Building Science 2 Report

SCHOOL​ ​OF​ ​ARCHITECTURE,​ ​BUILDING​ ​AND​ ​DESIGN BACHELOR​ ​OF​ ​SCIENCE​ ​(HONS)​ ​IN​ ​ARCHITECTURE

BUILDING​ ​SCIENCE​ ​II​ ​(BLD​ ​61303)

PROJECT​ ​1 AUDITORIUM:​ ​A​ ​CASE​ ​STUDY​ ​ON​ ​ACOUSTIC​ ​DESIGN THE​ ​ACOUSTIC​ ​DESIGN​ ​OF​ ​PJ​ ​LIVE​ ​ARTS,​ ​JAYA​ ​ONE

GROUP​ ​MEMBERS: BENJAMIN​ ​TAN​ ​ZI​ ​HERN​ ​0324857 CHEOK​ ​JIAN​ ​SHUANG​ ​0320089 CHONG​ ​KIT​ ​YEE​ ​0319748 CHONG​ ​XIN​ ​DEAN​ ​0325353 CHONG​ ​ZHAO​ ​LUN​ ​0320408 FRANCIS​ ​YEOW​ ​SHENG​ ​1101A12395 ONG​ ​TUN​ ​CHIEK​ ​0319939 TUTOR: AR.​ ​EDWIN​ ​CHAN​ ​YEAN​ ​LIONG

Table​ ​of​ ​Contents _________________________________________________________ 1.0​ ​Introduction​​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​1 1.1​ ​Aim​ ​and​ ​objective 1.2​ ​Introduction​ ​to​ ​site

2.0​ ​Acoustical​ ​Phenomenon​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​5 2.1​ ​Sound​ ​Reflection 2.2​ ​Sound​ ​Absorption 2.3​ ​Direct​ ​&​ ​Indirect​ ​Sound​ ​Path 2.4​ ​Reverberation​ ​Time

3.0​ ​Acoustical​ ​Analysis​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​11 3.1​ ​Auditorium​ ​Design​ ​Analysis 3.2​ ​Materials​ ​and​ ​Properties 3.3​ ​Acoustic​ ​Wall​ ​Panelling​ ​/​ ​Wall​ ​Treatment 3.4​ ​Sound​ ​and​ ​Noise​ ​Source 3.5​ ​Sound​ ​Propagations​ ​and​ ​Phenomenon

4.0​ ​Issues​ ​and​ ​Recommendations​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​37 5.0​ ​Conclusion

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6.0​ ​References​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​40

1.0​ ​Introduction Architectural​ ​acoustics​ ​is​ ​the​ ​science​ ​and​ ​engineering​ ​of​ ​achieving​ ​a​ ​desired​ ​sound​ ​within​ ​a building.​ ​This​ ​is​ ​the​ ​science​ ​of​ ​controlling​ ​a​ ​room's​ ​surfaces​ ​based​ ​on​ ​sound​ ​absorbing​ ​and reflecting​ ​properties.​ ​Reverberation​ ​time,​ ​which​ ​can​ ​be​ ​calculated,​ ​can​ ​determine​ ​the​ ​proper materials​ ​needed​ ​for​ ​absorption​ ​of​ ​sound.

Sound​ ​reflections​ ​create​ ​standing​ ​waves​ ​that​ ​produce​ ​natural​ ​resonances​ ​that​ ​can​ ​be​ ​heard as​ ​a​ ​pleasant​ ​sensation​ ​or​ ​an​ ​annoying​ ​one.​ ​Reflective​ ​surfaces​ ​can​ ​be​ ​angled​ ​and coordinated​ ​to​ ​provide​ ​good​ ​coverage​ ​of​ ​sound​ ​for​ ​a​ ​listener​ ​in​ ​a​ ​concert​ ​hall​ ​or​ ​music​ ​recital space.

1.1​ ​Aim​ ​&​ ​Objective The​ ​purpose​ ​of​ ​this​ ​case​ ​study​ ​is​ ​to​ ​observe​ ​the​ ​constitutions​ ​of​ ​good​ ​stage​ ​and​ ​audience acoustics.​ ​It​ ​is​ ​a​ ​study​ ​of​ ​the​ ​relationship​ ​between​ ​the​ ​auditorium’s​ ​layout,​ ​choice​ ​of​ ​exterior and​ ​interior​ ​envelope,​ ​acoustic​ ​manipulating​ ​devices​ ​such​ ​as​ ​reflective​ ​and​ ​dampening panels,​ ​and​ ​the​ ​resultant​ ​acoustic​ ​effects.​ ​The​ ​premise​ ​of​ ​good​ ​sound​ ​quality​ ​in​ ​our​ ​case would​ ​revolve​ ​around​ ​the​ ​reverberation​ ​time​ ​within​ ​our​ ​audience​ ​area.​ ​A​ ​longer reverberation​ ​means​ ​a​ ​lingering​ ​of​ ​background​ ​noise​ ​that​ ​may​ ​produce​ ​undesirable​ ​sound effects.

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1.2​ ​Introduction​ ​to​ ​Site PJ​ ​Live​ ​Arts​ ​Centre​ ​is​ ​a​ ​theater​ ​within​ ​Jaya​ ​One,​ ​a​ ​mixed​ ​use​ ​commercial​ ​hub​ ​located​ ​on the​ ​first​ ​floor.​ ​the​ ​theater​ ​opens​ ​weekdays​ ​12pm-7pm.

Jaya​ ​One​ ​can​ ​be​ ​reached​ ​via​ ​LDP,​ ​Sprint,​ ​Kerinchi,​ ​and​ ​Federal​ ​Highways.​ ​It​ ​is​ ​located along​ ​Jalan​ ​Universiti,​ ​Petaling​ ​Jaya.​ ​It​ ​is​ ​a​ ​10​ ​minutes​ ​commute​ ​from​ ​the​ ​Asia​ ​Jaya​ ​LRT station​ ​(opposite​ ​Menara​ ​Axis)​ ​by​ ​a​ ​taxi​ ​or​ ​Rapid​ ​KL​ ​Bus​ ​to​ ​Jaya​ ​One.​ ​It​ ​is​ ​also​ ​accessible by​ ​RapidKL​ ​buses,​ ​and​ ​is​ ​a​ ​30​ ​minute​ ​drive​ ​from​ ​KL​ ​city​ ​centre​ ​or​ ​Subang​ ​Jaya.

Historical​ ​Background Opened​ ​in​ ​2009,​ ​Selangor's​ ​first​ ​independent​ ​theatre​ ​facility,​ ​dedicated​ ​to​ ​presenting​ ​the best​ ​in​ ​family​ ​and​ ​comedy​ ​programming,​ ​PJ​ ​Live​ ​Arts​ ​is​ ​an​ ​organisation​ ​best​ ​known​ ​as​ ​a catalyst​ ​for​ ​community​ ​outreach​ ​and​ ​support,​ ​utilising​ ​arts​ ​as​ ​a​ ​platform​ ​to​ ​raise​ ​funds​ ​for charities​ ​and​ ​education;​ ​and​ ​to​ ​promote​ ​the​ ​community​ ​involvement​ ​in​ ​its​ ​theatre​ ​and audience​ ​development.

Figure​ ​1.2.1:​ ​Perspectives​ ​of​ ​theater​ ​from​ ​stage.

Figure​ ​1.2.2:​ ​Perspectives​ ​of​ ​theater​ ​seats​ ​to​ ​stage.

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Drawings: Plans

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Ground Floor Plan Scale 1 : 200

First Floor Plan Scale 1 : 200

Drawings: Section

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Section Scale 1 : 200

2.0​ ​Acoustical​ ​Phenomenon 2.1​ ​Sound​ ​Reflection When​ ​sound​ ​travels​ ​in​ ​a​ ​given​ ​medium,​ ​it​ ​strikes​ ​the​ ​surface​ ​of​ ​another​ ​medium​ ​and bounces​ ​back​ ​in​ ​some​ ​other​ ​direction,​ ​this​ ​phenomenon​ ​is​ ​called​ ​the​ ​reflection​ ​of​ ​sound.

The​ ​waves​ ​are​ ​called​ ​the​ ​incident​ ​and​ ​reflected​ ​sound​ ​waves.

Hard​ ​surfaces​ ​will​ ​reflect​ ​almost​ ​all​ ​incident​ ​sound​ ​energy​ ​striking​ ​them.​ ​Convex​ ​reflecting surfaces​ ​will​ ​disperse​ ​sound​ ​while​ ​concave​ ​reflecting​ ​surfaces​ ​will​ ​concentrate​ ​the​ ​reflected sound.

Reflections​ ​may​ ​be​ ​used​ ​in​ ​room​ ​acoustics​ ​to​ ​distribute​ ​and​ ​reinforcements​ ​sounds.

Figure​ ​2.1.1:​ ​Types​ ​of​ ​sound​ ​reflection.

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Figure​ ​2.1.2:​ ​Sound​ ​reflection​ ​on​ ​concave​ ​surface.

Focusing​ ​by​ ​concave​ ​surface

Figure​ ​2.1.3:​ ​Sound​ ​reflection​ ​on​ ​convex​ ​surface.

Dispersion​ ​by​ ​convex​ ​surface

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2.2​ ​Sound​ ​Absorption Sound​ ​absorption​ ​is​ ​the​ ​change​ ​in​ ​sound​ ​energy​ ​into​ ​some​ ​other​ ​form,​ ​usually​ ​heat​ ​when​ ​it passes​ ​through​ ​a​ ​material​ ​or​ ​strikes​ ​a​ ​surface.

Soft,​ ​porous​ ​materials​ ​and​ ​fabrics,​ ​and​ ​people​ ​absorb​ ​a​ ​considerable​ ​amount​ ​of​ ​sound energy​ ​when​ ​it​ ​impinges​ ​on​ ​them.​ ​In​ ​Room​ ​Acoustics,​ ​the​ ​surfaces​ ​of​ ​walls,​ ​floors​ ​and ceilings,​ ​room​ ​contents​ ​including​ ​people,​ ​and​ ​the​ ​air​ ​of​ ​the​ ​space​ ​contribute​ ​to​ ​sound absorption.

Sound​ ​Absorption​ ​Coefficient​ ​(α) Absorption​ ​coefficient​ ​(α)​ ​is​ ​a​ ​measure​ ​of​ ​the​ ​amount​ ​of​ ​sound​ ​absorption​ ​provided​ ​by​ ​a particular​ ​type​ ​of​ ​surface.​ ​This​ ​coefficient​ ​compares​ ​the​ ​amount​ ​of​ ​sound​ ​energy​ ​not reflected​ ​to​ ​the​ ​amount​ ​of​ ​sound​ ​energy​ ​arriving​ ​at​ ​the​ ​surface.The​ ​perfect​ ​absorber​ ​has​ ​an absorption​ ​coefficient​ ​of​ ​1.0​ ​and​ ​an​ ​example​ ​of​ ​such​ ​an​ ​absorber​ ​is​ ​an​ ​open​ ​window.

Absorption​ ​coefficient,​ ​α​ ​=​ ​Sound​ ​Energy​ ​Absorbed ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​Incident​ ​Sound​ ​Energy Types​ ​of​ ​Sound​ ​Absorbers I.​ ​Porous​ ​Absorbers

Figure​ ​2.2.1,​ ​2.2.2:​ ​Types​ ​of​ ​porous​ ​absorber.

It​ ​consists​ ​of​ ​cellular​ ​materials​ ​such​ ​as​ ​fibreglass​ ​and​ ​mineral​ ​wool.The​ ​air​ ​in​ ​the​ ​cells provide​ ​resistance​ ​to​ ​the​ ​sound​ ​waves​ ​which​ ​then​ ​loses​ ​energy​ ​in​ ​the​ ​form​ ​of​ ​heat.

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II.​ ​Panel​ ​Absorbers

Figure​ ​2.2.3,​ ​2.2.4:​ ​Types​ ​of​ ​panel​ ​absorber.

Panel​ ​absorbers​ ​are​ ​typically​ ​non-rigid,​ ​non-porous​ ​materials​ ​which​ ​are​ ​placed​ ​over​ ​an airspace​ ​that​ ​vibrates​ ​in​ ​a​ ​flexural​ ​mode​ ​in​ ​response​ ​to​ ​sound​ ​pressure​ ​exerted​ ​by​ ​adjacent air​ ​molecules.

III.​ ​Cavity​ ​Absorbers​ ​(​ ​Helmholtz​ ​Resonators)

Figure​ ​2.2.5,​ ​2.2.6:​ ​Types​ ​of​ ​cavity​ ​absorber.

It​ ​consists​ ​of​ ​enclosed​ ​body​ ​of​ ​air​ ​contained​ ​within​ ​rigid​ ​walls​ ​and​ ​connected​ ​by​ ​a​ ​narrow opening​ ​to​ ​the​ ​surrounding.​ ​A​ ​cavity​ ​resonator​ ​can​ ​absorb​ ​maximum​ ​sound​ ​energy​ ​in​ ​a narrow​ ​region​ ​of​ ​a​ ​low​ ​frequency​ ​band.​ ​Cavity​ ​resonators​ ​can​ ​be​ ​applied​ ​as​ ​individual​ ​units, as​ ​perforated​ ​panel​ ​resonators​ ​and​ ​as​ ​slit​ ​resonators.

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2.3​ ​Direct​ ​&​ ​Indirect​ ​Sound​ ​Path Direct​ ​sound​ ​is​ ​sound​ ​that​ ​travels​ ​straight​ ​from​ ​speakers,​ ​etc.​ ​to​ ​the​ ​ear​ ​without​ ​being affected​ ​by​ ​obstacles.​ ​Indirect​ ​sound,​ ​on​ ​the​ ​other​ ​hand,​ ​reaches​ ​the​ ​ear​ ​after​ ​reflecting​ ​off surfaces​ ​such​ ​as​ ​ceilings​ ​or​ ​walls.

Figure​ ​2.3.1:​ ​Direct​ ​sound​ ​path.

Figure​ ​2.3.2:​ ​The​ ​acoustical​ ​defects​ ​in​ ​an​ ​auditorium​.

Reflected​ ​sound​ ​beneficially​ ​reinforces​ ​the​ ​Direct​ ​sound​ ​if​ ​the​ ​time​ ​delay​ ​between​ ​them​ ​Is relatively​ ​short,​ ​that​ ​is​ ​a​ ​maximum​ ​of​ ​30msec.

Time​ ​Delay​​ ​=​ ​đ?‘…1+đ?‘…2​ ​−đ??ˇ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​0.34

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2.4​ ​Reverberation​ ​Time Definition​:-​ ​the​ ​time​ ​for​ ​the​ ​sound​ ​pressure​ ​level​ ​in​ ​a​ ​room​ ​to​ ​decrease​ ​by​ ​60dB​ ​from​ ​its original​ ​level​ ​after​ ​the​ ​sound​ ​is​ ​stopped.

Sound​ ​waves​ ​that​ ​cause​ ​reverberation​ ​loses​ ​energy​ ​as​ ​they​ ​are​ ​absorbed​ ​at​ ​each successive​ ​reflection.​ ​If​ ​the​ ​source​ ​of​ ​sound​ ​stops,​ ​then​ ​the​ ​reverberant​ ​sound​ ​level​ ​decays (loses​ ​sound​ ​pressure​ ​level​ ​over​ ​some​ ​time)​ ​The​ ​time​ ​it​ ​takes​ ​for​ ​sound​ ​pressure​ ​level​ ​to decay​ ​will​ ​affect​ ​the​ ​acoustical​ ​quality​ ​of​ ​an​ ​enclosure.

Figure​ ​2.4.1:​ ​Reverberation​ ​time​ ​diagram.

Reverberation​ ​time​,​ ​RT​ ​=​0.16V ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​A

Figure​ ​2.4.2:​ ​Sound​ ​pressure​ ​level​ ​over​ ​time​ ​graph.

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3.0​ ​Acoustical​ ​Analysis 3.1​ ​Auditorium​ ​Design​ ​Analysis I.​ ​Shape​ ​and​ ​Massing The​ ​theater’s​ ​overall​ ​shape​ ​is​ ​rectilinear​ ​with​ ​several​ ​angular​ ​and​ ​parallel​ ​walls​ ​at​ ​the​ ​sides of​ ​the​ ​theater.​ ​This​ ​configuration​ ​hints​ ​to​ ​a​ ​poor​ ​acoustical​ ​design​ ​as​ ​parallel​ ​walls​ ​tend​ ​to contribute​ ​to​ ​the​ ​issue​ ​of​ ​flutter​ ​echoes​ ​which​ ​consist​ ​of​ ​a​ ​rapid​ ​succession​ ​of​ ​noticeable small​ ​echoes​ ​that​ ​affect​ ​acoustic​ ​quality​ ​of​ ​a​ ​theater.

However,​ ​flutter​ ​echoes​ ​can​ ​be​ ​tackled​ ​when​ ​parallelism​ ​is​ ​being​ ​avoided.​ ​Slight​ ​tilt​ ​of​ ​the wall​ ​should​ ​be​ ​implement​ ​as​ ​it​ ​can​ ​prevent​ ​sound​ ​waves​ ​from​ ​being​ ​reflected​ ​back​ ​to​ ​the sound​ ​source.

Figure​ ​3.1.1:​ ​Shape​ ​and​ ​massing​ ​of​ ​the​ ​theater.

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II.​ ​Arrangements​ ​of​ ​seats The​ ​seats​ ​within​ ​the​ ​theater​ ​are​ ​arranged​ ​in​ ​a​ ​fan​ ​shaped​ ​configuration​ ​to​ ​ensure​ ​a maximum​ ​number​ ​of​ ​seats​ ​are​ ​fitted,​ ​as​ ​well​ ​as​ ​to​ ​obtain​​ ​an​ ​optimum​ ​view​ ​of​ ​the​ ​stage​ ​area from​ ​every​ ​seat.​ ​Most​ ​importantly,​ ​it​ ​helps​ ​to​ ​achieve​ ​the​ ​most​ ​effective​ ​acoustic​ ​quality​ ​as sound​ ​waves​ ​travel​ ​in​ ​a​ ​spherical​ ​order.​ ​In​ ​addition​ ​to​ ​this​ ​theory,​ ​it​ ​is​ ​also​ ​important​ ​to​ ​note that​ ​the​ ​angle​ ​at​ ​which​ ​the​ ​seating​ ​arrangement​ ​are​ ​fanned​ ​out.

It​ ​is​ ​tested​ ​that​ ​by​ ​including​ ​a​ ​140-degree​ ​sound​ ​projection​ ​angle​ ​from​ ​the​ ​center​ ​of​ ​the sound​ ​source​ ​on​ ​the​ ​stage.​ ​Should​ ​all​ ​seats​ ​fall​ ​within​ ​the​ ​angle​ ​of​ ​the​ ​sound​ ​projection area,​ ​the​ ​seating​ ​arrangement​ ​is​ ​well​ ​configured​ ​and​ ​effectively​ ​deemed.

Figure​ ​3.1.2:​ ​The​ ​pattern​ ​of​ ​sound​ ​propagation​ ​in​ ​the​ ​auditorium.

III.​ ​Leveling​ ​of​ ​Seats The​ ​seats​ ​in​ ​an​ ​auditorium​ ​follow​ ​the​ ​leveling​ ​order.​ ​The​ ​seats​ ​on​ ​each​ ​row​ ​are​ ​installed higher​ ​than​ ​the​ ​seats​ ​of​ ​the​ ​row​ ​before.​ ​This​ ​ensures​ ​that​ ​sound​ ​waves​ ​projected​ ​from​ ​the stage​ ​do​ ​not​ ​face​ ​obstructions​ ​of​ ​any​ ​kind​ ​and​ ​can​ ​be​ ​transmitted​ ​smoothly​ ​across​ ​the​ ​whole auditorium.​ ​By​ ​doing​ ​so,​ ​even​ ​the​ ​audience​ ​being​ ​seated​ ​at​ ​the​ ​back​ ​rows​ ​of​ ​the​ ​auditorium would​ ​be​ ​able​ ​to​ ​hear​ ​the​ ​sounds​ ​as​ ​clearly​ ​as​ ​the​ ​audience​ ​being​ ​seated​ ​at​ ​the​ ​front​ ​rows.

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Figure​ ​3.1.3:​ ​The​ ​elevated​ ​seats​ ​in​ ​the​ ​auditorium.

IV.​ ​Ceiling​ ​Reflectors​ ​and​ ​Absorbers There​ ​are​ ​both​ ​reflectors​ ​and​ ​absorbers​ ​used​ ​on​ ​the​ ​ceiling​ ​of​ ​the​ ​auditorium.​ ​The​ ​ceiling absorber​ ​is​ ​used​ ​to​ ​eliminate​ ​the​ ​sound​ ​reflection​ ​to​ ​improve​ ​the​ ​speech​ ​intelligibility​ ​while the​ ​reflectors​ ​are​ ​used​ ​to​ ​reflect​ ​the​ ​sound​ ​waves​ ​toward​ ​the​ ​audience​ ​especially​ ​the audience​ ​seated​ ​at​ ​the​ ​back​ ​rows.​ ​The​ ​occupants​ ​of​ ​the​ ​balcony​ ​would​ ​also​ ​be​ ​able​ ​to​ ​hear the​ ​sounds​ ​clearly​ ​through​ ​this​ ​design,​ ​as​ ​depicted​ ​in​ ​the​ ​diagram​ ​below.

Figure​ ​3.1.4:​ ​The​ ​expected​ ​sound​ ​reflection​ ​from​ ​ceiling​ ​reflectors​ ​to​ ​the​ ​audience.

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3.2​ ​Materials​ ​and​ ​Properties Finishing​ ​Materials

Building Component

Materials Material

Ceiling

Surface Area

Description

Coefficient 125Hz

31.68​m² 0.15 *​ ​3​ ​= 95.03m²

500Hz

2000Hz

0.03

0.05

Plywood

Hardwood veneer finishes​ ​on plywood core

Rockwool

Rockwool 226.75 30mm​ ​direct m² to​ ​masonry

0.10

0.80

0.90

Plywood

Perforated plywood panels

0.30

0.70

0.30

56.09​m² 0.20

0.10

0.04

37.2​m²

Balcony

Plasterboard Plasterboar d​ ​ceiling​ ​on battens​ ​with large​ ​air space above

Wall

Rockwool

Rockwool 38.48​m² 0.10 30mm​ ​direct to​ ​masonry

0.80

0.90

Fabric covered panel

Fibrous​ ​web fabric

223.18 m²

0.07

0.20

0.75

Melamine based​ ​foam 25mm

223.18 m²

0.09

0..54

0.88

Concrete

Smooth painted concrete

120.64 m²

0.01

0.02

0.02

47.88​m² 0.15

0.07

0.04

Plasterboard Plasterboar d​ ​on​ ​cellular core partition

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Curtain

Blackout Red​ ​main 47.88​m² 0.06 Fabric​ ​in​ ​fold act​ ​curtain *​ ​5= (0.5kg/​m²) x1 239.4m² Black​ ​Grand Drape​ ​x1 Black Border​ ​x3

0.38

0.7

Seatings

Plastic​ ​and Metal​ ​chairs

Unoccupied

0.06

0.10

0.30

0.30

0.40

0.43

Concrete

Raised 550mm

59.52​m² 0.01

0.02

0.02

Plywood

Wood​ ​board on​ ​joists

51.11​m² 0.15

0.10

0.10

Plywood

Hardwood veneer finishes​ ​on plywood core

226.75 0.15 m²​ ​(First floor) 56.09m² (Second Floor)

0.08

0.05

Door

Solid​ ​timber door

Painted​ ​into black

0.85​m² *​ ​2 1.5m²​ ​* 2 9.4m²

0.14

0.06

0.10

Hand​ ​Railing

Stainless steel

-

-

0.07

0.14

0.14

Floor

0.37​m²* 450=16 Occupied​ ​by 6.5m² Adult

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Materials​ ​Location

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Construction​ ​Materials I.​ ​Interior​ ​wall Plasterboards​​ ​with​ ​cellular​ ​core​ ​are​ ​being​ ​installed​ ​on​ ​the​ ​sides​ ​of​ ​the​ ​auditorium​ ​as​ ​well the​ ​partitions​ ​between​ ​front​ ​and​ ​back​ ​stage.​ ​Plasterboard​ ​has​ ​low​ ​sound​ ​absorption,​ ​hence, sound​ ​waves​ ​will​ ​be​ ​reflected​ ​and​ ​forming​ ​echoes​ ​subsequently.​ ​On​ ​the​ ​other​ ​hand,​ ​to​ ​aid with​ ​the​ ​sound​ ​absorption,​ ​Hollow​ ​cellular​ ​core​ ​was​ ​sandwiched​ ​in​ ​between​ ​the plasterboards.​ ​The​ ​air​ ​pockets​ ​within​ ​these​ ​hollow​ ​core​ ​absorb​ ​sound​ ​wave​ ​to​ ​reduce echoes.​ ​To​ ​prevent​ ​flutter​ ​echoes,​ ​parallelism​ ​is​ ​avoided​ ​on​ ​the​ ​sides​ ​of​ ​the​ ​auditorium.

Figure​ ​3.2.1:​ ​Construction​ ​materials​ ​of​ ​interior​ ​walls.

Painted​ ​concrete​ ​walls​​ ​are​ ​rarely​ ​being​ ​used​ ​throughout​ ​the​ ​auditorium​ ​due​ ​to​ ​their​ ​lower sound​ ​absorption​ ​coefficient​ ​than​ ​drywalls.​ ​Concrete​ ​walls​ ​provide​ ​the​ ​mass​ ​required​ ​to effectively​ ​reduce​ ​the​ ​transmission​ ​of​ ​sound,​ ​particularly​ ​low​ ​frequency​ ​sounds​ ​such​ ​as those​ ​from​ ​audio​ ​systems.

Figure​ ​3.2.2:​ ​Construction​ ​materials​ ​of​ ​interior​ ​walls​ ​(2).

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II.​ ​Floor​ ​(Ground​ ​Floor) Plywood​ ​covered​ ​with​ ​veneer​ ​laminate​ ​floorings​​ ​contribute​ ​to​ ​the​ ​sound​ ​absorption​ ​of​ ​the auditorium.​ ​Veneer​ ​laminate​ ​flooring​ ​with​ ​a​ ​layer​ ​underlayment​ ​which​ ​add​ ​a​ ​feeling​ ​of​ ​solidity to​ ​the​ ​floor​ ​and​ ​reduce​ ​the​ ​hollow​ ​percussive​ ​sound​ ​that​ ​footfalls​ ​can​ ​produce​ ​when​ ​laminate flooring​ ​is​ ​floated​ ​over​ ​a​ ​subfloor​ ​without​ ​the​ ​benefit​ ​of​ ​underlayment.​​ ​Veneer​ ​laminate​ ​floor combine​ ​a​ ​long​ ​lasting​ ​resilient​ ​core​ ​with​ ​a​ ​mass​ ​loaded​ ​acoustic​ ​barrier​ ​to​ ​effectively​ ​control the​ ​hollow​ ​percussive​ ​noises​ ​associated​ ​with​ ​hard​ ​floor​ ​finishes.

Figure​ ​3.2.3:​ ​Construction​ ​materials​ ​of​ ​ground​ ​floor’s​ ​floor.

III.​ ​Floor​ ​(Balcony) On​ ​the​ ​other​ ​hand,​ ​plywoods​ ​are​ ​used​ ​to​ ​construct​ ​the​ ​floorings​ ​of​ ​the​ ​balcony.​ ​Plywoods are​ ​not​ ​as​ ​exceptional​ ​at​ ​providing​ ​airborne​ ​sound​ ​insulation​ ​as​ ​concrete​ ​slabs.

Nonetheless,​ ​it​ ​is​ ​proficient​ ​for​ ​sound​ ​reduction​ ​with​ ​the​ ​addition​ ​of​ ​the​ ​concrete underlayment,​ ​adding​ ​a​ ​feeling​ ​of​ ​solidity​ ​to​ ​the​ ​floor​ ​and​ ​reducing​ ​the​ ​hollow​ ​percussive sound​ ​that​ ​footfalls​ ​can​ ​produce​ ​when​ ​the​ ​plywood​ ​is​ ​floated​ ​over​ ​a​ ​subfloor​ ​without​ ​the benefit​ ​of​ ​an​ ​underlayment.

Figure​ ​3.2.4:​ ​Construction​ ​materials​ ​of​ ​balcony’s​ ​floor.

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IV.​ ​Floor​ ​(Stage) The​ ​materials​ ​used​ ​to​ ​construct​ ​the​ ​theater​ ​stage​ ​are​ ​similar​ ​to​ ​the​ ​materials​ ​used​ ​to construct​ ​the​ ​balcony’s​ ​floor​ ​-​ ​plywoods​ ​as​ ​decking​ ​on​ ​timber​ ​floor​ ​joists.​ ​However,​ ​to increase​ ​its​ ​stability​ ​as​ ​a​ ​performance​ ​stage,​ ​aluminium​ ​galvanized​ ​steel​ ​posts​ ​were​ ​added underneath​ ​the​ ​timber​ ​bearers.

Figure​ ​3.2.5:​ ​Construction​ ​materials​ ​of​ ​stage.

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3.3​ ​Acoustic​ ​Wall​ ​Panelling​ ​/​ ​Wall​ ​Treatment I.​ ​Side​ ​walls Acoustic​ ​wall​ ​panellings​ ​are​ ​installed​ ​along​ ​the​ ​side​ ​walls​ ​of​ ​the​ ​theater​ ​in​ ​the​ ​form​ ​of​ ​fabric wrapped​ ​melamine​ ​foam.​ ​By​ ​installing​ ​porous​ ​membrane​ ​such​ ​as​ ​melamine​ ​foam,​ ​this​ ​could absorb​ ​the​ ​medium​ ​to​ ​high​ ​frequencies​ ​to​ ​reduce​ ​reverberation​ ​time​ ​subsequently.​ ​Fibrous web​ ​fabric​ ​is​ ​used​ ​for​ ​covering​ ​the​ ​foam​ ​to​ ​allow​ ​sound​ ​waves​ ​to​ ​be​ ​dissipated​ ​through​ ​the porous​ ​membrane​ ​before​ ​being​ ​trapped​ ​and​ ​dampened.

Figure​ ​3.2.6,​ ​3.2.7:​ ​Wall​ ​panelling​ ​on​ ​the​ ​side​ ​walls​ ​of​ ​the​ ​theater.

II.​ ​Rear​ ​walls The​ ​rear​ ​walls​ ​of​ ​the​ ​theater​ ​are​ ​treated​ ​with​ ​a layer​ ​of​ ​rockwool,​ ​which​ ​also​ ​functions​ ​as​ ​sound absorption​ ​element.​ ​The​ ​rockwool​ ​is​ ​being​ ​used​ ​to absorb​ ​the​ ​sound​ ​waves​ ​after​ ​it​ ​has​ ​passed​ ​over the​ ​audience​ ​and​ ​prevents​ ​a​ ​second​ ​wave,​ ​as known​ ​as​ ​echo​ ​from​ ​occurring.

Figure​ ​3.2.8:​ ​Wall​ ​treatment​ ​on​ ​the​ ​rear​ ​wall​ ​of​ ​the​ ​theater.

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3.4​ ​Sound​ ​and​ ​Noise​ ​Source Technically​ ​similar​ ​in​ ​definition,​ ​noise​ ​and​ ​sound​ ​differ​ ​based​ ​on​ ​the​ ​user’s​ ​perception.​ ​Noise is​ ​simply​ ​undesirable​ ​sound​ ​that​ ​emanates​ ​from​ ​a​ ​variety​ ​of​ ​sources.​ ​Sound​ ​on​ ​the​ ​other hand,​ ​is​ ​almost​ ​always​ ​intentional​ ​and​ ​directed​ ​towards​ ​its​ ​audience.

Sound​ ​Source Sound​ ​Surround​ ​System The​ ​PJ​ ​Live​ ​Arts​ ​using​ ​the​ ​5.1​ ​surround​ ​sound​ ​system​ ​since​ ​August​ ​2009.​ ​Most​ ​auditorium had​ ​used​ ​this​ ​surround​ ​sound​ ​system​ ​as​ ​to​ ​reinforce​ ​the​ ​basic​ ​stereo​ ​sound.​ ​With​ ​this system,​ ​it​ ​provides​ ​a​ ​high​ ​standard​ ​quality​ ​of​ ​sound​ ​for​ ​the​ ​audience​ ​who​ ​is​ ​watching​ ​the performance​ ​in​ ​a​ ​large​ ​space​ ​of​ ​auditorium.​ ​The​ ​speaker​ ​consists​ ​of​ ​5​ ​speakers​ ​with installed​ ​on​ ​each​ ​location​ ​differently​ ​and​ ​a​ ​subwoofer​ ​which​ ​is​ ​an​ ​ideal​ ​solution​ ​to​ ​increase audio​ ​clarity​ ​and​ ​intelligibility​ ​in​ ​a​ ​large​ ​auditorium​ ​space.​ ​The​ ​placement​ ​of​ ​speakers​ ​need to​ ​be​ ​considered​ ​where​ ​mostly​ ​installed​ ​on​ ​high​ ​level​ ​and​ ​mounted​ ​on​ ​the​ ​sidewall​ ​to​ ​deliver enough​ ​of​ ​the​ ​sound​ ​to​ ​the​ ​audience.

Equipment​ ​Location

Figure​ ​3.4.1:​ ​Placement​ ​of​ ​the​ ​sound​ ​sources.

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Figure​ ​3.4.2:​ ​Placement​ ​of​ ​the​ ​speaker.

There​ ​are​ ​two​ ​different​ ​location​ ​of​ ​speakers​ ​that​ ​are​ ​installed​ ​in​ ​this​ ​auditorium.​ ​8​ ​speakers with​ ​divided​ ​into​ ​two​ ​group​ ​are​ ​mounted​ ​on​ ​top​ ​of​ ​the​ ​ceiling​ ​level​ ​and​ ​two​ ​portable​ ​speakers on​ ​the​ ​stage​ ​which​ ​to​ ​cover​ ​up​ ​the​ ​whole​ ​space​ ​that​ ​can​ ​available​ ​to​ ​receive​ ​the​ ​sound clearly​ ​whether​ ​is​ ​on​ ​the​ ​balcony​ ​or​ ​the​ ​floor​ ​level.​ ​The​ ​4​ ​subwoofer​ ​are​ ​installed​ ​on​ ​the ceiling​ ​of​ ​the​ ​auditorium​ ​which​ ​produce​ ​low​ ​frequencies​ ​of​ ​bass​ ​sound​ ​to​ ​balance​ ​the​ ​music or​ ​speech​ ​on​ ​the​ ​equalization​ ​for​ ​the​ ​audience​ ​the​ ​perfect​ ​sound.

Figure​ ​3.4.3:​ ​Sound​ ​source​ ​diagram.

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Equipment​ ​Specification Specification​ ​(A) Product​ ​Brand

VRX932​ ​LAP​ ​Loudspeaker System

Dimensions​ ​(H​ ​x​ ​W​ ​x​ ​D)

349mm​ ​x​ ​597mm​ ​x​ ​444mm

Frequency​ ​Range

57​ ​Hz​ ​-​ ​20​ ​kHz​ ​(-10dB)

Weight

24​ ​kg

Power​ ​Rating

1750W​ ​Peak​ ​/​ ​875W​ ​Continuous

Placement​ ​(colour)

Ceiling​ ​level​ ​(Red) Specification​ ​(B)

Product​ ​Brand

VRX915S​ ​Bass​ ​Reflex​ ​Subwoofer

Dimensions​ ​(H​ ​x​ ​W​ ​x​ ​D)

495mm​ ​x​ ​420mm​ ​x​ ​597mm

Frequency​ ​Range

35​ ​Hz​ ​-​ ​250​ ​Hz​ ​(-10dB)

Weight

26.3​ ​kg

Power​ ​Rating

800W​ ​/​ ​1600W​ ​/​ ​3200W

Placement​ ​(colour)

Ceiling​ ​level​ ​(Orange)

Specification​ ​(C) Product​ ​Brand

EON​ ​206P​ ​P.A.​ ​System

Dimensions​ ​(H​ ​x​ ​W​ ​x​ ​D)

530mm​ ​x​ ​705mm​ ​x​ ​340mm

Frequency​ ​Range

64Hz​ ​-​ ​22kHz​ ​(-10dB)

Weight

11.38​ ​kg

Power​ ​Rating

160​ ​W

Placement​ ​(colour)

Stage​ ​(Red)

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Noise​ ​Source I.​ ​External​ ​Sources There​ ​are​ ​multiple​ ​noise​ ​sources​ ​from​ ​the​ ​external​ ​environment​ ​of​ ​PJ​ ​Live​ ​Arts.​ ​These include​ ​the​ ​walking​ ​and​ ​talking​ ​noises​ ​from​ ​the​ ​restaurants​ ​and​ ​bars​ ​and​ ​the​ ​background hum​ ​from​ ​the​ ​mall​ ​nearby.​ ​Noise​ ​is​ ​undesirable​ ​sound​ ​so​ ​steps​ ​to​ ​control​ ​the​ ​penetration​ ​of noise​ ​into​ ​the​ ​auditorium​ ​are​ ​necessary.​ ​The​ ​auditorium​ ​utilises​ ​methods​ ​of​ ​wall​ ​acoustic treatments​ ​covered​ ​in​ ​section​ ​3.3.​ ​The​ ​diagram​ ​below​ ​indicates​ ​the​ ​ground​ ​floor​ ​plan​ ​and the​ ​potential​ ​external​ ​noise​ ​sources.

Figure​ ​3.4.4:​ ​Jaya​ ​One​ ​block​ ​layout.

Jaya​ ​One​ ​being​ ​a​ ​commercial​ ​hub​ ​for​ ​small​ ​and​ ​large​ ​retail​ ​stores​ ​attracts​ ​a​ ​steady​ ​flow​ ​of patrons.​ ​Located​ ​away​ ​from​ ​the​ ​main​ ​road,​ ​the​ ​most​ ​prominent​ ​noise​ ​comes​ ​from​ ​chatter from​ ​the​ ​bars​ ​and​ ​restaurants​ ​near​ ​the​ ​auditorium.

Figure​ ​3.4.5:​ ​Jaya​ ​One​ ​bars​ ​and​ ​restaurants.

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Even​ ​though​ ​these​ ​are​ ​not​ ​evident​ ​in​ ​our​ ​case​ ​study,​ ​further​ ​suggestions​ ​can​ ​be​ ​made​ ​to append​ ​the​ ​degree​ ​of​ ​insulation​ ​from​ ​external​ ​noises​ ​if​ ​need​ ​be.​ ​For​ ​instance,​ ​the​ ​installation of​ ​a​ ​drywall​ ​with​ ​an​ ​air​ ​channel​ ​and​ ​connected​ ​using​ ​resilient​ ​clips.​ ​To​ ​further​ ​insulate​ ​from external​ ​noise,​ ​the​ ​addition​ ​of​ ​mass​ ​to​ ​the​ ​drywall​ ​will​ ​reduce​ ​the​ ​noise​ ​energy​ ​transfer thereby​ ​losing​ ​the​ ​energy​ ​as​ ​heat​ ​within​ ​the​ ​wall.

II.​ ​Internal​ ​Sources Internal​ ​sound​ ​and​ ​noise​ ​sources​ ​include​ ​the​ ​overhead​ ​speakers​ ​adjacent​ ​to​ ​the​ ​stage, HVAC​ ​systems​ ​such​ ​as​ ​ceiling​ ​air​ ​vents​ ​and​ ​air​ ​conditioning​ ​vents​ ​installed​ ​at​ ​the​ ​lower​ ​floor ceiling.​ ​The​ ​overhead​ ​speakers​ ​and​ ​ceiling​ ​light​ ​produce​ ​a​ ​dim​ ​static​ ​noise​ ​when​ ​operating.

More​ ​background​ ​noises​ ​include​ ​the​ ​thudding​ ​produced​ ​by​ ​footsteps​ ​on​ ​the​ ​auditorium​ ​floor and​ ​stage​ ​and​ ​noises​ ​from​ ​backstage.

Air​ ​cond​ ​and​ ​diffuser Japan​ ​Ventech​ ​Air​ ​diffuser​ ​round​ ​shape

ceiling​ ​diffuser​ ​Aluminum​ ​air​ ​vent​ ​jet nozzle

CB​ ​series​ ​Linear​ ​slot​ ​diffuser

Fluorescent​ ​light (purple​ ​Neon)​ ​Leyton​ ​lighting​ ​13w​ ​T15 slimline

Ceiling​ ​Light Watt​ ​Frosted​ ​Round​ ​LED​ ​Ceiling​ ​Light

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​ ​Figure​ ​3.4.5:​ ​Internal​ ​sounds​ ​produced​ ​by​ ​existing​ ​sound​ ​system.

Note​ ​that​ ​the​ ​sound​ ​path​ ​travelling​ ​towards​ ​the​ ​stage​ ​is​ ​dimmed.​ ​This​ ​is​ ​because​ ​sound refracts​ ​upwards​ ​at​ ​night​ ​due​ ​to​ ​temperature​ ​differences​ ​and​ ​is​ ​subsequently​ ​absorbed​ ​by the​ ​panels​ ​immediately​ ​behind​ ​the​ ​speakers.

Figure​ ​3.4.6:​ ​Absorbent​ ​panel.

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Figure​ ​3.4.7:​ ​HVAC​ ​vents​ ​on​ ​the​ ​lower​ ​ceiling.

Any​ ​noise​ ​from​ ​people​ ​or​ ​objects​ ​using​ ​the​ ​walkways​ ​are​ ​highly​ ​legible​ ​to​ ​the​ ​existing audience​ ​due​ ​to​ ​a​ ​lack​ ​of​ ​carpeting.​ ​However,​ ​the​ ​use​ ​of​ ​a​ ​timber​ ​laminate​ ​flooring​ ​finish​ ​on top​ ​of​ ​plywood​ ​decking​ ​are​ ​inherently​ ​sound​ ​absorbent​ ​materials​ ​due​ ​to​ ​their​ ​elasticity.​ ​This property​ ​allows​ ​vibrations​ ​to​ ​filter​ ​through​ ​a​ ​little​ ​better​ ​than​ ​hard​ ​rigid​ ​materials​ ​like concrete.

​ ​ ​ ​ ​Figure​ ​3.4.8,​ ​3.4.9:​​ ​Stage​ ​and​ ​Seating​ ​Area​ ​Floor​ ​Cut​ ​Section.

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Figure​ ​3.4.10:​​ B ​ ackground​ ​noises​ ​from​ ​HVAC​ ​system.

3.5​ ​Sound​ ​Propagations​ ​and​ ​Phenomenon I.​ ​Sound​ ​shadow The​ ​diagram​ ​highlighted​ ​the​ ​deep​ ​balcony​ ​as​ ​a​ ​potential​ ​acoustic​ ​shadow​ ​area​ ​,​ ​the application​ ​of​ ​absorption​ ​wall​ ​possibly​ ​reflect​ ​to​ ​lose​ ​the​ ​energy​ ​,​ ​received​ ​low​ ​intensity​ ​of those​ ​reflected​ ​sound​ ​towards​ ​the​ ​area​ ​below​ ​forming​ ​a​ ​sound​ ​shadow​ ​area.

Figure​ ​3.5.1:​ ​Sound​ ​shadow​ ​diagram​ ​in​ ​section.​ ​The​ ​result​ ​shows​ ​the​ ​low​ ​sound​ ​intensity​ ​at​ ​the​ ​acoustic​ ​shadow area​ ​by​ ​sound​ ​clapping

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Figure​ ​3.5.2:​ ​Potential​ ​sound​ ​shadow​ ​area.

II.​ ​Sound​ ​Concentration The​ ​diagram​ ​shows​ ​the​ ​sound​ ​intensity​ ​levels​ ​of​ ​the​ ​sound​ ​source​ ​with​ ​the​ ​distinct​ ​sound​ ​at the​ ​concentrate​ ​zone​ ​which​ ​located​ ​at​ ​centre​ ​of​ ​auditorium​ ​,​ ​ ​has​ ​the​ ​highest​ ​intensity​ ​level.

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Figure​ ​3.5.3:​ ​Sound​ ​intensity​ ​level​ ​diagram

Figure​ ​3.5.4:​ ​Sound​ ​reflection​ ​diagram.

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The​ ​diagram​ ​shows​ ​that​ ​the​ ​sound​ ​concentration​ ​zone​ ​has​ ​been​ ​formed​ ​because​ ​of​ ​the rectangular​ ​shape​ ​of​ ​the​ ​auditorium.​ ​This​ ​rectangular​ ​design​ ​of​ ​the​ ​auditorium​ ​will​ ​fit​ ​well​ ​into many​ ​conventional​ ​new​ ​buildings.​ ​This​ ​form​ ​is​ ​only​ ​well​ ​suited​ ​for​ ​lecture,​ ​film​ ​or​ ​speech type​ ​theatre.​ ​However,​ ​this​ ​design​ ​does​ ​not​ ​facilitate​ ​a​ ​close​ ​relationship​ ​between​ ​performer and​ ​the​ ​audience​ ​which​ ​the​ ​PJ​ ​Live​ ​Arts​ ​Center​ ​is​ ​striving​ ​for.

On​ ​the​ ​other​ ​hand,​ ​a​ ​fan​ ​shaped​ ​massing​ ​of​ ​the​ ​auditorium​ ​with​ ​a​ ​130​ ​degrees​ ​wide​ ​spread from​ ​a​ ​central​ ​focal​ ​point​ ​will​ ​be​ ​able​ ​to​ ​pull​ ​the​ ​attention​ ​of​ ​the​ ​audience​ ​towards​ ​to​ ​the performers.

III.​ ​Sound​ ​Reflection To​ ​make​ ​better​ ​use​ ​of​ ​the​ ​sound,​ ​the​ ​reflected​ ​sound​ ​has​ ​to​ ​be​ ​controlled​ ​properly​ ​to​ ​avoid echoes.​ ​Therefore,​ ​reflectors​ ​have​ ​to​ ​be​ ​used​ ​so​ ​that​ ​maximum​ ​amount​ ​of​ ​sound​ ​in​ ​the auditorium​ ​can​ ​be​ ​reflected​ ​to​ ​the​ ​audiences.

Figure​ ​3.5.5:​ ​Sound​ ​reflection​ ​towards​ ​audience​ ​at​ ​row​ ​6.

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Figure​ ​3.5.6:​ ​Sound​ ​reflection​ ​towards​ ​audience​ ​at​ ​row​ ​11.

Figure​ ​3.5.7:​ ​Sound​ ​reflection​ ​towards​ ​audience​ ​at​ ​the​ ​balcony​ ​area.

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The​ ​sound​ ​is​ ​effectively​ ​reflected​ ​back​ ​to​ ​the​ ​audience​ ​by​ ​the​ ​ceiling​ ​reflector.​ ​However,​ ​the flooring​ ​of​ ​the​ ​auditorium​ ​should​ ​be​ ​covered​ ​with​ ​more​ ​absorbent​ ​material​ ​to​ ​minimize​ ​the reflection​ ​of​ ​sound.

IV.​ ​Echoes​ ​and​ ​Sound​ ​Delay An​ ​echo​ ​is​ ​distinctly​ ​different​ ​from​ ​a​ ​reverberation​ ​as​ ​it​ ​is​ ​a​ ​constant​ ​repetition​ ​of​ ​the​ ​original sound.​ ​The​ ​nature​ ​of​ ​the​ ​programme​ ​influences​ ​the​ ​desired​ ​sound​ ​delay​ ​period​ ​and​ ​hence, the​ ​definition​ ​of​ ​its​ ​echo.

In​ ​this​ ​analysis,​ ​only​ ​reflective​ ​surfaces​ ​will​ ​be​ ​treated​ ​as​ ​effective​ ​sources​ ​of​ ​sound​ ​delay.

Generally,​ ​in​ ​a​ ​theater​ ​designed​ ​for​ ​performances,​ ​any​ ​sound​ ​delay​ ​above​ ​100ms​ ​will​ ​be considered​ ​as​ ​an​ ​echo.

Figure​ ​3.5.8:​ ​5.49ms​ ​of​ ​sound​ ​delay​ ​is​ ​acceptable​ ​for​ ​a​ ​performance​ ​theater.

Echo =[(8.0+7.9)-7.7]*0.34 =5.40ms

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Figure​ ​3.5.9:​ ​2.24ms​ ​of​ ​sound​ ​delay​ ​is​ ​acceptable​ ​for​ ​a​ ​performance​ ​theater.

Echo =[(11.4+8.1)-12.9]*0.34 =2.24ms

Figure​ ​3.5.10:​ ​0.82ms​ ​of​ ​sound​ ​delay​ ​is​ ​acceptable​ ​for​ ​a​ ​performance​ ​theater.

Echo =[(15.1+2.8)-15.5]*0.34 =0.82ms

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The​ ​sound​ ​delay​ ​present​ ​in​ ​PJ​ ​Live​ ​Arts​ ​is​ ​very​ ​minimal​ ​that​ ​it​ ​is​ ​close​ ​to​ ​impossible​ ​to discern.​ ​Therefore,​ ​this​ ​theater​ ​will​ ​not​ ​suffer​ ​from​ ​any​ ​intelligible​ ​sound​ ​caused​ ​by​ ​echoes.

V.​ ​Reverberation​ ​Time​ ​Calculation *Absorption​ ​of​ ​surface​ ​at​ ​500Hz Ceiling a. Rockwool​ ​:​ ​0.80​ ​x​ ​226.75​m²​ ​=​ ​181.4​ ​m²sabins

b. Perforated​ ​plywood​ ​panels​ ​:​ ​0.70​ ​x​ ​37.2m²​ ​=​ ​26.04​ ​m²sabins

Balcony

a. Plasterboard​ ​:​ ​0.10​ ​x​ ​56.09m²​ ​=​ ​5.61​ ​m²sabins Wall

a. b. c. d.

Rockwool​ ​:​ ​0.80​ ​x​ ​38.48m²​ ​=​ ​30.78​ ​m²sabins Fibrous​ ​web​ ​fabric​ ​:​ ​0.20​ ​x​ ​ ​223.18m²​ ​=​ ​44.64​​ ​m²sabins Melamine​ ​based​ ​foam​ ​:​ ​0.54​ ​x​ ​223.18m²​ ​=​ ​102.72​ ​m²sabins Concrete​ ​:​ ​0.02​ ​x​ ​120.64m²​ ​=​ ​2.41​ ​m²sabins

Curtain

a. Blackout​ ​fabric​ ​:​ ​0.38​ ​x​ ​239.4​ ​m²​ ​=​ ​90.97​ ​m²sabins Seating

a. Unoccupied​ ​:​ ​0.1​ ​x​ ​6.5m²​ ​=​ ​0.65​ ​m²sabins Floor

a. Veneer​ ​finishes​ ​:​ ​0.08​ ​x​ ​282.84m²​ ​=​ ​22.67​ ​m²sabins b. Plywood​ :​ ​ ​0.1​ ​x​ ​51.11m²​ ​=​ ​5.11m²sabins c. Concrete​ :​ ​ ​0.02​ ​x​ ​59.52​ ​m²​ ​=​ ​1.19​ ​m²sabins Total​ ​absorption​ ​areas​ ​: 181.4​ ​+​ ​26.04​ ​+​ ​5.61​ ​+​ ​30.78​ ​+​ ​44.64​ ​+​ ​102.72​ ​+​ ​2.41​ ​+​ ​90.97​ ​+​ ​0.65​ ​+​ ​22.67​ ​+​ ​5.11​ ​+​ ​1.19 =​ ​514.19​ ​m²sabins

Reverberation​ ​Time​ ​=​ ​(0.16​ ​x​ ​Volume​ ​of​ ​the​ ​room)​ ​/​ ​Total​ ​absorption​ ​area RT​​ ​=​ ​(0.16​ ​x​ ​3473.25)​ ​/​ ​514.19 ​ ​ ​ ​ ​ ​ ​=​ ​1.08​ ​s According​ ​to​ ​the​ ​calculation,​ ​the​ ​reverberation​ ​time​ ​of​ ​the​ ​theatre​ ​is​ ​1.08s​ ​which​ ​is​ ​within​ ​the recommended​ ​range​ ​of​ ​1.00s​ ​-​ ​1.25s​ ​for​ ​a​ ​medium​ ​sized​ ​multipurpose​ ​room.​ ​This​ ​shows that​ ​the​ ​materials​ ​used​ ​is​ ​good​ ​absorbers​ ​and​ ​causes​ ​less​ ​echoes​ ​are​ ​heard.​ ​Sounds​ ​within the​ ​halls​ ​does​ ​not​ ​linger​ ​around​ ​for​ ​a​ ​long​ ​period.​ ​However,​ ​it​ ​does​ ​not​ ​suitable​ ​for​ ​music performances​ ​as​ ​the​ ​sound​ ​diminished​ ​too​ ​quickly.

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4.0​ ​Issues​ ​and​ ​Recommendations Issue​ ​1​ ​:​ ​Finishing​ ​materials​ ​of​ ​floor

​ ​ ​Figure​ ​4.0.1:​ ​Addition​ ​of​ ​pile​ ​carpet​ ​to​ ​floor​ ​materials.

The​ ​present​ ​floor​ ​in​ ​PJ​ ​Live​ ​Arts​ ​Theatre​ ​consist​ ​of​ ​concrete,​ ​plywood​ ​with​ ​veneer​ ​finishing acts​ ​as​ ​a​ ​form​ ​of​ ​noise​ ​source.​ ​This​ ​is​ ​mainly​ ​due​ ​to​ ​the​ ​low​ ​absorption​ ​coefficient​ ​of​ ​the finishing​ ​material​ ​which​ ​contributes​ ​the​ ​most​ ​to​ ​sound​ ​absorption.

Recommendation​ ​: The​ ​thickness​ ​of​ ​hardwood​ ​veneer​ ​finishing​ ​can​ ​be​ ​increased​ ​to​ ​improve​ ​the​ ​efficiency​ ​of sound​ ​absorption.​ ​6​ ​mm​ ​pile​ ​carpet​ ​bonded​ ​to​ ​open-cell​ ​foam​ ​underlay​ ​which​ ​has​ ​0.2 absorption​ ​coefficient​ ​also​ ​can​ ​be​ ​added​ ​to​ ​help​ ​reduce​ ​noise​ ​from​ ​both​ ​the​ ​reflection​ ​and also​ ​the​ ​impact​ ​sound​ ​of​ ​between​ ​shoes​ ​and​ ​floor.

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Issue​ ​2​ ​:​ ​Wall​ ​Reflective​ ​Panel

Figure​ ​4.0.2:​ ​Application​ ​of​ ​acoustic​ ​timber​ ​panel​ ​as​ ​reflector.

Recommendation: Timber​ ​side​ ​wall​ ​panel​ ​can​ ​be​ ​applied​ ​to​ ​the​ ​first​ ​⅓​ ​portion​ ​of​ ​the​ ​auditorium​ ​in​ ​order​ ​to supply​ ​additional​ ​sound​ ​energy​ ​which​ ​ensure​ ​the​ ​uniform​ ​distribution​ ​of​ ​sound​ ​wave​ ​in​ ​the theater.

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5.0​ ​Conclusion Through​ ​this​ ​project,​ ​we​ ​understand​ ​that​ ​a​ ​successful​ ​design​ ​of​ ​theater​ ​depends​ ​on different​ ​acoustics​ ​design​ ​such​ ​as​ ​theater​ ​layout,​ ​types​ ​of​ ​absorption​ ​materials​ ​and also​ ​type​ ​of​ ​acoustics​ ​features​ ​used.​ ​Acoustic​ ​plays​ ​a​ ​role​ ​in​ ​enhancing​ ​the​ ​quality​ ​of sound​ ​and​ ​to​ ​eliminate​ ​noise​ ​and​ ​undesired​ ​sound.​ ​After​ ​visiting​ ​and​ ​doing​ ​research on​ ​our​ ​chosen​ ​theater,​ ​we​ ​learnt​ ​about​ ​material​ ​absorption​ ​coefficient​ ​and​ ​how​ ​to identify​ ​existing​ ​acoustic​ ​and​ ​sound​ ​sources.​ ​Through​ ​understanding​ ​all​ ​the information,​ ​we​ ​learnt​ ​how​ ​to​ ​calculate​ ​and​ ​analyze​ ​the​ ​data​ ​we​ ​collected​ ​from​ ​site.

Thus,​ ​enabling​ ​us​ ​to​ ​learn​ ​about​ ​sound​ ​reflection,​ ​sound​ ​intensity​ ​level​ ​and reverberation​ ​time.

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5.0​ ​References Sound​ ​Transmission​ ​and​ ​Flooring​ ​Types.​ ​(2010,​ ​March​ ​26).​ ​Retrieved​ ​September​ ​30,​ ​2017, from https://www.builddirect.com/learning-center/home-improvement-info/sound-transmission/ Ovation​ ​Reflector​ ​Panels.​ ​(n.d.).​ ​Retrieved​ ​September​ ​30,​ ​2017,​ ​from http://www.kineticsnoise.com/interiors/ovation.html Absorption​ ​Coefficients.​ ​(n.d.).​ ​Retrieved​ ​September​ ​20,​ ​2017,​ ​from​ ​http://www.akustik.ua/ Material​ ​data.​ ​(n.d.).​ ​Retrieved​ ​September​ ​20,​ ​2017,​ ​from https://cds.cern.ch/record/1251519/files/978-3-540-48830-9_BookBackMatter.pdf Sound​ ​Insulation​ ​Properties​ ​of​ ​Concrete​ ​Walls​ ​and​ ​Floors​ ​(2009,​ ​March).​ ​Retrieved September​ ​18​ ​2017,​ ​from​ ​http://59.167.233.142/publications/pdf/SoundInsulation.pdf Acoustic​ ​Reflectors.​ ​(n.d.).​ ​Retrieved​ ​September​ ​25,​ ​2017,​ ​from http://www.totalvibrationsolutions.com/page/289/Acoustic-Reflectors.htm Inc.,​ ​T.​ ​S.,​ ​Says,​ ​J.,​ ​Says,​ ​N.,​ ​Says,​ ​R.​ ​C.,​ ​Says,​ ​E.,​ ​Says,​ ​H.​ ​S.,​ ​&​ ​Says,​ ​S.​ ​(2017,​ ​June​ ​30).

Auditorium​ ​Seating​ ​Layout​ ​&​ ​Dimensions​ ​Guide.​ ​Retrieved​ ​September​ ​30,​ ​2017,​ ​from http://www.theatresolutions.net/auditorium-seating-layout/

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