B. SC ll
Project 1 : Auditorium Case Study On Acoustic Design Bachelor Science (Hons) In Architecture
Chang May Chen 0322636 Chloe Teh Shu-Ern 0324101 Dana Kan Jia Torng 0323648 Danica Gan Jia-En 0323708 Lee Kylie 0326655 Ng Ji Yann 0323713 Shum Li Sze 0322822 Yang Jing Loo 0323066
Selected Case Study / Istana Budaya, Panggung Sari Kuala Lumpur
Mr. Azim Sulaiman
TABLE OF CONTENTS 1.0 Introduction 1.1 Aim & Objectives 1.2 Site Introduction 1.3 Site History 1.4 Technical Drawings 1.5 Design Features of Panggung Sari 1.6 Methodology 2.0 Material and Properties 2.1 Furniture Materials 2.2 Wall Materials 2.3 Ceiling Materials 2.4 Floor Materials 2.5 Balcony Materials 2.6 Curtain Materials
1 2 3-4 5-8 9 - 10 11
12 13 14 15 16 17
3.0 Sound Analysis 3.1 Sound Source 3.2 Sound Reflection 3.3 Sound Echos 3.4 Sound Absorption 3.5 Table for Absorption Coefficient 3.6 Reverberation Time (RT) 3.7 Sound Lock 3.8 Sound Diffusion 3.9 Sound Concentration 3.10 Sound Shadow Area 3.11 Sound Reading
18 - 21 22 - 24 25 - 27 28 - 31 32 - 33 34 - 35 36 37 - 41 42 43 44 - 45
4.0 Existing Noise Sources 4.1 External Noise 4.2 Internal Noise 4.3 Noise Control
46 - 47 48 - 50 51 - 53
5.0 Comparison of Istana Budaya and Dewan Filharmonik Petronas
54 - 55
LIST OF FIGURES 1.0 Introduction Figure 1.2
An interior view of Panggung Sari.
An exterior view of Panggung Sari.
Figure 1.5.1 (a) Figure 1.5.1 (b) Figure 1.5.2 Figure 1.5.3 (a) Figure 1.5.3 (b)
Fan-shaped Panggung Sari. Fan-shaped arrangement. Side walls angle. Circular concentric seatings of Panggung Sari. Seating levelling.
Figure 1.6.1 Figure 1.6.2 Figure 1.6.3
A digital sound level meter. A digital single-lens reflex camera (DSLR). A measuring tape.
2.0 Material and Properties Figure 2.1 (a) Figure 2.1 (b)
Curved row of seats in Panggung Sari. Seats made of plywood and polyurethane foam.
Figure 2.2 (a) Figure 2.2 (b) Figure 2.2 (c) Figure 2.2 (d)
Curvature of ceiling reflects and dampens vibrations. Plaster ceiling below grand circle. Curved plaster ceiling above the hall. Layering of the ceiling.
Figure 2.3 (a) Figure 2.3 (b) Figure 2.3 (c)
Wall surfaces primarily made of timber materials. Timber panels along the side wall. Texture of timber panel.
Figure 2.4 (a) Figure 2.4 (b) Figure 2.4 (c) Figure 2.4 (d) Figure 2.4 (e) Figure 2.4 (f)
Woollen carpet as flooring. â€œMerbauâ€? wooden stage floor texture. Carpeting in sound lock area. Backstage of Panggung Sari. Comparative sound absorption. Carpet underlayment.
Figure 2.5 (a) Figure 2.5 (b) Figure 2.5 (c)
Balcony protrusions on the wall surfaces. Rounded bottom of balcony. Motif frames.
Figure 2.6 (d) Figure 2.6 (e)
Vernacular carvings. Vernacular carvings.
3.0 Sound Analysis Figure 3.1 (a) Figure 3.1 (b) Figure 3.1 (c) Figure 3.1.1 Figure 3.1.2 (a) Figure 3.1.2 (b) Figure 3.1.2 (c) Figure 3.1.2 (d) Figure 3.1.2 (e) Figure 3.1.3 (a) Figure 3.1.3 (b)
Location of speaker arrays and subwoofers. Example of speaker arrays. Example of subwoofers. Location of speaker arrays and subwoofers on plan. Location of smaller speakers. Example of a smaller speaker. Location of smaller speakers on the first floor. Location of smaller speakers on the second floor. Location of smaller speakers on the third floor. Location of the sound control system. Location of the sound control system on plan.
LIST OF FIGURES Figure 3.2 (a) Figure 3.2 (b) Figure 3.2.1 (a) Figure 3.2.1 (b) Figure 3.2.1 (c) Figure 3.2.1 (d) Figure 3.2.1 (e) Figure 3.2.2 (a) Figure 3.2.2 (b) Figure 3.2.2 (c)
Ceiling of Panggung Sari. Sound Reflectors. Sound Reflection for ceiling - plan view. Sound Reflection for ceiling - section view. Ceiling at the center part of the theatre. Ceiling on the stage. Ceiling on the third floor. Sound reflection for wall - plan view. Reflective wooden wall panel. Sound reflection for wall - section view.
Figure 3.3.2 (a) Figure 3.3.2 (b)
Time delay analysis on floor plan. Time delay analysis on section.
Figure 3.4.2 (a) Figure 3.4.2 (b) Figure 3.4.2 (c) Figure 3.4.2 (d) Figure 3.4.2 (e) Figure 3.4.2 (f) Figure 3.4.2 (g) Figure 3.4.2 (h) Figure 3.4.2 (i) Figure 3.4.3 (a) Figure 3.4.3 (b) Figure 3.4.3 (c) Figure 3.4.3 (d) Figure 3.4.4 (a) Figure 3.4.4 (b) Figure 3.4.4 (c)
Carpet flooring outside the auditorium on plan. Lobby uses carpet flooring and fabric wall. Corridor uses carpet flooring and half fabric wall. While people step on carpet, sounds of footsteps absorbed to the carpet flooring and half fabric wall finishing. Carpet flooring in the auditorium on plan. Carpet flooring in the auditorium on section. Carpet flooring in the audience sitting area. Carpet flooring along the staircase. Carpet staircase absorbed the sounds of footsteps when the audience is walking. Timber wall panel on section. Timber wall panel. Timber wall panel section cut. Diagram shown the absorption of unwanted sound and reflection of the sound happening at the same time. Fibreglass reinforced gypsum ceiling on section. Fibreglass reinforced gypsum ceiling. Diagram shown the section cut of fibreglass reinforced gypsum ceiling. The arrow shown reflection and absorption of sound happening at the same time from the direction.
Figure 3.7 (a) Figure 3.7 (b) Figure 3.7 (c) Figure 3.7 (d) Figure 3.7 (e) Figure 3.7 (f)
Sound lock system on plan. Sound lock system on plan. Sound lock with carpet flooring. Sound lock with soft door closing. Sound lock with half fabric finishing wall. Diagram shown the reducing noise through the sound lock system. Two sound lock system used to minimize the noise transmitted into auditorium.
Figure 3.8.2 (a) Figure 3.8.2 (b) Figure 3.8.3 (a) Figure 3.8.3 (b) Figure 3.8.4 (a) Figure 3.8.4 (b) Figure 3.8.5 (a) Figure 3.8.5 (b) Figure 3.8.6 (a) Figure 3.8.6 (b) Figure 3.8.7 (a)
Sound diffusion in section drawings. Sound diffusion in third floor plan drawings. VIP boxes with curved edges. Sound diffusion diagram. Coffers at the back of auditorium. Sound diffusion diagram. Sound diffusion diagrams of the balcony. Sound diffusion diagrams. Sound diffusion diagrams of the ornaments. Sound diffusion diagrams of the ornaments. Sound diffusion diagrams of carpets.
Sound concentration diagrams of the area.
Sectional drawing showing the dimension of the sound shadow area and differences of sound intensity level.
LIST OF FIGURES Figure 3.11 (a) Figure 3.11 (b) Figure 3.11 (c) Figure 3.11 (d) Figure 3.11 (e)
First floor plan of Panggung Sari. First floor plan of Panggung Sari. First floor plan of Panggung Sari. Second floor plan of Panggung Sari. Third floor plan of Panggung Sari.
Figure 4.1.2 (a) Figure 4.1.2 (b)
Outdoor ongoing construction work opposite the theatre. Location of Istana Budaya just right beside the busy highway. Yet trees and the surrounding spaces serve as a barrier to filter the noises out. People eating in the outdoor cafe. Existing noise sources coming from the external environment of the theatre. People gathering at the entrance hall of the theatre. The lobby outside the theatre where people gather before entering the theatre delays the sound travel distance from going into the theatre. Rain and thunder noises are also not heard in the theatre because of the distance.
Figure 4.1.3 (a) Figure 4.1.3 (b) Figure 4.1.3 (c) Figure 4.1.3 (d)
Figure 4.2.1 (a) Figure 4.2.1 (b) Figure 4.2.1 (c) Figure 4.2.1 (d) Figure 4.2.2 (a) Figure 4.2.2 (b) Figure 4.2.3 (a) Figure 4.2.3 (b) Figure 4.2.4 (a) Figure 4.2.4 (b) Figure 4.2.4 (c)
Curtains installed in front of entry doors. Automatic hydraulic door closers at the entry doors. Sound lock area. Location of doors that may cause noise during opening and closing. Aluminium strips at the threads to prevent slipping. internal connections of foldable seats cause squeaky noise. Backstage operations. Mechanical systems that may cause noise when operating. Some AC diffusers in the theatre badly in need of maintenance create a continuous buzzing sound. Section showing the source of noise from backstage and mechanical ventilation. The circular grills on the floor that were previously seat holders now serve as vents that open to below of the secondary seating or orchestra stage. Slight whooshing noises can be heard at times because of the hollow space below.
Figure 4.3 Figure 4.3.1
Recommended background noise levels. As the barrier is closer to the receiver, the more efficient noise can be controlled as refractive atmospheric effects is not present. Design of air conditioning units in Istana Budaya. Design of spaces and sound locks present in the building. Use of soft surface materials such as carpets and cushions. A diagram illustrating the absorption of noise. Backdrop of the stage in the theatre.
Figure 4.3.2 Figure 4.3.3 Figure 4.3.4 (a) Figure 4.3.4 (b) Figure 4.3.5
1.0 INTRODUCTION 1.1 AIM & OBJECTIVES The aim of this assignment is to conduct a case study on the acoustic functions of a local auditorium whereas our objectives are to study the design layout of Istana Budaya, analyse its acoustic characteristics, identify the types of materials used and the suitability of sound absorption materials in building this auditorium and provide a concise and well-documented analysis that can showcase our understanding of this case study on acoustical theory in an auditorium hall. We, as a group has conducted a site visit to our selected auditorium, Istana Budaya and documented the necessary information required for this assignment via photographs, drawings and also on-site observations. By analysing the data collected, we are able to: -
study and understand the design layout of the auditorium and analyse its influence on the effectiveness of the acoustical design for its designated purpose. study the acoustic characteristics of the auditorium. identify the types of materials used in designing the auditorium. determine the suitability of the sound absorption materials and acoustic methods used in relation to the function of the auditorium.
After analysing the acoustic characteristics of Istana Budaya thoroughly, we documented our findings into a report as well as Powerpoint slides on our case study for an oral presentation.
1.2 SITE INTRODUCTION
Figure 1.2 An interior view of Panggung Sari.
Istana Budaya is Malaysia's National Theatre which is 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. Istana Budaya is designed by local architect, Muhammad Kamar Ya'akub. The main theatre hall (Panggung Sari) can accommodate up to 1,421 audiences. The uniqueness of Istana Budaya architecture is its Malay culture concept. Viewed from above, Istana Budaya looks like Kelantan “wau”. The shape of the building is liken to the “sirih junjung” which is an arrangement of betel leaves that is symbolic of the Malays customs and traditions as it is often used in Malay wedding ceremonies and reception ceremonies. The interior of Istana Budaya follows the concept of a Malay house with three main sections: “serambi” which is the lobby, “rumah ibu” is the main theatre hall, as well as the kitchen which is the main stage and practice hall. The stairs to the main theatre hall is based on the traditional stairs of Malaccan Malay houses.
Figure 1.3 An exterior view of Panggung Sari.
1.3 SITE HISTORY Since 1964, the Minister of Communication and Multimedia and the Minister of Tourism and Culture had suggested to build a National Cultural Center. Early talks suggested that the Cultural Center should be located at Lembah Pantai, situated in between Malaysian Broadcasting Center and University Malaya. The Cultural Center was planned to be a cultural complex which includes a historical museum, National Art Gallery, Planetarium, a theatre, restaurants and a shopping mall which sells cultural products. In 1971, the National Cultural Congress planned and discussed regarding the construction of the National Theatre. As a result, â€œKumpulan Budaya Negaraâ€? (KBN) was established in 1972 by the Arts Development Division, Cultural Division and Ministry of Culture, Youth and Sports or in short known as KKBS but it had only move amicably. The KBN office, was located at Wisma Keramat hence all activities were held in a house along Jalan Ampang till the end of 1973 when KBN was moved to the National Cultural Complex at Jalan Tun Ismail as it is the location of Akademi Seni Budaya dan Warisan Kebangsaan (ASWARA). Since 1974, KBN was actively involved under the Arts Development Branch, Cultural Division and KKBS. However, the attention was more towards cultural dances and traditional music. Later in 1982, the Young Symphony Orchestra also recognised as OSM was established, followed by the National Choir Group which was established in 1992. In 1993, the Experimental Theatre (ET) was built in the National Cultural Complex and in the same year, OSM was upgraded to become the National Symphony Orchestra or known as OSK.
1.3 SITE HISTORY In 1994, ET was launched by Yang Berbahagia Tun Dr. Mahathir Mohamad. KBN then became part of the National Theatre under the Ministry of Culture, Arts and Tourism or known as KKKP. In the same year, the construction of the National Theatre has begun by determining its site, design and financial planning. The construction of ET and the existence of Tunku Abdul Rahman Auditorium at Malaysia Tourism Information Center (MATIC) at Jalan Ampang was an attempt to gain experience in administering a National Theater in the future. The construction of the National Theatre in 5.44 hectares and 21 000 meter square site started in July 1995, involving a total cost of RM 210 million. As soon as the construction was completed on 1st December 1998, the National Theater administration was moved to a premise located at Jalan Tun Razak. A year later, on September 15, 1999, the National Theater was officially known as Istana Budaya.
1.5 DESIGN FEATURES OF PANGGUNG SARI 1.5.1 Room Shape The shape of Panggung Sari is designed as a fan shape, creating a more intimate space between the audience and the performance. The immediate advantage of this kind of auditorium plan is that it engages with the audience better compared to a rectangular auditorium. The narrow width of the stage end helps with sound reflections, promote projections towards the audience, as well as help the performers to hear each other better. However, there is a disadvantage to the fan-shaped auditorium. The rear auditorium wall is automatically generated as a concave curved surface, which produces focused echo back to the stage. Thus, absorption (refer to Sound absorption 3.4) and diffusion elements (refer to Sound Diffusion 3.8) were designed to solve this problem.
Figure 1.5.1 (a) Fan-shaped Panggung Sari.
Figure 1.5.1 (b) Fan-shaped arrangement.
1.5.2 Angle of Arrangement The side walls were arranged to have a maximum of 130 degrees from a central point to bring the distance audience closer to the performers, thus ensure visual and acoustical quality. Panggung Sari design arrangement falls within 130 degree, which is an ideal fan shape auditorium for a music performance auditorium, ensuring the visual and acoustical quality.
130 degree Maximum angle for Optimum acoustical And visual condition
Figure 1.5.2 Side walls angle.
1.5 DESIGN FEATURES OF PANGGUNG SARI 1.5.3 Seating Arrangements The seating arrangement in Panggung Sari is circular concentric scheme with projecting stage. The concentric seatings is designed to increase the efficiency visually and acoustically. There are both movable and permanent seats offered to accommodate different types of occasions and usage. The layout of the auditorium complements with the design features for each seating levels to achieve desirable acoustical quality.
Figure 1.5.3 (a) Circular concentric seatings of Panggung Sari.
2nd floor terrace ViP box balcony 1st floor terrace Ground floor terrace
Figure 1.5.3 (b) Seating levelling.
1.6 METHODOLOGY 1.6.1 Digital Sound Level Meter
1.6.3 Measuring Tape
Figure 1.6.1 A digital sound level meter.
Figure 1.6.3 A measuring tape.
We used this device to measure the sound levels at a particular point within the auditorium. The unit of measurement is decibels (dB).
This measuring tool is used to measure the auditorium for our drawings and calculation purposes.
1.6.2 Digital Single-Lens Reflex Camera (DSLR)
Figure 1.6.2 A digital single-lens reflex camera (DSLR).
A digital camera is used to capture images of the auditorium. Images captured were used as evidences for our analysis.
2.0 MATERIAL AND PROPERTIES 2.1 FURNITURE MATERIALS
Figure 2.1 (a) Curved row of seats in Panggung Sari.
The theatre, also known as Panggung Sari, houses specialised furniture which aids in providing maximum quality of sound acoustics. There is a total of 1421 seats; ● 796 seats in stalls, ● 322 seats in the Grand Circle, ● 303 seats in Upper Circle. These chairs are made of premier high density plywood with painted surface. Its cushion is made of polyurethane high flexibility foam. The foam serves as a useful sound absorption and sound insulation tool. Plywood is a smooth and light material, with a thick, dense surface is used but it does not have particularly good sound insulation performance. However, it can dampen and reflect sound particularly well. In Panggung Sari, plywood is made into surfaces that channel sound reflections. Polyurethane High Flexibility Foam High Density Plywood
Polyurethane foam used for the seats exhibits excellent shock absorption, high dynamic load capacity, excellent vibration dampening, noise reduction and the highest modulus of elasticity of all elastomers.
Figure 2.1 (b) Seats made of plywood and polyurethane foam.
2.2 CEILING MATERIALS
Figure 2.2 (a) Curvature of ceiling reflects and dampens vibrations.
Figure 2.2 (b) Plaster ceiling below grand circle.
Figure 2.2 (c) Curved plaster ceiling above hall.
Plaster is one of the most commonly used materials to literally shape the architecture of concert hall acoustics. Panggung Sari uses fiberglass reinforced gypsum (FRG) ceiling board with a thickness range of 38mm to 50mm. Regular gypsum board will be too thin for most purposes in concert hall acoustics. The thickness of the gypsum board keeps it stiff and prevent vibrations, as well as low frequencies absorptions.
Fiberglass Insulation Wood Studs Gypsum Drywall Figure 2.2 (d) Layering of the ceiling.
FRG has the ability to dampen sound transmission by using the inner polymer layer as a kind of shock absorber that slows board vibrations and dissipates the sound energy into thermal energy. Additionally, it performs well acoustically over an extended range of frequencies, resulting in increased Sound Transmission Class (STC) ratings for the assemblies.
2.3 WALL MATERIALS
Figure 2.3 (a) Wall surfaces primarily made of timber materials.
Evidently, majority of the wall surfaces in Panggung Sari is made of timber panels of â€œmerbauâ€? wood. As mentioned in furniture material, timber is not a particularly good sound insulator. Therefore, these panels are able to reflect performance sounds. On the other hand, the foam beneath the layer of timber is able to absorb unwanted sounds from the other side of the concert hall, thus eliminating disturbances during a performance.
Figure 2.3 (b) Timber panels along the side wall.
Figure 2.3 (c) Texture of timber panel.
These panels can enhance the visual beauty of Panggung Sari. However, there are some precautionary measures have to be taken. If a wood panel is too thin and there is air space behind it, it will cause panel vibration as well as low frequencies absorption which is similar to thin plaster or gypsum board. Therefore, there are thick layers of plaster backing up wood panels to prevent low frequency absorption.
2.4 FLOOR MATERIALS
Figure 2.4 (a) Woollen carpet as flooring.
Figure 2.4 (b) “Merbau” wood stage floor texture.
Figure 2.4 (c) Carpeting in sound lock area.
Carpet is an outstanding sound absorptive material. No other acoustical material performs the dual role of a floor covering and a versatile acoustical aid. Panggung Sari utilizes woollen carpet as a sound insulator, especially for when audience members travel along the aisles. Woollen carpet is made of 80% wool and 20% nylon. The concert hall also uses timber flooring on stage. The type of timber used is “merbau”. Due to its hardness and strength, it is able to reflect and channel sounds in various directions, thus amplifying performance sounds. Properties of “Merbau” Wood Excellent strength characteristics Hardness: 1,840 lbf (7,620 N) Rupture Modulus:: 21,060 lbf/in2 (145.2 MPa) Elastic Modulus: 2,310,000 lbf/in2 (15.93 GPa) Crushing Strength: 10,650 lbf/in2 (73.4 MPa) Figure 2.4 (d) Backstage of Panggung Sari.
Figure 2.4 (e) Comparative sound absorption.
Figure 2.4 (f) Carpet underlayment.
Comparatively, carpet has a higher absorption property compared to a hard floor. Among the layers, the carpet underlayment acts as the sound absorber and insulator.
2.5 BALCONY MATERIALS
Figure 2.5 (a) Balcony protrusions on the wall surfaces.
Balconies in Panggung Sari form part of the wall consisting of timber panels. Needless to say, the balcony surfaces are made of similar sound-insulating timber panels, thus reflecting performance sounds and keeping out external sounds on the other side of the surface.
Figure 2.5 (b) Rounded bottom of balcony.
Figure 2.5 (c) Motif frames.
Figure 2.6 (d) & Figure 2.6 (e) Vernacular carvings.
The curvature beneath each balcony aids in the dispersal of sounds when sounds get reflected and channelled into a different direction. The balcony surfaces also display traditional vernacular motifs in reflection of Malay local culture, thus setting the mood and identity of Istana Budaya.
2.6 CURTAIN MATERIALS
Figure 2.6 (a) Curtain drape of main stage serving acoustic and aesthetic purposes.
It is usually essential to have curtains or drapes in a concert hall to conceal stage preparation. Curtains can absorb sound energy therefore having curtains behind the orchestra will rob them of some essential early reflections. In some special cases, it is required that the concert hall acoustics be adjustable based on the nature of the performance. As such, the curtains can be designed to be concealed when needed so that they do not affect the sound of the instruments on stage. Specifications
Figure 2.6 (b) Main stage.
Black Borders Curtains 5m drop X 20m width 0% fullness Qty: 1
Figure 2.6 (c) Curtain leading to exits.
They are made of heavy duty, flame retardant fabrics and have the ability to absorb and insulate sounds. Curtain products for concert theatres are commonly made of wool serge or velvet velour. In Panggung Sari, velvet velour is used. For maintenance, acoustic curtain fabric can only be cleaned with a vacuum cleaner or soft brush. Wet cleaning of flame retardant material will compromise the fire resistance and must be avoided.
Black Entrance Curtains 12m drop X 12m width 50% fullness Qty: 4
3.0 SOUND ANALYSIS 3.1 SOUND SOURCE Sound amplifiers are the primary source of sound in the theatre. They amplify sounds from the stage to the entire auditorium, ensuring a good quality of sound throughout.
Figure 3.1 (a) Location of speaker arrays and subwoofers.
Speaker Arrays The three speaker arrays suspended from the ceiling directly in front of the stage directs sound to the front, left and right of the auditorium. The vertical arrays provide a narrow vertical output pattern useful for focusing sound at audiences without wasting output of energy on ceilings or empty air above the audience.
Figure 3.1 (b) Example of speaker arrays.
Subwoofers 6 subwoofers are located, one on every level in the booths on both front sides of the auditorium. They amplify the lower sound frequencies to create a balanced sound. They are tilted at an angle to direct sound towards the front quarter of the auditorium. Some of them are hidden behind black cloths to reduce the attenuation of lower frequency sounds. Figure 3.1 (c) Example of subwoofers.
3.1 SOUND SOURCE 3.1.1 Location of Speaker Arrays and Subwoofers
Speaker Arrays Subwoofers
Figure 3.1.1 Location of speaker arrays and subwoofers on plan.
3.1 SOUND SOURCE 3.1.2 Location of Smaller Speakers
Figure 3.1.2 (a) Location of smaller speakers.
Smaller speakers are located at equal distances around the back of the auditorium to provide a surround sound. This comes in handy when there is a large crowd and a single source of sound from the front is not sufficient for audience to get the best sound experience.
Figure 3.1.2 (b) Example of a smaller speaker.
Figure 3.1.2 (c) Location of smaller speakers on the first floor.
Figure 3.1.2 (d) Location of smaller speakers on the second floor.
Figure 3.1.2 (e) Location of smaller speakers on the third floor.
3.1 SOUND SOURCE 3.1.3 SOUND CONTROL SYSTEM
Figure 3.1.3 (a) Location of the sound control system.
Figure 3.1.3 (b) Location of the sound control system on plan.
The volume, balance and tonality of sound is controlled at the sound control panel located at that back center of the auditorium, as a result hearing of sound is optimum.
3.2 SOUND REFLECTION Sound Reflection occurs on hard surfaces and if a sound is not absorbed or transmitted when it strikes a surface, it will be reflected. The waves are called incident or reflected sound waves; Angle of incident = angle of reflection Convex are reflecting surfaces which disperse sound and promoting good diffusion.Concave surfaces focus on sound waves, therefore concentrating the reflected sound in specific areas. In general, reflections are used in room acoustics to distribute and reinforcements sounds. Apart from that, the concave shaped structure in plastered ceiling of Panggung Sari in Istana Budaya has no function in directing sound waves towards the audiences, it only acts as an aesthetic piece at the centre core of the auditorium. It only provides minimal function in diffusing and disperse sound in random directions.
Figure 3.2 (a) Ceiling of Panggung Sari.
Primary Reflectors Secondary Reflectors
Figure 3.2 (b) Sound Reflectors.
3.2 SOUND REFLECTION Geometric Spreading - Direct and Indirect Sound Path 3.2.1 Ceiling Reflection
Sound Source Direct Sound Incident Sound / Reflection
Figure 3.2.1 (c) Ceiling at the center part of the theatre.
Figure 3.2.1 (a) Sound Reflection for ceiling - plan view.
B C B A
Figure 3.2.1 (d) Ceiling at stage.
Figure 3.2.1 (b) Sound Reflection for ceiling - section view.
Figure 3.2.1 (e) Ceiling at third floor.
In the auditorium of Istana Budaya, material used in convex and concave surfaces are plaster boards. Tilted ceiling often provides useful and effective sound reflections. In this case study, convex structure plays an important role in reflecting surfaces that creates sound dispersion in an open space.
3.2 SOUND REFLECTION 3.2.2 Wall Reflection Sound Source Direct Sound Incident Sound / Reflection
Figure 3.2.2 (b) Reflective wooden wall panel. Figure 3.2.2 (a) Sound reflection for wall - plan view.
wall reflection Stage wall reflection
Sound Source Figure 3.2.2 (c) Sound reflection for wall - section view.
Reflections of sound energy are formed when it strikes to the hard surfaces. Wall panels used in auditorium of Istana Budaya are mainly reflective wooden wall panels. These reflectors used in auditorium to distribute better reinforcement sounds. Indirect sound path occurs when sound paths bouncing off the wall and reflect towards the audience.
3.3 SOUND ECHOS 3.3.1 Definition Sound echoes is the reflection of a single sound source, and it can be used to estimate the distance of an object. It is a sound wave that is reflected back to the sound source. Echo in auditorium happens when sound waves bounce back and forth between the walls, ceilings and floors. It makes conversations difficult as it creates acoustic issues for the audio and conversational atmosphere. It is known as the most serious of room acoustical defects. 3.3.2 Time Delay and Sound Echo Analysis A time delay of the auditorium is identified to ensure that the time delay reinforced the direct sound instead of creating unwanted echo within the auditorium. The formula to measure time delay is stated below : Time Delay = R1 + R2 - D 0.34
Figure 3.3.2 (a) Time delay analysis on floor plan.
Sound source Indirect sound path Direct sound path Location
3.3 SOUND ECHOS
R1 R1 D
Figure 3.3.2 (b) Time delay analysis on section.
Sound source Indirect sound path Direct sound path Location
Time Delay, T1 = 22.3 + 15.4 - 9 0.34 = 84.41 msec (<100 msec, suitable time delay)
Time Delay, T2 = 5.9 + 5.4 - 7 0.34 = 12.64 msec (<100 msec, suitable time delay)
3.3 SOUND ECHOS
Time Delay, T3 = 6.3 + 4.6 - 7.5 0.34 =10 msec (<100 msec, suitable time delay)
Time Delay, T4 = 13.6 + 14 - 12.7 0.34 = 43.82 msec (<100 msec, suitable time delay)
Time Delay, T5 = 13.6 + 10.8 - 10.8 0.34 = 103 (sound echo)
T1, T2, T3 and T4 reinforce the direct sound as the time delay is within 100 msec , which is within the acceptable range. T5 will experience sound echos which might affect the acoustic of the sound in the auditorium. However, sound echos can be overcome by improving sound diffusion and sound absorption in certain area. To overcome the sound echo at T5, curtains and scattering elements were designed on the balcony to help with sound diffusion and sound absorption.
3.4 SOUND ABSORPTION 3.4.1 Definition Sound is produced by the speakers and it is reflected by timber wall panels and plaster ceiling. These sound waves cause air particles to vibrate, and hit against our eardrum so that we hear sound. Sound absorption happens through the materials and it is used to control unwanted sound reflections.
Figure 3.4.1 Absorption
Figure 3.4.2 (a) Carpet flooring outside the auditorium on plan.
Figure 3.4.2 (b) Lobby uses carpet flooring and fabric wall.
Figure 3.4.2 (c) Corridor uses carpet flooring and half fabric wall .
Carpet flooring used to absorb impact noise which direct physical contact a surface. Lobby and corridor (figure 3.4.2(b) and 3.4.2(c)), used carpet flooring and fabric wall to absorb the sound of footsteps when people are walking along the corridor or waiting and chatting in the lobby before enter to auditorium.
Figure 3.4.2 (d) While people step on carpet, footsteps sounds are absorbed to the carpet flooring and half fabric wall finishing.
3.4 SOUND ABSORPTION
Figure 3.4.2 (e) Carpet flooring in the auditorium on plan.
Figure 3.4.2 (f) Carpet flooring in the auditorium on section.
Figure 3.4.2 (g) Carpet flooring in audience sitting area.
Figure 3.4.2 (h) Carpet flooring along the staircase.
Carpet flooring in auditorium used to absorb the footsteps when the audience walks on the stairs and stroll to his seat. Therefore, the show will not be interrupted when the audience or staffs move around the auditorium.
Figure 3.4.2 (i) Carpet staircase absorbed the sounds of footsteps when the audience is walking .
3.4 SOUND ABSORPTION 3.4.3 Timber Wall Panel
Figure 3.4.3 (a) Timber wall panel on section.
Figure 3.4.3 (b) Timber wall panel.
Transmitted unwanted sound Reflected sound
Timber panel wall is not only used to reflect sound but also to absorb unwanted sound source. It used to isolate the sound source between the corridor and auditorium. Therefore, the show will not be interrupted when people move along the corridor.
Figure 3.4.3 (c) Timber wall panel section cut.
Timber wall panel Absorb unwanted sound
Reflection of sound Direction of sound Sound source
Figure 3.4.3 (d) Diagram shown the absorption of unwanted sound and reflection of the sound happening at the same time.
3.4 SOUND ABSORPTION 3.4.4 Fibreglass Reinforced Gypsum
Absorbed unwanted sound
Figure 3.4.4 (a) Fibreglass reinforced gypsum ceiling on section.
Plaster is used to reflect sounds and at the same time, unwanted sounds will be absorbed in the fibreglass insulation. This happens when the air particles are driven into motion by the sound waves, then attempt to pass through the dense sound-absorbing material. The fibreglass will absorbed the noise while the staffs are walking on the catwalk. Figure 3.4.4 (b) Fibreglass reinforced gypsum ceiling.
Gypsum Drywall Wood studus Fiberglass insulation Gypsum Drywall
Figure 3.4.4 (c) Diagram shown the section cut of fibreglass reinforced gypsum ceiling. The arrow shown reflection and absorption of sound happening at the same time from the direction.
3.5 TABLE FOR ABSORPTION COEFFICIENT Common Building Materials
Absorption Coefficient 500Hz
Medium Pile Carpet On Sponge Rubber Underlay
3.5 TABLE FOR ABSORPTION COEFFICIENT Common Building Materials
Absorption Coefficient 500Hz
Fabric With Wooden Panel
Solid Timber Door
3.6 REVERBERATION TIME (RT) Volume of Panggung Sari =30m x 35m x 15m =15750 m³ Component
Surface Area (m²) /Quality
Absorption Coefficient 500Hz
Medium pile carpet on sponge rubber underlay
Fabric with Wooden Panel
Solid Timber Door
Total Absorption (A) 1489
3.6 REVERBERATION TIME (RT)
Table 3.6 Reverberation Table
Graph 3.6 Reverberation Graph
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 60 dB 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. Reverberation time 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 ³ ) A = Total absorption of room surfaces 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 Reverberation Time (RT) = (0.16xV) ÷ A =(0.16 x 15750 ) ÷ 1489 =1.70s Panggung Sari is a large auditorium room with a long reverberation time (RT). This means that the room acoustics is suitable for musical performances.
3.7 SOUND LOCK Sound lock is the passage connecting entrances, corridor and the auditorium with different reverberation times.
Figure 3.7 (a) & (b) Sound lock system on plan.
Figure 3.7 (c) Sound lock with carpet flooring.
Figure 3.7 (d) Sound lock with soft door closing.
Figure 3.7 (e) Sound lock with half fabric finishing wall.
Entrance from lobby Sound lock 1 Entrance from corridor Reduction of noise
Sound lock 2 Auditorium
Figure 3.7 (f) Diagram shown the reducing noise through the sound lock system. Two sound lock system used to minimize the noise transmitted into auditorium.
The sound lock room must use absorbing materials to reduce noise transform from the outside, namely the corridor and the entrances. Therefore, the material used in the sound lock room for Istana Budaya includes carpeted flooring, soft door closer and fabric finishing on half of the wall to reduce and separate the noise that enters into the auditorium.
3.8 SOUND DIFFUSION 3.8.1 Definition Sound diffusion is when sound energy is spread evenly to all parts of the auditorium. It is essential in acoustic architectural design as it encourages uniform distribution of sounds, thus improving the qualities of music in Istana Budaya. It does not remove sound energy but it helps to minimize distinct echoes and reflections resulting a good sounding auditorium. 3.8.2 Sound Diffusion in Istana Budaya
Figure 3.8.2 (a) Sound diffusion in section drawings. Figure 3.8.2 (b) Sound diffusion in third floor plan drawings.
3.8 SOUND DIFFUSION 3.8.3 Curved Edges The VIP boxes at the side walls of Panggung Sari were designed with curved edges, diffuse sound uniformly in all direction to the audience.
Figure 3.8.3 (a) VIP boxes with curved edges.
Figure 3.8.3 (b) Sound diffusion diagram.
3.8 SOUND DIFFUSION 3.8.4 Coffers
Figure 3.8.4 (a) Coffers at the back of the auditorium.
Coffers are found at the side walls of Panggung Sari, changing the reflection of sound from the source and disperse the sound wave evenly. Without the coffers, sound echoes will occur as sound energy reflects slightly later at the back of the auditorium.
Figure 3.8.4 (b) Sound diffusion diagram.
Figure 3.8.5 (a) Sound diffusion diagrams at the balcony.
Figure 3.8.5 (b) Sound diffusion diagrams.
Irregularity of geometrical edges of the balcony helps in sound diffusion. When sound travels and being delivered to the audience, it hits the sharp geometrical edges of the balcony and diffuses evenly in all direction.
3.8 SOUND DIFFUSION 3.8.6 Ornamentations
Figure 3.8.6 (a) Sound diffusion diagrams at the ornaments.
Detailed ornamentation uses sharp and edgy geometrics motifs instead of curves motifs to promote sound diffusion. Other than improving aesthetical value to the auditorium, it also enhances the acoustic quality of the interior.
Figure 3.8.6 (b) Sound diffusion diagrams at the ornaments.
3.8 SOUND DIFFUSION 3.8.7 Carpet
Figure 3.8.7 (b) Sound diffusion detailed diagram at the carpet.
Other than absorbing sound, the irregular surface of carpet helps in acoustical treatment by diffusing the sound. Figure 3.8.7 (a) Sound diffusion diagrams at carpets.
3.9 SOUND CONCENTRATION The auditorium controls sufficient sound travel from the stage towards the audience. Main speakers and smaller speakers are installed around the auditorium to achieve better vocal clarity. From the sound sources, sound intensity are concentrated at the centre core of the auditorium, caused by the reflected sound waves which spread the sound in the area.
Figure 3.9.1 Sound concentration diagrams of the area.
3.10 SOUND SHADOW AREA 3.10.1 Definition The effect produced is perceived as a reduction of loudness. High frequencies are more easily absorbed than lower one since they are less susceptible to 'diffraction'; which means they move less easily around objects because of their short wavelengths. Therefore, it is the attenuation of high frequencies is noted to be in a sound shadow. 3.10.2 Sound Shadow in Istana Budaya Sound shadow defect can be determined when the sound wave failed to propagate due to the auditorium obstruction. After we collected the data of sound intensity level from the staff and our group members, we found out that there is intermediate sound shadow under the balcony as the sound intensity level dropped from 68.6 dB to 60.3 dB when we were moving from the front seating area to the seating under the balcony. Ideally, Panggung Sari Auditorium overhang depth should be less than twice the height of the auditorium underside.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 Panggung Sari Auditorium is made of timber panel to reflect sound into sound shadow area.
60.3dB 68.6dB STAGE Figure 3.10.2 Sectional drawing showing the dimension of the sound shadow area and differences of sound intensity level.
3.11 SOUND READING
Level 1 ( Back ) Silent | 40 dB When People Talking | 55.4 dB When People Talking On Stage | 60.3 dB Air-cond | 51.1 dB
Figure 3.11 (a) First floor plan of Panggung Sari.
Level 1 ( Middle ) Silent | 36.3 dB When People Talking | 50.5 dB When People Talking On Stage | 67.3 dB
Figure 3.11 (b) First floor plan of Panggung Sari.
Level 1 ( Front ) Silent | 35.1 dB When People Talking | 41.8 dB When People Talking On Stage | 68.6 dB
Figure 3.11 (c) First floor plan of Panggung Sari.
3.11 SOUND READING
Level 2 Silent | 35.6 dB When People Talking | 53.0 dB When People Talking On Stage | 76.6 dB
Figure 3.11 (d) Second floor plan of Panggung Sari.
Level 3 Silent | 39.3 dB When People Talking | 48.2 dB When People Talking On Stage | 63.0 dB
Figure 3.11 (e) Third floor plan of Panggung Sari.
4.0 Identifying Existing Noise Sources 4.1 External Noise 4.1.1 Definition Noise is usually defined as undesirable sound impeding at unwanted times but it is subjective based on each individual's attitude toward the noise source. Even as Istana Budaya is designed with acoustic considerations to achieve the best environment for sound propagation, yet, there would still be some noise disturbance that cannot be avoided within the theatre. Acceptable background noise in an auditorium ranges from 20 dbA to 25 dbA, and any levels higher or lower than that may either cause disturbance or not be heard respectively. Noise pollution disrupts speech and music intelligibility and can disallow the audience from understanding what is being said. How undesirable a sound is will depend on various factors such as the frequency, continuity, loudness, content, time of occurrence, place, activity being carried out, and the personal state of mind of the listener. 4.1.2 Traffic and Outdoor Construction Work However, due to the location and the existence of soundproof system in Istana Budaya, external noise source can be prevented so that it does not disrupt the performances inside the auditorium. The spaces around the auditorium hall also form a buffer zone which helps distance the noise coming into the hall. Istana Budaya is located in a busy city centre where it is surrounded with buzzing traffic. Being adjacent to the Jalan Tun Razak highway which connects to the Kuala Lumpur city centre, many vehicles drive along this road and it becomes congested during peak hours. Furthermore, during our visit to Istana Budaya, an ongoing construction project was seen opposite the site. Vibration and structure borne sound from the vehicles and construction operations are prohibited from entering the theatre as the building is isolated a distance away from these noise sources, thus sound travelling distance is lengthened and this reduces the noise intensity. The surrounding trees and plantations also help create a buffer space to filter the noise coming into the building.
Figure 4.1.2 (a) Outdoor ongoing construction work opposite the theatre.
Figure 4.1.2 (b) Location of Istana Budaya just right beside of busy highway. Yet trees and the surrounding spaces serve as a barrier to filter the noises out.
4.1 EXTERNAL NOISE 4.1.3 Human Activities Besides that, social activities like chit-chatting, greetings and other interactions as people gather outside the theatre, at the receptionist and the outdoor cafe may also contribute to the noise occurrence. However, even though it is crowded with visitors during performances and events, the soundproofing and sound locks outside the theatre provide a barrier to reduce the noise from entering the hall.
Figure 4.1.3 (a) People eating in the outdoor cafe.
Figure 4.1.3 (b) Existing noise sources coming from the external environment of the theatre.
Figure 4.1.3 (c) People gathering at the entrance hall of the theatre.
Figure 4.1.3 (d) The lobby outside the theatre where people gather before entering the theatre delays the sound travel distance from going into the theatre. Rain and thunder noises are also not heard in the theatre because of the distance.
4.2 INTERNAL NOISE 4.2.1 Entry Doors In Istana Budaya, the closing and opening of doors as audiences enter and exit out of the room does not make any obvious air-borne noise that may disrupt the performance. This is because a sound lock is designed within the inner and outer door at the main entrance of the theatre to trap the sound waves and bring the noise level down to less than 35 dbA. Furthermore, curtains and hydraulic door closers are also installed on every door so they are closed automatically and in a slow motion as the wooden door panel comes in contact with the door frame.
Figure 4.2.1 (a) Curtains installed in front of entry doors.
Figure 4.2.1 (b) Automatic hydraulic door closers at the entry doors.
Figure 4.2.1 (c) Sound lock area.
Figure 4.2.1 (d) Location of doors that may cause noise during opening and closing.
4.2 INTERNAL NOISE 4.2.2 Stairs and Seating It may be disturbing to other people when the audience enters or leaves during a performance, as some of the collapsible seats in the theatre are also found to produce some squeaky noises when moved down. This might occur because of the internal connections have rusted and may need maintenance as the noise produced would disrupt the audienceâ€™s attention. The aluminium strip found on the stairs have also found to make a clicking noise when people stepped on them. These are structural borne noises that result from an impact or vibration against it. But the surrounding soft carpet actually helps to absorb the noise so it is less obvious.
Figure 4.2.2 (a) Aluminium strips at the threads to prevent slipping.
Figure 4.2.2 (b) internal connections of foldable seats cause squeaky noise.
4.2.3 Backstage Activity Besides that, internal noises can also be produced from the backstage operations. This is due to the interactions between the performers and the staff when making preparations for the show to start. The mechanical systems of the cranes or other media operating equipment make noises that are dwarfed by the sound of the performances on stage.
Figure 4.2.3 (a) Backstage operations.
Figure 4.2.3 (b) Mechanical systems that may cause noise when operating.
4.2 INTERNAL NOISE 4.2.4 Mechanical Ventilation The overall mechanical ventilation HVAC system in Istana Budaya has a low noise unit, as the noise output level can be as low as NR25 and they have ensured it to be running at a low speed. Yet, there are a few air conditioner diffusers that may need maintenance and have continuous sounds that the audience may find distracting. The air vents may sometimes produce whooshing sounds as the air flows out of the outlets.The linear air diffusers however does the opposite of regulating air out of the hall. These noises are caused by the small opening of the vents that restrict the airflow from the aluminium panels.
Figure 4.2.4 (a) Some AC diffusers in the theatre badly in need of maintenance create a continuous buzzing sound.
Backstage activity Figure 4.2.4 (b) Section showing the source of noise from backstage and mechanical ventilation.
Figure 4.2.4 (c) The circular grills on the floor that were previously seat holders now serve as vents that open to below of the secondary seating or orchestra stage. Slight whooshing noise can be heard at times because of the hollow space below.
4.3 NOISE CONTROL METHODS To better tackle the issue of noise is best to understand how noise can be reduced. Background noise can still occur but may be acceptable at specified values for certain spaces as seen in the table given below. There are two main ways in which noise can be reduced: sound absorption and sound insulation. The absorption of direct, reflected and reverberated noise in the receiving room can be absorbed to an extent by the materials used in the room. Insulating noise however, is defined as reducing the energy that is travelling into an adjoining airspace.
Figure 4.3 Recommended background noise levels.
4.3.1 Suppression of Noise at the Source One of the basic methods is to have the audience to switch off their mobile phones and other electronic devices as well as to refrain from making noises during the show. Staffs and backstage operations should make preparations at a quieter pace. Furthermore, the location of the theatre is also surrounded with buffer spaces that help serve as a barrier to keep noise away from the theatre.
Figure 4.3.1 As the barrier is closer to the receiver, the more efficient noise can be controlled as refractive atmospheric effects is not present.
4.3 NOISE CONTROL METHODS 4.3.2 Mechanical and Electrical Design
Figure 4.3.2 Design of air conditioning units in Istana Budaya.
Istana Budaya has also installed HVAC systems that do not produce too much noise. Circular and linear diffusers are set to low power so that the audiences can feel comfortable and yet also reduce noise of high pressure air being forced out of the smaller openings to inaudible levels. Regular maintenance is done as well to ensure that they do not produce defective noises.
4.3.3 Architectural Design Quiet and noisy quarters are also grouped and separated from each other horizontally and vertically. This is done by using compartmentalisation of using hallways and corridors as sound buffers. The noise from the pre-function area where people would gather outside of the theatre is separated between two doors and a corridor. This sound lock diffuses the external noise from coming into the theatre space as the doors are closed.
Figure 4.3.3 Design of spaces and sound locks present in the building.
4.3 NOISE CONTROL METHODS 4.3.4 Noise Absorption Besides that, the noise level in the theatre is further reduced by the use of sound absorptive treatment such as soft carpets and seating. Minor noises such as people walking, shifting seats can be absorbed into the soft surfaces to prevent from interfering with the audienceâ€™s attention during a performance.
Figure 4.3.4 (b) A diagram illustrating the absorption of noise.
Figure 4.3.4 (a) Use of soft surface materials such as carpets and cushions.
4.3.5 Sound Insulation Sound Transmission Class (STC) of certain materials or construction types are also able to come into effect in noise control. This is seen in the heavy drapery that has high STC rating blocking the noise produced in the backstage. The walls, floor, doors and partitions inside the Istana Budaya theatre have high STC rating to stop the unwanted sound or airborne noise to reach the audience's ears when the performance is going on.
Figure 4.3.5 Backdrop of the stage in the theatre.
5.0 COMPARISON OF ISTANA BUDAYA AND DEWAN FILHARMONIK PETRONAS Istana Budaya
Dewan Filharmonik Petronas
13300 m³ to 18975 m³
Tilted ceilings and wooden wall panels are commonly used in the auditorium to reflect sound.
The gently arched perforated metal ceiling allows sound to travel to the upper ceiling, which consist of seven movable ceiling panels to control the volume in the hall, stimulating a wide range of acoustical experience.
Different types of materials are used in the auditorium for sound absorption.
Year of Built
Prevention of noise intrusion
Movable acoustical wall at backstage. Adjustable absorptive sidewalls adjust the resonance.
Both auditoriums has a sound lock room which includes carpeted flooring, soft door closer and fabric finishing on half of the wall to reduce and separate the noise that enters into the auditorium. -
Coffers Geometrical balcony Irregularity shapes of ornamentation
The theatre is noise insulated by using high Sound Transmission Control rating materials such as the double timber wall panels, soft carpet material compared to timber flooring of Dewan Filharmonik Petronas.
Convex surface of balcony Wall surface of concert halls
The hall sits on resilient pad and is surrounded by two concrete wall separated by an isolation joint.
5.0 COMPARISON OF ISTANA BUDAYA AND DEWAN FILHARMONIK PETRONAS Istana Budaya
Dewan Filharmonik Petronas
Sound Reflection Diagram
Despite of the difference in shape of the auditorium, both the auditoriums have implemented architectural acoustical design through different acoustical elements such as sound reflection, sound absorption, sound diffusion and other audio aspects. Both auditoriums have fulfilled its purpose of being an auditorium for musical performances.
6.0 CONCLUSION Upon completion of this project, we have learnt a lot on the different characteristics that can affect the acoustic performance of an auditorium. The layout of the auditorium, materials used for the interiors and many other factors play a large role in determining the acoustic quality of an auditorium. Music consists of a wide range of sound levels and frequencies all of which must be heard for a full appreciation and enjoyment of any performance. Some desirable qualities of music depend on the listenerâ€™s judgement and taste but overall, the shape and volume of the floor used , audience capacity and surface acoustical treatment all contribute to the transmission path and receiver sequence. Based on our analysis, the materials used for the interiors of the auditorium is suitable as it has achieved a reverberation time of the Panggung Sari is 1.7 seconds, which is considered as an acceptable acoustical quality for a large auditorium like Panggung Sari as music is always used during performances. The reverberation time plays an important role in auditoriums as establishing a carefully controlled reverberation time would increase fullness of tone and help in loudness, definition and diffusion of sounds. Balconies in the auditorium are also designed to be 1.5 meters wide in order to achieve uniform quality sound over the entire seating area. Although the reverberation time of the auditorium is long, echo is noticeable at a point in the auditorium. Besides, time delay was calculated at different part of the auditorium and all of them fall within the acceptable range, which is within 100ms where no sound echo occurs. In conclusion, this auditorium is more suitable for musical performances compared to plays, dramas, speeches and other events that involve communications.
7.0 REFERENCES Book Stein, B., Reynolds, J., & McGuinness, W. J. (1992). Mechanical and electrical equipment for buildings. New York: J. Wiley & Sons.
Ebook Reid, E. (2016). Understanding buildings: A multidisciplinary approach. London: Routledge. Barron, M. (2010). Auditorium acoustics and architectural design. London: Taylor & Francis.
Website Mominzaki Follow. (2014, April 07). Auditorium Acoustics. Retrieved from https://www.slideshare.net/mominzaki/auditorium-acoustics-33230112?qid=5bbf6ce8-70d6-4301-ba76-49 6fea0369d1&v=&b=&from_search=4 Acoustic properties of wood. (2014, January 09). Retrieved from https://www.woodproducts.fi/content/acoustic-properti DIY. (n.d.). Sound Insulation. Retrieved from https://www.diynetwork.com/how-to/rooms-and-spaces/floors/soundproofing-a-floores-wood Istana Budaya. (n.d.). Retrieved from http://www.istanabudaya.gov.my/ Malaysian National Theatre, Istana Budaya - Data, Photos & Plans. (n.d.). Retrieved from https://en.wikiarquitectura.com/building/malaysian-national-theatre-istana-budaya/ Architectural Acoustic & Design Archives. (n.d.). Retrieved from https://www.soundzipper.com/blog/category/architectural-acoustic-design/ DEWAN FILHARMONIK PETRONAS. (n.d.). Retrieved from http://mpo.com.my/dewan-filharmonik-petronas/ Of Dewan Filharmonik Petronas, Malaysia - ANZAScA. (n.d.). Retrieved from http://www.bing.com/cr?IG=1CA52FB6EE484BD89011F201DCADF4EC&CID=33CF7C4508836CD819B877A D092C6D0F&rd=1&h=RVU8qw4ua4Oi5pW8Z519ZNfUAZI4TpIbndogwt8gL-w&v=1&r=http://anzasca.net/wpcontent/uploads/2014/08/ANZAScA2004_Husin.pdf&p=DevEx.LB.1,5543.1 Dewan Filharmonik PETRONAS. (n.d.). Retrieved from http://dfp.com.my/#