"Transparency in Audio/Video Design"

by Keith Yates

A few years ago I got a commission to design a Media Room with a difference. The client wanted the room’s purpose—an all-out assault on the state-of-the-art in A/V hardware and acoustical engineering—to be clear to the audience, yet he still wanted the room to be conducive for chatting and entertaining before and after the movie screenings. Instead of hiding the mechanics that made the room a successful entertainment venue—e.g., the speakers, subwoofers, diffusors, reflectors, absorbers, pressure traps and so on—I decided that these elements should be revealed and even celebrated in a theatrical, peek-a-boo way.

Upon entering the room, you’d encounter a calm, expansive grid of stretched gray fabric on the walls and ceiling. But as soon as the client took his seat on one of the tiered platforms and touched the “Showtime!” button on the touchscreen controller, the house lights would ramp down and, for about 10 seconds the lights behind the fabric walls and ceiling would turn on, illuminating a vast array of whirring, rotating machinery behind it.

The faces of the individual rotating acoustic panels would be brightly painted in stoplight colors—red, yellow and green—according to their acoustic function, and the speakers would move to optimized positions on a custom, motorized platform system I dubbed the SpaceShuttle™ while the 15-foot wide video screen swung down from the ceiling. I wanted the audience to suddenly realize that they weren’t just inside a large room, they were inside the belly of a giant machine, a machine that by itself could provide a short but intense sense of occasion, a techno-spectacle, an industrial ballet if you will.

Philosophically, my design owed a lot to Le Corbusier’s famous argument 70 years ago that “a house is a machine for living in.” And while Swiss-born Charles-Edouard Jeanneret (or “Corbu” as he became known) made a profound impact on 20th century architecture and furniture design, ending up as well-known in the US as Frank Lloyd Wright and even living to see his mug on the cover of Time magazine, his house-qua-machine ethic was passe by the time media rooms became de riguer in custom homes in the 1990s.

In a way it’s a shame, as speakers like the Italian-made Sonus Fabers and a handful of others from small specialty manufacturers have finally turned speakers into sculptural art. It’s too little, too late: No matter what style the entertainment venue—a lively Art Deco home theater, a restrained, Armani-like media room, or anything in between—modern practice is to conceal the A/V and acoustical hardware. The trend can be seen in the feature spreads in home theater magazines, in the equipment itself, and in the way electronic components are organized into systems.

Disappearing Acts
Twenty years ago, speaker designers started “domesticating” their product lines by introducing 3-piece satellite-subwoofer systems that were easier to place and less conspicuous than their hulking floor-standing ancestors. Ten years ago, speaker companies like Triad and KEF began turning the in-wall speaker into a respectable hi-fi device. Now, in the late ’90s, new breeds of in-wall and on-wall panel speakers are emerging that promise even less visual presence and more uniform sound coverage.

Video displays have slimmed down, too. Rear-projection sets which consumed nearly three feet of depth in the mid-1980s took up barely half that depth just a decade later. For more impactful, cinema-like presentations, front-projection screens have become motorized, remote-controlled affairs that drop into place through a slot in a cabinet or soffit.

In the meantime, A/V electronics have been doing their own disappearing act. Increasingly ensconced in professional 19-inch racks docked behind cabinet doors or in their own closets or control rooms, racked components provide a unified appearance, reduce space (“real estate”) requirements and facilitate cable management, electrical distribution, ventilation, service access and even software storage. All of this has been duly noted by writers in the popular press, who like to refer to it as the growing “stealth” effect in modern entertainment systems.

Room for Improvement
But there’s a lot more to getting goosebump experiences than simply buying the latest gear and hanging a few movie posters on the wall. As anyone who has ever spent serious money on A/V components has learned, the engineering of the room itself is the weakest link in the playback chain, and usually, therefore, the missing ingredient in the recipe for immersive playback experiences.

To begin with, residential spaces need more absorption and more diffusion than an untreated or casually treated room typically offers. To be effective, absorbers and diffusers must operate across the broadest possible range of the audible spectrum, which typically means they must be big (many square feet) and at least 4 or 5 inches deep, and usually more. It’s one of Murphy’s laws, natch, that they also need to be placed right where they’d look most hideous-at ear- or eye-level or in front of a window or doorway or just where a prized painting was going to go.

The sheer size and ugliness of acoustic devices have given rise to a boom in the wall upholstering industry, which has been scrambling to keep up with the demand for stretched fabric track systems to conceal speakers and bulky acoustic treatment in media rooms and home theaters. In the simplest cases, an acoustically transparent fabric is stretched pretty much floor to ceiling on all four walls and on the ceiling. The fabric has to stand off from the face of the walls themselves a sufficient distance to accommodate the surface-mounted absorbers, diffusors, etc., meaning the room “nets down” roughly a foot less in width and length and maybe half a foot less in height after the fabric is up. (In my no-holds-barred Le Corbusier-inspired project, the acoustics consumed six feet of width, six feet of length, and three feet of height.)

The result is that we’ve got rooms that give unprecedented control over acoustics and look better, too—no speakers loitering in the corners tethered by a tangle of fat wires—but we’re also saddled with walls that are relatively expensive to put up (the fabric track and installation typically run $8-10 per lineal foot) and which can be soiled, torn, dimpled and distorted with normal use. Built-out fabric walls also require careful detailing at doors, windows and other architectural features if they’re to avoid looking like an afterthought.

A Window to the Future?
While it’s true that acoustic treatment is as space-consuming as it was decades ago, there is one area of acoustic treatment that appears to be mirroring, if you will, the “stealth” trend in audio/video hardware. At an international acoustics conference in Berlin a few weeks ago I spotted a thin, perforated, see-through film that its maker claims provides significant absorption across a broad frequency spectrum. The material can be used in a fixed panel or roller-shade mechanism to provide optical transparency and acoustic absorption directly in front of a window.

Like other attendees, I was delighted but a little dubious, though it turns out that Kaefer’s “Microsorber” was developed at Germany’s well-known Fraunhofer Institute for Building Physics and is based on the work of an eminent Harvard physics professor 20-odd years ago. (The key to its operation is in the diameter of the perforations and the thickness of the material.) The data just emerging from the testing labs look promising, and the German manufacturer promises availability in the US by the end of the year.

If he’d lived to see it, no doubt Le Corbusier would have been disappointed by the invisibility of such a “machine,” but I suspect most of our clients will want to continuing applauding.

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