Seen and Heard

by Alison Rose / Canadian Architect (November 2002)

Earlier this fall, Toronto's Roy Thomson Hall unveiled the results of a controversial architectural renovation to address problems with its acoustics.

When the acoustic enhancement of Roy Thomson Hall was well under way in the summer of 2002, Charles Cutts, President and CEO of Massey Hall and Roy Thomson Hall, was so enthusiastic that he said he thought the refurbished Hall could rival Carnegie Hall in acoustic quality and had a good chance of having among the best acoustics of large halls in the world.

The design team for the renovation was led by Thomas Payne of Kuwabara Payne McKenna Blumberg (KPMB) Architects and Russell Johnson of Artec Consultants Inc., the man Cutts considered the finest acoustician in the world. And construction managers Steve Metcalfe and Steve Seifert of Ellis Don had been keeping the $20 million project proceeding smoothly.

The refurbished hall opened to high praise in the local press with a gala concert held on September 21st. National Post reviewer Tamara Bernstein was thrilled: "For the first time, I've heard singers' consonants resonate through Roy Thomson Hall... Artec Consultants Inc. has transmuted the hall's leaden acoustics into something that sounds an awful lot like gold." In the Toronto Star, William Littler wrote that "there was a depth and richness to the sound that surpassed what the original hall was able to offer." "Does Toronto now have one of the world's greatest musical venues?" he asked. "Not really. But it is much closer to having the kind of hall the Toronto Symphony Orchestra needs and music lovers want than many of us believed possible."

The preliminary reviews agreed: Roy Thomson Hall's $20 million acoustic enhancement project, completed on time and on budget, had succeeded. All that would be left to determine, in the months and years ahead, was by how much.

The beginning of the renovation was surrounded by well- publicized controversy. When the acoustic enhancement was first announced in January 2000, the hall's original architect, Arthur Erickson, publicly and pointedly criticized the project. He wrote that acoustics were an "intangible pseudo-science" and wanted to know why the hall had hired Johnson rather than an acoustician comfortable working in a round hall like his. The public acrimony ultimately ended with Erickson calling Johnson and writing a conciliatory letter to the editor in which he wrote that he understood why the acoustic changes were necessary--the acoustic science relied on when Roy Thomson Hall was built was imperfect. Erickson expressed hope that Cutts would include him the discussions about how to render the necessary changes, but that was not to be. Cutts concluded "why put Russell or our organization through another strong force on the team, when I had already hired the strong force that was driving the project?"

The relationship was further complicated by the fact that Cutts held Erickson responsible for the acoustic failings of the hall. In discussing his reasons for not including him, Cutts recalled that "I had also heard through several individuals who are still around and active in this corporation who were around at the building of Roy Thomson Hall how it was Arthur's force, his personality, his drive that overrode some of the considerations of size and special elements that [acoustician] Ted Schultz had wanted."

Cutts couldn't imagine giving Erickson a seat at the table in an honorary, consultative way. He didn't see that having Erickson as a resource might have benefited the project; if anything, he concluded the opposite.

In 1981, Edward Pickering, Cutt's predecessor, gushed that Toronto would have "one of the premier concert halls of the world." He, along with Erickson and acoustician Ted Schultz of Cambridge, Massachusetts-based Bolt, Beranek and Newman (BBN), wanted to build a hall that would rival the greatest halls in the world.

In Seven Stones, a book of Erickson's work written while Roy Thomson Hall was being built, the architect recalled that the design team built 32 different models in order to establish the shape of the room and to make sure the acoustics would be correct. In contrast to the notion that its architects rejected traditional hall design, among the models was a traditional shoebox shape like 19th century concert halls, with three or four levels of boxed balconies. Erickson said Ed Pickering rejected the shoebox because he thought boxes were "elitist." He recalled that "one of the things he [Pickering] didn't like about modern architecture is the straight line that you never find in nature." Both Erickson and Pickering considered their acoustician, Ted Schultz, "one of the foremost acousticians alive today." And Schultz believed he could make the acoustics of the round hall work; he was supervising the acoustics of three other similar halls at the time. All were attracted to the idea of a hall in which sight lines, leg room and visual intimacy were dramatically enhanced by widening the hall and bringing the rear balconies forward.

However, Pickering assured the press, "nothing would be subordinated to getting superlatively good sound."

Referring to the context in which the first Roy Thomson team was working, Russell Johnson said it "was a brave new world, and everyone thought that science and technology would win the day, and all you had to do is be very, very smart and very adept with... a slide rule... it's taken a long, long time for the world to gradually recognize that you just can't sort of thumb your nose at mother nature."

Johnson's first significant contribution to the field of symphony hall design was to resolutely turn his back on modernist instincts. Studying architecture at Yale University, Johnson analyzed the halls of the 18th and 19th centuries, and assessed the things they all had in common with respect to shape, volume, seat counts, and building materials. In 1954 he was invited to join the fledgling firm of Bolt, Beranek and Newman, the first large commercial acoustical consulting firm in the world, where he worked with, among others, Ted Schultz. When he eventually established his own firm, he began to reproduce the qualities of 19th century halls as precisely as he could, and then sought to improve upon them.

Charlie Cutts arrived at Roy Thomson Hall from The O'Keefe (now the Hummingbird) Centre--another modern performing arts space with its own acoustical problems--in 1992. In a 1994 strategic planning exercise, Cutts proposed that Roy Thomson Hall investigate what would be required to improve its acoustics. In September and December 1995, Artec produced two reports: What's Wrong with Roy Thomson Hall?, and a follow-up set of recommendations on how to make it better.

Artec set out a total program for upgrading the acoustics and advised that to make a significant improvement, the program must be executed in total. The program included 10 recommendations, of which Roy Thomson Hall decided to implement eight, postpone a ninth until the symphony's new conductor could have a say, and eliminate only one. The installation of a new musicians' riser system was postponed so that a new conductor could participate in this part of the renovation. And in consultation with KPMB and Artec, RTH decided to reject the one item on the list having the least acoustical impact but a significant architectural one: a redesign of the balcony front profiles.

The Hall invited three Toronto-based architecture firms to present drawings interpreting this work in architectural terms, from which Thomas Payne and KPMB were selected. Ellis Don were hired to manage the project. The clients wanted the work done with the least amount of down time possible, which was finally agreed to be 22 weeks, between March and August 2002.
The list of acoustical changes included: making the room as silent as possible by improving the noise and vibration control of the air handling systems and installing new quieter dimmers, lamps and ballasts; reducing the volume of the hall and narrowing a portion of the hall; replacing the original acoustical system of fabric banners and tubes and clear plastic disks with one or two very large, moving acoustic canopies; adding seating boxes on the main floor; adding retractable sound absorbing banners on the walls; rebuilding and extending the front edge of the stage three feet out; and replacing the carpet in the hall with a hard finish.

In the upper reaches of the hall, above the highest balconies, the walls were brought in by as much as 20 feet, reducing the hall's overall volume and introducing parallel walls for running reverberation. The new bulkheads reduced the room volume by 135,000 cubic feet, or 13.5 percent. The walls were brought in to the edges of Erickson's oculus--his ceiling treatment of banners, sound reflective canopies and lights. This was replaced with a very large sound reflective canopy weighing 38 tonnes and a smaller, crescent-shaped canopy weighing 10.5 tonnes, both of which can be lowered and raised. Johnson explained that only a very large acoustic canopy reflected all frequencies of sound evenly. By adjusting the canopies' height, the hall could be adapted for different kinds of performances. Built into the canopy are theatre lights, sprinklers and a retractable speaker system.

On the floors, sound-absorbing carpeting was removed and replaced by maple hardwood flooring. All steps were edged for contrast in a dark, exotic wood from Brazil called ipe.

Retractable sound absorbing banners were concealed within the bulkheads, to be dropped down over the walls during amplified performances. These were sewn out of two layers of 26-oz. custom-dyed grey velour. When not in use, these banners fold up like roman blinds inside banner boxes at the tops of the walls.

One invisible acoustic change to the hall occurred at the stage. KPMB and Artec eliminated a plywood underlay and used thicker 1-1/8 inch maple flooring, resulting in a more reverberant while still durable surface.

Thomas Payne and KPMB's difficult task was to render these acoustic improvements architecturally. Describing his admiration for the architecture of the Hall and for Erickson's work in general, Payne spoke in terms of "re-honouring" the building's original architecture. His architectural solution to Artec's precise requirements was to think of the changes to the hall in their sum, describing the process as one where he and his team were constructing a wooden acoustic instrument to sit inside Arthur Erickson's original concrete case.

The stage surface was already built of maple. Payne proposed to extend the same Canadian maple throughout the hall, in new wooden flooring, the veneers on the new walls of seating boxes on the floor level and the bulkheads, and the surface of the acoustic canopies.

The architects found that five inches of oriented strand board in 5/8-inch plies provided the desired density of 16.5 pounds per square foot. The faces of the bulkheads and of the acoustic canopies are constructed of this, and then covered in 1/10-inch Canadian maple veneer. The veneer was run through corn rollers to raise the grain, because Artec specified that they preferred a textured surface with a positive micro-acoustic impact to a smooth lacquered surface.

Wood also served in terms of the construction timeline: the components could be constructed off-site, brought in through the stage door in pieces and assembled relatively quickly once inside.

But one of Arthur Erickson's strongest objections was precisely to the use of wood, and he questioned KPMB's reasons for introducing this material within the hall, arguing that wood had no inherent acoustic advantages over concrete. In fact, Artec specified the new surfaces had to have the equivalent mass of three-inch concrete. The only other material proposed to cover the new wall surfaces was plaster, which KPMB considered but rejected early on as being architecturally unsatisfactory.

Payne defends his choice of wood for Roy Thomson Hall from a psychological perspective: musicians and performers said they liked wood, the wood would add warmth to the cerebral cool of Erickson's concrete, and it would have a psycho-acoustical benefit for both performers and listeners. He argued that if patrons enjoyed their experience of music in the hall more, they would actually like the hall better. He further argued that the use of wood would allow the new to be distinguished from the original. Finally, he said, "It's an expressive decision. It's an interpretation of a situation, and an impulse to create something that will be successful beyond anything else that might be done."

The large canopy, called the sunburst, is a disk of thick, closely set wooden beams radiating from the centre and studded periodically with rectangular onyx light fixtures. The smaller crescent-shaped canopy nests around it, and is constructed of the same materials. Compared with Erickson's and interior designer Francisco Kripacz's original ceiling treatment, they are not visually complex enough to distract the eye from the structure of the ceiling above, which is constructed of pie-shaped pre-cast concrete slabs and was never intended to be so visible.

Visually, the most significant changes to the hall are the volume-reducing bulkheads. The bulkheads narrow the walls above the upper balconies creating a thick, blocky overhang that closes the hall in. One can only try and imagine if the alternatives--constructing the bulkheads of concrete, or surfacing them in grey plaster--could have been visually less intrusive, and might have contrasted with the wood of the canopy, identifying it as a unique element. But the awesome soaring quality of the original sheer concrete walls would have been lost regardless.

"When you're improving an existing room, you can only aim for the possible, the reasonable and the doable" said Russell Johnson. He was speaking about what one could expect to achieve in an acoustic renovation, but his comments seem to apply to the architectural changes as well.

Also difficult from a visual point of view are the parterres, or seating boxes, added to the orchestra level. Artec recommended replacing the last four rows on the orchestra level with three-row boxes, and replacing seats at the ends of rows with two-row boxes separated by aisles. These have been designed with angular walls in the curved space, and the effect is slightly jarring.

Charlie Cutts said from the beginning this was an acoustically-driven project, not an architecturally-driven one. His acoustician promised that "the changes will positively affect the musicians and those attending performances or programs." And on this promise, he delivered. The insertion of Payne's wooden instrument as a lining to the hall's concrete case may take some getting used to, visually. But it sounds very, very good.