Acoustical Renovation of Queen Elizabeth Theatre, Vancouver BC Project Highlights QUEEN ELIZABETH THEATRE ACOUSTICAL RENOVATION, VANCOUVER B.C. Introduction tion, all of which can be influenced by the shape and size of a building. Only one of these compo- Like so many other performing arts centres, the nents came close to the required levels in the ex- renovation of Vancouver’s Queen Elizabeth Theatre isting building. took a very long time to complete. The acoustical assessment and design started in 1994 and the The acoustics of the Queen Elizabeth Theatre have completed building didn’t open until November long been lamented. It was typical of its post-war 2009. That period saw three complete designs of era. It had a very dry acoustic – it wasn’t reverber- the renovation, each fraught with financial chal- ant enough. It had a poor or non-existent spatial lenges requiring innovative engineering response. sound. It wasn’t loud enough, that is to say, it Schedule & Finance Challenges didn’t have enough impact. It lacked warmth. The ventilation system was very noisy. And there was a Much of the project was driven by acoustical de- lot of sound transfer between it and the adjacent sign requirements. Working in the prevailing Ca- Playhouse Theatre. The only thing it had going for nadian environment – one that has chronically it was acoustical Clarity, if anything, too much of it. underfunded performing arts infrastructure – the acoustical recommendations and their architectur- Reverberance al implementation had to be far more cost effec- The first renovation design, completed in the late tive than anything our colleagues overseas might 1990s, attempted to fix the building without re- face. To put this into perspective, Seattle renovat- moving the ceiling. The Queen Elizabeth Theatre ed a similar sized building for their opera company simply didn’t sound as reverberant as the tradi- in 2003 at a cost of US$127M. In 2009, the tional Reverberation Time measurements would Queen Elizabeth Theatre was renovated for only suggest. We noticed that the room, in its original C$45M. Toronto and Oslo opened opera houses state, was very wide and not very tall. Could this within two years of each other; Toronto’s cost be the reason for the poor Reveberance? Aban- C$103M, Oslo’s C$800M. Compounding these doning our building design tasks for a while, we challenges was a scheduling disaster halfway developed a series of experiments. Computer and through construction. Hazardous materials on the scale model studies on a number of simple six sid- site, in the form of lead dust, had to be removed, ed boxes (representing a theatre or concert hall) forcing a major redesign so that the project could revealed that perceived Reverberance can indeed be finished before the 2010 Vancouver Olympics. be related to the Height to Width Ratio of a room. Acoustical Challenges This concept has since been published several times and is becoming a recognised component of Much of the focus of the acoustic design was on acoustical design. the needs of the Vancouver Opera. To ensure good acoustics, modern opera house design typi- Then, the first renovation design fell victim to fi- cally limits the number of seats in the room. In the nancial shortages and was put on hold for more Toronto and Olso examples, the seat counts were than six years. 2,000 and 1,450 respectively. This was simply not an option for the Queen Elizabeth Theatre renova- Spaciousness tion. Opera only occupies the room 30% of the In the second design, the existing ceiling was re- time. For the rest of the year, popular music acts moved, a decision that was informed by our dis- are booked and they can fill a lot more than 2,000 coveries about Height to Width Ratios. The design seats. In short, the leading acoustical engineers of also included two new balconies (for a total of the world would never set out to build an opera three) and incorporated some of the more modern house this big. We did, because we had no other concepts of the so-called “Directed Energy” halls. choice. In a room that is too big acoustically (typically over 2,000 seats) it is possible to compensate with When the original room was built, the nascent sci- strategically located reflecting surfaces. In addi- ence of acoustics had identified only one aspect of tion, if those reflectors direct sound to arrive at sound they thought to be critical to the apprecia- listeners from the sides, an overly wide room can tion of sound in a room. We now know that there be made to sound more like the well-loved narrow are at least six components of acoustical apprecia- shoe-box shaped rooms of the 19th century, i.e. the space. This software, for the first time, allowed us sound will have a better Spatial quality – a single to calculate reflection direction and coverage in violin can appear to fill the whole room. Two de- real time. The reflectors needed to compensate sign precedents were employed; large lateral re- for what we lost in the lead dust crisis are aston- flectors in the ceiling space (similar to the Christ- ishingly small. The tilt on many of them has been church Town Hall in New Zealand) and a terraced optimised to within less than a degree. We have seating level in the orchestra level (inspired by the conferred with our colleagues overseas and we Berlin Philharmonie). These are both concert halls, believe that we are the first to optimise reflectors which are fundamentally different from a prosceni- on this scale and this accurately. um arch theatre such as the Queen Elizabeth. The Loudness only documented success of Directed Energy in a proscenium arch room of this size is the Seger- Some rooms are naturally louder than others. The strom Hall in Costa Mesa, USA. There was risk Queen Elizabeth Theatre was not loud enough. involved to be sure. Loudness was a very big design challenge. One of the concerns with a Directed Energy hall is that the Construction work on the building began in the first few reflections are sent to the acoustically summer of 2006. The plan was to do the work in absorbent seats, which presumably precludes the phases during the summer months when the thea- opportunity for further reflections that would even- tre was less frequently in use. In that first summer, tually embellish the later part of the decay and, of the building was literally cut in two. This was done course, the overall Loudness of the room. to prevent structure-borne noise between the two theatres housed in the building, the second being It seems a legitimate concern, at least at first the smaller Playhouse Theatre. The next summer glance. But during the design, a scientific paper the ceiling was removed and a new ventilation sys- was published suggesting that the opposite might tem installed. be true. It turns out there was also a previous pa- per suggesting the same in 1988. Two papers, Ventilation Noise however, are rather thin evidence on which to base Performers on stage need a quiet room in the critical engineering decisions. The veracity of the same way that painters need a white canvas. Most science in these papers was hard to challenge but, of the background noise in a concert hall or opera once again, the risk is clearly evident. In the end house comes from the ventilation system. Many the newly renovated Directed Energy Queen Eliza- new venues now use a displacement system to beth Theatre performed exactly as predicted in the provide air slowly and very quietly. Air is blown into two papers. a plenum below the seats and is allowed to drift up Results through holes in the floor. At the Queen Elizabeth Theatre this option was precluded by an existing The new sound in the room has been widely ac- parking lot underneath the audience. The solution, claimed by the client, users, press and public. first developed by Aercoustics, was to turn the concept upside down. Air is now blown into a se- What has transpired as a result of Aer- ries of plena in between the roof joists. The plena coustics Engineering’s work is, in my act as a noise control mechanism and take up a lot estimation, a minor miracle. We are de- less of the room’s precious acoustic volume than a lighted and – more importantly – the normally ducted system would. audience is thrilled. James W. Wright Half way through the summer of 2007 the lead General Director, Vancouver Opera dust disaster struck. The room had to be rede- signed, and rather quickly as construction was go- The renovated acoustics have also been quantified ing to re-commence in May 2008. The two new extensively with objective scientific measurements. balconies had to be deleted from the design, as In the cases of Reverberance, Spaciousness, did the terraced seating levels that were providing Loudness and Warmth, measurements in the ren- the critical lateral reflections for Spaciousness. ovated room exceed Just Noticeable Differences Quite fortunately, it was at this point that we dis- (JND), proving the audible improvement. In the covered a new software tool, originally intended to latter case (Warmth) a comparison was made be- optimise lighting in green buildings. tween eight of the world’s favourite opera houses. The original Queen Elizabeth Theatre came last out It is extremely difficult to design a reflector to its of the eight. The renovated room came first. optimum location and orientation in 3-Dimensional Owner: Vancouver Civic Theatres Rae Ackerman, Natalka Lubiw Acoustician: Aercoustics Engineering Ltd.