Building Science II Project 1 Report

BACHELOR OF SCIENCE (HONS) IN ARCHITECTURE

BUILDING SCIENCE II (BLD 61303)PROJECT 1 : CASE STUDY ON ACOUSTIC DESIGN

SUBMISSION : 5TH AUGUST 2017

SHANTANAND AUDITORIUM

PREPARED BY

TUTOR : MR. EDWIN CHAN

NAME ID NUMBER

CHONG CHIN PIN

ERICA CHIN CHING

LIEW MIN YEE

LOONG BO LIN

MICHELLE SIAW WI WEE

OSCAR WONG ZHENG YANG

TAN JINGWEI

TAY JING HENG

0319595

0320460

0324525

0321469

0325883

0319674

0320137

0325230

TABLE OF CONTENT

CONTENT PAGE

1.0 INTRODUCTION

1.1 AIM AND OBJECTIVE

1.2 BACKGROUND OF SITE

1.3 HISTORY

1.4 PHOTOS

1.5 DRAWINGS

2.0 ACOUSTICS AND ARCHITECTURE

2.1 LITERATURE REVIEW

2.2 METHODOLOGY

3.0 ACOUSTIC DESIGN ANALYSIS

3.1 SOUND REINFORCEMENT SYSTEM

3.2 SOUND CONCENTRATION

3.3 SOUND SHADOW

3.4 SOUND REFLECTION AND SOUND TRANSMISSION

3. 5 FLUTTER ECHOES AND SOUND DELAY

3.6 NOISE INTRUSION

3.7 MATERIALITY & SOUND ABSORPTION COEFFICIENT

3.8 CALCULATION - REVERBERATION TIME

3.9 DESIGN CONSIDERATION AND SUGGESTIONS

4.0 CONCLUSION

5.0 REFERENCES

1

2

3

4

7

11

12

14

17

18

23

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25

28

33

47

54

56

58

60

1.0 INTRODUCTION

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1.1 AIM AND OBJECTIVE

In this project, our aim and objectives are :

1. To produce an in-depth acoustic design analysis of our chosen auditorium, and the effectiveness that contribute to the acoustic quality of Shantanand auditorium,

2. To study and analyse the characteristics of acoustic auditorium and suggest way(s) to improve the acoustic qualities within the space,

3. To generate a documentation report based on the researched datas and on-site analysis that are able to show the relationship between acoustical design with space.

Name of auditorium: Shantanand auditorium

Location: 114-116, Jalan Berhala, Brickfields, Kuala Lumpur

Type of auditorium: Community auditorium

Year of completion: 2011

Total Volume: 8769m3

Total seats: 618

Description:

The building that we have selected is The Temple of Fine

Arts in Kuala Lumpur. It is known to be the main centre for

learning classical Indian music in Malaysia. It is located at

Brickfields also known as Little India of Kuala Lumpur.

1.2 SITE INTRODUCTION

Figure 1.2.1 Key plan showing the location of Temple of fine arts at Brickfields, Kuala Lumpur.

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DESCRIPTION:

Temple of fine arts are well-known as the cultural performance stage at Shantanand auditorium. The

auditorium has fullfill the needs of acoustical design and treatment without significant live and dead

spot. Hence, it is able to provide ultimate sound quality throughout the whole auditorium. The

purpose of this auditorium are normally for lavish and polished musical production such as, dance

dramas, vocal music, acting and so on. The hall itself has built-up area of 8769m3. It can

accommodate up to 618 people in which the main hall provides a number of 400 capacity followed by

218 addition capacity at the first floor balcony. Besides, addition of 100 extra seats could be arranged

in the auditorium when it is needed.

The founder of Temple of fine arts, His Holiness Swami Shantanand Sawaswathi, aimed to

provide a platform for Malaysian Youth to show their appreciation towards cultural, artistic and

spiritual wealth. Besides, Shantanand Auditorium provides an avenue for cross-cultural initiatives for

different races in Malaysia. The auditorium was named after Swamiji as an inspiration which signifies

and continuity presence and guidance. From His Holiness Swami Shantanand Sawaswathi. The

auditorium aimed known as ‘Heartspace for creating. Expression’ to promote the beauty of Indian

arts and performances that allow youngster to get involve of Indian dance and learn to appreciate the

beauty of art.It is soft launced in January 2011 and official launching by the honourable Prime

Minister on 4th of July 2011.

1.3 HISTORY

Figure 1.2.2 Three-storey building of temple of fine arts at Jalan Brickfields.

Figure 1.3.1 Shantanand auditorium became choice of venue for art performing.

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1.2 SITE INTRODUCTION

1.4 PHOTOS

Figure 1.4..1 Shantanand auditorium portray a sense of classic and elegant with lighting

Figure 1.4..3 The stage of Shantanand auditorium is made up timber

flooring with rubber finishes

Figure 1.4..2 Shantanand auditorium illustrates a sense of humbleness without complete lighting

Figure 1.4.4 Curtain provides a sense of mystery and initiate the excitement of the audience towards the performances

4

1.4 PHOTOS

Figure 1.4.6 Panorama view showing the seating and balcony of Shantanand auditorium

Figure 1.4.5 Side view of Shantanand auditorium with two different leveling

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1.4 PHOTOS

Figure 1.4.6 Shantanand auditorium has 2 main entrance at both side which provides a narrow

passage for the audience to access to the auditorium

Figure 1.4.7 The convex reflective ceiling with 4 meter height enhances the entirety of the

auditorium which provides a better visuality for performer and audiences

Figure 1.4.8 Flying tower illustrates a linear visuality for aesthetic appearance

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1.5 DRAWINGS - PLAN

GROUND FLOOR PLANScale 1:200

7

1.5 DRAWINGS - PLAN

FIRST FLOOR PLAN (BALCONY)Scale 1:200

8

1.5 REFLECTED CEILING PLAN

REFLECTED CEILING PLANScale 1:200

9

1.5 DRAWINGS - SECTION

SECTIONScale 1:150

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2.0 ACOUSTIC AND ARCHITECTURE

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2.1.1 ACOUSTIC IN ARCHITECTURE

Acoustics is defined as the science that deals with the production, control, transmission, reception, and effects of sound. Sound can be defined as vibrations that travel

through elastic mediums like gases, liquid (air, water) or any solid, physical object that can return to its normal state after being deflected.

Sound can be reflected, absorbed, transmitted and diffracted. A sound wave is a longitudinal wave where particles of the medium are temporarily displaced in a direction

parallel to energy travelling and then return to their original position. The vibration in a medium produces alternative waves of relatively dense and sparse particles

which are termed as compression and rarefaction respectively.

Acoustics in the built environment is normally evaluated on noise curve and reverberation time (RT). By employing sound absorption materials as wall and ceiling

cladding, the desired RTs can be achieved. The sound absorption materials are rated with sound absorption coefficient. The absorption and transmission loss are

dependent on the fiber or material size, volume of fiber, porosity, air flow resistance, thickness, density, compression and placement or position of materials. Fiber or

material size, porosity, thickness, and density are the major factors for sound absorption within an interior space. Sound absorption however are inversely proportional

to the diameter or width of the fiber.

2.1.2 SOUND INTENSITY LEVEL (SIL)

Sound energy is conveyed to our ears (or instruments) by means of a wave motion through some elastic medium (gas, liquid, or solid). At any given point in the medium,

the energy content of the wave disturbance varies as well as the square of the amplitude of the wave motion. That said, if the amplitude of the oscillation is doubled, the

energy of the wave motion is quadrupled.

Sound intensity also known as acoustic intensity is defined as the power carried by sound waves per unit area. The SI unit of intensity, which includes sound intensity, is

the watt per square meter (W/m2). One application is the noise measurement of sound intensity in the air at a listener's location as a sound energy quantity.

Normally sound intensity is measured as a relative ratio to some standard intensity. The response of the human ear to sound waves closely follows a logarithmic function

of the form “R = k logl”, where “R” is the response to a sound that has a intensity of “I”, and “k” is the constant of proportionality.


12

https://en.wikipedia.org/wiki/International_System_of_Units

https://en.wikipedia.org/wiki/Intensity_(physics)

Thus, we define the relative sound intensity level as

SL (dB) = 10 log I Io

The unit of SL is called a “decibel” (abbreviated as dB). “I” is the intensity of sound expressed in the watts per meter and the “Io” is the reference intensity defined to be

10-12 W/m2. This value of “Io” is the threshold (minimum sound intensity) of hearing at 1 kHz, for a young person under the best circumstances. Notice that “I/Io” is a

unitless ratio, the intensities need only to be expressed in the same units.

2.1.3 REVERBERATION, ATTENUATION, ECHOES AND SOUND SHADOW

Sound reverberation is the persistence of sound reflection after the source of the sound had ceased. Reverberation is the sound that persists in an enclosed space due to

multiple reflections, even after the source of the sound has stopped. Reverberation is an important parameter for describing speech intelligibility and the perception of

music and is used to correct or normalise sound insulation and sound power measurements. For example, specifying highly reflective ceiling panels directly above the

stage area in the auditorium will help direct the sound towards specific seating area, thus enhancing the room’s acoustical performance. However, the same reflective

performance will become a negative factor, if said highly reflective walls and ceiling materials are installed in the rear of the auditorium. That’s because the sound of

reflections from the rear of the room take too long to reach the audience, resulting in a distracting echo effect.

When sound travels through a medium, its intensity diminishes with distance. In idealized materials, sound pressure (signal amplitude) is only reduced by the spreading

of the wave. Natural materials, however, all produce an effect which further weakens the sound. This further weakening results from scattering and absorption. Scattering

is the reflection of the sound in directions other than its original direction of propagation. Absorption is the conversion of the sound energy to other forms of energy. The

combined effect of scattering and absorption is called attenuation.

An acoustic shadow or sound shadow is an area through which sound waves fail to propagate, due to topographical obstructions or disruption of the waves via

phenomena such as wind currents, buildings, or sound barriers. A short distance acoustic shadow occurs behind a building or a sound barrier. The sound from a source is

shielded by the obstruction. Due to diffraction around the object, it will not be completely silent in the sound shadow. The amplitude of the sound can be reduced

considerably however, depending on the additional distance the sound has to travel between source and receiver.

Sound reflection occurs when sound waves bounce off smooth, hard wall, ceiling and floor surfaces. Concave surfaces tend to concentrate or focus reflected sound in one

area. Convex surfaces do just the opposite; they tend to disperse sound in multiple directions.


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SOUND LEVEL METER

2.2 METHODOLOGY

The sound level meter is used to measure and record noise level precisely. It calculates the pressure caused by sound waves travelling through the air from noise sources.

The unit of measurement of sound intensity is in decibels (dBA) which reflect the frequency-dependent nature of human hearing at low sound levels.

Figure 2.2.1: Sound Level Meter

Loudness of Musical Noise

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DIGITAL CAMERA

Digital cameras were used to capture photos of the existing context within our auditorium in order for us to refer back and analyse the noise intrusions, acoustics

finishings used to absorb unwanted sound, reflection sound concentration, sound absorption, sound reverberation time and etc.

MEASURING DEVICES

Measuring tapes and laser distance measurer were used to measure and record the reading of the dimension of our auditorium for drawings and calculation purpose. It

was used to measure the distance of the sound level meter from the sound source when taking the sound levels.

2.2 METHODOLOGY

Figure 2.2.2 Digital camera

Figure 2.2.4 Laser Distance Measurer

Figure 2.2.3 Measuring tape

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BLUETOOTH SPEAKER

It is used to present the acoustic performance of the auditorium. A constant sound in terms of volume and frequency at a single point was released as sound level and the

readings were taken from various distance.

DATA COLLECTING METHOD

There was a rehearsal on our site visit day. Therefore, we assumed that the auditorium is having a formal performance and we analysed the acoustic performance of the

auditorium during performance. By using the equipment above, we had recorded every necessary detail of the auditorium which included its layout and form, sound

sources, types of furniture, finishings, materials and etc. All the readings were taken for drawing and calculation purposes. On-side sketches for the floor plans and

sections were also taken for further analysis on acoustic performance of this auditorium.

2.2 METHODOLOGY

Figure 2.2.5 Bluetooth speaker

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3.0 ACOUSTIC DESIGN ANALYSIS

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3.1.1 TYPE OF SPEAKERS

The experiential auditorium uses two kinds of speakers

i) Compact 3 way symmetrical line array module speakers

ii) 2 watt compact versatile full range system speakers


Compact 3-way symmetrical line arraymodule speakers

- Provides a point source with aflexible coverage of sound.

- Its ability is allow additional soundpressure and further dispersionoption

Sensor controlled subwoofer

- Sensor controlled subwooferswere added to the system toprovide better sound qualityfor low frequency

2- way compact versatile full range systemspeaker

- Located around the central part of thetheatre. To achieve a more balanced soundthroughout the theatre

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SINGLE SPEAKER CABINET

Single Speaker Cabinet ultimately reproduces tone as sound waves in the air - which reaches the listener ear, or a studio microphone

There are 2 speakers cabinet placed at the bellow front of the stage . The speaker are placed elevated on stage platform so that the high frequencies project over the

heads of the audience members closest to the stage. Both speakers are placed to the each side of the stage to produce wider sound waves in the auditorium.

Figure 3.1.1.1 shows speaker cabinet position in auditorium plan

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STAGE MONITOR SPEAKER

A stage monitor is a type of speaker used on stage in auditorium and halls were located front stage. Accurate audio reproduction is crucial. These speakers helpamplify the sound when acoustics instruments or voices are used, allowing the performers on stage to hear themselves.

There are 2 of these speakers placed in each corner side of the stage by the stairs. They are placed on the ground, allowing it to project sound towards the stage .helping musician on stage to focus and monitor the audio, allowing acoustics instrument and vocals to be heard over electronic instrument and drum.

Figure 3.1.1.2 Position of stage monitor in auditorium plan


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ARRAY SPEAKERS

An array speaker is a loudspeaker system that is made up of a number of usually identical loudspeaker elements mounted in a line. The distance between adjacent drivers

is close enough that they constructively interfere with each other to send sound waves with a more evenly distributed sound output pattern.

These speakers are slanted angled down to provide extra coverage at locations close to the front of stage, where else the top half will be angled upwards towards theaudience at the top mezzanine floor of the auditorium.

Figure 3.1.1.3 Position of 2 speakers placed in the hanging position above the stage on the left and right.


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3.1.2 SOUND SYSTEM

A typical sound system in an auditorium may include a combination of microphones, signal processors amplifiers and loudspeaker in speaker cabinets. These system

reinforce sound to enhance its volume, then distribute it to a larger audience.

Figure 3.1.1.4 shows the position of speakers in section

Problem associated with sound system .

- Audience will hear two sounds arriving at two separates times. The ideal difference shall not be more than 1/30 seconds- When the speaker is placed halfway down the auditorium, the audience might hear the sound from the loudspeaker first, followed by the direct sound as a

faint echo. This problem could be solved by adding a delayed mechanism in the loudspeaker- The distance of the speaker is far from audience , sound attenuation might occur, the sound path is affected which reduces the intelligibility.

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3.2 SOUND CONCENTRATION

3.2.1 SOUND ATTENUATION

From a point source the sound waves will be spherical, and the intensity of sound will be approximate the Inverse Square Law. After we collected the data of sound

intensity level using sound level meter from 9 performers during their rehearsal, we plotted out the sound distribution throughout the seating area and found out that

energy loss of sound propagation in Shantanand Auditorium is low because of its wide shallow plan. The distance from the stage to the end is only 14.9 metres long

because of its concave arrangement of seating relatively close to the stage.

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Figure 3.2.1.1 The wide shallow concave plan of the

Shantanand Auditorium spread sound evenly.

<Figure 3.2.1.2 Sound distribution in the seating area

taken from the sound source from the stage.

3.3 SOUND SHADOW

Sound shadow defect can be determined when the sound wave failed to propagate due to the gallery obstruction. After we collected the data of sound intensity level from

9 performers, we found out that there is intermediate sound shadow under the balcony as the sound intensity level dropped from 65 dB to 55 dB when we were moving

from the front seating area to the seating under the balcony. Ideally, the gallery overhang depth should be less than twice the height of the gallery underside but

Shantanand Auditorium has relatively low floor to ceiling height of 2.38m with 4.76m depth under the balcony. The ratio of the floor to ceiling height and depth is exactly

1:2 which means sound shadow will be occurred. Hence, the side wall of Shantanand Auditorium is made of timber panel to reflect sound into sound shadow area.

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Figure 3.3.1 Sectional Drawing showing the dimension of the sound shadow area and differences of sound intensity level.


3.4.1 GEOMETRY & THEATRICAL BUILT FORM

The built form of auditorium is the most basic acoustical design consideration, it can be rectangular, semi-circular, trapezoidal, curvilinear and so on. Shantanand

Auditorium has a wide shallow plan with its seating laid out in straight stepped rows and separated angled side blocks focusing toward the stage. Since sound travel in

straight path from its source, sound can be reached to every corner of the auditorium by reflection of sound. Trapezoidal shape of Shantanand Auditorium well

distributed sound to every seating in the auditorium evenly, unlike poor distribution of sound as curvilinear shape that concentrate sound to the centre of its propagation

only. Strong early reflection of sound at the concrete wall of backstage need to be absorbed to avoid unpleasant flutter echoes while early reflection from side wall can be

used to enhance direct sound toward the audiences. Reflection of sound at the side wall cladded with timber panel is very important in reducing sound shadow under the

balcony.

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Figure 3.4.1.1 Plan indicate early sound reflections from side walls that

enhance sound wave to the direct sound towards the sound shadow area.

Figure 3.4.1.2 Plan indicate unwanted strong prolongated reflection that

caused sound echoes from rear wall.


3.4.2 CEILING REFLECTION PATTERN

Shantanand Auditorium is initially designed as art performing centre for Indian community to perform traditional Indian dance instead of musical theatre for orchestra.

Hence, position of sound source (speakers) and reflective element must be considered in order to deliver sound to every corner of the auditorium. The distribution of

acoustic energy originating from a single or multiple sound sources is the combination effects of reflection, diffraction and absorption. Flat ceiling reflector and concave

ceiling reflector are slightly tilted to project sound energy towards the rear seatings of the gallery. The reflected sound from convex surface diverge, enhancing diffusion

and evenly distribute across a wide range of frequencies.

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Figure 3.4.2.1 Section indicate reflective

elements that deliver sound to the balcony area.

Potential echo-producing surfaces should be treated with efficient sound- absorbing materials. The front portion of the ceiling is lowered to reduce the delayed reflections

from overhead and reoriented to provide useful reflections toward the rear of the auditorium. The initial-time-delay gap is the time interval between the arrival of the

direct sound and the first reflected sound of sufficient loudness. Flutter echoes does not found in Shantanand Auditorium because it does not have repetitive inter-

reflection of sound energy between opposing parallel or concave sound-reflecting surfaces.

Time delay = R1 + R2 - D

0.34

= (4.4+5.8)m - 3.2m

0.34

= 20.6msec < 30msec


0.34

= (8.5+3.8)m - 12.2m

3.5 FLUTTER ECHOES AND SOUND DELAY

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Thus, direct sound is reinforced. No echo can be heard.

Thus, direct sound is beneficially reinforced. No echo can be heard.


0.34

= (12.7+3.3)m - 15.4m

0.34

= 1.8msec < 30msec


0.34

= (7.8+4.7)m - 11.3m

0.34

= 3.5msec < 30msec

3.5 FLUTTER ECHOES AND SOUND DELAY

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Figure 3.5.1.1 shows the relationship between four different position of human figure with sound delay time



3.6.1 NOISE SOURCES

EXTERNAL NOISE SOURCES

There are multiple noise sources from the outside of the hall. For example, the sound produced by the opening and closing of the doors, human sounds and human

chatters, etc. The conversation of the people in the lobby outside the hall will enter the auditorium through both sides of the main entrance, which shows the lack of

sound treatment on the doors. While the additional curtains covering the doors have slightly increased the effectiveness to reduce noise intrusions from the outside of

the hall. In addition, the curtains also help to avoid the light penetrates from the other side of the entrances, which will distract the people inside the hall when the

people enter the hall from outside. Besides, the people need to take off their shoes before entering the hall, this helps on avoiding the noise produce by human walking,

which will affect the people and the performances happening inside.

The corridor beside the auditorium is used as a passageway for crews to get to the front and back of the auditorium conveniently without disturbing other occupants.

However, the seatings near the doors will be exposed to the noise disturbance if there’s people using the passageway.

Figure 3.6.1.1 People need to take off the shoes before enter the hall.

Figure 3.6.1.2 Curtain helps to absorb noise and avoid light penetrates from outside.

3.6 NOISE INTRUSION

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3.6.1 NOISE SOURCES

INTERNAL NOISE SOURCES

One of the most unwanted sound among the multiple noise sources in the hall are mostly come from the electrical appliances. Other than that, there are also other

noises, such as human sounds and chatters, foot stepping on the timber floor, doors opening and closing, etc. The air flowing creates low frequency noise that comes out

from the air-conditioning diffusers, especially the linear diffusers. The noises might not affect the audience that is sitting near the stage due to the distance between the

settings and the ceiling is too large. While it might affect the audience who seats under the gallery and also on the gallery, due to the close distance from the seats to the

ceiling, where the diffusers are located. The doors at the entrances and the the doors connected to the passageway also create noises while people using it, such as

performers and technicians or staffs. However, the additional curtains in front of the doors helps to reduce these noises created by the people at the entrances. The floor

of the empty space between the stage and the audience area are timber floor, which will produce foot stepping noises when people walks through. The timber surface of

the stage is covered with rubber sheet, however, this does not help very much on reducing the noise create by the stepping of the performers on the timber board. Unlike

the timber surface, the floor of the audience area is covered with soft pile carpet, which avoid the creation of the foot step noises produced by the people.

Other than that, the people from the seats also creates various noises. The noises from the audience area are mostly created by human, such as chatters, sneezing, cough,

body movement, etc. These noises are mostly absorbed by the fabric seat and the acoustic holes beneath the seats. Besides, the noises can also be absorbed by the

acoustic absorption panel.

3.6 NOISE INTRUSION

Figure 3.6.1.3 The acoustic absorption panel against the wall absorbs sounds and noises efficiently.

Figure 3.6.1.4 The additional curtain in front of the door helps to reduce noises created at the entrance and lights

penetrates from outside..

Figure 3.6.1.5 The auditorium chairs with acoustic holes at beneath help to absorb the sound and noises efficiently.

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3.6 NOISE INTRUSION

AUDIENCE AREA

Human sounds &

chatters

ENTRANCE (G FLOOR)

Timber door open & closing

ENTRANCE (1ST FLOOR)

Timber door open & closing

AREA IN FRONT OF THE STAGE

Foot stepping on timber floor

STAGE

Foot stepping on stage

DOORS TO PASSAGEWAYS

Timber door open &

closing

3.6.2 INTERNAL NOISE SOURCES LOCATION (FLOOR PLAN)

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3.6 NOISE INTRUSION

AUDIENCE AREA

High ceiling round air-

conditioning diffuser

CORRIDOR

Linear air-conditioning

diffuser

GALLERY AREA

High ceiling square air-

conditioning diffuser

3.6.3 INTERNAL NOISE SOURCES LOCATION (REFLECTED CEILING PLAN)

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3.7 MATERIALITY AND SOUND ABSORPTION COEFFICIENT

INTERIOR : SEATING

INTERIOR : STAGE

GROUND FLOOR PLAN

GROUND FLOOR PLAN

INTERIOR : SEATING

INTERIOR : CONTROL ROOM

FIRST FLOOR PLAN

FIRST FLOOR PLAN

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AREA COMPONENT MATERIAL

ABSORPTION COEFFICIENT(⍺)

125 Hz 500 Hz 1000 Hz

SEATING WALLS

ACOUSTIC ROUGH PLASTER TO SOLID BACK

0.30 0.50 0.80

TIMBER ACOUSTIC PANEL

0.18 0.42 0.59

FIBERGLASS ABSORPTION PANEL

0.15 0.75 0.80

CEILING

GYPSUM BOARD WITH CEILING GRID

0.15 0.04 0.04


3.7.1 TABLE OF MATERIALITY AND SOUND ABSORPTION COEFFICIENT

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125 Hz 500 Hz 1000 Hz

SEATING FLOOR

WOODEN FLOOR ON JOIST

0.15 0.10 0.07

PILE CARPET BOUNDED TO CLOSED-CELL UNDERLAY

0.30 0.25 0.31

FURNITURE

FABRIC UPHOLSTERED TIP-UP SEATS (UNOCCUPIED)

0.13 0.59 0.58

FABRIC UPHOLSTERED TIP-UP SEATS (OCCUPIED)

0.37 0.68 0.73



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125 Hz 500 Hz 1000 Hz

SEATING DOOR

SOLID TIMBER DOOR

0.14 0.06 0.08

RAILING

6mm GLASS RAILING (1ST FLOOR)

0.10 0.04 0.03

STEEL RAILING (G FLOOR)

0.13 0.08 0.09

CURTAIN/ DRAPERY

PLEATED MEDIUM VELOUR CURTAINS

0.05 0.13 0.22



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125 Hz 500 Hz 1000 Hz

STAGE WALL

ACOUSTIC ABSORPTION PANEL

0.15 0.75 0.80

SMOOTH PAINTED CONCRETE

0.01 0.01 0.02

FLOOR

RUBBER SHEET, OVER TIMBER FLOOR

0.01 0.15 0.25

PAINTED SMOOTH CONCRETE

0.01 0.02 0.02



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ABSORPTION COEFFICIENT (⍺)

125 Hz 500 Hz 1000 Hz

STAGE CURTAIN/ DRAPERY

50% PLEATED MEDIUM VELOUR CURTAINS

0.14 0.53 0.75

STAGE DECK

STEEL DECKING (FLY TOWER)

0.13 0.08 0.09

CONTROLROOM

DECK OPENING

TIMBER PANELS WITH TIMBER FRAME

0.14 0.06 0.08

STAGE &

SEATING

VENTILATION GRILLE

PER METER SQUARE

0.60 0.60 0.60



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3.7.1 FLOOR MATERIAL

Rubber Mat

Parquet Flooring

Piles Carpet

Figure 3.6.1.6 Floor plan material indicate different area

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3.7.2 ACOUSTIC TREATMENT & COMPONENT

Acoustic treatment is a crucial hall construction, it can affect the sound surrounding by adding different acoustic element on different surface. A good design can

equally distribute sounds to all the seats, which depends on proper shaping and finishes on the interior surface.

A standard acoustic treatment should meet following requirement :

○ Freedom from the acoustical faults of echoes, flutter & focus

○ Freedom from disturbing noises produced by construction materials

○ Proper room’s volume & shape to control the environment sounds transmission.

3.7.3 CEILING (GYPSUM PLASTER WITH CEILING GRID)

The ceiling material used in the auditorium is gypsum plaster, commonly can be seen in a well designed auditorium. The gypsum board comes with extra thickness in

1 ½ inch to resist panel vibration, due to its mass it can lower the absorption frequency and higher the reflections frequency. The height of the auditorium is around

9m, which hardly transmit sound. Therefore the suspended ceiling provide short delayed of sound transmitting and lower down the volume of the auditorium. The

angle of the ceiling helps reflect sounds leads to the seating area and avoid room echos.

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3.7.4 HARD ACOUSTICAL WALL (TIMBER ACOUSTIC PANEL)

Timber acoustic panels are installed not only for aesthetic purposes, but also to absorb sound energy. There are air gap in between each panel to absorb unwanted low

frequency through panel vibration. The solid back of the timber acoustic panel is smooth plaster, for a standard acoustic panel back solid structure, plaster or gypsum

board must be use as base.

3.7.5 HARD ACOUSTICAL WALL (ROUGH PLASTER TO SMOOTH CONCRETE BACK)

Rough plaster are layered above smooth concrete solid back to prevent vibration and reflect sound effectively in four columns in this room.


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3.7.6 SOFT ACOUSTICAL WALL (FIBREGLASS ACOUSTIC PANEL)

Fibreglass are often used for the most absorption surface in an auditorium. The acoustic panel function as controlling echoes, and sound foci from the rear wall and

balcony faces. The reverberation time in the room is related directly to the volume of the room and, inversely, to the total sound absorption of the auditorium. A good

placement of soft acoustic panel can achieve proper sound distribution diffusion, envelopment, intimacy and reverberation.


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3.7.7 SEATING FLOORING

i) Wooden floor on floor joist

Acoustic joist strips are an economical way of reducing impact noise through conventional timber joist floors. The strip is supplied in 20m self adhesive rolls that are easily

placed on the top of the joists. It greatly reduces the impact sound insulation. Also, it improves the acoustic performance and therefore reduce the impact sound level.


Figure 3.7.7.1 The photo above shows the wooden flooring of the seating

floor area.

Figure 3.7.7.2 The wooden floor is nailing into the decking with allow sound to

mechanically transfer through the nail into the deck negating the top

soundproofing.

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3.7.7 SEATING FLOORING

ii) Pile carpet bounded to closed-cell underlay

While carpets reduce noise transmission through floor in multi-storied buildings, the degree of actual noise reduction, as well as people’s perception of it, are dependent on

the frequency distribution of the sound. Carpets are extremely effective sound absorbers because the individual fibres, pile tufts and underlay have different resonant

frequencies at which they absorb sound.


Figure 3.7.7.3 Construction details of acoustical floor carpetFigure 3.7.7.3 Carpets absorb sounds up to ten times better than hard flooring.

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3.7.8 STAGE - CURTAIN

i) Pleated medium Velour Curtain

The curtain used behind the stage in the auditorium will reduce reverberation and echo in a large room, as well as reduce interference from outside noise. Also, it uses a

powerful sound blocking lining to provide maximum sound protection. The acoustic curtain is thick and highly porous. The thicker the absorption material, the more

effective it will be against a longer wavelength (lower frequency) of sound.


Figure 3.7.7.3 The curtain make an acoustically excellent finish that fully

preserves the absorptivity of the substrate.

Figure 3.7.7.3 Photo of the curtain behind the stage of the auditorium.

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3.7.9 SEATING FURNITURE

Figure 3.7.8.1 Floor plan that indicate the seating furniture Figure 3.7.8.2 Materials for upholstered tip-up seats

Polyurethane foam with a high porosity allows effective sound absorption coefficient. It has a cellular structure which allows air flow, the absorbed sound energy is then converted into heat energy. The geometry pattern of these types of absorbers will affect the scattering of the sound and

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GROUND FLOOR (N.T.S)

FIRST FLOOR (N.T.S)

Figure 3.8.1.1 : To show the location of the materials

3.8 CALCULATIONS

3.8.1 AREA OF FLOOR MATERIALS

F1

F2

F3

F3

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3.8 CALCULATIONS

3.8.1 AREA OF FLOOR MATERIALS

F1 (Stage rubber sheet over timber floor)

A : 79.68m2

⍺ : 0.15

A⍺ : (79.68 )(0.15) = 11.95m2

F2 (Wooden Floor On Joist)

A : 148.12m2

⍺ : 0.10

A⍺ : (148.12)(0.10) = 14.81m2

F3 - G floor (PILE CARPET BOUNDED TO CLOSED-CELL UNDERLAY)

A : 307.22m2

⍺ : 0.25

A⍺ : (307.22)(0.25) = 76.81m2

F3 - 1st floor (PILE CARPET BOUNDED TO CLOSED-CELL UNDERLAY)

A : 152.26m2

⍺ : 0.25

A⍺ : (152.26)(0.25) = 38.07m2

𝚺 FA⍺ = 11.95 + 14.81 + 76.81 + 38.07 = 141.64m2

SABINE FORMULA : RT = 0.16V / A

Where, RT : Reverberation Time (sec)V : Volume of the RoomA : Total Absorption of Room

Surfaces

Note, A : Area⍺ : Absorption CoefficientA⍺ : Absorption Surface

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3.8 CALCULATIONS

3.8.2 AREA OF WALL MATERIALS

W4W5

W6

W1

W2 W2

W3 W3

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W1 (Stage Smooth Painted Concrete Wall)

A : (24.51)(7.39) = 181.13m2

⍺ : 0.01

A⍺ : (181.13)(0.01) = 1.81m2

W2 (Acoustic Absorption Panel)

A : (2)(3.8)(7.39) = 56.16m2

⍺ : 0.75

A⍺ : (56.16)(0.75) = 42.08m2

W3 (2 Stage Smooth Painted Concrete Wall)

A : (2)(4.7)(7.39) = 69.47m2

⍺ : 0.01

A⍺ : (67.47)(0.01) = 0.67m2



Surfaces

W4 (Timber Acoustic Panel)

A : (2)(6.48)(5.90+4.01) = 128.43m2

⍺ : 0.42

A⍺ : (128.43)(0.42) = 53.94m2

W5 (2 Sides Acoustic Absorption Panel)

A : (2)(35.92) = 71.84m2

⍺ : 0.75

A⍺ : (71.84)(0.75) = 53.88m2

W6 (Timber Panels With Timber Frame)

A : (12.37)(0.75) = 9.28m2

⍺ : 0.06

A⍺ : (9.28)(0.06) = 0.56m2

𝚺 WA⍺ = 1.81 + 0.56 + 0.67 + 53.94 + 53.88 + 0.56 = 102.27m2


3.8 CALCULATIONS

3.8.2 AREA OF WALL MATERIALS

51

3.8 CALCULATIONS

3.8.3 AREA OF OTHER MATERIALS

M4

M3

M2

M1

M5

M6

M7

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M1 (Pleated Medium Velour Curtains)

A : (5.97)(22.41) = 133.79m2

⍺ : 0.53

A⍺ : (133.79)(0.53) = 70.90m2

M2 (618 Seats-Unoccupied)

A : (618)(0.47) = 290.46 m2

⍺ : 0.59

A⍺ : (290.46)(0.59) = 171.37m2

M3 (Gypsum Board With Ceiling Grid)

A : 337.33m2

⍺ : 0.04

A⍺ : (337.33)(0.04) = 13.49m2

M4 (6mm Glass Railing)

A : (1.04)(30.4) = 31.62m2

⍺ : 0.04

A⍺ : (31.62)(0.04) = 1.26m2



SurfacesM5 (Doors)

A : 10.55 + 5.04 + 4.58 = 20.17m2

⍺ : 0.06

A⍺ : (20.17)(0.06) = 1.21m2

M6 (Acoustic Rough Plaster To Solid Back)

A : (2)(0.85)(7.09)+(4)(0.7)(7.09) = 31.91m2

⍺ : 0.50

A⍺ : (31.91)(0.50) = 15.96m2

M7 (Ventilation Grille)

A : (0.61)(17.25) = 10.52m2

⍺ : 0.60

A⍺ : (10.52)(0.60) = 6.31m2

𝚺 MA⍺ = 70.90 + 171.37 + 13.49 + 1.26 + 1.21 + 15.96 + 6.31= 280.50m2


3.8 CALCULATIONS

3.8.3 AREA OF OTHER MATERIALS

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3.8 CALCULATIONS

3.8.4 REVERBERATION TIME

V = 8769m3

A =𝚺 FA⍺+ WA⍺+MA⍺= 141.64 + 102.27+ 274.19 = 524.41m2

RT = 0.16 (8769.00) / 524.41

= 2.68 secs



Surfaces


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Shantanand Auditorium has a reverberation time of 2.68 seconds which is slightly offthe recommended range but still served its purpose as music theatre in large roomscale ( >7500 m³ ) . After all the calculation and overall acoustic design properties,Shantanand Auditorium can be acceptable satisfactory to served the function asperforming art hall but not conducive for good speech intelligibility (>1.25 seconds ).In order to get the recommended range of reverberation time,, more absorption ofthe surface should be added. Ideally, larger room will have a longer reverberationtime, 2.68 seconds is only achieved acceptable level of acoustical quality.

3.9.1 NOISE INTRUSION

SUGGESTION 2: MATERIALITY FOR DOORS AND WALLS

Material for door and wall at the buffer zone area are significant due to it

absorption and reflection ability. Acoustic wood door is introduce to

Shantanand auditorium as it has better sound proofing quality to reduce

the sound being transmitted through the door. Besides, acoustical wood

door must come with proper intumescent seal at both sides and bottom.

Threshold plates provides an optimum seal surfaces for the bottom of

door.


Acoustic foam panel

Shantanand auditorium has only one entrance or exit

for accessibility. The solid timber door for main entrance to

the auditorium with an absorption coefficient of 0.06 has

low intensity sound intrusion.

SUGGESTION 1: PROVIDE BUFFER ZONE

Extension of auditorium after the main entrance to create a buffer

zone area that enables the sound transmission being trapped between

door to door and absorb by acoustic wall panel at the both sides of

wall. The sound created by open or close the door can be lock within

the buffer zone.

Figure 3.9.1.2 Sound reflects at the buffer zone

Figure 3.9.1.3 shows area extension at the main entrance to create a buffer zone

Wall are covered with

acoustic foam panel to

absorb the sound which

minimizes the sound

reflection.

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Figure 3.9.1.1 shows the extension of buffer zone at the ground floor plan of Shantanand auditorium


3.9.2 SOUND CONCENTRATION

BALCONY (SOUND SHADOW)

SUGGESTION 3: PROVIDE CONCAVE-SHAPED BALCONY PARAPET

Concave-shaped balcony parapet allowed direct and reflected sound to

concentrate at the balcony underside. Sound will be transmit into the

balcony underneath for the audiences to receive clearer sound without

flutter echoes.

SUGGESTION 4: PROVIDE TILTED CEILING AND INCREASE BALCONY HEIGHT

The balcony height of the lower floor can be escalated to its dimension.

It should not be less than the depth of the balcony which caused the

acoustical shadow underneath. Due to the space limitation of

Shantanand auditorium, it is to increase the balcony height at its most

in the same time provide tilted ceiling on top of balcony underside to

avoid the energy loss while sound reflected and absorbed by the

fiberglass absorption panels.

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Figure 3.9.1.4 shows the addition of concave shape at the balcony parapet

Figure 3.9.1.5 shows escalated balcony height and tilted ceiling at the ground floor

4.0 CONCLUSION

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4.0 CONCLUSION

In summary, this auditorium case study project has brings us a huge learning outcome for eight of us in the group. It let us understood how the acoustic design works

better depends on the functions of the auditorium, and uses the acoustic design to make the users comfort. The auditorium layout and the materials used on the structure

and furnitures, such as walls, floor, chairs, curtains, etc, can effectively affect the acoustic inside the auditorium hall and even can efficiently affect the sound from the

outside of the auditorium hall.

An auditorium is a special room built to enable an audience to hear and watch performances and may be used for rehearsal, presentation, performing arts productions.

Apart from entertainment, an auditorium also used for a space for speech delivery such as lecture theatres, reading performances and competitions. A successful design of

an auditorium depends on its acoustic design such as the auditorium layout and absorption materials used to preserve and enhance the desired sound and to eliminate

noise and unwanted sound.

In conclusion for our accumulated finding and subsequent analysis, the requirement of Shantanand Auditorium to be a performing art centre and music hall is in

acceptable and sufficient range based on its acoustical design and optimum reverberation time of 2.68 secs. The overall considerations for acoustical quality is suitable to

be served as musical and dance performance hall but not for speech related events. In order to achieve the recommended range of reverberation time for better quality,

the acoustical design of Shantanand Auditorium could slightly changed based on the suggestions and the absorption coefficient of the materials should be always

considered to further improve.

Throughout this case study, we are now more clearly understand about how the acoustic design such as architectural layout and material used can control the desired

sound and unwanted noise caused by various sound sources, and how it affects the people using the auditorium. This project had benefits us as future architects, to design

more effective and comfortable space for the people in the future.

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5.0 REFERENCES

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6.0 REFERENCES

1. Facilities. (n.d.). Retrieved October 02, 2017, from http://shantanand-adt.org/index.php/facilities#seating

2. The Temple of Fine Arts. (n.d.). Retrieved October 02, 2017, from http://www.visitkl.gov.my/visitklv2/index.php?r=column%2Fcthree&id=63&place_id=896

3. Sound Intensity. (n.d.). Retrieved October 02, 2017, from http://hyperphysics.phy-astr.gsu.edu/hbase/Sound/intens.html

4. Attenuation of Sound Waves. (n.d.). Retrieved October 02, 2017, from https://www.nde-ed.org/EducationResources/CommunityCollege/Ultrasonics/

Physics/attenuation.htm

4. Decibels dBA. (n.d.). Retrieved October 02, 2017, from https://silentpc.com/cgi-bin/e/decibels.html

5. How To Prevent Hearing Damage When Using Headphones. (n.d.). Retrieved October 02, 2017, from https://headphonesaddict.com/safe-headphone-use/

6. Absorption Coefficient Chart. (n.d.). Retrieved October 02, 2017, from http://www.acoustic-supplies.com/absorption-coefficient-chart/

7. Acoustic Damping using Polyurethane/Polymer Composites. (n.d.). Retrieved October 02, 2017, from http://www.appropedia.org/Acoustic_Damping_using_

Polyurethane/Polymer_Composites

8. Network, D. (2015, March 16). Soundproofing a Floor. Retrieved October 02, 2017, from http://www.diynetwork.com/how-to/rooms-and-spaces/floors/soundproofing-

a-floor

9. Soundproofing floors and noise absorption. (n.d.). Retrieved October 02, 2017, from http://www.carpetyourlife.com/en/about-carpet/advantages/soundproofing-floors

10. Room Acoustics. (2014, January 25). Retrieved October 02, 2017, from https://www.soundandvision.com/content/room-acoustics

11. Littlefield, D. (2012). Metric handbook: planning and design data. London: Routledge.

12. Network/, W. (n.d.). Acoustics Doors,Acoustic Sliding Doors, Sound profing doors. Retrieved October 02, 2017, from http://www.earconsacoustic.com/acoustic-doors.html

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