From Issue #2 , Page #26 | By Sandra Miller

There's no need to see audio to appreciate it. Here's a peek at advances in ultra-thin audio.

With so much music available through your PC, you need something better than the plastic boxes that shipped with your desktop.

New advances in audio technology are making it possible to hear rich sound from speakers you can't even see. It's not magic, but technology integrated into flat surfaces, using materials both transparent and opaque.

Two companies currently offering thin audio technology are Manifold and NXT. These technologies are showing up in places, such as on computer screens, as well as some unique areas, such as interior trim in automobiles.

In addition to the complete redesign of products with integrated audio components, ultra-thin audio technology operates quite differently from traditional speakers, thus allowing better sound quality in devices where previously audio fidelity woefully suffered.

Transparent Audio
West Newton, Mass.-based Manifold Products has introduced Thin Film Audio (TFA) as a revolutionary application producing stereo-quality sound from a transparent membrane.

Similar to existing audio equipment, TFA uses piezoelectronics to energize a thin membrane, thus generating sound. However, TFA differs in that the vibration is in the plane of the film, instead of perpendicularly as with conventional audio. The unique geometry of TFA also allows the film to be divided into separate segments to produce true stereo sound on a single membrane.

Another significant difference between TFA and traditional audio is that it operates in the 2,500-to-4,000-Hz range. What this means is that the performance of the speaker is not affected by its size or placement. While traditional speakers need an enclosure, TFA can be directly overlaid on a flat surface, such as a monitor, and continue to deliver complete fidelity. Manifold's TFA technology, trademarked as Clear-Fi, is actively being integrated into consumer electronics such as computer monitors, laptops, televisions and handheld devices.

"Thin Film Audio and the Clear-Fi solution establish a new benchmark for audio/video integration, with two important advantages," says Kevin Johnson, CEO of Manifold Products. "First Clear-Fi liberates the desktop space which is now taken up by loudspeaker enclosures, and second, it does this while providing the ideal listening experience in the multimedia world."

A Speaker Revolution
NXT is also working on thin audio formats. The UK-based company has developed audio using piezoelectric materials instead of a loudspeaker diaphragm as a modal velocity transducer.

With most conventional audio, the diaphragm of the speaker acts as a piston—moving rigidly to displace air at the surface. Therefore, the power of the speaker is dependent upon the diaphragm's size . Higher frequencies are delivered from the vibration of the narrower angle of the diaphragm, thus the size and shape of the cone determine the quality of sound attainable. But the NXT technology works by initiating and exploiting bending resonance in the panel, which they refer to as "distributed mode." Unlike the diaphragm, this sound quality is not affected by the panel's dimension.

SurfaceSound, which is opaque, and SoundVu, their transparent product, are NXT's core technologies.

The automotive industry has welcomed the idea of invisible speakers in the new vehicles. The advantages are a smaller installation footprint and less weight. Using NXT's Audio Full Range (AFR) technology, flat speakers can match the bass capability of cone drivers, yet continue to deliver distributed-mode radiation at higher frequencies.

One such application example is in the super-sleek Buick Bengal. When Dave Lyon, chief designer at Buick Brand Centre, was creating the prototype, he went looking for the bleeding edge in audio technology. What he found was NXT's SurfaceSound, which allowed them to integrate 5.1-channel surround sound right into the interior of the concept roadster. NXT's technology is showing up in lots of expected places as well. Brookstone's Wafer-Thin CD system and TDK's Tremor speaker series both sport NXT's SurfaceSound technology.

The transparent version of NXT's technology, SoundVu has increased the resonance area on Siemens mobile devices from 600 Hz to 3.4 kHz, thus offering much better sound quality for hands-free operation. NEC has also licensed NXT's technology for integration into their Valuestar desktop computer LCD monitors. By adding audio to the video display, image and sound achieve full synchronicity to enhance the user experience.

Other companies are also on-board. For instance, Pioneer and KEF are each offering their own home-theater-in-a-box products with NXT inside.

Looking down the road, contractors and interior designers are expected to jump on the bandwagon taking full advantage of these revolutionary technologies. Some audio speakers will be making a disappearing act, by blending into surroundings such as windows, walls and suspended ceilings.

So next time you think you hear something, but aren't sure where it might be coming from, it's not your mind playing tricks, it might just be the magic of thin-audio technology at play. -Sandra Kay Miller