IV. The Acoustics
What follows is an interview with Russell Johnson, of Artec Consultants, the acoustical designer of the Kimmell Center for the Performing Arts, by Charles Linn, FAIA. Mr. Johnson is widely acknowledged as one of the world’s leading theater design consultants and acoustics specialists. Click here fo a complete listing of the people and products behind in this project.

Architectural Record: There has been a great deal of discussion about the "Philadelphia Sound," and whether it will still be heard in the new hall. Can you explain what that is?

Russell Johnson – Photo Courtesy Artec Consultants Inc.

Russell Johnson: The players love to talk about the Philadelphia Sound. The Academy of Music, where the Philadelphia Orchestra has been playing, is a magnificent building. It is a clever room, in that they squeezed a tremendous seat count into a small space—it is an opera house. There are people everywhere, from the floor up to ceiling, from the proscenium right around to the proscenium. To improve the acoustics they put a concert shell into it, made of wood about 3/16 of an inch thick. The place is massively absorbing, and dreadfully designed, but they worked in it for decades. What Leopold Stokowski and then Eugene Ormandy—who conducted the orchestra in a very similar way—did to overcome the lack of reverberance in the room—this comes from legend—they encouraged the musicians to play in a completely unusual way.

I heard one musician say back in 1958, "we were taught at the end of a note you take the bow across and release the pressure a little bit and we simulate acoustical reverberation by the way we handle our bows"! They were taught never to bow in unison, it was every man for himself, which gives a kind of fuzzy sound. Again, this was to compensate for utterly too much clarity at the Academy.

Of course when they went to Carnegie Hall, and played the same way they did at the Academy—where they were trying to overcome a somewhat dry, weak acoustical situation—they played exactly the same way. The combination of that playing plus the good acoustics of Carnegie, made a wonderful sound. It made the reputation of the Philadelphia Orchestra.

A.R. Can you explain how the acoustics of the new concert hall work?

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R.J. Somewhere back around 1958-1962 I came up with the idea of making both multipurpose auditoriums and concert halls with quite a bit of acoustic adjustability, using things I kind of invented. Many of them were used years back in isolated places—it wasn’t as if I was manufacturing them afresh—but I came up with them before I knew of some of the old examples.
Here, we used three architectural design features. First, the hinged panels. They can open up to the acoustics control chamber, or close to make a solid wall around the perimeter of primary audience chamber. If you want to increase the reverberance you open the doors, and let the sound energy out into the chamber. There, it reverberates and mixes with the sound from the stage to give you the sound you’re looking for.

Over the stage there is a three-part canopy system, each part can go up and down independently. This has a tremendous impact on changing the acoustical environment. The third feature is to be able to put lots and lots of fabric everywhere. There are closets for it, and it’s all mechanized, so you can store it or you can bring it out into the inside primary chambers.

We put all of these features together in a kind of preliminary design. We laid out where all of the tiers were; how many seats were in each tier; where all of the seats in each of the tiers were, and where the organ chamber was. We designed that completely, and presented that to the building committee and Mr. Viñoly in the form of a model, and drawings. As Mr. Viñoly was working on it, he began looking for something new and exciting. He decided to take this basic design, and make it in the shape of a cello. Now, every surface is curvy, all of the balcony rails curve in and out in a sinuous way, the ceiling is swooping and rising and falling—so this simple acoustical design has been transformed into a completely different sculptural design.

The advantage of doing it in a simple way, as we did in the beginning, is you can use the previous 15 halls that are something like it as your model. But if all of the sudden you have a completely different architectural approach. You can’t go anywhere in the world to and find an example of that to study. And I can tell you that studying it in a computer or a scale model is fantastically difficult. In effect, Rafael, presented us with a tremendous challenge, but I think that the result is an extremely handsome room.

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