Accoustical Consideration
Accoustical Consideration
Accoustical Consideration
ABSTRACT
The auditorium within the Heydar Aliyev Center serves for an audience of 1200 and incorporates conference, concert
and opera use altogether. Confronting the multi-functional performance program of the space together with uncom-
promising aesthetic considerations, coupled space concept has been adopted as an acoustical and architectural design
aid. This paper presents mainly the dependable acoustics attained by the coupling of auxiliary spaces by employing of
the right-sized coupled volume connected with proper finishing materials and variable aperture size which conse-
quences in the differentiation of reverberation time within the main volume -namely multi-purpose auditorium- and
the coupled room. Fixing the volume and room finishes as for getting the desired energy decay behavior, aperture
size has come up to be the essential parameter to concentrate on. The proposed solution for conference, music and in-
ter-related activities is for the best of early and late sound field energy decay control. The proper reverberation times
are studied for the main hall alone and coupled space separately to find the results as of the optimum reverberation
times over frequency range of the auditorium for performance-specific. Aperture size has an essential role in balanc-
ing the reverberation time distributions of the auditorium and coupled space. Stage tower acoustics and thoroughly
wooden surfaces of auditorium are studied together with the coupled volume in search of optimum reverberation
times for different purposes of coupling spaces. Within this study coupled volume is used as a design tool out of re-
cent acoustical innovations. The form and materials within the main volume is worked out together to get the opti-
mum sound energy decay forms for different activities. Apart from coupled space concept, stage house design, audi-
torium main back-wall design and side-wall face irregularities are studied within the aim of having an even-
distribution of sound field throughout the hall. This paper presents the successful outcomes of a coupled volume de-
sign within such a collection of irregular forms out of minimum aesthetic compromises.
INTRODUCTION
The museum building faces out into the landscape with its
Heydar Aliyev Center as a landmark building for the city of glass facade forming the mild rising crest. The other dominat-
Baku, Azerbaijan houses majorly a library, a museum, an ing figure of outer skin is the library building. This north
auditorium and a multi purpose hall. This paper intends to structure has a more distinctive inclination rising out up high
discuss the acoustical properties and corresponding research from the landscapes natural topography.
on probable acoustical measures and design solutions of audi-
torium within the limits of architectural and aesthetic consid-
erations. Having the signature of Zaha Hadid the proposed
design has an exterior skin as a single continuous surface
folding around in defining individual functions of the Center,
while providing each element its own identity and privacy
(e.g. Figure 1).
ISRA 2010 1
29-31 August 2010, Melbourne, Australia Proceedings of the International Symposium on Room Acoustics, ISRA 2010
slope of the topography. The auditorium and multi purpose Table 1. Space configurations for different scenarios
hall with their associated facilities have a direct access to the Design Stage Pit Coupled Orchestra
plaza. The auditorium is located in the void created by the Proposal shell room
outer skin being stretched between volume of the museum apertures
and the library tower. Confe- Lifted and Closed Closed Absent
rence Use stored in
The auditorium serves for an audience of 1200 and incorpo- the stage
rates conference, concert and opera use altogether. The visi- tower
tor main entrances of the auditorium open into the inner gal- Concert In place Closed Open On the
leries (e.g. Figure 3) of the Center, the acoustical characteris- Use stage
tics of which are to be presented within the scope of a sup- Opera Lifted and Open Partially In the pit
plementary research paper [1]. Use stored in open
the stage
tower
Source: (alkan, 2004) [2]
ACOUSTICAL DESIGN
The acoustical design of the auditorium in Heydar Aliyev Source: (MEZZO Studio, 2010)
Cultural Center incorporates the challenge of providing multi Figure 4. View from Stage, auditorium
purpose requirements of the hall. Considering the conference,
Estimated main hall acoustical volume excluding stage is
concert and opera uses to be embraced in one single enclo-
8215m. A series of new simulation studies is carried out by
sure, the optimization of the functional needs through the
MEZZO Studio using this new graphical model and acoustic-
acoustical requirements is of priority.
al data obtained by measurements in the laboratory for wood-
In brief, the given pre-design concept project has proved not en surfaces.
to be efficient for providing the acoustical parameter limits
Recommended ranges for acoustical parameters used in the
for these three functions. The finishing cloth as announced to
assessment study are listed in Table 2. Sources and corres-
be hardwood floor, wall and ceiling material is respected in
ponding receivers are defined and located in major locations
terms of architectural requirements. However, having this
(e.g. Figure 5). The present condition of the concept design
highly reflective material lined out through such single and
and the proposed alternative acoustical design solutions are
multi functional space some further precautions are thought
discussed in later sections. Ray tracing is used majorly in
to be in the core of major consideration.
sound path analysis (e.g. Figure 6).
The challenge has started with fixing the requirements for
conference and concert use, or for concert and opera, and for
opera and conference uses. No tolerance has given to any
visual alteration in architectural design terms. As presented in
following sections of this paper the required absorption for
the conference use has become above limits for the concert
use in a very brief assessment. Considering the design strag-
gles and prospective variable acoustics, the coupled space
concept has been found to be the most realistic and managea- 1
2 ISRA 2010
29-31 August 2010, Melbourne, Australia Proceedings of the International Symposium on Room Acoustics, ISRA 2010
ISRA 2010 3
29-31 August 2010, Melbourne, Australia Proceedings of the International Symposium on Room Acoustics, ISRA 2010
time of 1.93s. The original design without any acoustical This acoustical precaution helped greatly to decrease overall
intervention does not function for multi-purpose functions reverberation by around 0.3s (e.g. Figure 8) throughout the
including conference, concert and opera uses altogether. full octave frequency range. Certain amount of diffusion on
Thus, the coupled space concept is chosen to be the most the rear wall that can be obtained through various diffuser
effective variable acoustics solution and presented for appli- designs is also kept in place for minimizing probable echoes
cable activities in following sections. caused by the large concave surfaces of rear wall. On the rear
wall as long as opening area is 30% of total area a lot many
CONFERENCE USE ANALYSIS different alternatives of diffusers can be worked until it satis-
fies architectural design group. With all the precautions taken
Conference performances involving activities related to the Auditorium has come to a point that minor later tunings
speech is known to be the initial use of this multi-purpose on materials will help for the performance needs together
auditorium. For that reason, the hall is designed for speech with a good electronic sound amplification design (e.g. Fig-
performances initially. Adjusting the excessive reverberance ure 9).
due to highly reflective wood surfaces and extreme volume is
the first goal for providing sufficient speech intelligibility.
The Auditorium is initially tested with its present condition
as given in previous section. Adding absorptive materials to
the rear wall and increasing the amount of absorption sup-
plied by the seating area is helpful to some extent but not
totally fulfill the requirements. The need for another design
solution is ended up by using the advantage of stage tower as
a sound attenuation center of the hall.
The removable ceiling panels on the stage shell that are as-
sumed to be raised in opera/ballet performances are removed
for conference use as well. By opening the panels on stage
shell, stage tower is coupled to the main hall. Stage tower has
to be made totally absorptive for decreasing the excessive
reverberance of the hall. Leaving the backstage floor area as
similar to the stage floor, rest of the surfaces including walls Source: (MEZZO Studio, 2010)
and ceilings are covered with highly absorptive materials Figure 9. STI distribution map, for conference use
made up of rock wool with geo-textile facing.
CONCERT USE ANALYSIS
4 ISRA 2010
29-31 August 2010, Melbourne, Australia Proceedings of the International Symposium on Room Acoustics, ISRA 2010
For opera and ballet function the pit cover is opened and an
orchestra surface to represent the orchestra is added into the
pit. The shell is removed exposing the stage tower (e.g. Fig-
ure 15). All other materials applied for conference use is kept
Source: (MEZZO Studio, 2010) in place. Initially, aperture of the coupled room is kept
Figure 12. C80 distributions at 500Hz, concert use closed. The auditorium with full audience is found to be too
ISRA 2010 5
29-31 August 2010, Melbourne, Australia Proceedings of the International Symposium on Room Acoustics, ISRA 2010
6 ISRA 2010
29-31 August 2010, Melbourne, Australia Proceedings of the International Symposium on Room Acoustics, ISRA 2010
short at 4000 Hz with a ratio of 0.79, that is, lower than the 3 J.C.Jaffe, Selective Reflection and Acoustic Coupling in
ideal value of 0.84. The distribution of sound levels within Concert Hall Design, in Music & Concert Hall Acous-
the auditorium also complies with the requirement of level tics Conference Proceedings from MCHA 1995, (Aca-
differences to be less than 10 dB. Clarity aspect also con- demic Press, New York, 1995), pp.85-94.
forms to the targeted values. 4 R. Johnson, E. Kahle, and R.Essert, Variable Coupled
Volume for Music Performance, in Music & Concert Hall
A design proposal is presented above for the improvement Acoustics Conference Proceedings from MCHA 1995
and adjustment of acoustical characteristics of the Audito- (Academic Press, New York, 1995), pp.372-385
rium in Heydar Aliyev Center to manage three different sce- 5 Z. S, Systematic Investigations on Energy Decays in
narios of use anticipated by MEZZO Studio. The proposal Acoustically Coupled Spaces Using Scale-Model Tech-
involves adoption of coupled space concept by forming a nique, (Masters Thesis, RPI, July 2006, Troy, NY, USA)
volume of specific size with definite aperture dimensions 6 M.Long, Architectural Acoustics, (Elsevier Academic
within the space over the auditorium ceiling. The motivation Press, 2006)
behind the proposal is the proven record of coupled space
concept in some well known halls built in recent years all ACKNOWLEDGEMENTS
over the world. It is believed that this choice is attractive in
halls like the one in Heydar Aliyev Center because any poss- Authors are indebted to Ms Deniz Manisal and Mr. Saffet
ible loss in visual appearance due to flexible passive reverbe- Bekiroglu of Zaha Hadid Architects of London for granting
ration control approaches cannot be tolerated. permission on the use of images and support. SANSET
IKOOR, the subcontractor of the auditorium is gratefully
In the proposal the hall is firstly tuned to acoustical require- acknowledged for the cooperation and support for this study.
ments of speech-centered conference use as 70% of use has
dictated to be for speech-oriented performances in the pro-
gram. Major differences from the present design concept lie
in the assignment of heavily upholstered seating for the au-
dience area and removal of orchestra shell from the stage. For
reverberation control the stage tower required to be treated
with absorptive material. These attempts have yielded rela-
tively flat reverberation time profile with frequency, well
suited for the conference use.
When the orchestra shell is placed on the stage with the pit
closed, the resulting mid frequency reverberation times along
with the bass ratio perfectly match to the requirements of a
concert hall for symphonic music. However, there is a need
for fine tuning for the improvement of lateral energy fraction
figures. When the pit is opened with the performing orchestra
for opera-ballet use and the stage tower is exposed after re-
moving the stage shell, the inclusion of the coupled space
above the ceiling increases the mid frequency reverberation
times to the ideal levels. Bass ratio is improved resulting in
the favorable warmth characteristics for this mode of func-
tioning.
REFERENCES
1 Z. S-Gl and M.alkan, Acoustical Design of Inner
Galleries in Heydar Aliyev Center Proceedings of 20th
International Congress on Acoustics, ICA 2010, 23-27
August 2010, Sydney, Australia.
2 M.alkan, Architectural Acoustics, Lecture Notes,
(IZOCAM Isolation Education Center, 2004)
ISRA 2010 7