Sydney Opera House Concert Hall – Rose Tracey

Posted: October 13, 2011 by utsrosiet in 2011

Report focus:

This report will examine the various practices used to address the historical and confounding acoustic inadequacies of the Sydney Opera House’s Concert Hall.

 Sydney Opera House

Created as a “premiere venue for music and culture”[1] the Sydney Opera House (SOH) was originally envisaged as a venue for Sydney that would foster, attract and inspire both international and local artists and that could and would be enjoyed by all[2]. Since it’s completion in 1973, the Sydney Opera House has earned a reputation not just as a world-class performing arts centre that has arguably evolved as a symbol of both Sydney and the Australian nation[3].

However, this reputation, despite the earlier controversies[4] and the “compromised” final construction ultimately recognises and celebrates almost exclusively in regard to its significant contribution to modern architectural design.

In June 2007, this was acknowledged by UNESCO in listing the SOH on the World Heritage List, stating that it “represents multiple strands of creativity, both in architectural form and structural design…it stands by itself as one of the indisputable masterpieces of human creativity, not only in the 20th century but in the history of humankind.”[5]

But the silence in regard to its acoustic achievements is deafening. Since the SOH opened in 1973, both performers and critical listeners have acknowledged the acoustic deficiencies of the Concert Hall [6]. While at the time it might have been considered to be one of the top 10 concert halls in the world[7], this was not necessarily in regard to its acoustic quality. Advancements in live performance expectation, experience and technologies have seen the Opera House’s Concert Hall voted the 18th worst in major classical music venue in Australia in a recent poll conducted by Limelight Magazine of 200 performers, critics and industry experts[8]. Even David Claringbold, SOH Technical Director, acknowledges that “up until recently, changing audience and industry expectations had resulted in a lessened reputation for the SOH.” [9]

It’s acoustic deficiencies has long been a source of ongoing riddle to renowned acousticians and sound engineers who manoeuvre around the various acoustic inadequacies. These include, inconsistent sound, patchy sound, whirls in the roof cavities, sound leakage between the venues, and the difficulties modifying the space for more complex sound requirements arrangements (including the placement of the PA).

These requirements can neither understood or solved in isolation.  Their solution requires a multi-faceted approach that considers all range of technical, logistical and aesthetic requirements central to the performance needs and audience experience.

“Over a long period of time it has involved acquiring expert advice and balancing that advice with financial and artistic resources as well as the enhanced functionality and ultimate quality to be balanced””[10]. Often one solution causes additional problems that again have to be compensated for.

Heritage imperatives, the politicization of the arts and costs to government and at times conflicting goals constrain much of the decision making. The absence of revenue and the lack of adequate performance space available to the SOH while modifications are tested let alone conducted further constrain these decisions.

Challenges

There are a number of challenges and obstacles that confront the SOH in finding a solution to the sound deficiencies in the Concert Hall.

Intended design and purpose

Originally intended for the Opera, the Australian Broadcasting Commission (and owner of the Sydney Symphony Orchestra) successfully lobbied for the Major Hall to be dedicated to Symphony (as a way to get the SSO out of Sydney Town Hall)[11]. Against Utzen’s wishes, this demand was met and the Opera was relegated to the smaller performance Hall.

In 2009, Kirkegaard Associates[12] ensapsulated the problems beholding the Opera House as follows: “Ultimately the Concert Hall is a dramatic architectural space inserted into a void which had been intended for an Opera Theatre. From that basic fact derive the series of compromises which have created dysfunctional aspects of the concert hall”

These limitations include a “fraught”[13] sound reinforcement in the Concert Hall which has “long been a source of frustration”[14] to the highly knowledgeable technical staff.

Today, the acoustic performances (of the Symphony) also have technical requirements in relation to recording and live broadcasting performances on radio, live broadcast on radio, television and the internet as well as amplified “sounds” within the specific scores.

Space configuration

The Concert Hall is uniquely almost triangulated shaped, located within the largest of the Sydney Opera The Hall and the sails are themselves a compromise of original design. Specifically Utzon’s competition winning Opera House design had envisaged a very different and lower ceiling arrangement to the Hall[15].

House sails. The ceiling crown is a staggering height of 25 metres. The ceiling void is narrow and also confined and lined with technical equipment and stage support machinery including electricity, phantom power, airconditioning, fire hoses, comms and pagine systems. Laying any new cabling requires complex navigation.

Options to modify internal or external features are limited to say the least. No modifications that can be done externally to the sails. Limited Options to expand beneath the stage and floor are prevented by the presence of structural concrete beams the run the full length of the Hall.[16]

Demands of multiperformance venue

The demands on a international multiperformance space are constant and challenging both in terms of technology and staff and not always obvious to the program planners. Today, the Opera House houses four resident companies: Sydney Symphony, Opera Australia, The Australian Ballet and the Sydney Theatre Company. It has seven primary venues, including the much vexed Concert Hall. The Concert Hall’ primary function had since the completion of its construction, had been to host acoustic orchestral performances. The Symphony alone plays 120 days a year in the Concert Hall. But in 2009, of the 303 performances in the Concert Hall, 197 required amplification[17] for all performances that were rock, jazz and other genres. But even some of the acoustic performances are recorded for live or pre-recorded broadcast on radio, television and other platforms such as internet. These also require the Hall to be able to also manage these requirements in regards to the PAs, microphones, reverberation and fold back.

Developments in modern music and ambitious artistic programming technological aims has required regular modification to the Hall’s amplified sound and acoustic configurations. The Hall is required to be a space that is somehow able to seamlessly adapt to its technical and sound requirements efficiently and with no impact on the audience experience. As Taylor and Claringbold discuss, the Concert Hall’s standard configuration is for symphony, but on any given day, the Hall is used for both acoustic and amplified events. The more commercial events require a “sophisticated overlay of temporary staging, lighting, rigging, sound and audio visual elements”[18]. The turnaround of these events is crucial to the Opera House’s income.

The SOH has both an artistic and commercial need to create a venue that international artists wanted to perform at. But the venue also needs to cater to the Ballet, visiting international artists, modern music concerts, cultural events and School Speech days, Australian Idol finals, dance, opera, spoken word events, literary readings, physical theatre. The Hall has even been converted to a Dolby Cinema for the Star Trek 11 World Premiere. And host (and live stream) the Youtube Symphony.

Impact of renovating the Hall

The development to the Concert Hall’s acoustics must be holistic and complimentary to the SOH’s programing and operational needs. Therefore, any recommended modifications represent time no revenue is being generated, and hence represent a multi million dollar commitment.[19]

New approaches to these sound deficiencies recently adopted include:

New PA sound system & arrangement of speakers

Interestingly enough, visual trials were required as a first step in the testing of modifications to the PA for the Hall[20].

Arrangement of the speakers originally focussed central speaker cluster which was replaced in 2009 and has “substantially improved the quality of amplified sound and the visual aesthetic of the hall”[21].

The non-central placement of the speaker arrangement was acoustically required to be arranged in way that was not balanced visually but the visual requirements for balance (from the audience perspective) required visual symmetry which did not equate initially with a balanced sound experience. Other compensations were sought.

But after a second Sound Out, a new configuration of speakers was agreed upon for the hall. This configuration saw a left/right hang of J Series and J subs, E3 Front fills and Qs for first position and side hang and out above the upper stalls for delays[22].

The new configuration allowed for the delay speakers to remain in the hall, regardless of performance which has saved the Opera House endless hours of packing and patching a variety of different sound systems to cater for its diverse program, including subwoofers for rock concerts.

The speakers are suspended via a hanging system comprising of 14 lines operated by electric winches and 4 additional maintenance winch sets.[23] Improved amplified sound and a significant improvement on the turnaround time between productions [24]. There is now also a large cavity in the rear stall areas that allows the permanent placement of a console, processing equipment and pre-configured cables, which again significantly reduces the set up time and greatly enhances the over all sound quality.

This was considered to have the least impact on audience visibility and was selected. However, agreeing on the preferred PA was only the first chapter. Permanently installing the new one system was another challenge altogether. “Integrating the cabling, the infrastructure and machinery to drive the system proved to be a serious test of skill and ingenuity”[25].

Initially the specs had required the amps to be as close to the arrays as possible – but issues relating to excessive heat and lack of serviceability drove a better solution. A platform between the inner shell in the void between the inner and outer concrete shells was found – which was cooler and slightly easier to access. Even in agreeing on this location, a labyrinth had to be charted of networks of power supply, air-conditioning ducts, existing power, fire drencher pipes, structural support. New power sources, to ensure clean power, were also provided for the system components at stage level and at front of house.[26]

Rob McCormack from Rutledge explained that the space is unique in terms of its problems and it’s configuration. [27] The roof space is so tight that it required all equipment be carried by hand up the stairs. A chain hoist was required to lift the heaviest of equipment. The system that was being replaced had included a winch for the centre cluster of speakers which to be cut out[28]

Draping

Bruce Jackson, a world regarded audio specialist, was called in to review the Hall’s sound, and formulated one of the cheapest solutions to the acoustic problems in the Hall[29]: drapes. Jackson hired $2000 worth of drapes, standard 380 GSM theatrical cloth[30], were hung above the stage to “dampen the acoustic down”[31] and contain reverberation[32] at performances requiring amplified sound. These were positioned between the lighting truss positions so as to reduce “swirling into the crown void above the stage”[33] and thus diluting sound clarity and audibility.

“Clouds”

Earlier modifications to the Hall had previously resulted in 18 acrylic rings (often referred to as “Clouds”) placed in a moveable canopy thought to reflect sound back on to stage. The clouds were originally “hollow” so as to allow maximum ceiling light to illuminate the stage. Sound tests by Kirkegaard found that “filling” in the donuts (with clear disks) further improved the sound quality for the performers with no impact on lighting. So much so, that the SSO requested that fillers remain for all their performances so as to reduce reverberation on stage[34].

Panelling – Sawtooth Walls & Wool bordred

Kirkegaard also found that placing reflective flat wall panels in the stalls and on the stage. One metre tall wool borders were also suspended on the upper auditorium walls to attenuate high frequency reflections causing echoes. These measures were for implemented following complaints from performers and audience members alike.

Conclusion

David Claringbold attests that  “ The new system… now means the Concert Hall is one of the best places on earth to see a live show. Artists love playing here, and now our audiences share the thrill. That coupled with giving school speech days, community events and global superstars the same treatment is what Opera House is all about – something for us all to enjoy”[35]

It is not unreasonable to expect that a world class performance space such as the SOH would at least meet the expectations its audience and performers. The modifications have hopefully improved the acoustic experience. But it remains a final frontier of the SOH to ensure that a superb sound experience is enjoyed by and accessible to all.

Bibliography

Associates, Kirkegaard. “The Concert Hall at Sydney Opera House | Recommendations for Acoustics Improvements.” 2007.

Claringbold, Lisa Taylor and David. “Acoustics of the Sydney Opera House Concert Hall.” In 20th International Congress on Accoustics, ICA 2010. Sydney: ICA 2010.

Holder, Christopher. “Sail of the Century.” AV Magazine: News from AV, 2010, 42-48.

Lesnie, Melissa. “Sydney Opera House “Biggest Loser” in Survey.” Limelight Magazine, 2011.

Messent, David. Opera House Act One.  Sydney: David Messent Photography, 1997.

Sydney Opera House. “Overview | the Building.”  http://www.sydneyoperahouse.com/about/house_history_landing.aspx.


[1] Foundational Plaque at Opera House steps, laid on XXX 1973.

[2] David Messent, Opera House Act One  (Sydney: David Messent Photography, 1997). P 42

[3] Sydney Opera House, “Overview | The Building,”  http://www.sydneyoperahouse.com/about/house_history_landing.aspx.

[4] Messent, Opera House Act One.

[5] UNESCO in Sydney Opera House, “Overview | The Building”.

[6] Lisa Taylor and David Claringbold, “Acoustics of the Sydney Opera House Concert Hall,” in 20th International Congress on Accoustics, ICA 2010 (Sydney: ICA 2010).

[7] Ibid.

[8] Melissa Lesnie, “Sydney Opera House “biggest loser” in Survey,” Limelight Magazine 2011. p24

[9] Claringbold, “Acoustics of the Sydney Opera House Concert Hall.” p4

[10] Ibid. P1

[11] Messent, Opera House Act One.

[12] Kirkegaard Associates, “The Concert Hall at Sydney Opera House | Recommendations for Acoustics Improvements,” (2007).

[13] Christopher Holder, “Sail of the Century,” AV Magazine: News from AV 2010.; p 42

[14] Ibid.

[15] Messent, Opera House Act One.

[16] Claringbold, “Acoustics of the Sydney Opera House Concert Hall.” p4

[17] Ibid. P1

[18] Ibid. P1

[19] Holder, “Sail of the Century.”

[20] Claringbold, “Acoustics of the Sydney Opera House Concert Hall.” p5

[21] Ibid. p3

[22] Holder, “Sail of the Century.”

[23] Claringbold, “Acoustics of the Sydney Opera House Concert Hall.”

[24] Ibid.

[25] Holder, “Sail of the Century.” p 44

[26] Ibid. p46

[27] Ibid.

[28] Ibid.

[29] Claringbold, “Acoustics of the Sydney Opera House Concert Hall.” P4

[30] Ibid. p4

[31] Holder, “Sail of the Century.” p 44

[32] Claringbold, “Acoustics of the Sydney Opera House Concert Hall.”p 4

[33] Ibid. p 4

[34] Ibid.

[35] Holder, “Sail of the Century.” p 48

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