

more exquisite and accurate

Main features: The reflection board is mainly used for the proscenium of the halls and the box boom at two sides with the purpose to reflect the sound wave to the auditorium in the

Common specification: Refer to dimensions of various products; Sizes are optional Scope of application: Music halls, Multi-functional halls, Auditoriums, etc.

SD25-A( 1m ) (Developed surface1m 2 )

halls to prevent acoustic coloration, sound focusing and sound field problem of standing wave to make the sound more exquisite and accurate; the product is greatly effective for

White

Light Green

Green

Original

Redwood

Walnut

tone tuning and necessar y for acoustic places Light Yellow Orange

Common specification: W600 * L1200/2400 * D25/50mm

Light BrownDark Brown Light Grey Dark Grey

Black

Scope of application: Music halls, multi-functional halls, large auditoriums, etc. White

Light Yellow Orange

Light Green

Green

Original

Redwood

Light Brown Dark Brown Light Grey Dark Grey

Diffuser Application Principle (I)

Walnut

The sound wave is continuously reflected on various reflection surfaces in the rooms, and the

Black

transmission direction keeps on changing. This type of sound field that can make the sound wave at any position in the rooms transmit in all directions is called diffusion sound field. In a strict 1.1

sense, a diffusion sound field must meet the following three requirements:

1.0

Absorption Coefficient

0.9

Clamp

0.8

1.The indoor sound energy density is uniform, i.e. the sound energy density is the same

0.7

everywhere;

Keel

0.6

2.The chance of the sound energy being transmitted in all the directions is equal;

0.5 0.4

3.The phase of the sound wave from all the indoor directions to any point is irregular. In such a

0.3

Acoustic reflection board

SR50 Reflection

0.2

SR25 Reflection

4000

5000

2500

3150

1600

2000

1000

1250

630

800

400

500

250

315

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0.0

125

0.1

Sound absorption glass wool

SD25-B( 1m ) 2 (Developed surface1m )

sound field, the sound wave will not accumulate no matter in terms of spatial position or transmission direction; instead, the sound wave expands and diffuses along with the progress of transmission until it covers all the space and all the directions.

Frequency (Hz)

Clamp

Keel

Diffuser Features: 1.Possible to have diffusion and reflection of the sound of various frequency ranges;

Skirting

2.Possible to be hidden in the artistic design of the audio-visual rooms of the theaters; 3.Simultaneous installation and testing with sound absorption treatment.

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DIFFUSER

Diffuser Application Principle (II)

Diffuser Application Principle (III)

During the design and arrangement of diffusers, the following matters shall be noted:

With good diffusion characteristics, the sound attenuation is smooth and the

(1)The diffusers cannot be used as the sound absorbers at the same time;

indoor sound is uniform at different places. All the convex surfaces have the

(2)The diffusers shall as much as possible be made of materials with a large specific

capability to diffuse the sound wave, including inclined surfaces, curved

gravity and certain rigidity, such as concrete, plastered masonry, marble and granite;

surfaces and convex curved surfaces. In case the diffusion sound wave

(3)If wood is used, solid hard wood is preferred, e.g. teakwood, oak, rosewood or hard

frequency is restricted by the dimensions of the convex surfaces, diffusion

wood, with multi-layered composition board on the surface. It is prohibited to use threeply board or five-ply board to make hollow ones,which will result in strong absorption of SD25-C( 1m 2 ) 2 (Developed surface1m )

board can be used. The audio rooms have different building acoustic 2

SD25-F( 0.5m ) (Developed surface 0.5m 2 )

characteristics, and different objects have different reflection and absorption

low frequency sound;

performance to the sound. Therefore, to improve the audio environment,

(4)The diffusers shall as much as possible not be cast by gypsum. Though the cost is low,

sound absorption and diffusion treatment in the rooms is an important step

there will be metal sound coloration, negative for the sound quality;

of acoustic treatment.

(5)For good diffusion effect, the geometric dimensions of the diffusion surfaces of the diffusers must match with the sound wave length. According to diffusion theories, if the dimensions of the diffusers are fixed, the diffusion degree of the indoor sound wave increases progressively along with the increase of frequency. Therefore, during the design of sound diffusion, diffusers with large dimensions shall be used to improve the diffusion 2

capability for low sounds.

SD25-G( 0.6m ) (Developed surface 0.6m 2 )

SD25-D( 1.1m 2 ) 2 (Developed surface1.1m )

SD25-E( 1.1m 2 ) 2 (Developed surface1.1m )

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DIFFUSER

Name: Acoustic Diffuser Unit

Name: Original Wood Sound Diffuser Unit

Model No.: MLS800

Model No.: DIY300

Base material: Solid rubber wood / HDF flame retardant board / MDF

Base material: Solid rubber wood

Environmental protection: In accordance with national environmental protection

Environmental protection: Tested and found totally in accordance with national

standards

environmental protection standards

Finish: Veneer paint/PP finishing/ HPL/PU matte paint

Finish: Raw wood NC paint, raw wood color, light red wood, dark red wood

Main features: To achieve a diffusion acoustic field; To avoid fluttering echoes; Ensure the

Main features: This adjustable combined sound absorption diffuser is composed of

rich music and sense of space.

solid wood diffusion strip and sound absorption soft strip. It can make adjustment to

Common specification: H1200 * W3100 * D175mm; Customized size is optional

the reverberation time as per the uses. With free combination, it can provide both

Scope of application: Music halls, Multi-functional theaters to improve sound richness

good diffusion sound field and clean sound, effectively improving the fullness, articulation and stereoscopic impression of the environmental sound. Common specification: L2400 * W300 * D100mm Scope of application: Wall mounted at high grade places e.g. music halls, home theaters, HIFI listening rooms and recording rooms, and places requiring improvement of sound quality and articulation.

MLS800 Acoustic Diffuse unit White

Light Green

Light Yellow Orange

Green

Original

Redwood

Light BrownDark Brown Light Grey Dark Grey

Walnut

Comparing to MLS diffusers, it is a unit diffuse wall panels made by workers at sites,

flexibly, saving spaces. 1.1 1.0 0.9 0.8

Light Yellow Orange

Light Green

Green

Original

Redwood

Walnut

Light BrownDark Brown Light Grey Dark Grey

Black

Easy operation, simple procedure, controllable quality and production time, cost

Variable Reverberation Design to Meet Requirements of Various Functions

effective.

The reverberation time in the rooms is adjusted as per the uses of the rooms to achieve

0.7

comfortable listening effect. In a medium sized theater, the two modes of performance

0.6 0.5

and conference are both important. When a room has more than two acoustic uses,

0.4

4000

5000

2500

3150

1600

2000

1000

Absorption Coefficient

Frequency (Hz)

1250

800

500

630

315

0.8

400

0.9

200

0.1 0.0

250

1.0

160

1.1

100

0.3 0.2

125

Absorption Coefficient

White

which is totally different with traditional processing method. This panel can fit into walls

Black

controllable sound absorption device can ser ve all the uses. This is an acoustic measure with the lowest cost while the best effect. With an adequate number of the devices, the reverberation time in the rooms can be adjusted within the range of 0.3-

0.7 0.6

0.5s.

0.5 0.4 Cotton fill

0.3

No cotton

0.2

5000

3150

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Frequency (Hz)

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DIFFUSER

Name: Original wood sound diffuser unit

Name: Eco Wood Sound Diffuser Unit

Model No.: D8

Model No.: D8S

Base material: Imported beech

Base material: Environmental friendly ecological wood

Environmental protection: Tested and found totally in accordance with

national environmental

national environmental protection standards

protection and firefighting codes

Finish: Ecological raw wood grain (color can be customized)

Finish: Raw wood color NC paint

Main features: The product has good sound diffusion effect and greatly

Main features: The product has good sound diffusion effect and

improves the reverberation time. The acoustic characteristics have

greatly improves the reverberation time.

reached the national standard for materials of the same kind, effectively

The acoustic characteristics have reached the national standard for

improving the fullness, articulation and stereoscopic impression of the

materials of the same kind, effectivelyimproving the fullness, articulation White

Light Yellow Orange

Light Green

Green

Original

Redwood

Original

Walnut

Light BrownDark Brown Light Grey Dark Grey

Black

Redwood

environmental sound.

Walnut

and stereoscopic impression of the environmental sound.

Specification: L3000 * W123 * D27 mm

Common specification: L2440 * W100 * D27 mm

Scope of application: Wall mounted at high grade places e.g. multi-

Scope of application: Wall mounted at high grade places e.g. music halls,

functional halls, churches, home theaters and HIFI listening rooms, and

home theaters, HIFI listening rooms and recording rooms, and places

places requiring improvement of sound quality and articulation.

requiring improvement of sound quality and articulation.

Diffusion Theor y

0.80

The QRD diffusers are made of a series of parallel caissons with column variation depth. When the incident sound wave is 135°onto the horizontal QRD, it can reflect the sound out with an equal intensity within the range

Leave 5mm seam to fill 100 thick 32K cotton Leave 3mm seam to fill 100 thick 32K cotton Leave 2mm seam to fill 100 thick 32K cotton Leave 5mm seam to fill 100 thick 48K cotton Leave 3mm seam to fill 100 thick 48K cotton Leave 2mm seam to fill 100 thick 48K cotton

0.70

0.60

of 30°-150°.

Close fitting paste

0.50 1.1 1.0

0.40

Absorption Coefficient

0.9 0.8

0.30

0.7 0.6

0.20

0.5 0.4 Diffusion

0.10

0.3 0.2 Absorption

0.00

Frequency (Hz)

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4000

5000

3150

2000

2500

1600

1000

1250

800

500

630

315

400

250

160

200

125

0.0

100

0.1

100

125

160

200

250

315

400

500

630

800

1000

1250

1600

2000

2500

3150

4000

5000

0.25

0.22

0.26

0.73

0.74

0.69

0.59

0.53

0.47

0.42

0.32

0.30

0.31

0.30

0.23

0.20

0.06

0.57

0.63

0.74

0.64

0.58

0.52

0.48

0.41

0.34

0.29

0.30

0.29

0.28

0.22

0.19

0.04

0.50

0.45

0.44

0.64

0.63

0.60

0.54

0.43

0.39

0.32

0.27

0.29

0.28

0.27

0.25

0.22

0.18

0.06

0.55

0.47

0.45

0.71

0.70

0.68

0.66

0.54

0.49

0.42

0.34

0.33

0.34

0.28

0.29

0.22

0.11

0.52

0.45

0.52

0.55

0.66

0.63

0.56

0.53

0.46

0.38

0.29

0.28

0.27

0.21

0.17

0.68

0.65

0.54

0.55

0.60

0.62

0.56

0.49

0.41

0.35

0.29

0.27

0.25

0.23

0.19

0.17

0.04

0.13

0.11

0.21

0.18

0.19

0.16

0.12

0.09

0.08

0.07

0.06

0.07

0.09

0.14

0.13

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DIFFUSER

Name: Movable Sound Reflection Baffle

Name: Sound Diffusion Stand

Model No.: AQ3500

Model No.: AQ4000

Base material: Composite honeycomb board

Environmental protection: Meeting E0 environmental protection standards

Environmental protection: E0 Eco-friendly

Finish: Absorption side is pile coating; diffusion size PU matte paint(refer to Color

Finish: PP/PU Matte Paint/ Wood Veneer(refer to Color Chart)

Chart)

Main features: Outstanding sound reflection performance; Height adjustable; Movable

Main features: Control reverberation, flutter echoes, standing waves in places of

for different functions and performances; Light honeycomb panel based; ECO-friendly

churches, auditorium, multi-functional halls.

Common specification: H3500 * W1500 * D800 12 Kg/Set

Common specification: H3500 * W800 * D800 mm 60 Kg/Sett

Scope of application: Directional sound reflection of medium and high frequencies

ZSW04

BZ912

W508

PTW05 White

S212

S210

S198

S206

Light Green Light Yellow Light Brown Dark Grey

The Movable Sound Reflection Baffle is an indispensable part for performance of

S203

1.2

natural and original voice/sound. It will be easy to create a environment for the 1.0

performance, making the best of natural sound without amplification system.

0.8

0.6

0.4

Diffusion Coefficient Scattering Coefficient

0.2

Weighted base / silent pulley

Hand lifting device

Absorption Coefficient

Movable air pressure device 0 100

125

160

200

250

315

400

500

630

800

1000 1250 1600 2000 2500 3150 4000 5000

FREQUENCY(Hz)

1.1 1.0

Absorption Coefficient

0.9 0.8 0.7 0.6 0.5 0.4 0.3 0.2 Reflection

5000

3150

4000

2000

2500

1250

1600

800

1000

500

630

315

400

200

250

125

160

0.0

100

0.1

Frequency (Hz)

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GROOVED ACOUSTIC PANEL

Name: Grooved Acoustic Panel

Name: Solid wood Grooved Acoustic Panel

Model No.: SM124-4 / 60-4 / 30-2 / 29-3 / 14-2 / 9-2 / 6-2

Base material: MGP (non inflammable)/HDF (flame retardant)/ MDF

Base material: Solid rubber wood

Finish: Veneer paint/Melamine /HPL/PU matte paint.

Environmental protection: Tested and found totally in accordance with the national

Main features: Based on scientific calculation and acoustic theories, this

environmental protection E0 standard

panel has excellent noise reduction and sound absorption performance,

Finish: PU varnish/NC matte paint.

especially for medium and low frequencies.

Main features: The product has good sound absorption effect and greatly improves

Common specification: L2440 * W128 * D15/18 mm

the reverberation time. The acoustic characteristics have reached the national

Scope of application: Multi-functional halls, conference rooms, cinemas,

standard for materials of the same kind, effectively improving the fullness,

auditoriums and hotels, etc.

articulation and stereoscopic impression of the environmental sound. Common specification: L2440 * W128 * D15/18 mm Scope of application: Wall mounted at high grade places e.g. music halls, home

Wood color Original 124/4

theaters, HIFI listening rooms and recording rooms, and places requiring

White

Light Green

Green

Light Brown Dark Brown Light Grey

60/4

Walnut

improvement of sound quality and articulation.

COLOR CHART 128

Redwood

Light Yellow

Orange

Dark Grey

Black

Sound Absorption Board Installation Drawing

Wall 30/2

MGP (non inflammable)+HDF (flame retardant Grade A)

HDF (flame retardant)+Wood veneer paint(Grade B)

MDF+Melamine Light steel keel (main frame) Lv1 Auxiliary keel Glass Wool

29/3

Lv2 Installation insert Sound absorption board 14/2

Sound absorption board 9/2

6/2

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Lv1 Auxiliary keel

Lv2 Installation insert

LV1/LV2 Installation mode

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GROOVED ACOUSTIC PANEL

Name: Perforated Acoustic Panel

Model No.: CK-1 (5mm digital code)

Model No.: CK-2 (3-10mm in gradual)

Base material: FC (8mm/12mm)

Base material: FC (8 mm / 12 mm)

Environmental protection: In accordance with national environmental protection

standards

Finish: Raw board (Back cloth not included) / Eco friendly paint

Main features: This round holes structure is designed by acoustic theories

Main features: It is designed to control NRC by calculating special holes diameters.

calculation. Excellent function in medium and low frequencies

Adopting different diameters, this panel functions excellently in broad band

Common specification: 300 * 600 mm / 600 * 1200 mm / 1200 * 2400 mm

absorption, including low, medium and high frequencies.

Scope of application: Gymnasium, Multi-functional hall, Conference hall,

Common specification: 300 * 600 mm / 600 * 1200 mm / 1200 * 2400 mm

Classroom, Musical practice room,hearing room etc.

Scope of application: Gymnasium, Multi-functional hall, Conference hall, Classroom, Musical practice room,hearing room etc.

White

Light Green

Green

Light Yellow

Light Brown Dark Brown Light Grey Dark Grey

Orange

White

Black

Light Green

Green

Light Yellow

Light Brown Dark Brown Light Grey Dark Grey

Orange

Black

1.0

1.0 0.9

0.9 0.8

0.7

Absorption Coefficient

0.6 0.5 0.4 0.3 0.2

0.4 0.3

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5000

4000

3150

2500

2000

1600

1250

1000

800

630

500

400

315

250

200

160

0.0

125

5000

4000

3150

2500

2000

1600

1250

800

1000

630

500

400

315

250

200

160

125

100

0.1

Frequency (Hz)

0.5

0.2

0.1 0.0

0.6

100

Absorption Coefficient

0.8 0.7

Frequency (Hz)

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GROOVED ACOUSTIC PANEL

Name: Perforated Acoustic Panel

Name: Jumboard Perforated Acoustic Panel

Model No.: CK-3 (6mm diamond pattern)

Model No.: CK-16 (16mm Big Act)

Material&Finish: FC (8mm) & Raw panel(Back cloth not

Base material: E1 MDF / HDF (flame retardant)

included)/Eco-friendly paint HDF (12mm) & Melamine/Eco-friendly

Finish: PU matte paint

paint/Wood veneer/ Fire retardant veneer.

Main features: Based on scientific calculation and acoustic theories, the round hole structure of the

Main features: Designing by scientific acoustical calculation, this

perforated sound absorption board has excellent noise reduction and sound absorption

panel has excellent noise reduction and sound absorption

performance, especially for high and medium frequencies.

performance, especially for medium and high frequencies.

Common specification: 600 * 1200 mm / 600 * 2400 mm

Common specification: 600 * 1200 mm / 1200 * 2400 mm

Scope of application: Gymnasiums, music halls, opera houses, multi-functional halls and

Scope of application: Multi-functional halls, conference rooms,

auditoriums.

cinemas, auditoriums and hotels, etc. COLOR CHART White

Light Green

Green

Light Yellow

Orange

Dark Grey

Black

COLOR CHART White

Light Green

Green

Light Brown Dark Brown Light Grey

Light Yellow

Orange

Dark Grey

Black

Light Brown Dark Brown Light Grey

Installation keel

LV4-keel

Sound absorption cotton P=12.8%

LV3-keel

Wall

LV3-keel

Light steel keel

Sound absorption board

LV4-keel LV4-keel

Skirting

Installation keel

LV4-keel

Sound absorption cotton

LV3-keel

Wall

LV3-keel

Light steel keel

Sound absorption board

LV4-keel LV4-keel

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Skirting

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ACOUSTIC WOOL

MG48-50

MG48-50T

Name: Yellow Acoustic Wool

Name: White Acoustic Wool

Model No: MG48-50/50T

Model No: ME48-50/50T

Fireproof performance: The fireproof inspection results meet the

Fireproof performance: the fireproof inspection results meet the

requirements of A2 in GB 8624-2006 and can be directly used for

indoor fire prevention.

Color : Yellow

Color : White

Finishing coating

Main features: As it has the advantages of fireproof and anti-corrosion

ME48-50

Finishing coating

performance, no toxicity, small volume weight, low heat conductivity,

Sound Absorption Description With natural ores as the main raw materials, e.g. quartz sand, limestone and dolomite, along with some chemical substances like sodium carbonate and borax, the centrifugal glass wool is smelted into glass. In the melted state, it is blown by external forces to be flocculent fine fibers, which cross and intertwine each other with many small gaps in between. As the fluffy fibers cross each other, there are abundant small holes, and thus it is a typical perforated sound absorption material with good sound absorption

strong chemical stability, and good hydrophobicity etc., it is considered the best heat preser vation, heat insulation, sound absorption and noise reduction material with significant effect, and can be widely used. Common specification: W600 * 1200 * D50mm Density: 48kg/m 3 Scope of application: Acoustic absorption filling

properties. The centrifugal glass wool can be made into wall sheets, ceiling

Main features: it is fireproof, durable and environmental friendly with

ME48-50T

long fibers and without residue balls, not easy to generate dust, helpful for keeping the construction environment clean and thus

Sound Absorption Description

good for the health of the construction personnel. It has good sound

The red environmental friendly centrifugal glass sound absorption cotton is

absorption effect and shows no sinking.

made by fibration of the melted glass and adding of environmental friendly

Common specification: W600 * 1200 * D50mm

bonding agents, mainly thermosetting resin. It is felty and elastic, composed

Density: 48kg/m 3

of glass fibers with a diameter of just a few microns. As the internal fluffy fibers

Scope of application: Acoustic absorption filling

cross each other, there are abundant small holes, and thus it is a typical perforated sound absorption material with good sound absorption properties.

sheets and spatial sound absorbers, etc. to largely absorb the sound energy in the rooms to reduce the reverberation time and the indoor noise. When there is a layer of air behind the glass wool sheet, the sound absorption effect

Sound Absorption Coefficients

is similar to that of the glass wool sheet of the same thickness without the air Frequency (Hz)

layer. In particular, the sound absorption performance for the medium and Sound absorption coefficient (25mm)

low frequency sound signals will be much better than that of hard bottom surfaces with attached materials. The sound absorption coefficient will

Sound absorption coefficient (50mm)

increase along with the increase of the thickness of the air layer. Through the superposition of glass wool of different volume weight values to gradually

Good flame retardant performance meeting requirements of A2 in GB8624-2006

increase the total volume weight, even better sound absorption effect can be

Test item

achieved.

Average remaining length (mm) Flame retardancy

sound absorption coefficient (reverberation room method) Inflammability

Sound absorption coefficient (25mm)

150

Test result 452.3

Remaining length of any test piece (mm)

Qualified

Average fume peak temperature (â&#x201E;&#x192;)

Edge ignition test

Frequency (Hz)

Surface ignition test

None of the flame tips of the five test pieces reaches the scale mark None of the flame tips of the five test pieces reaches the scale mark

Qualified

Sound absorption coefficient (50mm)

Good flame retardant performance meeting requirements of A2 in GB8624-2006 Test item Average remaining length (mm) Flame retardancy

Test result 587.5

Qualified

Average fume peak temperature (â&#x201E;&#x192;)

Edge ignition test Surface ignition test

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150

Remaining length of any test piece (mm)

Inflammability

None of the flame tips of the five test pieces reaches the scale mark None of the flame tips of the five test pieces reaches the scale mark

Qualified

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NATIONAL STANDARD REFERENCES

ACOUSTIC WOOL

Name: Byer Acoustic Fiber Wool Model No.: MP24-20 Environmental protection: the standard requirement for

Best Reverberation Schedule for Various Halls All the data in the table is taken from the American Architecture Encycloped “Architectural graphic standards (intermediate frequency500-1000Hz)”

formaldehyde emission is 1.5mg/L, while the test result is ≤0.1mg/L, meeting requirement of E1 in the national standard GB18580-2001,

Add clarity Gradually turbid

and thus can be directly used for indoor decoration. Large Choir, Sports Centre

Main features: as it does not contain any resin bonding agent and The polyester fiber sound absorption board is based on the theor y of perforated

has good environmental protection performance, it is mainly used

material sound absorption. There are a large number of small interconnected

for households and some building acoustic places with high

holes inside the polyester fiber sound absorption board materials, and the sound

environmental protection requirements to replace the traditional

wave can go deep inside the material through these holes, and turns the sound

centrifugal glass wool.

energy to be heat energy by means of friction with the materials. It is a type of

Common specification: W500 * 1000 * D20mm

perforated sound absorption materials. Along with the increase of frequency, the

Density: 24kg/m 3

sound absorption coefficient gradually increases, which means that the

Scope of application: Acoustic absorption filling

Classical Symphony Professional choir, disco opera Modern orchestra, recital, club music Entertainment venues Music Drama An open-air concert General Assembly Hall General Assembly Hall moving forward to 2.5 seconds College Auditorium A small cinema

absorption of low frequency sound signals is not as good as that of high cinema

frequency sound signals. The preconditions for sound absorption by the

Lecture hall, conference room

perforated material are as follows: there are a lot of holes in the material, the

Drama production

holes are interconnected, and the holes are deep into the material.

Ordinary teachers Studio, studio

Measured value of sound absorption coefficient (reverberation room method) Reverberation time(s)

Frequency (Hz)

The grade of burning performance of decoration materials in public buildings Sound absorption coefficient (25mm)

Combustion Performance Grades for Decoration Materials Buildings and Places

Sound absorption coefficient (50mm)

Good flame retardant performance meeting requirements of B1 in GB50222-95 B1

Test item Average remaining length (mm) Flame retardancy

Average fume peak temperature (℃)

Inflammability

Surface ignition test

587.5

150

Remaining length of any test piece (mm)

Edge ignition test

Test result

Qualified

0 200

143.7

None of the flame tips of the five test pieces reaches the scale mark None of the flame tips of the five test pieces reaches the scale mark

wall Platfond surface A

＞3000 Seating or located in high-rise and underground buildings

≤3000seat

area＞100m² Or in high-rise and underground buildings

National, provincial

Below provincial level

built-up area＞10000m² High-rise and Underground Buildings

Cinemas, halls, auditoriums, theatres, concert halls

＞800 Seating or located in high-rise and underground buildings

Song and dance halls, restaurants, entertainment buildings, labor intensive production workshops

Decorative fabrics Other Fixed decorative furniture curtain prelude materials B1 B1 B1 B1

Terminal, bus station, railway station, waiting room(ship) restaurant, shopping mall, etc..

Public sports venues

ground cut off

built-up area≤1000m² ≤800seat

Business area≤100m²

Hospital ward building, sanatorium

Qualified Memorial, exhibition hall, museum, library

Below provincial level Environmental indicators meeting requirements of E1 in national standard GB18580-2001 Test item

Test method

Indicator requirement

Scope of application

Test result

Unit conclusion

Air sound insulation standard Weight sound insulation(db) Premium Residence

Formaldehyde emission amount

Drier method

1.5

Grade E1: can be directly used in indoor environments

0.1

Qualified

Crash sound isolation standard Gauge weight standardized impact sound pressure level(db)

Enclosure structural site

Judgedgrade E1

Interhousehold floor

Class B

Class C

≥50

≥45

≥40

≤65

≥40

≥35

Between the ward and the room that makes the noise

≥50

≥45

Between the operating room and the ward

≥50

≥45

≥40

Between the operating room and the room that makes the noise

≥50

≥45

≥50

Hearing room enclosure structure

≤75 ≤65

Guest room and guest room walls

≥50

≥45

≥40

Room and corridor walls(including doors)

≥40

≥35

≥30

External walls of guest rooms(including Windows)

≥40

≥35

≥25

≥20

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≤75

≤65

≤55

≤65

≤75

≤55

≤65

Upper floor of the listening room

Floor floor between guest rooms and various vibrating rooms

Class C ≤75

≥40 ≥45

Guest Room Layers

Class B

≤65

≥45

Walls and floors between general classrooms and various noisy activity rooms

Between Ward and Ward

Hospital

Class A

≤65

General Classroom and Classroom Wall and Floor

Hospital

Premium

≥50

Walls and floors between rooms with special quiet requirements and ordinary teachers School

Class A

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APPLICATION REFERENCE FOR STADIUM

For stadiums, the acoustic design indicators shall be determined from the type, class, scale, uses and features of the stadium using simulations and careful calculations. In case of multiple functions, the acoustic indicators shall be based on the main functions, while other functions are considered by means of diffusion system. The acoustic solutions shall take into consideration structural type, configuration of the venue, loudspeaker setting and fireproof and moisture proof requirements. To deal with sound absorption, reflections and to prevent acoustic defects, the natural sound sources and the loudspeakers shall be taken as the main sound sources, and building acoustic design and sound amplification design shall be carried out simultaneously in coordination.

The broadcasting rooms, commentator's rooms and sound control rooms related to radio and TV ser vices in a stadium shall be subject to acoustic treatment to achieve The correct standards. The practicing rooms/halls, athletes' lounges and coaches' rooms, etc. are provided with wire broadcasting and intercom system, which should be clearly heard throughout the areas. The regulated noise allowance level shall not be exceeded. The impact of noise generated during sports events and by the sports facilities on the surrounding environment shall be in accordance with the current standards of the Standard Environmental Noise of Urban Area. The main acoustic indicators for a stadium are preferred to be in accordance with Table 1. I.The acoustic design for a stadium shall meet the following requirements: a.Adequate sound level at the auditorium to realize the necessar y functions and requirements of a stadium. b.Entire auditorium covered by sound amplification c.Sufficient articulation when transmitting languages and adequate fullness when transmitting music. d.Less acoustic disturbance to the outside. e.Safe structure, easy operation, convenient maintenance, wind resisting, rainproof and reliable performance. II.The sound amplification design indicators of a stadium shall be in accordance with the current industrial standard Code for Acoustical Design and Measurement of Gymnasium (JGJ/T131). The related facilities can be executed according to the current industrial standard Code for Electrical Design of Civil Buildings (JGJ/T16). III. The reverberation time of a stadium shall be subject to a fully occupied situation with 80% audience, which is also taken as the basis for design calculation and inspection. The 500-1000Hz reverberation time indicators of a sports hall of a comprehensive stadium at fully occupied status as well as the ratio of the reverberation time at various frequencies and the reverberation time at 500-1000Hz are preferred to be in accordance with Table 2 and Table 3. IV. In case the sports halls, VIP lounges, sound amplification control room, commentator's rooms and sound amplification broadcasting rooms are not occupied, the background noise limits for the halls/rooms shall be in accordance with Table 4 on the condition of normal operation of ventilation, air conditioning and dimming equipment. V. Noise control shall meet the following requirements: a.Lounge galleries and so on are preferred to be used for the sports halls to isolate external noise, and the lounge galleries are preferred to undergo sound absorption and noise reduction treatment. b.The weighted transmission loss of enclosing structures of the VIP lounges “Rw” shall be determined based on the environmental noise level. c.The partition walls between the TV commentator's rooms shall be of sufficient weighted transmission loss “Rw”; the reverberation time of the commentator's rooms shall not be more than 0.5s within the frequency range of 125-4000Hz. Therefore, the rooms must undergo sound absorption treatment as well as isolation and soundproofing. d.The air supply and return ducts to the sports halls, VIP lounges, control rooms, TV commentator rooms and broadcasting rooms shall be provided with silencing, noise reduction and vibration control. All noise generating hardware should be decoupled and isolated against vibrations. e.The equipment rooms, such as the air conditioner rooms and boiler rooms, shall be away from the rooms with silencing requirements like the sports halls and VIP lounges. If these rooms are adjacent to the main buildings, soundproofing and vibration control should be implemented. Raw board (Back cloth not included)

Design code for spor ts building JGJ 31-2003 Table 1: Recommended Indicators for Stadium Acoustic Design Maximum sound pressure level in the field(dB)

Sound field unevenness(dB)

Table 3: Ratio of Reverberation Time at Various Frequencies and Reverberation Time at 500-1000Hz

Sound reinforcement system(dB)

Regional effective frequency range(Hz)

frequency(Hz) Ratio

Note: According to the different scales of sports venues, relevant indicators may be appropriately changed. Table 4: Background Noise Limits for Halls/Rooms e.g. Sports Halls

Table 2: 500-1000Hz Reverberation Time of a Sports Hall of a Comprehensive Stadium at Fully Occupied Status Comprehensive gym level

The mixing time of the stadium under different volumes

according to the grade (s)

Noise level of different grades and rooms in the gym Hall/ room category

Premium, Class A

Class B and Class C

Competition hall Premium, Class A

VIP lounge

Class B

Sound reinforcement control room

Class C Note: The specified reverberation time indicator allows the range of variation of ±0.15s

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Commentator room Sound reinforcement studio

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APPLICATION REFERENCE FOR CLASSROOM

As teaching methods and contents keep changing, traditional classroom no longer provide a modern teaching environment. To enhance the effect of learning including sensible Understanding strengthening and more knowledge impacting, teachers have to make full use of all kinds of information like pictures, essays, videos etc to integrate students' vision and hearing. Therefore, multi-functional classrooms have become the main current in universities construction. But during construction,building a good sound environment is usually ignored. Sound is a strong tool in multi-functional classrooms teaching to insure clear speeches and music fidelity so as to improve the quality of education. Classrooms acoustic field is essential to modern teaching, integrating vision and hearing effectively for study effectiveness. The acoustic field is affected by many factors for instance, internal and external noise source, interior acoustic design, architectural design and amplification system that require our hard work to make a better sound environment.

1. Interior acoustic factors Based on interior acoustic theories, sound is transmitted by direct sound, early reflections and reverberation. Direct sound is the sound transmitted directly by sound source. In acoustic field, suitable early reflection strengthens direct sound loudness, improving speeches clearness. But sound location will be destroyed so that impact speeches clearness if there's too much reflection. Reverberation is the sound reflected by early reflection. Reverberation is the situation that sound waves keep still when sound source stops. So reverberation exists in obstacle spaces. In the classroom, speeches from teachers will be reflected by walls and become strong reverberation. The more reverberation, the more difficult to identify the speeches. Even the classroom is very quiet, reverberation still exist and make the impact on sound. Comparing to normal person, reverberation adds a further complication to hearing impaired children,making it more difficult to listen and understand. As a result, reverberation control is fundamental to classroom acoustic treatment. Appropriate reverberation helps to obtain a sense of space. While too much reverberation destroys speeches clearness. It depends the ratio of direct sound and early reflection to reverberation. For clearer speeches, direct sound and first two reflection have to be strengthened to be prior to reverberation. The most important, the shorter reverberation time, the better for the sake of clearer, easier understanding speeches. To reduce sound defects for better acoustic environment, it is an effective method to make use of amplifying system to increase sound pressure and clearness so as to balance the acoustic field. In practical application, reverberation should be modified to adapt to different situation. For example, regarding musical hall, low frequencies reverberation is supposed to be stronger than mid and high frequencies to make music richer. The reverberation time is an important parameter for listening music and studio music quality. Civilian architectural sound insulation design specification GBJ118-2010 Chapter Four Classroom acoustic specification Permitted noise level 4.1.1 Noise level in all kinds teaching rooms and subsidiary rooms should be coincided with the graph 4.1.1. Interior noise level

Graph 4.1.1 Permitted Noise Level（A sound pressure，dB） Room Type A

Special requirement

≤40

Common classroom

≤50

Without special requirement

≤55

Note:① Special requirements room are those for language learning rooms, studios and reading rooms. General classrooms are for normal ones for history and geography, science, music, instruments practice, multi media and arts teaching. Rooms without special requirements are those for gymnasium, dancing,operation labs, offices and rest rooms. ② For the situation that nearby noise would distract students' attention(like Singing),permitted noise level is supposed to be 5dB lower than whtat graph 4.1.1 shows. Regarding sound insulation design for school buildings near main road, it is better to arrange playground along the main road to work as sound isolation belt. And it is supposed to design a sound isolation belt with certain distance between factories and teaching buildings. For those classrooms face to playground, distance between classroom walls and playground is not supposed to be less than 25 meters. No.4.3.2 Inside teaching buildings, if there's no certain noise reduction treatment,machinery generate strong noise and vibration is not allowed. No.4.3.3 Corridors,main entrance and ceiling in staircase, if possible, it is supposed to mount absorptive materials NRC >=0.50(500 1000Hz) inside. Or it is acceptable to mount absorptive materials NRC>=0.30 on ceiling and walls. Absorptive materials are supposed to satisfy requirement of fire resistance. No.4.3.4 Reverberation time in all kinds of classrooms shall satisfy regulations on graph 4.3.4.

Graph 4.3.4 Room Type

Common classroom

volume(m 3 )

≤200

＞200

≤300

＞300

≤250

＞250

≤50

＞50

≤2000

＞2000

≤1000

＞1000

500-1000hz RT60s(Empty seated )

≤0.8

≤1.0

≤0.6

≤0.8

≤0.6

≤0.8

≤0.4

≤0.6

≤1.2

≤1.5

≤1.2

≤1.5

Language&Multi media room

Music room

Instrument practice room

Exercise room

Dance studio

Note: 0.1s difference is allowed in above reverberation time graph. 10% difference is allowed for the room volume. No.4.3.5 Rooms arise noise(music rooms, dance studios, instruments practice rooms, exercise rooms) shall be divided into special area and treated by noise reduction measures if they are together with other teaching rooms in the same teaching building.

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Some pictures from the Internet

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APPLICATION REFERENCE FOR CHURCH AND MOSQUE

There are mainly two problems on Church audio system design. With the fast development of modern churches, the electronic band performance is becoming the main way of compliments and worship among churches. But how to set the audio system and make it fulfilling the usage requirements of churches and theaters? To build up a proper acoustic environment is the answer for this. The reproduction of sound can be perfect only if the acoustic environment reconstruction of churches and theaters is proper and good. The sound and music delivers to the disciples and audience is actually the complement and match of electronic sound and acoustic environment reconstruction. Acoustic environment reconstruction is part of natural sound reinforcement, and with the complement of electronic sound amplifying, it creates a good sound field and thus achieves the best audio performance.

According to our projects experiences, the acoustic design for churches can be mainly divided into architectural acoustics and electroacoustics. Architectural acoustics is focusing on controlling the reverberation time, and avoiding the sound defect by well church design. It is embodying by the concept of acoustic feedback, reverberation, sound focusing and sound shadow region and so on. A church with good acoustic environment can easily achieve the lecturing and music performing demand without audio amplifying equipments. Electroacoustics is to ensure enough SPL and even sound field inside the church, and also appropriate performance of the equipments in different applications, so as to present the essence of the sound. Only when architectural acoustics and electroacoustics is well match and complement, it is possible to obtain good art and sound effects with minimum investment. Thus we suggest the church to do architectural acoustics design. 1.Optimum reverberation time (RT60). Reverberation time is an important parameter in sound quality evaluation. Without reverberation, it will be lacking of the sense of space and people inside will feel the sound is dry and dumb. In general, short reverberation time will result in dry, boring sound without warmth and vitality. However, if the reverberation time is too long, the reverb sound on the front will cover up the subsequent direct sound and early reflections, it will cause the bathroom effect and make the sound ambiguous and poor. The length of reverberation time is related to the sound source, so in application, it should be decided by specific demand. The reverberation time ratio between medium frequency (500 Hz) and the other frequencies is an important parameter affecting the sound quality. The reverberation time of low frequency should be longer than medium frequency, so the sound can be rich, vigorous and powerful. Those for high frequency (4kHzď˝&#x17E;8kHz) should be same or slightly shorter than medium frequency, so the bright, gorgeous and exquisite sound can be presented. While at the same time, it wouldn't put too much pressure on the high frequency speakers. The reverberation radius is also called the extreme distance, that is to say, the sound is emitted from the sound source, and transmitted to a certain distance, and then gradually attenuated. In the place where the sound reflections and direct sound is equal, the distance from the sound source to them is called reverberation radius. It is related to the sound clarity. When the sound continue to spread, the reflected sound can not be greater than direct sound, and at this point the sound clarity is poor. According to the actual needs, there should be sound absorbers on wall to attenuate reflection and ensure clarity. 2.Well-balancing absorption and diffusion. When doing the church design, the shape of church should be take into account. Shape design is important in ensuring stable work of audio amplifying system. It includes the wall sound absorption and diffusion inside, and some other acoustic defect. Echoes. Due to the reflection of the wall, if the difference between the direct sound and the reflections is more than 50 milliseconds, or the distance of audience to the two speakers is more than 17 meters, there will generates obvious echoes. Between a pair of parallel walls, a sound in between goes back and forth will also produce a number of such a sound, or between the walls of the regular multilateral form will also occur such phenomenon. Sound focusing. Because of the characteristics of reflected sound, sound will produce sound focusing if meeting the concave wall, the sound pressure level of a point or a small area will much bigger than that of other position, and thus make the sound field uneven. If this happens in the stage, it is very easy to cause howling. Sound shadow region. Because of construction or decoration, the sound of some areas are blocked by buildings, for example, nowadays, many large churches have a lot of pillars, the sound can not be transmitted directly to such area, so only the reverberation and some reflections can be heard here. Dead point. In some small spaces, the sound of certain frequency will be offset because of sound interference. The sound pressure levels will be decreased a lot, and here is called the dead point. Plate cavity resonance. Because of the decoration design, material selection and improper construction, when the SPL of the low frequency in the hall is high, the cavity structure or the decorative plate will be excited and generated resonance. The fractured vibration of the plate will affect the music and singing, thus do badly to the sound quality. The most popular ceiling of church nowadays is wavy shape, whose reflection function is strong, and affects a lot to the whole sound reinforcement system. It will destroy the sound performace and quality, thus we suggest to do good sound absorption treatment on ceiling. But as a natural sound reinforcement, the wavy surface is the most ideal solution. In conclusion, in acoustic design, we should consider the design of interior decorating company, so as to complete a perfect acoustic reconstruction. 3.Control of near reflection sound. There are three forms of sound transmission, that is direct sound, early reflected sound (near reflection), and multiple reflections. The control of the near reflection is to control the reverberation of the whole church, which involves the concept of reverberation radius. It is called extreme distance, when sound travels beyond the limit distance, the direct sound and near reflection will generate a full volume feeling, in this case, we must be control it according to the actual situation. The control of near reflections by effector. Balance of early reflected sound and reverberation sound. The early reflected sound of reverberation is closely related to its processing effect, but the reverberation sound array pitch is not that changeful, so the two parts of the digital reverb are separated. This parameter is used to adjust the early reflected sound and reverberation sound loudness balance matrix.

Some pictures from the Internet

The delay time of early reflected sound and reverberation sound. With longer time, the effect of the front reverberation will be more clear. If this time is shorter, the early reflection sound and reverberation sound will overlap together, so the effect of the front reverberation is more turbid. 4.Background-noise control. The audience background noise includes environment introduction, air conditioning, lighting and sound environment noise. With the improvement of noise control level in China, and in purpose of acting on international convention, the noise control standard is now improved by 5 dB. In the machine rooms, we suggest using mineral wool as absorption board to reduce the noise. Using sound insulation window for optical-controlled room, plastic-steel window for sound control room, and insulating glass. The air conditioning system will transmit the noise through air outlet, so we have to put composite muffler on the air outlet when design, and if needed, can put one on air diffusing outlet.

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APPLICATION REFERENCE FOR MUSIC HALL

The music halls are the buildings for music performance. Specialized music halls came into being In Europe in the 17th centur y. After more than 300

The sound quality design for theaters share the same principles with the design of music halls. The difference is that there is a large stage in theaters and an orchestra pit in front. The acoustic support to the actors on the

years' development and evolution, there have been abundant types of music halls. It is a complicated process to play and listen, as it is closely related

stage depends on the stage setting. Besides, the acoustic power of singing is far less than that of a large orchestra. Thus the selection of forms for sound quality design focuses more on the direct sound intensity and the

to the style of the music pieces, performance level of the musicians and spatial environment of the music halls, etc. Such a combination of art and

volume for the backseat audience. The reason why the traditional horseshoe type multi-storey balcony form is in use is exactly because it shortens the distance from the backseat audience to the stage, and thus provides

science brings substantial difficulty and specificity to the design of music halls.

sufficient volume to the audience, while in the control of the reverberation time and the sound quality defects, it is simpler than music halls. This is because theaters have a wider range of best reverberation time. It can be

In terms of acoustic characteristics, the relation between music playing and music halls is similar to that between the musical instruments of “sound

deemed as the best so long as it is within the range of 1.1-1.6s at fully occupied condition at medium frequency (500Hz). Thus it is flexible in the selection of materials and measures for the places negative for sound

excitation device” and “acoustic resonator ”. After the complicated acoustic course of generation, transmission, mixing, reflection and absorption of

reflection (e.g. to provide diffusers or sound absorption materials). The expected reverberation time will not be affected by the provision of sound absorption materials or structures.As there are different best values of reverberation time to the audience halls depending on the types of operas, and some theaters are also used for musical performance, adjustable reverberation device is required in the audience halls. For example,

I. Classification of Music Halls

Ordway Theater in the U.S. is provided with lifting sound absorbers and curtain adjusting device, which enlarges the scope of application of the theater. The design principles for music halls totally apply to the plane

1.Symphony halls; 2. chamber music halls; 3. chorus halls; 4. solo halls; 5. pipe organ concert halls.

design of audience halls. However, in the sectional design and stage design for the audience halls, the following matters shall be noted.

II. Classification of Spatial Forms of Music Halls

1.Ground Rise of the Audience Halls

1.Traditional “shoebox” type music halls; 2. “non-shoebox” type music halls.

In a theater for performances with natural sound, the height of the actors, as the sound source, on the stage is about 1.6-2.7m, and the stage is usually 0.9-1.0m higher than the front row, the total height of which is

The traditional “shoebox” type music halls are developed and evolved from the concert rooms of the earlier stages. Such halls have a rectangular plane and a spatial ratio of about 1:1:2 (width: height: length). Along the

about 2.5-2.7m. The slope of ground rise shall be determined upon the distance between the height of the sound source and the audience and the principle of reducing the sound absorption (sound interference) of the

back and side walls, shallow balconies are provided. Playing and listening happen in the same space. The halls are decorated elegantly and magnificently inside, with many sculptures and large chandeliers. The high and

front row audience. From the perspective of increasing the direct sound intensity, the ground rise shall be far larger than the sight line design requirement (C value), and the distance between the sound source and the

narrow spatial form of this type of music halls is a result of the technology on architectural structure at that time. Some famous “shoebox” type music halls provide high quality sound and excellent architectural space,

last row of seats shall be shortened as much as possible. The theater of the Cultural Palace of Nationalities has the highest ground rise in all the theaters in Beijing, and thus has good vision and high direct sound intensity.

and thus are recognized as excellent examples in the construction histor y of music halls. The modern “non-shoebox” type music halls are established with the aim to hold more audience, create a more comfortable

However, the rise shall also take into consideration the convenience of passage, height of ceiling and safety of seats (or balconies). A higher ground slope can also reduce the sound attenuation when the sound passes

audio-visual environment, and break through the traditional mode of isolated audience and players. There are a variety of forms of halls, e.g. round, oval, sectorial, polygonal and irregular forms. The design concept is

through the enclosure from the orchestra pit and thus improve the intensity of accompany. The figure below shows the comparison between the sound attenuation amounts subject to two ground slopes.

to inherit the advantage of high quality of sound of the traditional “shoebox” type music halls, and to satisfy various requirements of the modern music halls. III. Acoustic Design of Music Halls The building acoustic design of music halls is essential to the sound quality in the halls and is an important component of architectural design of the halls. The final sound effects after the complicated acoustic course of sound generation, transmission, mixing, reflection and absorption are critical to the application of the music halls, and are the most important factor in judging whether the architectural design of the halls is successful.

Directional reflection surface

There is a high requirement for sound quality, and musical performances are mainly in form of natural playing. It is the final goal of acoustic design to make full use of the limited acoustic energy to deliver beautified sound with sufficient volume and purity to the audience. The acoustic design of music halls is a combination of comprehensive technologies of various disciplines. In the engineering practice of music halls, the building acoustic design runs through the complete course from design to commissioning after completion of construction. Sound source “s”

Loop sound

Sound absorption structure

Diffusion structure

Reflection structure

IV. Form Design of Music Halls 1.To make full use of the limited natural acoustic energy to provide sufficient volume; 2.To ensure uniform sound intensity at the auditorium and good sound diffusion to prevent “dead corners”, free from sound qualify defects like echo, flutter echo, sound focusing and room resonance; 3.To provide early reflected sound with sufficient intensity and large coverage to the auditorium and late reflected sound by the plane form, the former increasing the direct sound intensity and apparent sound source

2. Ceiling Design for Audience Halls

width, while the latter important for imparting sense of space to the audience;

The ceiling design for the audience halls of theaters shall solve the following problems from the aspect of acoustics:

4.To achieve good sound diffusion in the concert rooms and to make it possible for the musicians to hear each other in time.

The inclined the opening of the sidewalls and the ceiling in front of the proscenium provides early reflected sound to the audience in the middle of the seat area and the musicians in the orchestra pit to improve the penetration of the singing voice and to reflect the accompany uniformly to the backseats and balconies. The ceiling of the halls shall distribute the integrated sound of singing voice and accompany uniformly to the

V. Determination and Control of Reverberation Time

entire halls and enhance the sound level at the backseats.

Reverberation time is another important acoustic indicator after sound pressure level (volume), closely related with the volume of the halls. The larger the volume of the halls, the longer the reverberation time will be; reversely, the smaller the volume of the halls, the shorter the reverberation time will be. Different music types or different pieces of similar music types have different requirements for reverberation time (Table 1). Music

3. Back Wall of Audience Halls

halls demand long reverberation, while chamber music halls, shorter, and chorus, solo and ensemble halls, further shorter.

The back wall of the audience halls, if treated improperly, is prone to lead to echo to the front of the seat area and the stage. Especially when the plane of the back wall is in a circular shape and the cur vature center lies in

Table 1: Reverberation Time Requirements of Different Music Pieces

the front seats or the stage, it is more prone to sound aggregation and echo. Thus acoustic measures must be taken in three ways, sound absorption, diffusion and intensification of the sound level at the backseats

In order to achieve the design-expected best reverberation time, besides good reverberation frequency characteristics, the following matter shall also be noted:

(through the back inclination surface). As the reverberation time for the audience halls of theaters is shorter than that for music halls, these three types of measures can all be taken as per the decoration requirements. If

1.To determine the volume of each seat reasonably in the music halls: the volume of each seat is determined upon the type of the music pieces, preferred to be 6-10m3 per seat;

the halls are also used for musical performance, equipped with adjustable reverberation device, sound absorption measures are not preferred, as such measures reduce the range of adjustable reverberation time. In

2.To reduce the sound absorption of the audience and the chairs: the sound absorption of the audience and the chairs takes about 80% of the total sound absorption in the halls; therefore, the selection of the chairs

theaters, the singers hope to get feedback of the sound, i.e. to hear the singing voice reflected back from the back wall and the breast board of balconies, but the sound reflected back shall not be echo. Based on the

shall not be ignored during the design of reverberation time control;

results of tests, Nakmamura et al. (1991) believed that when the delay time is 140ms and the first-come reflected sound is lower than the direct sound by 25-30dB (measured at the microphone 1.0m before the singers),

3.Design of reflectors and diffusers: reflection is to shorten the sound path difference between the reflected and direct sound, and diffusion is to make uniform sound field and good frequency response in the halls, and

sound feedback without echo can be realized. Okano (1994) had a group of sopranos judge the allowed sound level reflected back from the walls, and for the delay time of 120, 170 and 220ms (respectively equivalent

to eliminate sound quality defects.

to 20.5m, 28.5m and 37m from the back reflection surface), the most sensitive singers pointed out that the allowed sound level is below the direct sound, respectively 36, 38 and 42dB (measured 1.0m before the singers). In order to provide sound feedback to the singers from the back wall and the breast board of balconies, these surfaces cannot be made into diffusion structure; neither can the backseats be enhanced. Only

VI. Noise and Vibration Control

sound absorption measures can be taken in such a case. The reliable method for judging the sound absorption performance of the sound absorption materials (or structures) is to conduct reduced scale compensation

1.Sound insulation of enclosure structures: this mainly includes the sound insulation treatment to the walls, slabs, floors, roofs, doors and windows;

model test.

2.Silencing and shock absorption of the air conditioning system: silencing of the air conditioner system mainly means to reduce the noise of the ventilators to the halls through pipes and the noise of air flow at the inlets and outlets;

4. Orchestra Pit and Balcony Gazebo in Theaters

3.Silencing and vibration isolation of other engineering equipments: for example, the noise treatment and shock absorption measures for elevators, power generator rooms and stage lighting machineries.

The acoustic requirement of theaters is to distribute music clearly to the halls without distortion, better in a balanced and harmonious manner without lack of fidelity. To realize good coordination between the singers and the musicians, the singers must be able to hear clear and balanced sound of the orchestra to adjust their voice accordingly. The musicians in the orchestra pit shall be able to hear the other parts of the orchestra,

Type of music Organ music Romantic classical music Early classical music Opera Chamber music Baroque music Drama theatre

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Recommended reverberation time (intermediate frequency full field)

not delayed by the length of the orchestra pit, as well as the singing voice to keep good coordination. For visual requirement, the singers and the musicians shall be able to see the conductor easily. More importantly, the musicians and singers shall be able to hear each other. An open type orchestra pit has such advantages.

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APPLICATION REFERENCE FOR MUSIC HALL

APPLICATION REFERENCE FOR MULTI-FUNCTIONAL HALL

Building Acoustic Instructions for Multi-functional Halls:

I. Building Over view and Application Requirements The conference halls are mainly used for conferences and reports; small size performances and the projection of movies are also considered. The electroacoustic form is the main form during application.

II. Relevant Building Acoustic Design Codes GBJ118-88 Code for Sound Insulation Design of Civil Buildings GB/T50356-2005 Code for Architectural Acoustical Design of Theater, Cinema and Multi-use Auditorium GJ57-2000 Theater Building Design Code GBJ16-37 Fire Prevention Code for Building Design GBJ76-84 Reverberation Time Measurement Code for Halls

III. Guidelines for Building Acoustic Design for Lecture Halls The guidelines for the building acoustic design are as follows based on the acoustic requirements of the uses: 1.Reasonable indoor reverberation time design; 2.Sufficient volume and proper voice articulation; 3.Reasonable sound reflection and diffusion design; 4.Uniform sound field distribution without sound quality defects that disturb listening. Based on the above mentioned requirements, the contents of building acoustic design mainly include reverberation time control for the lecture halls and elimination of sound defects.

IV. Building Acoustic Design IndicatorsIn order to ensure articulation and fullness of the voices at the conferences, based on the requirements of uses, design code requirements and the current form, the best reverberation time for the conference halls is determined to be 1.0Âą0.1s (500Hz) for the medium frequency, and for low frequency, 20% increase is allowed.

V. Current Status Analysis

Sound absorption: The wall surfaces of the conference halls are treated by perforated sound absorption wood boards and sound absorption soft packets. With proper perforation rate and structural making method, the sound absorption requirements can generally be met. Based on the past experience, though the perforated sound absorption wood boards have good decoration effect, the base material is usually density board, which emits a large amount of formaldehyde after slotting and punching. Especially when in a relatively enclosed environment, the smell is hard to go out, disturbing the participants. Besides, the density boards are prone to deformation in a humid environment and prone to corrosion in the presence of water. Thus it is recommended to use some waterproof and environmental friendly materials to replace the density boards. During construction, proper structural design shall be made based on the acoustic inspection reports of the selected materials. The cloth wrapped on the surface of the soft packets is advised to undergo fireproof flame retardant treatment. The packing material is preferred to be sound absorption cotton with certain thickness and volume weight, meeting the acoustic requirements.

Diffusion: Some diffusion materials are recommended to be used on the back wall of the conference halls to enhance the primar y reflected sound of the back row audience and to make the sound field in the entire halls more uniform to prevent interference by the back wall reflected sound to the front row audience.

Stage: The sidewalls and the back wall of the stage also undergo some sound absorption treatment. The ceiling is sound absorption ceiling to meet the requirement of small size performances.

VI.Indoor Noise Control To create a quiet environment, the noise must be controlled for the conference halls. Without consideration to the entr y of the external noise, the indoor noise level shall be controlled below 35dB (A). The indoor noise mainly comes from the air conditioner vents, lighting apparatuses, moving of chairs and operation of the projector. The air conditioner rooms locate at two sides behind the podium. Proper sound isolation measures are recommended for the air conditioner rooms: use high sound isolation walls and doors, and conduct shock absorption treatment to the equipments in the rooms to prevent disturbance to the listening of the leaders at the podium during normal conferences. The background noise level in the halls affects the voice articulation and listening effect. Usually, at the position of the lowest sound level in the halls, when the signal to noise ratio (S/N) is more than 30dB, there will not be obvious influence on the articulation. If the signal to noise ratio is up to 50dB, high quality sound reproduction can be achieved. The average sound level in the voice electroacoustic system in the halls is generally about 70dB. The background noise is also the dynamic lower limit of the source component of the electroacoustic system, directly affecting the listening effect of the audience. According to international standard noise rating NR cur ve, this is the parameter for evaluating the noise disturbance and nuisance. The allowed noise value in various halls and specialized halls as well as the indicators used in some halls in china based on the actual noise level and design are usually below NR40. To ensure sufficient signal to noise ratio, on the condition that all the equipments generating noise in the conference halls are running, e.g. air conditioners and controllable silicon dimming equipments, the background noise with an empty auditorium shall be meet the requirement that the noise rating is NR35 or below.Effective sound and vibration isolation measures shall be taken for the conference halls. The sound and vibration isolation indicators shall be in accordance with Standard of Environmental Noise of Urban Area (GB3096-82) : 50dBA in the daytime and 40dBA in the nighttime, with good control on the sound isolation, local noise, sound resonance, sound focusing, sound scattering, sound diffusion and standing wave.

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APPLICATION REFERENCE FOR MULTI-FUNCTIONAL HALL

I.Building Acoustic Requirements for Conference Halls 1.The sound quality in the audience halls of the conference halls, lecture halls and multi-functional halls shall mainly meet the requirement of articulation. An adequate intensity factor and uniformity are preferred at all the places in the halls. There shall not be any defects like echo, multiple echo, flutter echo, sound focusing and resonance at any positions in the audience halls, and there shall not be any disturbance from the equipment noise, projector room noise and environmental noise. 2.If the volume of an audience hall is more than 1000m 3 , a sound amplification system is preferred to be used, and the positions of the loudspeakers shall be taken as the main points of sound source.

II. Form Design of Audience Halls 1.In case of natural sound as the sound source, the plan and sectional design of the audience halls shall make the early reflected sound field distribute uniformly. The delay time of early reflected sound reaching the audience halls, compared to that of direct sound, is preferred to be 50ms (equivalent to 17m) or below. 2.The volume of each seat in the audience halls is preferred to be 3.5-5.0m 3 /seat. (Note: for the audience halls with proscenium mirror frame type stages, the volume shall be calculated taking the curtain line of the stage as the boundar y.) 3.For the audience halls with balconies, the overhanging depth “D” of the gazebos is preferred to be not more than 1.5 times the net height “H” of the lower opening of the balconies. 4.For the audience halls with mainly natural sound, the rise of each row of seats shall be determined as per the vision rise difference “C”, which is preferred to be 120mm or above.

III. Reverberation Time for Audience Halls 1.The selection of the reverberation time for the fully occupied audience halls shall meet the following requirements: 2.When the frequency is within the range of 500-1000Hz, the proper ranges of reverberation time subject to different volumes shown in Figure 2 are preferred. 3.The reverberation time ratios subject to 500-1000Hz are preferred to be in accordance with Table 2. 4.The reverberation time shall be estimated subject to the frequencies of 125Hz, 250Hz, 500Hz, 1000Hz, 2000Hz and 4000Hz. The estimated values shall be two-digit effective values.

Reverberation time “T” (s)

Reverberation time ratio Hall、Report hall、Multipurpose auditorium

frequency(Hz)

Reverberation time ratio

IV. Influence of Reverberation Time on Indoor Sound Quality. A short reverberation time indicates a situation dominated by direct sound and early reflected sound, which can improve the voice articulation. But if the reverberation time is too short, the sound will become dr y and the volume will be weakened. A long reverberation time helps to achieve fullness of the sound, but too long a reverberation time will reduce the articulation of the sound, i.e. the speech intelligibility. It is generally considered that for the halls mainly used for language programs, the reverberation time is preferred to be short as appropriate to improve the intelligibility; for the halls used for musical performances, the reverberation time can be longer as appropriate to improve the sound fullness. It is critical to have a proper length of reverberation time. For the conference halls, the generally recommended best reverberation time for reference is 0.8-1.0s.

V. Matters to be Noted during Acoustic Decoration for Conference Halls. There are large differences between indoor acoustics and outdoor acoustics. As we all know, the indoor sound qualify effect is not the same as the outdoor sound effect. First, with the same sound source, it is louder in an indoor environment than outdoor due to superposition of sound as a result of reflection on the indoor wall surfaces. Secondly, the indoor sound field is different from the outdoor sound field. In the open air, the farther from the sound source, the smaller the sound will be, while in an indoor environment, there is not much difference within a certain area, because of less sound absorption and less sound energy loss as a result of reflection on the wall surfaces. According to indoor acoustic theories, the indoor sound is divided into direct sound, early reflected sound and reverberation sound. The sequence of these types of sound reaching the ears is as follows: direct sound first, and then early reflected sound within 50ms, and reverberation sound formed after various reflections of the sound wave beyond 50ms on the indoor interfaces. 1.The surrounding walls of the rooms are recommended to be corrugated sound absorption walls. In the meantime, prevent the wall surfaces from being at the same height as much as possible, and tr y to increase the unevenness of the overall wall surfaces to maximize the sound absorption. The specific methods include provision of decoration patterns or carpets and other accessories on the walls. 2.Thick and permeable carpets are recommended for the grounds of the rooms. Such a design has good sound absorption effect to the high frequency sound signals so as to prevent sound feedback. 3.Prevent the top surfaces of the rooms from being at the same height as much as possible, and tr y to increase the unevenness of the overall roof surfaces. Besides, sound absorption board is preferred to be used as the main decoration material.

Some pictures from the Internet

4.Use thick cloth similar to velvet as the curtains, and tr y to keep a distance of more than 15cm from the windows to create an empty space to effectively absorb the low frequency sound signals. 5.Select chairs with cloth or suede materials in the rooms. Besides, the conference table itself is a large reflector that is easily ignored. Till now, there is no effective solution but to reduce the surface area of the table, for example, to make the table to be round or circular shaped. 6.The sound absorption materials cannot be just one type. Other wise there may be excessive absorption to one frequency sound signals in the rooms, leading to defect in the overall sound signals. 7.The doors and windows shall be thickened, as they are most possible for sound leakage. Tr y to use double-layer ones if possible. The doors that are often used for entr y and exit shall be closed tight, better sealed. And in terms of structure, tr y to use the doors with packing (sound absorption cotton) to prevent sound leakage.

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APPLICATION REFERENCE FOR CINEMA

Classification of Cinemas: The cinemas are divided into super class, class A , class B and class C in terms of quality standard (to be combined with superlarge, large, medium and small scales in a cross manner). The requirements for the super class are determined upon specific conditions, while the requirements for classes A , B and C shall be as follows: I.Duration of the main structure: more than 100 years for class A , 50-100 years for class B and 25-50 years for class C. II.Fire resistance rating: not less than grade II for class A and class B, and not less than grade III for class C. There shall not be super large type in such a case. III.Audiovisual facilities: stereoscopic sound shall be arranged for class A. The main structure of the audience halls of class A and above is preferred to also have thecapability to play 70mm movies or have the possibility to be renovated to play 70mm movies. In the cinemas of class A , 5.3mm-gap BSV liquid cr ystal display shall be provided. In the ticket offices, there shall be not less than 16 sets of BSV. Plan Layout: The general plan layout shall have distinct functional areas. The pedestrian traffic and vehicles' traffic as well as the audience flow and the internal routes (for process and management) shall be arranged in distinct and convenient manner without interference between each other. Besides the following requirements shall be met: I.In case of fire or other emergencies, the audience and the staff can be evacuated rapidly to a lighted safe zone, and there are suitable passages and space for firefighting work; II.If the cinemas have one side facing streets, the medium and small scale cinemas shall have at least one other side facing an empty internal yard or connected to roads. The large and super large cinemas shall have at least two other sides facing an empty internal yard or connected to roads. The width shall not be less than 3.5m in all the cases; III.For the joint or attached cinemas, except that independent fire compartments are divided by fire walls with the adjacent buildings, the other parts facing empty shall still be in accordance with the above mentioned requirements; IV.The equipment rooms shall be located at places with the least disturbance to the audience, and care shall be given to safety, sanitation, silencing, shock absorption and convenience for equipment installation and maintenance; V.The parking lots for motor vehicles and bicycles are preferred to be set in the general plan layout, or under overall consideration of urban traffic planning; VI.Requirements for drainage, noise isolation and energy saving, etc. shall also be met in the general plan layout, and greening shall be arranged according to the conditions. Design of Audience Halls: The audience halls are an important component of the cinemas, and the screen is the basis for the design of the audience halls. The size of the screen determines the volume of the audience. The larger the screen, the more audience can the cinemas hold. If there is less audience, the screen in the audience halls is made smaller accordingly. Thus the size of the audience halls actually depends on the size of the screen. The shape of the screen also determines the form of the audience halls, especially for new type of movies. Different types of movies demand different shapes of the screen. The size of the screen for large vision movies determines the height ratio of the audience halls. The screen for circular screen movies demands round shaped audience halls, while the screen for arciform movies requires arciform audience halls. Generally, the cinemas with a plane screen are rectangular or trapezoidal in shape and the grounds have certain slope. I. Building Acoustic Requirements for Cinemas 1.The building acoustic design for cinemas shall provide suitable acoustic conditions for the audience halls for sound reproduction for movies. 2.The acoustic design for the audience halls of cinemas shall consider the space for the screen as an entirety. Balconies are not preferred in the audience halls of cinemas. 3.During the projection of movies, there shall be sufficient articulation at all the places inside the audience halls to reproduce the sound playback effect of the movies. 4.During the projection of movies, there shall not be any defects like echo, multiple echo, flutter echo, sound focusing and resonance, and shall not be any disturbance from equipment noise, projector room noise or external environmental noise. II. Form Requirements for Audience Halls 1.The length of the audience halls is preferred to be not more than 30m, and the ratio between the length and width of the audience halls is preferred to be (1.3-1.7):1. 2.The volume of each seat in the audience halls is preferred to be 6.0-8.0m 3 /seat. (Note: the space for setting the screen is considered in the volume calculation) 3.In the design of the audience halls, flutter echo due to the provision of surround sound loudspeakers on the sidewalls shall be avoided. 4.Measures shall be taken on the back wall of the audience halls to prevent echo. 5.The end wall behind the main loudspeaker unit shall undergo strong sound absorption treatment. The average sound absorption coefficient is preferred to be not less than 0.6 within the frequency range of 125-4000Hz, and the sound absorption coefficient at 125Hz is preferred to be not less than 0.4 6.The interior decoration of the audience halls shall take into consideration the installation positions and requirements of the loudspeaker units. During sound production by the loudspeakers, there shall not be vibration noise on the supports and surrounding structures of the loudspeakers. III. Reverberation Time for Audience Halls 1.The selection of the reverberation time for the fully occupied audience halls shall meet the following requirements: 2.When the frequency is within the range of 500-1000Hz, the proper ranges of reverberation time subject to different volumes shown in Figure 1 are preferred. 3.The stereoscopic sound cinemas with a volume of the audience halls of less than 500m 3 are preferred to have proper ranges of reverberation time matching with 500m 3 . 4.The reverberation time ratios subject to 500-1000Hz are preferred to be in accordance with Table 1. 5.The reverberation time shall be estimated subject to the frequencies of 125Hz, 250Hz, 500Hz, 1000Hz, 2000Hz and 4000Hz. The estimated values shall be two-digit effective values. Figure 1 shows the proper ranges of reverberation time “ T” subject to different volumes “V” of the audience halls at fully occupied condition within 500-1000Hz. Table 1 shows the reverberation time ratios at various frequencies subject to 500-1000Hz in the audience halls of cinemas.

Some pictures from the Internet

Reverberation time “T” (s)

Movie

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frequency(Hz)

Reverberation time ratio

Normal Stereo