Building Science II Report-Ilovepdf-Compressed
Building Science II Report-Ilovepdf-Compressed
Building Science II Report-Ilovepdf-Compressed
PROJECT 1
Auditorium : A Case Study on Acoustic Design
Group Members:
Angela Wee Kah Man 0322970
Cha Yun Xian 0322048
Cham Zheng Chee 0322317
Chan Koon Qi 0322000
Chia Keh Chian 0322062
Chin Shee Wei 0322499
Kok Xuan Ying 0322929
Michelle Wong Sook Yin 0322362
Tutor:
Mr. Edwin Chan Yean Liong
TABLE OF CONTENTS
1. Introduction 2
1.1: Aim and Objective
1.2: Site Introduction
1.2.1 Historical Background
1.3: Architectural Drawings
1.3.1 Plans
1.3.2 Sections
2. Literature Review 9
2.1 Acoustic in Architecture
2.2 Sound Intensity Level (SIL)
2.3 Reverberation, Attenuation, Echoes and Sound Shadow
2.4 Issues of Acoustic Design Strategies
3. Methodology
3.1 Equipment
3.2 Data Collection Method
4. Acoustical Analysis 15
4.1 Auditorium Design Analysis
4.2 Materials
4.3 Sound Source
4.4 Acoustic Treatment and Components
4.5 Sound Propagation, Related Phenomena
6. List of figures 59
7. Reference 62
An auditorium is a special room built to enable an audience to hear and watch performances at
venues, such as theatres and music halls. Auditorium can be found in entertainment venues,
community halls, and theatres, and may be used for rehearsal, presentation, and performing arts
productions. Apart from entertainment, an auditorium also used for a space for speech delivery such
as lecture theatres. A successful design of auditorium muchly depends on its acoustic design which
include the auditorium layout plus absorption materials used. It is essential to preserve and enhance
the desired sound and to eliminate noise.
This project aims to prepare students for the study of practical and effective auditorium designs
from auditorium layouts to choice of materials that will affect the acoustic properties in an
auditorium.
In a group of 8, a site visit had been carried out with objectives stated below:
1. To study the design of KLPAC auditorium through its layout and, analyse and deduct a
conclusion on the effectiveness and ideality of the acoustic properties found in KLPAC
auditorium.
2. To conduct effective on-site experiment and study general acoustic characteristics of an
auditorium hall for deeper understanding of the physics behind their functions.
3. To be able to produce a well-documented report that comprises all findings and analysis
through the case study.
Kuala Lumpur Performing Art Center (KLPAC) by Ar. Baldip Singh and Ar. Ng Sek San,
also known as Pentas Seni Kuala Lumpur is situated on Jalan Sultan Azlan Shah, Sentul, 51100
Kuala Lumpur, Wilayah Persekutuan Kuala Lumpur. Ever since established in month of May year
2004, the performing art center holds various of events of different genres including Drama,
Musical, Lecture, Dance, Film Screening, Participatory, Workshops, Traditional Performance as
well as Press Conferences and Opening Ceremonies. The center opens 7 days a week all year long
with no exception of public holidays from 10 in the morning around the clock. The overall
Performing Art Center is well equipped with multiple functional and public spaces such as Theatre
1 (Pentas 1; our focal auditorium), Theatre 2 (Pentas 2) which holds smaller events for smaller
expected crowds, Indicine which provides less acoustic enhancement for press conferences as well
as small opening ceremonies, sound chamber, resting room, lobby (foyer), cafeteria and last but not
least, Studio 5 which is equipped with full length studio mirrors and often used as a rehearsal room.
One of the most prominent features of Kuala Lumpur Performing Art Center is its external
facade and integration with an old building. “... Looks like a new structure, with today’s material,
riding on a building that was there yesterday.” quoted from Ar. Baldip Singh, the architect of
KLPAC is nonetheless the perfect description of the performing art center as it was originally a
wood crafting workshop and a sawmill back in the 17th centuries and part of the sawmill is still
preserved until today. In the 1900s, the building converted to a railway depot and workshop for the
trains, old National Railway (KTM) warehouse in YTL Corporation’s Sentul West. Unfortunately,
World War II broke out right after, transforming leaving scars and marks of the tragedy on the
masonry walls in the form of bullet holes. However, in the 1960s the building was left untouched
but functioned as a Golf Clubhouse for a brief moment.
Other relevant news that occurs in the near future, in 1995, Faridah Merican and Joe Hasham
first privately owned and operated a theatre in Malaysia, an underground theatre below Dataran
Merdeka, The Actors Studio at Plaza Putra, which unfortunately was inundated and destroyed by
flash floods in the year of 2003. It was out from the tragedy that the KLPAC was born from the
helding hands of The Actors Studio, YTL Corporation and Yayasan Budi Penyayang.
In the search of a new space, Ar. Ng Sek San was the one who initiated and invited Faridah
and Joe to visit the old National Railway (KTM) warehouse. Soon after, in the event of fundraising
event Banjir, Datin Paduka Seri Endon Mahmood (chairman of Yayasan Budi Penyayang) was
informed about the potential space and mentioned The Actors Studio’s interest in the old warehouse
when she met Tan Sri Francis Yeoh of YTL Corporation.
Malaysia’s first fully-integrated arts centre and a non-profit organisation launched in the
May of 2004 to grasp the attention of media and arts community. The Center opened it doors for the
very first time on date 9th of May 2005 and had been operating to date.
However, the 13 years old Performing Art Center risks closure after facing financial struggle
back in 2012 as well as in the year 2017 to date, as it is a non-profit organisation that only charges
rental from events to fulfill most of the operational costs and maintenance fees. Kuala Lumpur
Performing Art Center management priotises production against business.
Acoustics is the term used to describe the "science of sounds". It deals with the study of all
mechanical waves in matters such as gases, liquids and solids. Sound, however can be defined as
vibration in an elastic medium, or any solid object that can return to its normal state after being
deflected.
Architectural acoustics is concerned with control of sound in a space to provide the best conditions
for the production and the reception of desirable sound and to exclude unwanted noise. By
researching into new methods for measuring and predicting how sound transfers within rooms and
buildings, this enables us to develop innovative ways to design rooms and building elements.
Sound propagates outwards from a point source in a spherical wave front. During their propagation,
sound waves can be reflected, refracted, diffracted or attenuated by the medium. Sound reflection
occurs when sound waves bounce off a surface. When sound waves encounter a concave surface,
the reflected sound is concentrated in one direction. When strike on convex surface, reflected sound
tend to disperse in multiple directions. Sound reflection leads to echoes and reverberation. It can be
used in room acoustics to distribute and reinforce sound.
Refraction of sound occurs when waves undergo a change in direction as they pass from one
medium to another, as sound waves travel at different speeds in media of different densities.
Refraction, or bending of the path of the waves, is accompanied by a change in speed and
wavelength of the waves.
Diffraction involves a change in direction of waves as they pass through an opening or around a
barrier in their path Diffraction of sound waves commonly occurs; ; we notice sound diffraction
around corners or through door openings, allowing us to hear others who are speaking to us from
adjacent rooms.
Sound attenuation is a measure of the energy loss of sound propagation in media. i.e loss in intensity
. Most media have viscosity, and are therefore not ideal media. When sound propagates in such
media, there is always thermal consumption of energy caused by viscosity.
Sound intensity is a standard scale used to measure sound pressure, it is defined as the rate of sound
power flow across a unit area. The usual context is the measurement of sound intensity in the air at a
listener's location. The basic units are watts/m2 or watts/cm2. This span makes the absolute value of
the sound intensity impractical for normal use hence the sound intensity of 10-12 Watt/m2, the
lowest human hearable sound is used as the reference level.
Sound reverberation refers to the persistence of sound reflection after the sound source ceased. It
has both positive and negative effect in architectural design. For instance, specifying highly
reflective ceiling panels directly above the stage area in an auditorium will help direct the sound
towards specific seating areas, improving the acoustical performance in the room. However, the
reflectivity turns into a negative factor if reflective materials are installed in the wrong position.
Subsequently, it affects the overall acoustical performance as distracting echoes will be created.
When sound travels through a medium, the intensity diminishes with distance. In idealized
materials, sound pressure is only reduced by the spreading of the wave. Natural materials, however
all produce an effect which further weakens the sound. This further weakens results from scattering
and absorption. Scattering is the reflection of the sound in directions other than it's 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 known as sound attenuation.
An acoustic 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 acoustics shadow occurs behind a building or a sound barrier. The sound
from a source is shielded by the obstruction. Due to the diffraction around the object, it will not be
completely silent in the sound shadow. The amplitude of the sound can be reduced considerable
however, depending on the additional distance the sound must travel between source and receiver.
Acoustical conditions in an enclosed space is achieved when there's a clarity of sound in every part
of the occupied space. For this to occur, the sound should rise to a suitable intensity everywhere
with no echoes or distortion of the original sound, and with a correct reverberation time. This; these
acoustical defects in buildings are important to recognize, diagnose and rectify.
Acoustical reflectors or diffusers are implemented to evenly distribute the sound and to avoid areas
where the sound quality is either weak, too excessive or cannot be heard clearly. Acoustic diffusion
or sound reflection helps to provide a wider sound coverage for speech & music, and are often used
to improve speech intelligibility and clarity in theaters, assembly halls, auditoriums, recording
studios and classrooms. In addition to this, reflectors and diffusers are used to effectively reduce
interfering reflections in any one direction by distributing the sound more evenly across the space.
3.1 Equipments
a. Photography Devices
Digital camera and smartphones ares used to capture images of the auditorium environment,
including details such as the finishing materials of walls, floor, ceiling, seatings, etc. and
also the acoustic installation on site and its conditions. The images will later be used as
references and supporting elements to develop our analysis.
b. Measuring Devices
A 8m measuring tape is used to measure small measurements such as the distances between
each seats and thickness of the acoustic panels, whereas laser distance measurer is used to
obtain large measurements such as height of ceiling and walls distances. These
measurements will later be used for drawings and calculation purposes.
A digital sound level meter is used to measure the sound level from a particular point within
the auditorium. The unit of measure is decibels (dB).
In order to achieve first-hand experience, formal arrangement were made prior to the visit to ensure
that the auditorium would be unoccupied and allowing us to conduct a thorough investigation
without disturbance. With the help of all preceding tools above, we collected as many datas as
possible, including the auditorium’s layout, noise sources, furniture materials and notable acoustic
components. Measurements of the auditorium were also taken for drawings and calculation
purposes, along with on-site sketches of the floor plans and sections for supporting any analysis.
The auditorium has a height of 12m where the spreading of sound should be limited to ensure the
concentration of sound. It implies the use of all necessary surfaces in the auditorium being equipped
with effective sound absorbers and diffusers to maximize the acoustic efficiency.
Figure 4.1.1: The theater of a rectangular shaped space with sound absorbing materials lined along the walls
Figure 4.1.2.1 : The theater form of an “end stage” where the audience seats descend to the stage
The furniture seating arrangement and audience plays a highly active role by diffusing the sound,
thereby making existing physical sound absorbers and diffusers even more efficient.
Figure 4.1.3: The fan-shaped seating arrangement that accommodates 504 seats
Figure 4.3.1.1: Significant noises produced by performers and sound equipment such as the speakers, crucial to be used
to facilitate its main event.
The sound system that were incorporated as part of the primary sound source functions to:
a. Emphasize and bring clarity to low-frequency range sounds
b. Amplifies the sound in order to reach out to a huge crowd of audience.
c. Ensure minimum sound reverberation.
The sound system arrangement that was implemented in the theatre was centralized positioned
system, which individual loudspeakers were being placed over the source of the sound. This
particular system was able to achieve a realistic effect with its practicality-based positioning of its
system that was facing similarly with the sound source direction.
A total of ten speakers were located above the front of the stage. There were two speakers that can
be found located at the center, which are positioned vertically at a 30 degree angle facing the
audience seating area.
An addition of 2 pairs of speakers, with each pair positioned on both sides of the front stage. The
speakers were placed horizontally above one another, facilitating in the formation of a concave
projection in sound waves towards the audience.
The control room and control panels were located at the top-most position of the ascending audience
seating.It was used to control and carry out adjustment of the loudspeaker based on each varying
event’s specific requirements through the processor.
Figure 4.3.1.3: Speaker volume were adjusted based on its range in propagation of sound waves.
In some productions, a stereophonic system is required, which includes two or more clusters of
loudspeakers added around the proscenium opening or both sides of the audience seating. This
system is able to establish a three-dimensional sound effects, creating realistic environment,
enhances the illusion of sound beyond its stipulated positions.
Figure 4.3.1.4: The number and placement of additional speakers is solely driven by the type of production and the
budget of the production team.
Placement:
Wall / Ceiling
Frequency Response:
200Hz
Placement:
Ceiling
Table 4.3.1.1: Specification of the types of sound source.
In the theatre, there were three types of secondary sound source that were identified:
a. AC vents can be found located at the right side of the backstage above the chiller room.
b. Air Handling Unit (AHU) located at the left side of the top-most position of the ascending
audience seating, behind the walls.
c. The spotlights positioned above the centre stage.
The activation of motors and travelling air at the vents initiates low frequency sounds that
contributes to unwanted background noise during performances and it may be distinctly heard when
there is stillness in the theatre.
Light fixture such as spotlights produced a light buzzing sounds when being switched on take part
as form of secondary sound source. Its sound doesn’t have a major effect towards the performance
due to its minimal sound.
Figure 4.3.3.1: Audience movement in the theatre contributing to tertiary sound productions.
The theatre is situated away from environmental factored sound sources. There was an absence in
vehicular movement near the auditorium, or sound pollutants from constructions. The location is
considered an optimum environment that fits the purpose as a performing stage.
The tertiary sound source that was identified is in minimum and produced mainly by the audience.
A variety of audience movement, such as walking steps entering and exiting the theatre, adjustment
in seats and small chatter contributes to the tertiary sound waves produced in the theatre. However,
these sounds can be controlled by utilizing the opportunity during intermissions to remind the
audience, keeping them aware and decreasing the production of tertiary sounds, avoiding the
disruption towards the performance.
The performing stage is the main source of sound in the auditorium as additional speakers are rarely
used. As sound waves are produced from the stage, the sound waves travel across the auditorium
towards the direction of the walls. Thus, the auditorium walls are covered with sound absorbent
materials to reduce the reverberation time in the auditorium and percentage of creating an echo.
These sound absorbing materials absorb and soften the sound waves produced from the stage area,
resulting in a better performance experience in the audience.
Figure 4.4.1.1 (left): Sound waves produced from the stage travel towards the direction of the walls
Figure 4.4.1.2 (right): Sound absorbing materials located along the walls to absorb sound wave
Figure 4.4.1.3: Sound waves hitting the concrete’s porous surface, converting it into heat energy which is absorbed by
the concrete
Therefore, painting or plastering porous concrete increases its sound insulating characteristics yet
reduces sound absorption. In the theater, a special paint is layered on the concrete wall to close the
pore openings without decreasing the sound absorption capability. The paint is thinned to extend
before applied across the concrete wall preventing a dense deposit of film across the surface yet
sufficient to reduce noise from the exterior.
Apart from the concrete walls, material sustainability and reusability is highly kept into
consideration in the application of materials in KLPAC auditoriums. Most of the finishes, acoustic
materials and components in Pentas 1 are made of reused materials from the building’s historical
past as a railway station that includes original materials that have lasted from before World War II.
Figure 4.4.2.1 (left) & Figure 4.4.2.2 (right): The arrangement of PVC tubes along the wall
One of the two wall finishes are of PVC tubes that extend all the way to the ceiling. These PVC
tubes are remnants from the previous building and they play a role in terms of acoustic sound
reflection and absorption.
Figure 4.4.2.3: Sound waves from stage is mostly reflected by PVC tube along one side of the wall
The surface of the tubes are convex shapes and the PVC tubes is filled with sand. When a direct
sound hits the tube, the tube reflects the soundwaves and distribute the sound equally to the
Figure 4.4.2.4: Direct sound hitting the tube where the sound is equally distributed to the audience
The PVC tubes are aligned in a similar pattern where it begins and ends with shorter tubes whereas
the middle tubes are longer. The variation in PVC tube lengths help in reflecting sound waves
depending on the direction and frequency of sound waves from the stage. The concrete wall behind
the PVC tubes help absorb remaining sound waves.
The wall on the opposite side of the auditorium is covered with corrugated zinc sheets and wooden
blocks. These components are also used in sound absorption of sound waves from the stage.
The corrugated zinc metal sheets are reused form the roof of the railway station where the surface of
the metal is corrugated with a mix of concave and convex surfaces. Corrugated sheets are used to
increase audibility in noisy environments as well as reducing the level of noise from nearby spaces.
This allows the material to act as a good sound absorber where the surface is larger to absorb more
sound waves.
Figure 4.4.3.1: Sound waves from the stage is absorbed by the zinc metal sheet
Figure 4.4.3.2 (left): The zinc metal sheet is located on the upper part of the wall
Figure 4.4.3.3 (right): Zinc metal sheet location in the theater
Figure 4.4.4.1 (left) : The wooden blocks are located on the lower part of the wall
Figure 4.4.4.2 (right) : Wooden blocks location in theater
The wooden blocks in the auditorium are of a lightweight wood property which despite their poor
strengths, they are well suited as good sound reflectors. The efficiency of wooden blocks as sound
reflection is not 100% which results in a small percentage of scattered sound waves being absorbed
after hitting the block. Additionally, the wooden block’s smooth surface helps to dampen sound.
However, when the sounds are unable to reflect, they are scattered as they hit the wooden blocks
and then absorbed by it. Therefore, the wooden blocks help diffuse high frequency sounds.
Figure 4.4.4.3: Sound waves from the stage are absorbed by the wooden blocks on the opposite side of the wall
Figure 4.4.5.1 (left): The composite timber flooring location (stage area)
Figure 4.4.5.2 (right): The carpet flooring location (audience floor)
The composite timber flooring is composed of recycled wood and an additional layer of polymer
coated with a layer of black paint. This layer of composite timber flooring is an acoustic deck
overlay system designed to reduce sound transmission through existing timber and new concrete
floors. It is the simplest way of improving the airborne and impact sound performing of an existing
floor is through this method of overlaying the floor with an acoustic isolation layer of a new hard
wearing surface.
When necessary, central circular mics are added on the stage floor. This allows performers to
produce the best sound quality for the audience.
Figure 4.4.5.3: The stage and backstage which composite timber flooring
This helps reduce the noise of audience entering and exiting the auditorium or the moving of
furniture and equipment. Sound waves produced from these actions are absorbed into the carpet
instead of being reflected on the surface. Additionally, when carpets are used, background noise
disappears, speech comprehensibility increases and the audience automatically speak in a sofer
voice as the entire space is quiet. This prevents the audience from generating louder noise by trying
to make themselves heard above the surrounding sound.
Figure 4.4.5.4 (left) & Figure 4.4.5.5 (right): Covered carpet floor in the audience seating zone
The auditorium chairs are the tip-up type which creates minimal noise when in use. The seat
material determines the auditorium’s sound quality where each chair is covered with a sound
absorbing fabric. This controls the unoccupied reverberation period of the space, ensuring that the
presence or absence of audience will not affect the reverberation time.
The brick wall present in the backstage has been preserved from the old railway station is part of the
auditorium and plays a part in the acoustics. The brick wall is preserved as its thick and dense
material characteristic helps block sound waves from passing through into the auditorium. This
structural mass is the best defence against noise penetration which prevents external sound from
entering the auditorium. Thus, the brick wall helps minimize noise that will distract the audience or
performers present in the auditorium.
Figure 4.4.7. (left)1: The painted brick wall separating the exterior and interior of Pentas 1
Figure 4.4.7.2 (right): The brick wall that partially separates the audience from the stage
The brick size affects the insulation property where the thicker the brick, the more challenging it is
for sound waves to pass through. As the brick wall in the auditorium is old brick from the era before
World War II, it is relatively thick which allows the auditorium to less likely hear sounds from the
exterior side of the auditorium.
Due to its insulation property, as direct sound waves hit the brick wall, it is unable to absorb the
sound waves and instead the sound waves bounces off to the surrounding. Therefore, to prevent
sound wave leakage from penetrating the auditorium, the brick wall is constantly maintained and
has a layer of black paint over the raw material.
The blackout curtains in the auditorium are velour curtains which are located on stage where it acts
as a determinant on the required stage depth and where the stage ends. These acoustic fabric
curtains is a composite of a fire resistant wool fabric that is sandwiched between a decorative fabric
and a blackout liner. It separates the stage area from the backstage and also acts as sound absorbers.
The thick and heavy velour curtain plays a large part in absorbing excessive sound. Although the
curtains do not completely insulate the sound between both spaces, it helps improve the sound
quality and helps reduce the reverberation level of the theater.
Figure 4.4.8.1 (left) & Figure 4.4.8.2 (right): Velor curtains located in the backstage
Figure 4.4.9.1: Sound waves travelling from the stage to the ceiling
The ceiling is a wrapped black fabric that envelopes and additional gap of air space in the ceiling. It
is located above the audience seats which prevent sound from escaping the auditorium and it
absorbs noise. The additional air space lowers the impact on solids which prevents sound reflection
in large areas as well as controlling different frequencies. The material increases the sound quality
for the audience as well as contributing as a flexible and architectural design.
Figure 4.4.9.2: The ceiling where the black fabric wrapped ceiling is located above curved ceiling structures (that have
no part in acoustic performances)
Figure 4.4.9.3: Corrugated zinc metal sheets which lines the ceiling
Figure 4.4.10.2: Sound waves travelling from the stage to the rear acoustic wall panels
Figure 4.4.10.3 (left) & Figure 4.4.10.4 (right): Acoustic wall panels located in behind the auditorium in Pentas 1
The measurement of the sound intensity level (SIL) from the sound source show that there is a
distinct sound concentration zone can be found at the centre of Pentas 1 with the reading of 49dB.
The SIL readings are high at the front right of Pentas 1 due to the location of the speakers located on
top of each respective sections resulting in amplified sound in the specific area.
Sound from the speakers are more intense at the direction they are pointing at, which in return cover
its own area that overlap over another. This results audiences sitting in the darker area in the
diagram to receive a higher sound amplitude which is recommendable to sit (fig 4.5.1)
Figure 4.5.1.2 Sound path and reflection from sound source on the stage
On the other site, seats in the corners of front right and left side of the hall (fig 4.5.1.1) is nearby
walls of diffusion walls. However, these diffusion walls reflect certain incident of sound
simultaneously whereby audiences get distracted while receiving direct sound from the stage.
Horizontal shape of plane walls reflects sound ray at constant angle under law of reflection. This is
not efficient way of dispersing sound and does not promote concentration of sound efficiency.
Figure 4.5.2.1 Shows the distance of the audience from the sound source starting from front, middle to back rows
The highest incident of sound amplitude with louder volume will be received by audience that
sitting in the front row as they are nearer to the sound source.Meanwhile, a moderate incident of
sound amplitude and volume will be received by the audience who is sitting in the middle
rows.Lastly. the lowest incident of sound amplitude will be received by the audience that is sitting
in the last row as they are the furthest from the sound source.
As absorption materials are placed throughout the hall to absorb excess sound energy, reducing the
amount of acoustic interference, it helps maintaining an optimum reverberation time for
multi-purpose hall. Refer to topic 4.4 for location and details of absorption materials.
Figure 4.5.4.1 Sound hitting the diffuser and being reflected back in many different directions
Figure 4.5.4.1 explains how sound diffusion can be achieved with the help of surface scattering and
irregularities elements. Sufficient sound diffusion is essential in many types of rooms in order to
promote uniform distribution of sound,emphasize the natural qualities of music and speech and
preventing the occurrence of unpleasant acoustical defects. Unlike absorption, instead of absoard
sound energy as the act to preserve the liveliness of the room, the diffusers disperse it, spreading the
energy around the room.A sound diffuser is an acoustic panel used to treat echoes and reflections. A
diffuser jumbles up these reflections to avoid reflected sound from returning back into the room
directly or having echoes.
Figure 4.5.4.3 How sound travels within Pentas 1 thus amplifying the sound at right side of the hall
Figure 4.5.4.4 Horizontal and vertical planes scattered the diffused sound in different directions
An idea acoustic diffuser is a surface that causes an incident sound wave from any direction to be
evenly scattered in all directions. Having the same function as skyline diffuser, they are able to
scatter sound across two planes horizontal (left & right) and vertical (up & down). This
two-dimensional scattering broadens the soundscape and provide greater distribution of amplitude
of sound.
The diffusion panels are placed along the side walls of Pentas 1 all the way up high to reduce
echoes.
The PVC hollow pipes are arranged closely together leaving a small gap (highlighted in figure
4.5.4.7) in between to allow sound at certain frequency to be dispersed into many direction when
hitting the convex surface of the hollow pipes to provide better sound quality, especially to the right
side of the hall.
Figure 4.5.4.8 Shows the sound scattered after hitting the planes
When the sound is reflected from convex surfaces, the geometry of the surface will push back the
energy to disperse outwards and encourage uniform distribution of sound.
Trajectory of sound waves should be properly planned to allow better experience in a theatre.
Reflection of sound is one of the most common way to traject sound waves efficiently to audience
all across the theatre. Refer to topic 4.4 for location and details of reflector materials.
Pentas 1 uses straight parallel walls with diffusers to reflect sound waves against the walls towards
its audience. From the diagram, reflected sound are concentrated at the middle portion of the theatre
as compared to other areas. Sound absorbing materials are also strategically placed at the back of
theatre to absorb excess direct and reflected sound waves and prevent sound spill to adjacent spaces.
Pentas 1 utilises a flat horizontal ceiling that span halfway through the theatre to reflect sound
waves to the back of audiences. Reflection of sound waves is uniform throughout a horizontal
ceiling but there are limited amount of short delayed reflections from the sound source, resulting in
lesser reflected sound towards further back audience.
For front row audience, reflected sound is mostly insignificant as they’re exposed to great amount
of direct sound from the sound source whereas for audience sitting in middle and last back rows,
they receive indirect sound reflected from the ceiling.
There are two kinds of sound that reaches the audience, direct and indirect. The indirect source of
sound reaches audience through reflecting from the surfaces of the hall, also known as echoes.
Echoes travel longer distance than direct sound resulting in sound delay.
The hall’s main function is for live performances, such as musical, concert & live acting, which
categorizes the hall as a multipurpose hall. The echoes reinforces the direct sound if the delay
duration is less than 30ms.
500Hz
Category Surface Area (m²)
Absorption Abs. units (m²
coefficient sabins)
Conclusion
For a large multipurpose theatre catering mostly for performance like Pentas 1, a reverberation time
of 1.0-2.0s is optimum. The reverberation time calculated falls under the recommended
reverberation time and this shows a proper balance of absorption and reflection to provide a
favourable acoustical environment suited for large scale production such as musical, concerts and
big dramas.
The Kuala Lumpur Performing Art Center (KLPAC) building repurposed an existing building to its
current form. But due to budget constraints, the hall did not reach its full potential as they did not
modify the ceiling for acoustic purposes. The current design causes limited sound bounces off the
catwalk and others are absorb by the fabric above. This acoustic defect prevents the hall from
achieving a more appropriate reverberation time, resulting in the sound losing its richness as it
travel further towards the back of the hall.
Kuala Lumpur Performing Arts Centre (KLPAC) establishes theatre spaces that functions to cater
an optimum condition that best accentuates the quality of sound within the auditorium.
The layout of the auditorium is fanned outwards and run parallel along towards the back. In
addition, acoustical elements such as the wooden blocks and PVC tubes that were attached against
the wall, were elements to reflect sounds within the internal spaces and negates fluttering echoes
effect. One of the aspects that were lacking of in KLPAC’s auditorium is the emphasis towards
concentration in sound. This can be achieved by improving and innovating the ceiling design.
The existing elements on the ceiling weren’t contributing in enhancing the direct sound source,
preventing the hall from reaching its full potential. The huge amount of absorber material also
reduces the acoustical quality.
By improving the ceiling design, the reverberation time can be increased to a more optimum level
for the hall usage, increasing the richness of the sound reaching the audiences. The ceiling is able to
be manipulated to change the hall’s volume, to accommodate even more variety of performances.
By changing the arrangement of the ceiling, the reverberation time can be adjusted to cater to
specific kinds of performances, enhancing each performances for the audience to experience.
1.0 Introduction
1.3: Architectural Drawings
1.3.1: KLPAC Pentas 1 Ground Floor Plan 1:200
1.3.2: KLPAC Pentas 1 First Floor Plan 1:200
1.3.3: KLPAC Pentas 1 Second Floor Plan 1:200
1.3.4: KLPAC Pentas 1 Ceiling Plan 1:200
1.3.5: KLPAC Pentas 1 Section NTS
3.0 Methodology
3.1 Equipments
3.1.1: Digital Camera
3.1.2: Smartphone
3.1.3 Measuring Tape
3.1.4: Laser Distance Measurer
3.1.5: Bluetooth Speaker
3.1.6: Digital Sound Level Meter
5.0: Conclusion
5.1: Improvement in ceiling design, such as concave shaped ceiling.
Online Publishing:
1. Absorption Coefficients. Retrieved on May 3 2018, from
http://www.acoustic.ua/st/web_absorption_data_eng.pdf
2. Chrisler V.L. Effect on Paint on the Sound Absorption of Acoustic Materials. Retrieved on April 30,
from https://nvlpubs.nist.gov/nistpubs/jres/24/jresv24n5p547_A1b.pdf
3. Edwin, Y. (2018) Environmental Noise Control, week 4 notes [PowerPoint Slides]. Retrieved from
https://lookaside.fbsbx.com/file/Lecture%204-%20Environmental%20Noise%20Control%20-March
%202018%20Edwin.pdf?token=AWzI8Vc8b_0SOHlVCwXAdZP1J3oDPHamRPig0kiRK30Eb2xnWS
qfeF0ylbo5WAnWlVtHHJqwLhrYfitkEpeMHElIvgxHjJscw79aLaao3Uj9CACmbTzUAvE-vbs94XTIZ
dcCTJ4xdluXtStPpkc_T2E_
4. Edwin, Y. (2018) Noise & Noise Control, week 3 notes [PowerPoint Slides]. Retrieved from:
https://lookaside.fbsbx.com/file/Lecture%203-%20Noise%20%26%20Noise%20control%20March%
202018%20-%20Edwin.pdf?token=AWxxI_ub1v4Y_4iw0_JjbMKL5fXJqrOrMXyjG9Gr86BdpwjfnIl0
SS1PcbE1BZoEOPBOEKt0hLj0zMtViC1Vje0Jyzdk9AYbtYZw5imuqOL7ESDbUuEFOqbR59NrW0X
B6hQnquSiILN6j1o-ncSKRiL4
5. Edwin, Y. (2018) Room Acoustics, week 2 notes [PowerPoint Slides]. Retrieved from:
https://lookaside.fbsbx.com/file/Lecture%202-%20Room%20Acoustic%20March%202018%20Edwin
.pdf?token=AWz6xTHOguoTxAHpD7OZesrupNzF89dCClTAmfsHKLa3xJ0iM8h1_FE8tKMoTJFf-F
yViUYo6P2NQqONj78S_8pVowWehg7dgCzB-Hy_7zcVH7Ga44y-8hOKexH03FOFX6YJ5gYyjkS84i
Pe54Y5KT3v
6. Knauf, Acoustic Design According to Room Shape. Retrieved on April 29 2018, from
http://knaufdanoline.com/wp-content/uploads/Room-shape.pdf
7. Technical Data Sheet Pentas 1 (KLPAC) (March 29 2018). Retrieved on April 26 2018, from
http://www.klpac.org/wp-content/uploads/2018/04/klpac-P1-TDS-Revised_290318.pdf
Websites:
1. About KLPAC. Retrieved on April 25, 2018 from http://www.klpac.org/about-klpac/
2. Acoustic Deck / Floating Floor Overlay System. Retrieved on May 1, 2018 from
http://www.monarfloor.co.uk/products/traditonal-floating-floor-treatments/monarfloor-deck-9.aspx
3. Jerzy S. Sound Absorption of Wood-Based Materials (April 2015). Retrieved on April 30, 2018 from
https://www.researchgate.net/publication/270895491_Sound_absorption_of_wood-based_materials
5. Theater Solutions. I. Auditorium Design 101: The Complete Guide (2017, March 28). Retrieved on
April 27, 2018 from http://www.theatresolutions.net/auditorium-design/
6. Top 5 Benefits of Sound Absorbing Panels (2017 July 7). Retrieved on May 1,2018 from
http://www.iac-noisecontrol.com/uk/news/latest-news/136-top-5-benefits-of-sound-absorbing-panels/