1. CONNEXION
Case Study on Acoustic Design / Building Science II

2. Connexion Conference & Event Centre ( CCEC) is located in Nexus mall
at Bangsar South, in between Kuala Lumpur, Petaling Jaya and
Bangsar.
The auditorium is designed as a multi-purpose auditorium that is
suitable for different kind of events. The total area is around 1022.77m2
with 298 fixed and cushioned seats. The construction started in the year
of 2012 and was completed in the year of 2014.
Introduction
Background

3. Drawings
Floor Plan & Ceiling Plan
Floor Plan Ceiling Plan
Stage

4. Drawings
Section
Section
Stage

5. Methodology
Data Collections & Equipment
1. Preliminary study on the selected auditorium in Klang Valley.
2. Conduct a site visit to the selected auditorium after receive approval from the campus central.
3. Obtain the technical drawings such as floor plans, sections and elevation.
4. Delegate tasks among group members and clarify on the method of reading data and using the tools before data collection begins.
5. Collect data based on the proper procedures.
6. Observe and record the existing external and internal noise sources.
7. Compile and tabulate the data or reading.
8. Carry out calculation and analysis. Draw a conclusion or recommendations at the end of the analysis.
Data Collection
Equipment
Sound Level Meter Digital Camera Measuring Devices

6. Acoustic Treatment and Components
Design Analysis
Shape & Massing
The design of the auditorium employ a curvilinear form. Concave walls form the left and right sides of the spaces, with one side of shorter length than the other, enclosing
the seating area and stage area. The concave shape configuration hints a poor acoustical design of an auditorium because the concave surface have a tendency to
concentrate the reflected sound wave to the centre of its propagation, creating an undesirable sound foci. As the result, the sound is unevenly distributed to the audience,
the centre region received the loudest sound compared to the other areas.
Therefore, sound reinforcement system is installed in order to provide uniform coverage over the entire seating area. 12 speakers are installed embedded in the ceiling of
the auditorium to ensure.
Figure A: Expected sound path reflected by concave wall in plan view Figure B: Indication of sound reinforcements installed on the ceiling

7. Acoustic Treatment and Components
Design Analysis
The auditorium have a total of 298 foldable upholstered seats. The seat are arranged in a fan shaped configuration, fall within a 140° sound projection angle from the centre
of the sound source on the stage, which is an optimal visual and acoustical region for audience. This seating layout helps to preserve high frequency sounds for the
audience.
Seating Arrangement
Photograph: Seating of the auditorium
Figure: 140° wide layout ensures optimal visual and acoustical
experience for the audience

8. Acoustic Treatment and Components
Design Analysis
Seating Levelling
Sloping floor allows a more direct angle of incidence which in turn allow less
absorption. The sound waves is able to travel towards the furthest seats
without being interrupted or absorbed by objects in front of the seats. The
level terraced seating also provide proper sightlines from the audience to the
stage.
Ceiling reflector panels are included in the design of the auditorium’s ceiling,
forming a staggered ceiling which will direct the sound from the stage to the
seating area by reflection, particularly to the back of the auditorium. Therefore
audience at each of the seating zone from front to back can relatively receive
the same sound quality and equal sound intensity.
Ceiling

9. Sound
Acoustic Treatment and Components
Design Analysis
The auditorium possess adequate sound travel from the stage towards
the audience. In a silent environment, voices originating from the
stage is perceptible at an average level.
Tenants that uses the auditorium typically opts for utilising the sound
system for better vocal clarity. The main speakers are installed around
the framing around the stage, whilst several smaller speakers are
spread across the audience area installed embedded in the ceilings.
Because the ceiling and the audience layout inclines towards each
other at the back, the installation of the sound system becomes
unpleasant at certain spaces, specifically at the back of the audience
area and below the ceiling speaker points.
Sound Concentration
Further looking at the sound intensity
from the sound sources, concentrated
sound areas were discovered in the
centre region of the auditorium. The
cause of the resulted sound
concentration can be tied back to the
curvilinear form of the auditorium that
created a form of auditory focus from the
reflected sound waves which amplified
the sound in the area.

10. Noise / External
Acoustic Treatment and Components
Design Analysis
Filtering out external noise is one of the most prioritised aspects to deal with
for an auditorium. The Connexion Convention Hall experiences multiple
noises that originates mainly from human activities happening from outside
the hall.
Noise / Internal
Noise within the auditorium comes from the mechanical or material features that
occur during events. Entering the auditorium, the overall environment is filled with a
constant and steady noise of the air-conditioning at full blast and the buzzing noise
of the audio system fills the auditorium, and may potentially affect the constant noise
will affect the overall quality of the event.
Stage Audience
The floor of the audience uses a medium pile
carpet finish. The carpet helps to
significantly reduce the noise produced as
they walk or re-adjust themselves in their
seats.
The veneer timber flooring,
produces heavy footsteps when
walked on
Mechanical
Primary Entrance Secondary Entrance

11. Different materials are used in a space to create different textures. In an auditorium, the use of building materials must be chosen carefully as
each material has a different sound absorption coefficient that affects the acoustics of the auditorium.
Materiality
Fibre Panel Absorbers
The fibre panels are soft to the
touch which can absorb sound in
the auditorium.
Interior (House)
Timber Wall Panels
Part of the walls in the auditorium
is cladded with acoustic timber
veneer panelling that has sound
absorbing qualities.
Carpeted Flooring
The carpet is thick and is able
to muffle the sound of footsteps.
Interior (House)

12. Gypsum Plaster Ceiling
The thickness and mass of the
gypsum plaster ceiling resists panel
vibration, which causes low
frequency absorption and to achieve
good reflections at all frequencies.
These doors are heavy and thick,
therefore able to block out some
exterior noises.
Solid Timber Door
Upholstered Tip-Up Seats
Glass Window
Stainless Steel Handrail
The glass has a reflective solar film
on it, giving the glass a greyish black
tint.
Stainless steel handrails are installed
between the stage and the seating
area as well as the side of the
auditorium along the side stairs.
Each seat has a similar sound absorbing
coefficient to a human body.

13. Different materials are used in a space to create different textures. In an auditorium, the use of building materials must be chosen carefully as
each material has a different sound absorption coefficient that affects the acoustics of the auditorium.
Materiality
Interior (Stage)
Interior (Stage)
The plasterboard reduces the
reflection of sound in the stage area,
improving the sound quality in the
auditorium.
The fibre panel absorbers are glass
fibre with woven fabric and micro-
perforated vinyl facings that are
mounted on a frame with 20mm
cavity.
The flooring of the stage is
covered with timber veneer
panels.
Plasterboard with Mesh Fabric
Fibre Panel Absorbers
Timber Veneer Flooring

14. The curtain allows blocking external
noises from entering the auditorium.
Steel deck riggings are installed in the fly loft
above the stage. Steel mesh covers the top of
the steel deck.
Solid timber doors are installed at the
backstage and sealed at the bottom,
preventing outside sound from entering
the auditorium.
Solid Timber Door
Curtains
Steel Deck Rigging
Materiality
Interior (Stage)

15. Materials
Sound Absorption Coefficient
125 Hz 500 Hz 2000 Hz
Fibre Panel Absorbers 0.15 0.75 0.80
Timber Wall Panels 0.18 0.42 0.83
Carpeted Flooring 0.50 0.30 0.65
Gypsum Plaster Ceiling 0.45 0.80 0.65
Solid Timber Door 0.14 0.06 0.10
Upholstered Tip-Up Seats (Vacant) 0.13 0.59 0.61
Upholstered Tip-Up Seats (Occupied) 0.37 0.68 0.77
Stainless Steel Handrails 0.07 0.14 0.14
Glass Window 0.30 0.10 0.07
Plasterboard with Mesh Fabric 0.29 0.06 0.04
Timber Veneer Flooring 0.02 0.05 0.10
Steel Deck Rigging 0.13 0.08 0.11
Curtains 0.05 0.10 0.20
Others
Air (per m3) - - 0.007
Audience 0.21 0.46 0.51
Ventilation Grille (per m2) 0.60 0.60 0.60
Materiality
Sound Absorption Coefficient

16. Sound Path
Sound Reflection
Due to the concave layout of the auditorium plan, the sound are reflected towards the centre causes the audience may heard different volume of sound at different
positions.
Sound reflection diagram A Sound reflection diagram B

17. Sound Path
Sound Reflection
Sound Intensity Level (SIL) measured in the auditorium
From the figures on the left, we can know that the results of the sound intensity level
in the auditorium are considered as comfortable for ears of all audience on seats.
When using the microphone, the sound intensity level is even throughout most of the
part of the hall is because of the speakers located on the ceiling with carefully
designed placement. Except for the centre area due to the concave shape of the
fibre panel walls.

18. Sound Path
Direct / Indirect Sound & Echo
The direct sound produced hit the ceiling which is parallel to the stage
and reflected.
First Row = 5m + 4m - 5m
0.34 s
Flutter Echoes
Distance and direction of direct sound and indirect sound travel towards first row
Sound Travel / 1st Row
Sound Travel / 6th Row
Sixth Row = 5m + 6m - 7.5m
0.34 s
Sound Travel / Last Row
Last Row = 14m + 3m - 15m
0.34 s
= 5.9 m/s
= 10.3 m/s
= 14.7 m/s

19. Sound Path
Reverberant Sound
500Hz
Materials Area(m2) Sound Absorption
Coefficient
Absorption units
(m2 sabins)
Fibre Panel Absorbers 300 0.75 225
Timber Wall Panels 92 0.42 38.64
Carpeted Flooring 200 0.30 60
Gypsum Plaster Ceiling 250 0.80 200
Solid Timber Door 9 0.06 0.54
Stainless Steel
Handrails
2 0.14 0.28
Glass Window 3 0.10 0.3
Plasterboard with Mesh
Fabric
15 0.06 0.9
Timber Veneer Flooring 15 0.05 0.75
Curtains 30 0.10 3
Steel Deck 20 0.08 1.6
Seats (vacant) 200 0.59 118
Total Absorption (A) 649.01
RT = 0.16 V
A
= 0.16 (3780)
649.01
= 0.932 s
Where,
RT = Reverberation Time (sec)
V = Volume of the room
A = Total absorption of room surfaces
Sabine Formula
The volume for the hall is approximately 3780m3, and by using
the formula of calculating the reverberation time, the result is
that the reverberation time for CCEC is 0.932s. This value is
closed to 1s. From the figure above, we can conclude that the
hall has a clean articulation of speech and it is desirable as a
lecture hall or for speech only. But at same time, there is a loss
in richness and fullness when playing music. So it is less
desirable for performing purposes.

20. Thank You
Alexandra Go
Chong Wen Bin
How Seng Guan
Jacky Ting Sim Ming
Lee Suk Fang
Lee Wan Xuan
Tan Chin Yin
Woo Shir Ley
0325342
0327442
1007P73021
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