Auditorium: A Case Study on Acoustic Design Presentation
1. the
calvary
convention
centre .
The Calvary Convention
Centre (CCC) is a distinctive
convention centre that is
dedicated to the pursuit of
holistic activities.
Chong Hao Foong
Chung How Cyong
Foo Ji Sun
Tang Fu Hong
Tan Yan Jie
Teh Wei Hong
Teoh Zhe Kai
Thomas Ting Shii Kai
0322343
0324152
0323550
0323092
0323906
0323743
0322905
0323962
BUILDING SCIENCE II ARC3413
AUDITORIUM : A CASE STUDY
ON ACOUSTIC DESIGN
Tutor : Ar. Edwin Chan
2. Name of Auditorium: Calvary Convention Centre
Location: Jalan Jalil Perkasa 1, Taman Teknologi Malaysia,
57000 Kuala Lumpur, Wilayah Persekutuan Kuala Lumpur.
Type of Auditorium: Speech-based Auditorium, Holistic-
driven events
Total Built Up Area: 600,000 square feet
Year of Completed: 2013
Total Seats: 5,000 seat auditorium, with upholstered tip-up
theatre seat covered of 2,965 square metre and timber
padded retractable tip-up seat of 420 square metre.
introduction
8. equipments specification
L-Acoustics
P-Series 112P
Maximum SPL (Sound Pressure
Level), measured at 1m under
free field conditions is 133 dB.
L-Acoustics
ARCS Focus
Maximum peak SPL,
measured at 1m under
free field conditions is
139 dB.
L-Acoustics
P-Series 108P
Maximum peak SPL,
measured at 1m under
free field conditions is
125 dB.
9. There are three types of speakers used in the auditorium and all of them
are under a same brand, L-Acoustics.
equipment placement
The four P-Series 112P located
on the stage are used as stage
monitors. Stage monitors are
used whereby the performers
are able to listen to other
instruments as well as their
own voices.
L-Acoustics
P-Series 112P
The ARC Focus is a line array
loudspeaker system that is
purposed to project sound to
the back of the auditorium.
L-Acoustics
ARCS Focus
P-Series 108P is used to
project sound towards the
front 4 seating rows because
the ARC Focus sets are unable
to reach the 4 rows stated and
used as compensate for that
matter.
L-Acoustics
P-Series 108P
11. The shape of the auditorium is a unique variation of the horseshoe-type
hall with a combination of both curved and flat walls. The walls are flat at
the front of the hall but gradually curve into a concave shape as it leads to
the rear.
shape and massing
12. Correct levelling of the auditorium seats ensures that sound waves reach
all the occupants of the auditorium without obstruction. The seats
configuration of the CCC auditorium is very effective in bridging the
relationship between the audience and the speaker on the stage.
levelling of seats and stage
13. The seating arrangement in the auditorium is in a fan-shaped
configuration to allow greater seating area that is closer to the stage.
This allows louder and clearer sound quality to be heard throughout
the hall.
arrangement of seats
14. The auditorium implements a combination of concave shaped and
stepped ceiling systems that reflect the sound back down to the
audience. The concave shape also helps concentrate the sound
intensity and increase the volume of the sound.
layout of boundary surface
15. The materials can be divided into absorbent or reflector, depending on
their Noise Reduction Coefficient (NRC) rating, where the most
reflective is 0 and most absorbent is 1. Designers have to balance their
choice of materials to achieve the desired level of reverberation time.
materials and properties
THEATRE SEAT
upholstered tip-up
HEAVY CURTAIN
hung in fold against solid wallPLYWOOD
hardwood panels over 25mm airspace
PLASTERBOARD
decorative element
ROCKWOOL
30mm, 200 kg/m3 over 300mm Air Gap
16. The materials can be divided into absorbent or reflector, depending on
their Noise Reduction Coefficient (NRC) rating, where the most
reflective is 0 and most absorbent is 1. Designers have to balance their
choice of materials to achieve the desired level of reverberation time.
materials and properties
TIMBER PADDED
retractable Tip-up Seat
TIMBER FLOORING
on joist
THICK PILED CARPERT
heavy on Reinforced Concrete
18. The stage uses timber flooring to reduce the noise transmission to
tolerable levels. An acoustic layer is usually laid under the timber veneer
flooring to absorb the sound waves to a certain degree.
acoustic underlayment material
stage flooring
veneer timber
laminated finishing
concrete slab
Timber flooring reduce
noise transmission
Acoustic layer under timber
flooring absorb sound waves,
reduce vibrations, and lower
sound frequencies
19. Thick carpeted flooring contributes to sound absorption. Carpet is an
outstanding sound absorber which serves as an acoustical aid, as well as
a floor cover.
carpet flooring
timber veneer
rubber layer
concrete
Outstanding sound absorber
Absorb airborne noise efficiently
Rubber underlay further
improves absorption
Stairs wrapped with carpet to
reduce footstep noise
20. The walls of the auditorium feature a concave shape- a form that is
advantageous when used in the context of our building. Concave
surfaces have the tendency to reflect and concentrate sound waves to
the centre of its projection.
wall panel
Due to massive scale,
surfaces are covered with
absorptive material to reduce
reverberation
Surface of wall is fabric,
followed by sponge, plywood,
and rockwool
21. Ceiling panels are made of gypsum board as their smooth surfaces help
in sound reflection. They also provide for acoustical intimacy,
atmosphere, and strengthens the overall sound quality.
ceiling (gypsum board)
Suspended from the ceiling to
shorten delayed reflective
sound
Stepped ceiling form reduces
reverberation
Made of gypsum board
22. The cushioned chairs not only provide viewers with comfort, it is
also an excellent sound absorbent, which helps reduce the overall
reverberation time in the auditorium.
seating
Cushioned seats are
sound absorbent
Reduce reverberation time
24. Sound travelling forward towards the audience is known as direct sound.
Next, sound travelling upwards is either reflected or absorbed. There are
two ceiling surfaces, the upper ceiling surface that is heavily insulated and
the lower ceiling surface consisting of acoustic panels.
sound propagation without aid of speaker
direct sound reflected sound
25. The measurement of the Sound Intensity Level (SIL) from the sound
source, shows that a distinct sound concentration zone can be found
at the centre-back of the auditorium.
sound concentration
51db
53db 59db
62db
63db
61db
54db
51db
55db
26. Despite the (inefficient) coverage of acoustic paneling on virtually every
wall surface in the auditorium. The curvilinear form of the auditorium still
has a detrimental acoustic quality that creates auditory foci within,
amplifying sound in specific areas.
sound concentration
27. In order to make the use of sound more efficient, it is necessary for the
sound to be reflected back towards the audience. Reflections must be
carefully controlled to minimize the creation of echoes.
sound reflection
A
B
C
Ceiling reflectors serve to reflect sound effectively back to the
audience. Therefore, the rest of the auditorium must be covered with
sound absorbent materials to minimize the resultant reflected sound,
making it almost indiscernible.
Shows sound propagation towards
Point A.
Shows sound propagation towards
Point B.
Shows sound propagation towards
Point C.
DIRECT
SOUND
DIRECT
SOUND
DIRECT
SOUND
REFLECTED
SOUND
REFLECTED
SOUND
REFLECTED
SOUND
absorbent materials reflective materials
28. Echo also can define as the nature of the programme influences the
desired sound delay period. For speech-based auditorium, any sound
delay above 40ms will be considered as an echo.
echoes and time delay
TIME DELAY
= (16m + 18m) - 21m
0.34
= 13m
0.34
= 38.2ms
#
TIME DELAY
= (17m + 31m) - 40m
0.34
= 8m
0.34
= 23.5ms
#
TIME DELAY
= (16m + 45m) - 56m
0.34
= 6m
0.34
= 17.6ms
#
Shows a time delay of 38.2ms in
Point A.
Shows a time delay of 23.5ms in
Point B.
Shows a time delay of 17.6ms in
Point C.
DIRECT
SOUND
16m 18m
21m
DIRECT
SOUND
DIRECT
SOUND
A
B
C17m
31m
40m
16m
45m
56m
30. Based on the materials identified on site and the
measurements obtained from the drawings, we were
able to calculate the absorption of each surface and
determine the total room absorption of the auditorium.
reverberation time
31. Materials Area (m2)
Absorption
Coefficient,
α (Sabins)
Absorption of
Surface, as
(m2 Sabins)
Thick Piled Carpet, Heavy on
Reinforced Concrete
3295 0.50 1647.50
Timber Floor on Joists 115 0.10 11.50
Heavy Curtain, Hung in Fold
Against Solid Wall
465 0.55 255.75
Rockwool 30mm, 200 kg/m3 over
300mm Air Gap
1675 0.85 1507.50
Acoustic Timber Wall Panelling 2480 0.42 1041.60
Plywood, Hardwood Panels over
25mm Airspace
220 0.15 33
Plasterboard on Battens, 18mm
Airspace
2480 0.15 372
6mm Panel Glass 100 0.03 3
Upholstered Tip-Up
Theatre Seat
2965 0.64 1897.60
Timber Padded Retractable Tip-Up
Seat
420 0.15 63
Total Room Absorption, AT (m2 Sabins) 6832.45
32. As told by the architect from T.R. Hamzah
and Yeang Sdn. Bhd., the reverberation
time of Calvary Convention Centre
is approximately
Sabine Formula:
where:
RT = reverberation time (sec)
V = volume of the room (cu.m)
AT = total absorption of room
surfaces (sq.m sabins)
0.9s
RT
0.16v
AT
=
V = Volume, m3 = 39136.60 m3
AT = Total Room Absorption, m2 sabins
= 6832.45 m2 sabins
RT = 0.16V
AT
= 0.16 (39136.60)
6832.45
= 0.91 ≈ 0.9s
calculated
reverberation
time .
34. To sum up a conclusion from our accumulated findings and
subsequent analysis, Calvary Convention Centre has the
flexibility to cater both demands for speeches and music
performances. A multipurpose auditorium with the capacity of
having 5,000 occupants, situated on a disproportionate land
area with a well-considered tropical climate design strategies.
Isolation by air gaps and restructuring of systems is
employed to overcome noise emanating from outside and the
inside. Smart choice of materials aids the noise control and
creates conducive environment for event hosting.
Nevertheless, consideration of the type and position of
loudspeakers used is vital for acoustical control. Calvary
Convention Centre has successfully achieved an optimum
reverberation time of 0.9s for a speech-based auditorium.
Last but not least, we were able to truly understand and
appreciate a full scope on acoustics for our case study,
Calvary Convention Centre. In a short period of time, enabled
us to understand how different types of designs and their
acoustical treatments influence the sound efficiency and the
overall user experiences.
conclusion
