Project 1: Building Science 2 report

School of Architecture, Building and Design Bachelor of Science (Hons) in Architecture

Building Science II (ARC 3413 / BLD 61303) Project 1: Auditorium: A Case Study on Acoustic Design Lecturer: Ar. Edwin Chan

Group Members Chong Jin Feng Chong Yi Qi Chow Hong Da Clement Chen Kit Seong James Tay Jia Chuen Janice Lee Juen Yung Kong Xhiang Lynn Yong Yu Joon

0319645 0304898 0318571 0319574 0322210 0318695 0317730 0318299

ARC 3413 Building Science 2 A Case Study on Acoustic Design of an Auditorium

TABLE OF CONTENT 1.0 Abstract 1.1 Aims & Objectives 1.2 Site Study 1.2.1 Site Introduction 1.2.2 Site History 1.2.3 Site Selection Reason 1.3 Technical Drawings 2.0 Acoustic 2.1 Literature Review 2.1.1 Architecture Acoustic 2.1.2 Sound Intensity Level 2.1.3 Reverberation Time (RT) 2.1.4 Sound Reduction Index (SRI) 2.2 Case Study 2.2.1 Elbe Philharmonic Hall 2.3 Material and Properties 2.3.1 Furniture Material 2.3.2 Wall Material 2.3.3 Ceiling Material 2.3.4 Floor Material 2.4 Acoustic Tabulation and Calculation 2.4.1 Table for Absorption Coefficient 2.4.2 Reverberation Time (RT) 2.5 Sound Analysis 2.5.1 Sound Source 2.5.2 Sound Reflection 2.5.3 Sound Echo 2.5.4 Sound Absorption 2.5.5 Sound Diffusion 2.6 Existing Noise Sources 2.6.1 External Noise 2.6.2 Internal Noise 2.7 Noise Control 3.0 Conclusion 4.0 Reference

3 4-5 5-6 6 7-8 9 10 10 11 11 12-13 14 15 16 17 18 19 20-21 22-25 26-29 30-33 34-37 38-39 40-41 42-46 47 48

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ARC 3413 Building Science 2 A Case Study on Acoustic Design of an Auditorium

1.0 Abstract 1.1

Aims and Objectives In this project, students are required to conduct a case study on the acoustic

functions of a local auditorium. We conducted a site visits to our selected auditorium which is Istana Budaya and documented its history, floor layout, materials used and other necessary information via photographs, rough measurements and also on site observations. By analysing the data collected, we are to:   

Study and understand the acoustic characteristics of the auditorium Identify the types of sound absorption materials used and describe its properties Determine the suitability of the sound absorption materials and acoustic methods used



in relation to the function of the auditorium Propose solutions or better ways to improve the acoustic performance of the auditorium.

After thoroughly analysing the acoustic characteristics of Istana Budaya we are to compile our findings into an A4 report format as well as preparing slides for an oral presentation.

1.2.1 Site introduction

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ARC 3413 Building Science 2 A Case Study on Acoustic Design of an Auditorium

Figure 1.1 An exterior view of Istana Budaya

Figure 1.2 An interior view of Istana Budaya

Istana Budaya is Malaysia's National Theatre also known as The Palace of Culture. The building is located in the heart of Kuala Lumpur, next to the National Art Gallery on Jalan Tun Razak. It is Malaysia’s main venue for all types of theatre including local and international performances for musical theatre, operetta, classical concert and opera. Istana Budaya was rated as one of the world's top 10 most sophisticated theatres, the first theatre in Asia equipped with cutting-edge stage equipment that is on par with the Royal Albert Hall in London.

Istana Budaya is designed by local architect, Muhammad Kamar Ya'akub, it’s one of Kuala Lumpur's most striking structures due to its turquoise-blue tiled roof – the 'folds' remind one of a giant origami piece. As in traditional Malay house, the theatre is divided into three areas: the 'serambi' (lobby and foyer), the ' rumah ibu' (auditorium) and 'rumah dapur' (stage or rehearsal hall). The main building takes the shape of the 'sireh junjung' - traditional betel leaf arrangements used during Malay weddings and welcoming ceremonies – with the foyer claiming the spot as the theatre's most intricately design aspect. Additionally, the main theatre hall (Panggung Sari) which can accommodate up to 1,370 audiences is a classic opera house with a twist – its royal boxes open up like traditional Malay-style windows.

Istana Budaya is vast and opulent, with plenty of white marble and doors made of high-quality tropical wood with hand-carved flowers and leaf designs. The 4|Page

ARC 3413 Building Science 2 A Case Study on Acoustic Design of an Auditorium

entrance hall has lush carpeting, with the lobby prominently displaying the Cempaka Flower and Beringin tree.

The entrance to the theatre is said to be an imitation of a traditional Malay palace – noticeably the Balairong Seri at the Istana Budaya. The interiors of Istana Budaya are intricately designed using the finest quality marbles of the Malay Langkawi. The interiors doors and windows of the Theatre Hall are made from the highest quality tropical woods, which are beautifully designed and crafted by professional hands. The ambience leaves an everlasting impact on visitors.

1.2.2

Site History In 1971, the National Cultural Congress began discussions and planning for

the creation of the National Theatre. As a result, in 1972 the National Cultural Group (KBN) was formed under the Arts Development Branch within the Culture Division of the Ministry of Culture, Youth and Sports (KKBS), and began operations as an amateur outfit. While its central office is in Wisma Keramat, the group's activities were conducted at a house in Jalan Ampang. At the end of 1973, the group moved to the National Cultural Complex in Jalan Tun Ismail, the current home of The National Academy of Cultural Arts and Heritage (ASWARA).

The National Cultural Group turned professional in early 1974 under the Arts Development Branch, Cultural Division of the Ministry of Cultural, Youth and Sports.

However, at this juncture, the focus was only on the arts of dance and traditional music.

Then the Youth Symphony Orchestra (OSM) and the National Choir Group were formed in 1982 and 1992 respectively. Further in 1993, the Experimental Theatre (ET) was set up at the National Cultural Complex, and the Youth Symphony Orchestra was upgraded to National Symphony Orchestra (OSK) and began performing professionally.

In 1994, the Experimental Theatre was officially opened by the YAB Dato’ Seri Dr. Mahathir Mohamad, the fourth Prime Minister of Malaysia. The National Cultural 5|Page

ARC 3413 Building Science 2 A Case Study on Acoustic Design of an Auditorium

Group became part of the National Theatre Division under the Ministry of Culture, Arts and Tourism Malaysia (KKKPM). In the same year, the Prime Minister has helped realized the creation of the National Theatre with the approval of the proposed site, the selection of building design and financial planning. Both the construction of ET together with the establishment of the Tunku Abdul Rahman Auditorium at the Malaysian Tourist Information Centre (MATIC) in Japan Ampang, are endeavours to gain experience in administering the National Theatre.

The National Theatre of Malaysia began construction in July 1995 with a cost of RM210 million, comprising 5.44 hectares and a floor area of 21,000 square meters.

Once completed on December 1 1998, the administration of the National Theatre was moved to its permanent premise in Jalan Tun Razak. The following year, on September 15 1999, the National Theatre under the name of Istana Budaya, was successfully launched by the then Prime Minister, Dato’ Seri Dr. Mahathir Mohamad.

1.2.3

Site Selection Reason Istana Budaya,is the National Theatre of Malaysia and one of the most

popular tourist spots. Istana Budaya is the first theatre in Asia with stage-of-the-art stage equipment, it has been rated as one of the world’s top 10 most sophisticated theatres in the world. The theatre hall Panggung Sari, has its unique design of royal boxes inspired by the windows of the traditional Rumah Melayu. It is a good opportunity to study how does a successful design of the theatre much depends on its acoustic design including the auditorium’s layout and the materials that used for sound absorption. It is the essential to preserve and enhance the desired sound and to eliminate noise and undesired sound.

1.3

Technical Drawings

1.3.1 Plans

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ARC 3413 Building Science 2 A Case Study on Acoustic Design of an Auditorium

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Figure 1.3 Ground plan of Istana Budaya

1.3.2

Figure 1.4 First floor plan of Istana Budaya

Sections

Figure 1.5 Short section of Istana Budaya

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ARC 3413 Building Science 2 A Case Study on Acoustic Design of an Auditorium

Figure 1.6 Long section of Istana Budaya

2.1

Literature Review Acoustics is defined by the Oxford Dictionary as ‘Relating to sound or the sense

of hearing’. The study of acoustics is defined as the properties or qualities of a room or building that determine how sound is transmitted in it. Despite the definition, many mistakenly assume that acoustics is a strictly musical and architectural topic only. While acoustics does include the study of musical instruments and architectural spaces, it also covers a vast range of topics, including: noise control, SONAR for submarine navigation, ultrasounds for medical imaging, thermo acoustic refrigeration, seismology, bioacoustics, and electroacoustic communication.

Below is the so called "Lindsay's Wheel of Acoustics", created by R. Bruce Lindsey in J. Acoust. Soc. Am. V. 36, p. 2242 (1964):

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ARC 3413 Building Science 2 A Case Study on Acoustic Design of an Auditorium

Figure 2.1 Lindsay’s Wheel of Acoustics

The wheel describes the scope of acoustics starting from the four broad fields of Earth Sciences, Engineering, Life Sciences, and the Arts. The outer circle lists the various disciplines one may study to prepare for a career in acoustics. The inner circle lists the fields within acoustics that the various disciplines naturally lead to.

2.1.1

Architecture Acoustics Architecture acoustics is a branch of acoustical engineering about achieving an

adequate audible experience within a building. Architectural acoustics can be about achieving good speech intelligibility in a theatre, restaurant or railway station, enhancing the quality of music in a concert hall or recording studio, or suppressing noise to make offices and homes more productive and pleasant places to work and live in.

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As architects, it is important to understand architecture acoustics and how the behaviour of sound can affect the space within. Knowing and understanding the properties of sound help architects to control or manipulate the sound behaviour through designing the form of the space and materiality of the space.

2.1.2

Sound Intensity Level Sound intensity is defined as the energy carried by the sound wave per unit area.

The SI unit of sound intensity is watt per square meter w/m 2. The sound intensity level is a logarithmic quantity, measured in relation to the reference value, which is denoted as l , expressed in dB, and is defined by the formula:

SIL

2.1.3

= 10log10

l l0

Reverberation Time (RT) Reverberation is the prolongation of sound as a result of successive

reflections in an enclosed space after the sound source is shut/turn off. Reverberation Time is the time for the sound pressure level in a room to decrease by 60dB from its original level after the sound is stopped. It varies due to the following factors, the room volume, materials used and also the sound sources. RT can only be measured when it is an enclosed space.

RT

= 0.16V / A

Where, RT

= Reverberation time (sec)

V

= Volume of the room (m Âł )

A

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RT is controlled mainly by the acoustic absorption within the enclosed space and each material has its own material absorption coefficient. This question allows us to analyse on the effectiveness of the absorption of materials used in the selected site.

2.1.4

Sound Reduction Index (SRI) The sound reduction index is used to measure the level of sound insulation

provided by a structure such as a wall, window, door, or ventilator. The process of designing a space requires an understanding of sound reduction index in order to better reduce the possibility of sound permeating from loud spaces through the walls into the quieter space. The sound reduction index can be calculated through the following formula: SRI = 10log

1 T

Where, T = Sound transmission

2.2

Case Study

Elbe Philharmonic Hall, Germany

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Figure 2.2.1 The Elbe Philharmonic Auditorium

The recently opened Elbe Philharmonic Hall in Germany shares many characteristics with our aged Istana Budaya. From Acoustic ceiling panels, acoustic wall panels and furniture to the stunning design and layout. The spiralling hanging ceiling panels reflect sound back to the audience while the acoustic wall panels absorbs the sound echo.

The auditorium—the largest of three concert halls in the Elbphilharmonie—is a product of parametric design, a process by which designers use algorithms to develop an object’s form. In the case of the Elbphilharmonie, Herzog and De Meuron used algorithms to generate a unique shape for each of the 10,000 gypsum fibre acoustic panels that line the auditorium’s walls like the interlocking pieces of a giant, undulating puzzle.

2.2.1

Comparison of Elbe Philharmonic

Hall with Istana Budaya

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Figure 2.2.2 Elbe Philharmonic Hall and Istana Budaya Sections

The plastered ceiling of Panggung Sari in Istana Budaya serves as an aesthetic piece with lack of function as the angles and shape of the ceiling are not directing sound waves towards the audiences. The ceiling only helps to diffuse and disperse sound in all random directions, hence, weakening the sound energy towards the audiences. As compared to the Elbe Philharmonic Hall in Germany, the spiral hanging ceiling panels reflect sound back to the audience without weakening the sound energy as much as Istana Budaya.

Figure 2.2.3 Elbe Philharmonic Hall and Istana Budaya Ceilings

2.3

Material and Properties

2.3.1 Furniture Material

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Figure 2.3.1 Istana Budaya seat pictures and dimensions

The Furniture in Panggung Sari consists of 1370 seats ( 745 seats in Stalls, 323 seats in Grand Circle and 302 seats in Upper Circle) which is made up of premier high density plywood with painted surface on the backrest and seat while the cushion is made up of polyurethane high flexibility foam. This assists in sound absorption where the material used is a good sound insulator.

2.3.2 Wall Material

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Diagram 2.3.2 Wall panels and Sectional Detail

The Wall of Panggung Sari reflects many traditional elements of the culture of Malaysia. The wood carvings add to the elements of the hall providing a more classic malay style ambience. Besides that, the wooden wall panels are also specially made acoustic panels which helps absorb and reflect sound using High density fibreglass infill which has high sound absorption coefficient.

2.3.3 Ceiling Material

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Diagram 2.3.3 Gypsum ceiling board structure

The ceiling, which is approximately 18 metres from the ground is adjustable and is made up of gypsum ceiling board. They are specifically designed to reflect sound to the audience and the musicians while at the same time eliminating the echoing effect.

The hall sits on resilient pads and is surrounded by two concrete wall separated by an isolation joint to eliminate external noise. Therefore, the air-conditioning is virtually silent. Every element in the hall, every material and finishing, has been designed and selected to create a flexible performing environment that complements a variety of performances.

2.3.4 Floor Material

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Figure 2.3.4 Floor carpets and Stage flooring

The flooring of Panggung Sari is made up of woollen carpet consisting of 80% wool, 20% nylon while the stage is made up of detachable wood to create flexibility according to different performances. The carpet plays a vital role such that sound reflected from the ceilings and walls are absorbed, preventing any echo.

2.4 Acoustic Tabulation and Analysis 2.4.1

Table for Absorption Coefficient Common Building Materials

Absorption Coefficient 500Hz

Carpet

Medium pile carpet on sponge rubber underlay

0.28

Wood Boards

Hardwood boards over 25mm airspace

0.1

Plaster Ceiling

Gypsum plaster ceiling

0.02

Seats

Fabric with wooden panel

0.2

Audience

Per Person

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ARC 3413 Building Science 2 A Case Study on Acoustic Design of an Auditorium

Air

Per m3

0.007

Door

Solid Timber Door

0.06

Figure 2.3.5 Table of Absorption Coefficient

2.4.2

Reverberation Time, RT

Volume of Panggung Sari = 30m x 23m x 20m = 13800m 2 Material Absorption Coefficient 500Hz Component

Material

Surface Area

Absorption

Sound

(m2 )/ Quantity

Coefficient

Absorption

Floor

Carpet

690

0.28

193.2

Wall

Wood Boards

1520

0.1

152

Ceiling

Plaster

900

0.02

18

Furniture

Fabric Seats

1370

0.2

274

Door

Solid Timber

48

0.06

2.9

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Occupant

1375

0.46

632.5

Air

13800

0.007

96.6

Total Absorption (A)

Reverberation Time, RT

1369.2

= (0.16 x V) / A = (0.16 x 13800) / 1369.2 = 1.61 s

2.5 Sound Analysis & Calculation 2.5.1

Sound Source

The Stage As Istana Budaya is the main venue for all types of theatre and events, the stage is the main performing area where the sound is produced and transmitted towards the audience. The shape of the theatre hall, also called the Panggung Sari, reflects this, as the audience is oriented to the stage, and the fan shape maximizes the sound traveling towards every audience evenly.

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Speakers Apart from direct sound from the stage, speakers are installed around the perimeter of the theatre hall as an alternative. For certain performances that use microphones, such as the full-house concerts by Dato’ Siti Nurhaliza, having speakers spreaded evenly throughout the theatre so the audience has the same audio experience regardless the seating location.

Types of Speakers Used

Curved Speakers The curved speakers are placed above the upstage, pointed towards the audience. These speakers are large, and serves to amplify the voice of the performers on stage, while the position mimics the sound source of the theatre. The curved shape helps distribute the sound radially to give the audience the similar feeling of listening to theatre.

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P.A.Speakers Dotted along the theatre are also smaller speakers, which are mounted on the walls near the back of the theatre. These speakers serve to project the sound from the stage to the back of the audience, to even out the sound of the performance to the audience sitting farther back.

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2.5.2 Sound Reflection

Figure 2.5.2.1 is a sound reflection diagram

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. Reflection of sound waves follows the law of, angle of incidence equals to the angle of reflection.

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ARC 3413 Building Science 2 A Case Study on Acoustic Design of an Auditorium

Figure 2.5.2. compares the shape of ceiling between Istana Budaya and Elbe Philharmonic Hall.

As previously mentioned, the plastered ceiling of Panggung Sari in Istana Budaya serves as an aesthetic piece with lack of function as the angles and shape of the ceiling are not directing sound waves towards the audiences. The ceiling only helps to diffuse and disperse sound in all random directions, hence, weakening the sound energy towards the audiences.

By changing the shape and the material of the ceiling, it will affect the direction of the sound that hits the ceiling and the reverberation time. Although it may require a long period of time to reconstruct the shape of the ceiling, we could also implement reflective acoustic ceiling panels in Panggung Sari. By doing so,it helps to direct sound reflection to the audience.

Figure 2.5.2.1 shows a staggered ceiling shape

Having a staggered ceiling shape with reflective acoustical panels is highly recommended to maximise the area of useful ceiling reflections towards users.

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2.5.3 Sound Echo

Figure 2.5.3 is a Sound Echo diagram

Echoes are probably the most serious of room acoustical defects. Echo is a reflection of sound that arrives at the listener with a delay after the direct sound. The delay is proportional to the distance of the reflecting surface from the source and the listener. Therefore the longer the hall, the longer the Delay/Echo.

There are two kinds of south paths which plays a role in defining time delay or echo of the enclosed space namely, direct sound path and indirect sound path. In a concert hall, reflected sound beneficially reinforces the direct sound if the time delay between them is relatively short, that is a below 100msec. A time delay of 100msec for music perceived as a sound distinct from that travelling directly from source to listener is deemed as an echo.

Echoes should not be confused with reverberation. Echoes are distinct repetition of the original sound whereas reverberation is multiple blended sound images created from reflection. For example, when you stand in a huge room and yell “hello�, the very first sound you hear reflected off the walls is a Delay/Echo whereas for reverberation that Delay/Echo quickly turns into reverberation as the sound is reflected off a second, third and fourth surface.

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2.6.3.1

Time Delay & Echo Analysis

Time Delay Formula:

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Figure 2.6.3.1 shows plan view of direct sound and indirect sound path

Figure 2.6.3.2 shows section view of direct and indirect sound path

Time Delay Calculations:

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Good:

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T1, T3, T4 and T5 would experience reinforcement of the direct sound at optimum levels as all the time delays are below 100msec.

Bad: T2 would experience some echo effect which may affect pleasure of music as the time delay is more than 100msec.

2.5.4 Sound Absorption

Figure 2.5.4 is a sound absorption diagram

Sound absorption is defined, as the incident sound that strikes a material that is not reflected back. Sound absorption is the change in sound energy into some other form, usually heat when it passes through a material or strikes a surface.

An open window is an excellent absorber since the sounds passing through the open window are not reflected back but makes a poor sound barrier. Painted concrete block is a good sound barrier but will reflect about 97% if the incident sound striking it.

In Room Acoustics, surfaces of walls, floors and ceilings, room contents including people contribute to sound absorption.

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2.5.4.1Medium Pile Carpet (Absorption)

Figure

2.5.4.1 is a cross

section diagram of sound absorption on medium pile carpet

Of all flooring materials, carpet offers the best noise reduction. It strongly reduces sound reverberation and absorbs over ten times more airborne noise than any other flooring material.

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When a sound wave strikes an acoustical material like carpet, the sound wave causes the fibres or particle makeup of the carpet to vibrate. This vibration causes tiny amounts of heat due to the friction and thus sound absorption is accomplished by way of energy to heat conversion. The more fibrous the carpet, the better the absorption; conversely denser materials are less absorptive. The sound absorbing characteristics of acoustical materials vary significantly with frequency. In general low frequency sounds are very difficult to absorb because of their long wavelength.

By creating more quietness, carpet considerably enhances the feeling and offers audience a more pleasurable and quality music played in the concert hall.

Used in Panggung Sari

Figure 2.5.4.2 shows a comparison graph on the absorption coefficient of different flooring

Besides Panggung Sari, the whole concert hall is covered with medium pile carpet with sponge rubber underlay having an absorption coefficient of 0.28. Medium pile carpets have moderate length fibres whereas the sponge rubber underlay, also 34 | P a g e

ARC 3413 Building Science 2 A Case Study on Acoustic Design of an Auditorium

known as rubber waffle underlay also allows air circulation and support for the carpet, minimising dampness and condensation under the carpet.

2.5.4.2

Wood Panel Absorber

Figure 2.5.4.2.1 is an image of the panel of the panel absorber

Figure 2.5.4.2.2 is a cross section diagram absorbers in Panggung Sari

Typically, panel absorbers are 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. Common panel (membrane) absorbers include wood panelling over framing, lightweight impervious ceilings and floors, glazing and other large surfaces capable of resonating in response to sound. Panel absorbers are usually most efficient at absorbing low frequencies. This fact has been learned repeatedly on orchestra platforms where wood panelling traps most of the bass sound, robbing the room of "warmth."

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In Panggung Sari, panels of plywood panels are placed over a spacer of 25mm air space. When mounted on a wall with a spacer, sound gets behind the wood panels so its rear surface can absorb. This air gap increases absorption as much as 50%, causing it to have an absorption coefficient of 0.1 and also extends absorption to lower frequencies when compared with flat wall mounting.

2.5.5

Sound Diffusion

Figure 2.5.5 is a diagram of sound diffusion

When a sound wave hits an irregular surface like foam or carpet, the vibration breaks up and travels along many much smaller paths. This divides the energy of the wave, sending it in many different directions which deplete its energy faster.

Adequate sound diffusion is essential in many types of rooms because it promotes uniform distribution of sound, accentuates the natural qualities of music and speech and prevents the occurrence of undesirable acoustical defects. Sound diffusion may be achieved with the aid of surface irregularities and scattering elements, alternate application of sound reflective and sound absorptive treatments.

2.5.5.1

Coffers

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ARC 3413 Building Science 2 A Case Study on Acoustic Design of an Auditorium

Figure 2.6.5.1 shows how sound diffuses on surface of coffers in Panggung Sari

In Panggung Sari, coffers can be found at the rear and sides of the concert hall at all 3 floors. Sound that enters these coffers of irregular shape diffuses and scatters everywhere evenly. Consequently, the sound diffused back to the audience will be weaker hence reducing the echo effect.

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2.5.5.2

Curved Edges

Figure 2.5.5.2 shows how sound diffuses on the curved edge design of VIP boxes

The design of the VIP boxes are of curved edges which acts as a surface to diffuse or disperse sound in all directions uniformly. Diffusion is very effective for high to medium frequencies, as the vibration strength is less than that of a low frequency sound, and therefore easier to disperse. As a result, this is a great way to reduce echoes.

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2.5.5.3

Medium Pile Carpet (Diffusion)

Figure 2.5.5.3 is a diagram of sound diffusion on carpet surfaces

Carpet, other than having the role of absorption of sound, also acts as an element of diffusion. The irregular shape of the medium pile carpet as seen from the cross section of figure above allows sound wave to be scattered uniformly in all directions after sound hits it.

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2.6

Existing Noise Sources

2.6.1

External Noise Source

2.6.1.1 Vehicles

Figure 2.6.1.1 is a picture of Jalan Tun Razak

Istana Budaya is located at the adjacent highway of Jalan Tun Razak, which is one of the main road connecting to the heart of Kuala Lumpur and it is mainly congested during the peaks hours including lunch time. However, Istana Budaya sits comfortably 100m away from the highway, increasing the sound travelling distance and therefore reducing the noise. Furthermore, Istana Budaya is also surrounded by many trees and bushes which act as a partial sound absorber that helps in aiding the reduction of background sounds. When one is inside Istana Budaya, you could hardly hear any noises from the busy road.

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2.6.1.2

People

Figure 2.6.1.2 is a picture of the entrance hall

On the inside, one of the main noise sources is the interaction between the receptionist and the audience, and also interaction between the performers and the staff at the backstage. Although it is crowded with visitors when there are performances or events, the sound lock system lengthens the traveling distance which made it possible to minimize the noise travel into the auditorium.

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2.6.2

Internal Noise Source

2.6.2.1 Backstage Activity

Figure 2.6.2.1 is a picture of the back stage

The preparation and communication between the staffs and the performers at the backstage are the main sources of noise. This issue is again easily tackled by using sound lock system where there are masking and drapery seals used by increasing the sound travelling distance and thus reducing the noise.

2.6.2.2

Air conditioning

Figure 2.6.2.2 are pictures of the air vents

The indoor cassette unit used in the auditorium are rather quiet as they have ensured that all of the units are running at a low speed to prevent any noise. Despite that, the linear diffusers used in the auditorium does the opposite as air had to force through the tiny gaps which in return creates whooshing noises that might affect the user’s experience.

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2.6.2.3

Seats

Figure 2.6.2.3 is a picture of the auditorium seats

The seats used in the auditorium are mostly noise free but that does not apply to all as some of the seats are found to produce squeaky noises when pulled down. This is due to the fact that the internal connections may have rusted and needed maintenance and if it is not done so, it might disrupt the performance and affect the user’s experience. Therefore, the auditorium will undergo maintenance every 6 months to ensure all of the furniture, systems, and insulation is working well.

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2.7

Noise Control

2.7.1

Noise Control Methods

2.7.1.1 Mechanical and Electrical Design

Figure 2.7.1.1 is a picture of the mechanical ventilation

For the Istana Budaya’s air conditioning, the shapes of the diffusers are carefully chosen as to reduce the noise produced that might affect the audience’s experience.

Using circular or square diffusers with the power set to low, the air conditioning needs can be met, while the noise from high pressure air being forced out of smaller openings can be reduced to inaudible levels.

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2.7.1.2

Sound Absorption

Figure 2.7.1.2 is a picture of the soft surfaces in the auditorium

There are multiple ways Istana Budaya implements sound absorption strategies to reduce noise affecting the audience’s experience. For minor noises from the audience such as moving seats, people walking, and etc., the cushioned seat and carpet floors can absorb these noises, reducing its power and keeping it localised.

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2.7.1.3

Sound locks

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ARC 3413 Building Science 2 A Case Study on Acoustic Design of an Auditorium

Figure 2.7.1.3 is a diagram of the sound locks used in Istana Budaya

The presence of compartmentalization of spaces using hallways acts as a sound buffer to reduce overall sound exiting the outside of Panggung Sari vice versa. Due to the separation of compartments, noise could not enter the concert hall as easily, giving audiences the comfort of focusing only the performance.

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2.7.1.2

Sound Insulation

Figure 2.7.1.4 is a diagram of the stage and its backdrop

For the noise produced backstage, the backstage is sound locked, so as to prevent noise escaping to the audience. The Masking and drapery seals the backstage, making noises from the backstage preparations would not be too loud as to distract the event up front.

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3.0

Conclusion

In this project we have learnt of the many characteristics that can affect the acoustic performance of an auditorium. Things like materials, sound analysis, noise control, existing noise and noise control play a big part in designing a good auditorium.

After this case study and analysis we have determined that the reverberation time of this Panggung Sari is 1.61s. The optimal amount of reverberation for a concert hall should be 2s and above. This value would be suitable for halls that conduct mostly speeches and talks but not in this case. We would suggest using more sound reflective materials on the ceiling and walls as mostly sound absorbing and diffusing materials are present.

The ceiling and wall ornaments also should be more focused on its acoustic properties rather than just being a grand aesthetic feature of the auditorium. The ceiling and wall ornaments are supposed to be designed to reflect sound to improve the user experience but the present ones in Panggung Sari mostly diffuse sounds at every direction.

The rest of the features of Panggung Sari such as noise control, material choice and noise control can be considered as good choices as there is the hall is relatively quiet when everybody is silent in the auditorium.

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4.0

Reference

1. Portal Rasmi Istana Budaya. (n.d.). Retrieved March 31, 2017, from http://www.istanabudaya.gov.my/#!slide-1 2. W. (n.d.). Reverberation Time. Retrieved April 23, 2017, from http://www.phy.mtu.edu/~suits/reverbtime.html 3. Inc., T. S. (2017, February 21). Auditorium Seating Layout & Dimensions Guide.

Retrieved April 21, 2017, from http://www.theatresolutions.net/auditorium-seatinglayout/ 4. Cilento, K. (2011, October 18). Update: Elbe Philharmonic Hall / Herzog and de Meuron. Retrieved April 01, 2017, from http://www.archdaily.com/177177/update5.

6.

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elbe-philharmonic-hall-herzog-and-de-meuron-2 Reverberation Time. (1941). A. Madigan.

Sound Source Localization. (Springer, 2005.). P. Arthur, F. Richard.

Sound- Joseph Midthun-Samuel Hiti - World BookďźŒ 2012 Absorption Coefficients. (n.d.). Retrieved April 20, 2017, from

http://www.acoustic.ua/st/web_absorption_data_eng.pdf 9. Sound absorption. (n.d.). Retrieved April 23, 2017, from http://www.paroc.com/knowhow/sound/sound-absorption 10. Reflection, Refraction, and Diffraction. (n.d.). Retrieved April 20, 2017, from http://www.physicsclassroom.com/class/sound/Lesson-3/Reflection,-Refraction,and-Diffraction

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