Breaking the Boundaries of Stereo

by FOH Staff • in
  • Editor's Note
  • March 2018
• Created: March 13, 2018
George Petersen, Editor of FOH Magazine

If you have wandered anywhere near industry tradeshows such as NAB, AES, CES, ISE and this month’s USITT Conference & Stage Expo (Fort Lauderdale, March 14 to 17), you will have been inundated with a lot of buzzwords. Perhaps the hottest term these days is “immersive,” in the form of immersive audio, immersive staging and nearly every other type of immersive experience.

In fact, last month’s ISE 2018 show in Amsterdam featured an expanded “Immersive Technology Zone,” which displayed a range of innovative Virtual, Augmented and Mixed reality products and experiences, highlighting their relevance for the AV marketplace.

‡‡         A New Dimension

In terms of audio immersion, we’ve moved way beyond those trippy Laserium planetarium light shows of the 1970’s that you might recall — or depending on your degree of chemical abuse, might not be able to recall. In fact, it was a couple decades ago that I went into a demo room at NAB that featured a Fairlight DAW playing back 64 channels of audio to 64 discrete speakers placed around the walls of an enclosure, providing an impressive demonstration of the system’s real time reproduction capability. But technology marches ahead, and in 2018, assembling a DAW playback system with hundreds of simultaneous tracks for any sort of special presentation is hardly a difficult ordeal.

In terms of cinema systems, we’ve progressed from mono to LCRS to 5.1, 6.1 and beyond. On the live audio side, Pink Floyd’s early tour experiments with Alan Parsons mixing a 4-channel surround system were interesting but didn’t exactly take off. (Note: That particular system was not quite “four-corner” quad, but was comprised of a center, extreme left, extreme right and rear speakers, with FOH in the center, so audience perspectives could have been odd, depending on seat locations.)

Even since its earliest days, productions such as Cirque du Soleil have broken new ground as far as sound design, simply by placing dozens of speakers with discrete feeds throughout the performance and audience areas, creating an “immersive” space. Here, even a single sound effect, instrument or other audio element coming from overhead (or under a seat!) can create a powerful impression. The idea is hardly new, as sound designers have been doing tricks like “speaker feed in the rear” style techniques for decades. Yet modern, DSP-driven loudspeakers offering digital steering capabilities open a world of possibilities to the audio pro that go well beyond the limitations of the proscenium border as presented by a conventional fixed system.

One of the forces driving new developments in spatial manipulation is Virtual Reality — and of late, VR has become a hot buzzword among the technologerati. Currently, Sennheiser has been spotlighting its AMBEO 3D Audio Technology, which is based around a 360-degree mic with four matched KE 14 capsules in a tetrahedral configuration. This exhibition, called “Pink Floyd: Their Mortal Remains,” is currently at Rome’s Museo d’Arte Contemporanea, after a successful run at London’s Victoria and Albert Museum. Playback is via 25 Sennheiser and Neumann speakers and subwoofers, distributed at different heights, and — mounted 20 feet above — speakers for “voice of God” effects.

‡‡         Taking the Plunge

And interest continues to grow. Rock band alt-J plans a special show this summer, featuring L-Acoustics’ L-ISA immersive audio system. (See main story on page 5 for more details.)

Aside from consumer directions, audio development for VR binaural headphone use also opens myriad possibilities for live pro applications. Certainly, headphone-based “silent concerts” are an obvious choice, but bringing more spatial manipulation opportunities into IEM rigs (such as the Klang Technologies systems) should be welcomed by artists.

Beyond the let’s “drop in some directional effects,” multichannel audio playback can also be used for acoustical simulations/recreations, such as the immersive audio installation at Cambridge, MA-based American Repertory Theatre (see related news story on page 12). Here, a Meyer Sound system — combining LINA line arrays, with 88 surround speakers driven on the D-Mitri audio platform under SpaceMap software control, not only affords creative 3-D panning/placement of audio elements, but also allows tweaking the room’s acoustical signature.

Whether for audio-only concerts, live theater, museum presentations and more, any expansion beyond the limits of traditional hard-left/hard-right can be a powerful thing. And if done responsibly — remember those nasty whirling corner-to-corner pans on early stereo LPs and surround audio releases? — imparting expanded spatiality into our audio lives can be a good thing that adds realism (or surrealism!) and a healthy dose of creativity into all our productions. Just go easy on those joystick panners…

Give it a try!

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