Architectural Design Studio A: Music Venue PT2

CHOSEN EXTRUSION LENGTH: 26M

The tests were run using a volume of 5000m3.

Testing the length of the auditorium gives a range from the most beneficial distances of 24-32m away from the stage to the furthest audience member. The most suitable lengths for the lowest values of SPLA and RT(20) is 2426m.

SPLA: 31.53-48.71 dBA

RT: 1.75-3.44 Sec

TEST CHANGING MATERIALS (WALLS)

ACOUSTIC PLASTER

SPLA: 34.94-49

RT: 1.75-2.78

SMOOTH CONCRETE

SPLA: 34.04-48.82

RT: 1.83-3.56

VELOUR HANGING

SPLA: 22.72-48.05

RT: 1.14-2.71

ACOUSTIC TILE 1/2”

SPLA: 23.46-48

RT: 1.16-2.15

ACOUSTIC TILE 3/4”

SPLA: 20.03-47.9

RT: 0.82-2.9

8MM PLYWOOD

SPLA: 30.62-48.61

RT: 1.33-2.3

SPLA 34 dBA

RT(30) 1.7 Sec

SPLA 49 dBA

CHOSEN MATERIAL: 8MM PLYWOOD

The tests were run using a volume of 5000m3.

Changing the material of the auditorium walls not only affects the aesthetics of the space but also the acoustic performance. The best material for consistency and low SPLA and RT(30)values is 8mm plywood. This will be the material proposed in the final design.

SPLA: 35.53-50.68 dBA

RT: 1.82-2.74 Sec

TEST

CHANGING MATERIALS (ROOF)

ACOUSTIC PLASTER

SPLA: 35.76-49.11

RT: 1.69-2.49

8MM PLYWOOD

SPLA: 32.69-48.71

RT: 1.59-3.41

ACOUSTIC TILE 1/2”

SPLA: 32.06-48.73

RT: 2.15-3.49

ACOUSTIC TILE 3/4”

SPLA: 31.79-48.74

RT: 1.94-4.18

SCHROEDER DIFFUSER

SPLA: 34.94-49

RT: 1.75-2.78

SMOOTH CONCRETE

SPLA: 31.29-48.77

RT: 2.07-3.62

SPLA 34 dBA

RT(30) 1.7 Sec

CHOSEN MATERIAL: ACOUSTIC PLASTER

The tests were run using a volume of 5000m3

The roof plays a major role in absorption, reflection and diffusion. Changing the material of the roof can drastically alter the SPLA and RT(20) values. The lowest and most consistent readings are for the Schroeder diffuser and smooth concrete. However since the aim is to get the geometry to change the values the material to be used and tested with is Acoustic Plaster.

SPLA: 35.63-50.57 dBA

RT: 1.92-3.1 Sec

TEST CHANGING MATERIALS (SEATS)

OCCUPIED UPHOLSTERY

SPLA: 34.94-49

RT: 1.75-2.78

UNOCCUPIED UPHOLSTERY

SPLA: 33.73-49.27

RT: 2-3.55

UNOCCUPIED WOOD OR METAL

SPLA: 35.31-50.27

RT: 2.04-3.35

CHOSEN MATERIAL: OCCUPIED UPHOLSTERY

The tests were run using a volume of 5000m3.

This matrix explored material of the floor, specifically seating. An auditorium can either be occupied or unoccupied which makes a different to how sound is absorbed. Overall the SPLA and RT(20) values are fairly consistent.

SPLA: 36.21-50.65 dBA

RT: 1.88-2.79 Sec

TEST DIFFERENT REVERBERATION TIMES

SPLA: 32.58-48.71

RT: 2.6-4.29

RT (20)

SPLA: 32.58-48.71

RT: 2.39-3.47

RT (30)

SPLA: 32.58-48.71

RT: 1.99-3.22

RT (40)

SPLA: 32.58-48.71

RT: 1.85-3.23

RT (50)

SPLA: 32.58-48.71

RT: 1.72-3.21

REVERBERATION TIME: RT(30)

The tests were run using a volume of 5000m3.

As the initial tests were completed at RT(20), without realizing, this matrix was created to compare the different RT levels to see the change in time to reach the decibel level indicated. RT(30) is higher than RT(20), therefore returning a lower Reverberation Time, and the previous simulation will return higher results than the desired Reverberation time.

SPLA: 32.58-48.71 dBA

RT: 1.99-3.22 Sec

CHOSEN GEOMETRY

SPLA: 32.58-48.71 dBA

RT: 1.99-3.22 Se

This geometry was chosen as it has the most consistent values for Sound Pressure Level (SPLA) and Reverberation Time (RT(30)). To create better SPL for the full audience ray visualization tests will be conducted to attempt to amend the ceiling and wall geometry to get early sound waves to all audience members.

Try to direct early rays to these areas for more consistent SPLA

Best RT(30) Values. Need the RT to be between 1.7-2.1 for all members

TEST ADDING CEILING ANGLE

GEOMETRY

FLAT

SPLA: 34.81-48.92

RT: 1.72-2.85

2 ANGLES

SPLA: 35.05-49.05

RT: 1.92-2.88

3 ANGLES

SPLA: 34.73-48.89

RT: 1.58-2.71

4 ANGLES

SPLA: 35.2-48.93

RT: 2.1-2.87

CHOSEN CEILING ANGLE: 3 ANGLES

The tests were run using a volume of 5000m3.

The added ceiling angled altered the SPLA and RT(30) values, becoming lower and enabling a more even distribution of sound. From these results the best ceiling form is the 3 angles.

SPLA: 34.73-48.89 dBA

RT: 1.58-2.71 Sec

Ceiling Angles

FLAT

2 ANGLES

3 ANGLES

4 ANGLES

Before 50ms

After 50ms

CHOSEN CEILING: 4 ANGLES

This test looked at adding ceiling angles to see how the sound reflects of the added surfaces. The test concludes that the more surfaces, the better and increase number of reflections throughout the full auditorium.

The aim is to get enough reflections towards the back most seating areas where direct sound is limited whilst still have some reflections throughout the remainder of the audience.

The most beneficial is the 4 angles of ceiling which could be increased to direct more reflections in the desired locations. As this is a preliminary test of how many angles too add the angles can be changed for increased benefit.

Balcony Seating

In an attempt to maximize the space a balcony level of seating was added. Simulation and Visualization tests will find the optimum ceiling angles for the balcony and stall seating to create a welcoming space in every seat.

Visualization of Sound

TEST 1- SEE RAY DISTRIBUTION

1 BOUNCE

2 BOUNCES

The rays show there is adequate sound to the back of the balcony however the stalls are getting lots in one space at the back, Therefore the angle needs to be adjusted to try and achieve a better distribution.

3 BOUNCES

TEST 2- ADD ROOF PANEL & ANGLE BALCONY

1 BOUNCE

2 BOUNCES

The new ceiling angle works better for distribution of reflections however the balcony angle needs to be inverted to get the sound to reflect down towards the audience rather than the back wall.

3 BOUNCES

TEST 3- ADJUST BALCONY ANGLE

1 BOUNCE

2 BOUNCES

This angle gets rays to the front of the stall area however now there are not many reaching the back. This angle needs to be lifted higher and made slightly smaller to allow rays to reach the back seats.

3 BOUNCES

TEST 4- ADJUST BALCONY ANGLE

1 BOUNCE

2 BOUNCES

Rays reaching all spaces in a reasonable distribution. SPLA and RT(30) tests will be run using this geometry to test if the balcony allows enough sound to the stalls and to see if the balcony seats achieve enough early reflections.

3 BOUNCES

TEST 4- SPLA & RT(30) OF BALCONY

SPLA: 39.4-54.2dBA

RT: 1.7-3.1Sec

BALCONY

SPLA: 40.7-46.9dBA

RT: 1.95-2.7Sec

SPLA 39.4 dBA

54.2

SPLA consistent across both levels. RT(30) not consistent in placement but not too bad in values.

Overall to make it simpler to calculate the balcony will be removed and space adjusted for single level seating.

TEST 3

CHOSEN CEILING: TEST 1

0- No angles so sound reflects at the normal. Not enough reflections getting to the back.

1- Lots of reflections at the back half the back angle still going to back wall. Front angle needs to be larger for more backwards reflections.

2- Lots of reflections at back wall. Not good

3- Due to convex angle all reflections at the back going to roof and back wall. No good.

4- Need steeper angles in mid for more backwards reflections. Back angle needs to be steeper as still reflecting to back wall.

5- Jagged angles are missing center audience reflections. Makes interesting concept but not suitable as too many back wall reflections.

Overall Test 1 has the best reflections and can be adjusted to reduce reflections to the back wall.

Ceiling Angles (Adjustments)

Before 50ms

After 50ms

These tests adjusted the angles slightly to achieve a better ray distribution.

V1 was taken from the previous matrix and had a few too many rays at the back of the auditorium.

V2 angles the roof panels in the back half to try and achieve a better distribution. Distribution achieved so will adjust back angle to minimize hits on back wall.

V3 Great ray distribution and will proceed with simulations and more visualizations.

Test change cut off time

ORIGINAL CUT OFF TIME 1000

VOL: 3000m3

SPLA: 33.84-51.01

RT: 2.22-2.98

VOL: 4000m3

SPLA: 34.38-50.99

RT: 2.08-3.08

VOL: 5000m3

SPLA: 34.13-50.89

RT: 2.22-3.34 12M

VOL: 6000m3

SPLA: 34.31-50.96

RT: 2.08-3.36

VOL: 7500m3

SPLA: 33.69-50.86

RT: 1.87-3.33

ADJUSTED CUT OFF TIME 2000 AVE RT(30)

GEOMETRY

SPLA

VOL: 3000m3

SPLA: 35.22-51.1

RT: 2.17-3.18

VOL: 4000m3

SPLA: 34.5-50.98

RT: 1.91-3.09

VOL: 5000m3

SPLA: 34.63-50.92

RT: 2.25-3.27 12M

SPLA: 33.99-50.91

RT: 1.66-3.46

VOL: 6000m3 15M

VOL: 7500m3

SPLA: 34.33-50.89

RT: 1.86-3.25

As per the feedback from the mid semester reviewers, the cut of time was increased from 1000 to 2000. These simulations were done on the height matrix as indicated that there would show the largest variation in results. The above matrices show the difference in results. Overall the results vary slightly but not to an extend to repeat any iterative matrices. For future studies a co time of 2000 will be used to ensure more accurate results.

Final Geometry

The final geometry works on the hexagonal typology of an arena or coffin style auditorium. The roof is angled to reflect sound providing reflections quicker than 50ms to all audience members creating an atmosphere within the music. The following pages will explore the simulation and visualizations completed on the final geometry.

Stage & Seating

There are 704 Seats and 6 disability spaces within the Auditorium.

Sloped Seating 452 Seats

6 Disability Spaces

Stepped Seating 252 Seats

Stage

Simulation (per seat)

AVERAGE SPLA & RT(30)

SPLA 40.3 dBA

SPL(A)

SPLA 29.7 dBA

RT(30) 2.7 Sec

RT(30)

RT(30) 1.5 Sec

RT PER FREQUENCY

62.5 HZ

RT(30): 1.13-2.83

125 HZ

RT(30): 1.15-2.85

250HZ

RT(30): 1.19-1.40

500 HZ

RT(30): 1.12-1.91

1000 HZ

RT(30): 0.69-1.19

2000 HZ

RT(30): 0.94-1.98

4000 HZ

RT(30): 1.01-1.76

8000 HZ

RT(30): 0.93-1.75

The simulations were run using the individual frequencies to identify the change in Reverberation time at different frequencies rather than looking at the average. The main 3 values of interest are for 500, 1000 & 2000hz as they are the frequencies that humans can hear clearly. Overall these frequencies and the average show a large variation of low and high values.

RT(30) 0.7 Sec

RT(30) 1.2 Sec

Visualization Final

Before 50ms

After 50ms

Doors: Timber Roof: Suspended Acoustic Plaster

Walls: 8mm Plywood

Seats: Red Upholstery Floor: Carpet with Felt Underlay

Stage: Wood Floor

Materials

Roof- Acoustic Plasterboard

Acoustic Plaster will be used to control the sound within the auditorium. These panels will be painted theatre black to create a uniform colour pallet within the space whilst creating depth.

Floor- Carpet Tile With Felt Underlay

The floors will be carpet tile for easy replacement of worn parts. They will be black in colour to match the surrounds. The carpet and felt underlay will absorb most of the sound that is not absorbed by the audience or the upholstered seating.

Stage Floor- Wood Panels

The stage will be black wood panels similar to most stages. This enables all type of performances and events to be run.

(Anderson Ladd n.d.)

(OFS 2021)

(MaterialDistrict 2017) (Bunnings n.d.)

(Plymasters n.d.) (Permachink 2021)

Walls- Plywood Panel With Walnut Stain

The wood paneling creates a unique atmosphere while enabling sounds to be reflected off the hard surface. The timber will be stained with a dark walnut to add depth and keep within the dark nature of an auditorium.

Seats- Upholstered Fabric

Seating will be red fabric, similar to many other auditorium spaces. The red adds a pop of colour and the material is highly sound absorbent. The seating will be paired with matte black features such as arm rests and joinery to match the environment of a theatre.

(HHF n.d.)

Doors- Wood Doors With Black Paint

The wooden doors allows for lightweight movement and easily accessible material. The doors will be painted black to match the roof and the atmosphere of space as well as creating a distinct location within the timber walls.

(Plymasters n.d.) (Bunnings n.d.)

Renders

Materials

Seats- Red Upholstered Fabric

Floor- Carpet Tiles With Felt Underlay

Walls- 8mm Plywood Panels

Roof- Acoustic Plaster

Stage- Wood Floor

Summary of Iterations

Overall the hexagonal geometry creates a vast open space for an auditorium whist having the outer wall angles correctly placed to direct sound towards the audience. The overall Volume per person of 8.57m3 was similar to the multipurpose hall optimum of 7.1m3 with the maximum and minimum being 5.1-8.5m3 respectively and the concert hall of 6.2-7.8-10.8m3.

The material choice of Acoustic Plaster, 8mm Plywood and Occupied Seating contained the SPLA and RT(30) values pulling them closer to the optimum reverberation time of 1.22.2ms.

The SPLA and RT(30) of the changes to the wall and ceiling angles created a much more welcoming space and dropped the values to a more reasonable figure to work with. The best way to get within the RT(30) bounds is to use some absorptive materials on places like the back wall where the reflections are hard to direct towards the audience. This will also stop any flutter echo happening when sound bounces back.

The final geometry will be the multi-angled roof. The main materials will be Acoustic Plaster(Roof) and 8mm Plywood(Walls).

Auditorium Statistics

Height: 3.4-11.2

Length: 32m

Width: 13-25m

Volume: 6090m

Volume Per Person: 8.57m3

Area: 604m2

SPLA: 48.1-50.33 dBA

RT(30): 1.06-1.94 Sec

PRIMARY THEMES

SECONDARY THEMES

Human Perception

Aesthetics

Geometry

Materiality

Functionality

Acoustics