Case Study on Acoustic Design

1. BUILDING SCIENCE II (ARC 3413 / BLD61303)
Project 1
Auditorium: A Case Study on Acoustic Design
(Cempaka Sari Auditorium)

2. INTRODUCTION

3. Name of auditorium : Auditorium Cempaka Sari
Location : Persiaran Perdana, Presint 3, 62100 Putrajaya, Malaysia
Type of auditorium : Multi Purpose Auditorium
Total Volume : 19000m³
Year of construction : 2012
Total seats : 610 fixed and cushioned

4. MASJID TUANKU MIZAN
ZAINAL ABIDIN /
MASJID BESI
PUTRAJAYA COMPLEX
PALACE OF JUSTICE
● Landmark
buildings along
Persiaran Perdana
● Masjid Besi at the
west while Palace
of Justice at the
east.
● The auditorium is
connected to the
Perbandaran
Putrajaya
Complex
● Traditional Islamic
architecture
● For events such
as exhibitions,
meetings, product
launch events,
seminars and
social events.

5. DRAWINGS

6. AUDITORIUM PLAN
SCALE : NOT TO SCALE

7. SECOND FLOOR PLAN
SCALE : NOT TO SCALE

8. THIRD FLOOR PLAN
SCALE : NOT TO SCALE

9. REFLECTED CEILING PLAN
SCALE : NOT TO SCALE

10. SECTION
SCALE : NOT TO SCALE

11. EXISTING SOUND SOURCE

12. EQUIPMENT LOCATION
STEREO SYSTEM
● Permits panning and adds profundity
to the acoustic picture.
● Speech reinforcement
● Enhances live or pre - recorded music
● Best horizontal coverage. Guarantees
that the audience members are very
much secured by the example.

13. EQUIPMENT LOCATION
● Subwoofer situated at the phase of the staircase
as the capacity of subwoofer is to deliver bass
and low frequency tones at both left and right.
● To spread the sound uniformly towards the
audience, the speakers are being arranged at
the highest position of both sides of the stage in
the auditorium.

14. PRODUCT BRAND SENNHEISER SUBWOOFER
MODEL PRO X SUB L FL
WEIGHT 67 Ibs
DIMENSIONS (H) 685mm x (W) 455mm
SOUND LEVEL 96 dB
FREQUENCY 45 Hz - 20,000 Hz
POWER CONSUMPTION 1500 W RMS, 4 Ohm
EQUIPMENT
SPECIFICATION

15. EQUIPMENT
SPECIFICATION PRODUCT BRAND BEHRINGER 2 WAY
SPEAKER
MODEL B 1220 PRO
WEIGHT 55.2 Ibs
DIMENSIONS (H) 640mm x (W)
400mm
SOUND LEVEL 95 dB
FREQUENCY 55 Hz - 18,000 Hz
POWER
CONSUMPTION
300 W Constant, 1200 W
Peak

16. ACOUSTICAL ANALYSIS

17. AUDITORIUM DESIGN
Shape
● Horseshoe shaped to enable great
perceivability, a feeling of closeness to the
sound source and common eye contact
between onlookers.
● Concentration of the early sound
reflections at the back of the room, causing
a non uniform spread of sound in the
auditorium.

18. Massing
● Cempaka Sari Auditorium is built in a hovering
egg like structure to increase the space from
lobby area to the auditorium to decrease the
noise destruction from the outside of the
auditorium.
● Double layer shell structure creates air gap
between the walls and thus act as a sound
insulation system preventing sound from
entering or escaping the auditorium.

19. LEVELLING OF THE STAGE
Raked seats and raised stage allow the occupants in the furthest-most seats to hear clearly.
This is possible due to the effectiveness of the sound waves reaching the ears of the
occupants without the presence of sound interrupting obstacles.

20. ARRANGEMENTS OF SEATS
● Hybrid configuration which are fan shaped
and end stage
● Ensure a maximum number of seats are
fitted, and obtain an optimum sightline to
stage area from every seat.
● As spherical wavefront will be formed when
sound emits from the source, this layout
helps to achieve the most effective acoustic
quality as all seats fall within the angle of
the existing sound projection area.

21. ARRANGEMENTS OF
SEATS
● Hybrid configuration of convex shaped and stepped ceiling that reflects the sound back towards the
seating zone and increases the volume of the sound.
● The convex shaped ceiling dissipate the sound to the centre and back part of auditorium. As the ceiling
is parallel to the floor, a little flutter echoes are being noted on stage.

22. MATERIAL AND PROPERTIES
Wall components

23. Floor components

24. MATERIAL AND PROPERTIES
Timber Veneer Flooring
Cotton Velour Curtain
Timber Structured Sitting
with Fabric Cushion
Nylon carpet Flooring
Timber Stairs with Nylon
Carpet

25. MATERIAL AND PROPERTIES
Timber Perforated Acoustic PanelsGranite Muslin Fabric with Cotton Felt

26. ACOUSTIC TREATMENT AND COMPONENTS

27. STAGE FLOORING
TIMBER VENEER FLOORING
● Made out of numerous layers of thin wood
● Prone to splitting / cracking
● Stronger than natural wood
● Durable
● Aesthetically pleasing
● Flat & smooth surface, tendency to reflect
sound
● Creates footstep noises.

28. WALL
GRANITE (w / uneven surface)
● Low absorption
● Diffuses acoustic sound
● Traject the sound wave from the speaker

29. TIMBER PERFORATED ACOUSTIC PANELS
FEATURES
● Hole Dimension : 34mm
● Spacing : 115 x 117mm align
● Perforated surface : 3.4%
● Thickness : 12mm / 16mm
Perforated panels are the most economical way to get an
acoustic treatment with a high degree of absorption. With
several variations of patterns and hole diameters, different
levels of absorption and aesthetic results can be achieved.
ACOUSTIC PANELS

30. CEILING
GYPSUM PLASTERBOARD CEILING
● Lightweight material
● Fire resistance
● Thicker in mass to resist vibration
● Different leveling an profile for sound to disperse and reflect

31. STAIRS
TIMBER WITH NYLON CARPET
● Help reduce footstep noises when climbing stairs.
● Act as an sound absorbent

32. SEATING
TIMBER STRUCTURE WITH FABRIC CUSHION
● Sound absorber
● Provide comfortability
Enable the space to accomplish a comparable nature of sound whether the auditorium is filled to
partial maximum capacity.

33. DOOR
SOLID TIMBER DOOR
● No fancy components
● Serves well as a reflector
● Produces squeaky noise when open / close

34. CURTAIN
COTTON VELOUR CURTAIN
● Thick piece of curtain that can absorb soundwave
● Creates a sound barrier that isolates mainstage with backstage and vice versa

35. EXTERNAL NOISE
● Occasions that situated at the
passageway ground floor.
● The occasion utilizes sound speaker
gadgets thus generates clamours.
● The lobby of the auditorium at the
sitting area create some external noises
as well.
● As the Cempaka Sari Auditorium is
located beside of the main road which
is Jalan Persiaran Perdana causes it to
create sound pollution and affect the
event in the building itself

36. INTERNAL NOISE
Overall internal noise source in the
auditorium.

37. INTERNAL NOISE
● The internal noises is that the wall of the backstage is made out of pure concrete without any
other absorbent material.
● Source of internal noise can be found on top of the stages, because of the timber materials of
the flooring of the stage that cause the noises.

38. INTERNAL NOISE
● Air conditioning on the ceiling of the auditorium is also source of noise. Because of the size of
the auditorium, circulation of air flow is important. Hence full fan speed is needed sometimes
to change the air freshness & internal temperature rapidly.

39. ● VIP entrance is also one of the causes for internal noises
● The air blower located at the end of the stage to help circulate the air in the spaces is also one
of the noises contributor to the space
INTERNAL NOISE

40. SOUND PROPAGATIONS & RELATED PHENOMENA

41. SOUND CONCENTRATION
● Sound concentration fluctuates in
Cempaka Sari Auditorium
● Formation of district sound
concentration at the back of room.

42. FACTORS OF NON - UNIFORM SOUND CONCENTRATION
The detrimental design of the auditorium
reflecting the sound path towards the back
seats.

43. FACTORS OF NON - UNIFORM SOUND CONCENTRATION
Selection of materials at different spaces.

44. SOUND REFLECTION
FRONT ROWS
MIDDLE ROWS
BACK ROWS
● Sound is reflected back to the audience
for better acoustic quality.
● Plasterboard ceiling as the sound
reflector
● Nylon Carpet as sound absorber to
minimize resultant reflected sound.
● Concrete rear facade causes excessive
sound reflection.

45. ECHO & SOUND DELAY
FRONT ROWS
MIDDLE ROWS
BACK ROWS
● In Auditorium Cempaka Sari, sound
delay of 40ms and above will be
considered as an echo
● Sound delay in the VIP area and the back
seats are optimum and suitable for the
use of speech.
● Front seats may suffer confusing sound
caused by the echoes as it has a sound
delay higher than the optimum level
40ms.

46. REVERBERATION TIME

47. REVERBERATION TIME CALCULATION
Reverberation Time:
RT = 0.16V
A
= 0.16 (19000m3
) / 1620.18m2
sabins
= 1.88 seconds

48. CONCLUSION

49. 1. A successful design of and auditorium depends on its acoustic design such as the auditorium
layout and absorption materials used to preserve and enhance the desired sound and to
eliminate noise and unwanted sound.
2. The auditorium layout and the materials used on the structure and furniture, such as walls,
floor, chairs, etc, can effectively affect the acoustic inside the auditorium hall and even can
efficiently affect the sound from the outside of the auditorium hall.
3. Based on our analysis and calculation, the auditorium has a optimum reverberation time for a
multipurpose hall, which create echoes that is suitable for both speech musical performance.
4. It let us understand how the acoustic design works better depends on the functions of the
auditorium and uses the acoustic design to make the users comfort.
CONCLUSION

50. RECOMMENDATIONS
Scheduled maintenance should be held to fix
the loose screw, bolt and grease the door hinge and
handle to prevent unwanted noise that would affect or
decrease the acoustic effect. Also major maintenance
also have to be organized by inviting professional
sound specialist to test out the acoustic level and
make sure it is well maintained.
Cempaka Sari Auditorium can reduce its
reverberation time to the desirable length by adding in
more sound absorbent to increase its acoustic effect.

51. Ventilation system will be improved so that
portable air blower that will give out huge noise to the
space can be eliminated. Air conditioning system
should be serviced occasionally in order to reduce the
noise destruction.
Old carpets and cushion should be replace from time
to time as new carpets are relatively softer and better. With
better absorption of sound, echoes are able to be absorb and
sound quality can be improved.

52. REFERENCE
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2. Architectural acoustics (November 13, 2013). Retrieved from
https://www.britannica.com/science/architectural-acoustics on April 22, 2018
3. Auditorium Cempaka Sari. Retrieved from https://10times.com/venues/auditorium-cempaka-sari
4. An Architect's Guide to Soundproofing. Retrieved from
https://www.soundproofcow.com/soundproofing-101/architects-soundproofing-guide/ on April 23, 2018
5. Noise and vibration control in building design. Retrieved from
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6. Reverberation Time. Retrieved from http://hyperphysics.phy-astr.gsu.edu/hbase/Acoustic/revtim.html on
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2018