The Sounds of Science

In space, no one can hear you scream–unless you have a really good sound system. Take the Space Theatre at the Hayden Planetarium, part of the new Rose Center for Earth and Space that opened at the American Museum of Natural History in New York this past February. Designed to transport visitors on a five-billion-lightyear tour of the cosmos, the theatre features a 3D spatial sound system designed by Paul Garrity of Auerbach + Associates, which provides multichannel movement and sound effects and music synchronized to moving projected images.

Designed by Polshek Partnership Architects, the Rose Center for Earth and Space is a massive, $210 million, 333,500-sq.-ft. exhibition and research facility that also includes the Lewis B. and Dorothy Cullman Hall of the Universe, the Heilbrunn Cosmic Pathway, and the Gottesman Hall of Planet Earth. The Hayden Planetarium is inside the top half of an 87’ reflective aluminum-clad sphere, which perches on a tripod and seems to float within a 95’ glass-walled tube. The bottom half of the sphere contains the Big Bang Theatre, which shows just that: a recreation of the first moments in the history of the universe. The top half of the sphere contains the Space Theatre, which seats 429 visitors in a surround configuration and features a digital dome system that employs a Zeiss Mark IX Star projector. This massive device, which is situated in the center of the room and is raised and lowered for each showing, currently projects a film titled Passport to the Universe on the dome ceiling overhead. This approximately 20—minute film takes the audience on a 3D tour of the cosmos via digital data sets based on actual astronomical data provided by NASA’s Jet Propulsion Laboratory and the Hubbell Space Telescope.

For Garrity, who served as design principal and project manager for the audio systems, one of the biggest challenges in the Space Theatre was the space itself. "You have this giant metal sphere that people are going to be sitting in–what is that going to do to soundwise?" he asks. "The real problem is that in a sphere, if you put a speaker on one side, if it bounces too much off the wall it sounds like the speaker is in the wrong place. You get an effect where the speaker actually sounds like it’s on the opposite wall from where it really is, which is not exactly conducive to surround-sound.

"So the first challenge" he continues, "was working with the acoustician [Shen, Milsom & Wilke] to fuzz the room as much as possible so that we could control things. But there was also a concern expressed by some of the consultants that by fuzzing the room too much, people would feel a bit claustrophobic; they’d feel like they were walking into a closet."

Finding just the right balance led Garrity and his crew to use Level Control Systems’ Variable Room Acoustics System (VRAS), which is capable of producing an unlimited number of acoustic environments. VRAS is based on an acoustic model of two coupled architectural spaces–in this case, the physical environment of the Space Theatre and a virtual, more reverberant space simulated by the reverberation algorithm. The combined acoustic characteristics of these two spaces form the reverberant environment perceived by the audience, and the quality and amount of this reverb can be modified at will through the system's programming.

"The basic idea," Garrity says, "is that as the audience comes in, the room has a much livelier feel that it normally would. So as you come in, you feel like you’re walking into, say, a capital rotunda, rather than a closet. The room sounds like you would expect it to sound, with lots of bounciness. And then when the film starts, you can turn it off."

VRAS consists of a complex electro-acoustic processing system built around a network of microphones feeding into a multichannel digital reverberator and out again to a set of loudspeakers in the room to be processed. The reverberation algorithm is implemented on a DSP card plugged into an additional LCS LD-88 audio engine that is fed into the standard LD-88 matrix, and the routing, equalization, and level control of the microphones and speakers are handled by the LD-88s.

When it came time to design the system, certain decisions, Garrity says, were no-brainers. "We knew right away we’d need self-powered speakers," he explains, "because there was no room in that space for amplifiers. There’s a crawlspace about 5’ high underneath the floor that had to be shared with all kinds of other equipment, not just sound. The control room was tiny, and we had to really work to squeeze in even a couple of audio racks. So we felt we had to use powered speakers, because we hardly had another choice.

"But it turned out that this was the perfect installation for powered speakers," he continues, "because there’s a catwalk that serves every single location. If you have a problem with an amp, you can walk right up to the speaker and push the button on the back."

What sets this surround system apart from typical surround configurations is that it doesn’t just surround the listeners, it practically envelops them, hitting them not only horizontally, but above and below. "If you think of a typical 5.1 system, you think of center, left, right, and surround, in front of and behind you," explains Garrity. "You don’t think about going over your head and around the side. But there’s no front to this room, and there is no left and right."

The Space Theatre's projection surface is a dome within a dome, consisting of a perforated metal hemisphere inside the upper half of the 87’ outer sphere. Most of the full-range loudspeakers for the 32—channel sound system are mounted in the space between the two domes. Three zenith speakers (Meyer CQ-1 and CQ-2s) are suspended at the very top; these are generally treated as a single channel, though they are separately controlled and tuned. A mid-level horizontal ring consists of eight equally spaced Meyer UPA-1P self-powered speakers, while 12 additional UPA-1Ps are spaced at 30° intervals at audience level. This last group is joined by 11 EAW UB-12 under-soffit rear fill speakers (for the back rows) fed via a Peavey MediaMatrix system slaved to the LCS outputs.

There are also four loudspeakers at the lip of the Zeiss projector's moveable platform, as well as three Bag End S18E-a/ELF-1 subwoofers above the dome and a monaural feed to the preshow area. The center platform speakers help to combat a sonic "behind-the-head" imaging problem that can often afflict audiences in the round. And just to give it that Millennium Falcon in hyperspace feel, Garrity added over 500 Aura AST-2B-4 bass shakers. "We added the Auras just to give it that extra sort of kick," he says. "We wired every single chair with a small direct radiating bass shaker, which actually puts bass frequencies right into the chair itself, and also on the floor, so you get a feeling in your toes as well as your back."

The sound system is controlled by an LCS SuperNova system with four LD-88G Audio Engines. Each LD-88 is a rackmounted automated matrix mixer with eight inputs and eight outputs, and the four modules together are configured as one large matrix with a total of 32 channels of audio I/O.

The prerecorded material for the show is played back from an integrated LCS Wild Tracks subsystem, which allows hard disks to be connected directly to an LD-88 mixer and to provide audio streams directly to the system's multichannel digital audio bus. Each of three LD-16S interface cards provides 16 tracks of instant-start playback from hard disk, for a total of 48 tracks. In addition, each Wild Tracks card has a second hard disk attached for safety backup, using the LCS SafetyNet feature.

The recorded sound material consists of narration by Tom Hanks, original music composed by Stephen Endelman, and sound effects designed by Paul Soucek. Sound designer François Bergeron did the final mixing of the show onsite. The music tracks were originally mixed on a 32—channel Sonic Solutions system and the voice and sound effects were on 24 tracks of Pro Tools. In order to integrate the component parts, the music was first transferred to the LCS Wild Tracks disks and then the voice and effects tracks were mixed onsite using the LCS with its SpaceMap feature to impart spatial movement and 360° panorama to the sounds.

"François took everybody else’s pieces and integrated them, mixed them, and made it into the wonderful show that it is," says Garrity. "And it was sort of a testament to our work when he came in, looked around, saw what we did, and said, ‘It looks great. Let’s do a show.’ "

SPL Integrated Solutions served as specialty contractors for the Space Theatre; Casey Sytems served as contractors on the rest of the project. Julio Marrero is the technical director of the AMNH; Benji Bernhardt is the sound enginer. Daniel Mei of Auerbach worked with Garrity on the project.

This was a big project for Auerbach + Associates; in addition to audio, the firm also designed key elements of the lighting, staging, and technical systems of the Planetarium. They also assisted Polshek Partnership Architects with the seating configuration, sightlines, and staging elements in the Space Theatre, designed the technical systems for the space show, and its lighting division, Auerbach + Glasow, designed the theatrical architectural lighting system in the theatre.

"The Hayden Planetarium is an example of a building that completely integrates an elegant architectural form with the service of a scientific and educational function," says S. Leonard Auerbach, president of Auerbach + Associates. "It gave us the opportunity to solve interesting theatrical design challenges within the Planetarium’s theatre, as well as to apply advanced technology in the creation of spectacular theatrical effects."