@U2 NOVEMBER 6, 2003 - by Sherry Colombaro


U2 is often the first band on the block with new touring technology. From Zoo TV's travelling television studio, to PopMart's screen with blue LEDs and Elevation's XL Video and LED video walls, the band has shown a tendency to focus on the visual side of the cutting-edge.

Until now. For the next tour, U2 may break sound barriers with the Audio Spotlight, created by Watertown, Massachusetts-based Holosonics.

Around July 2000, Bono, Edge and Brian Eno arrived at the opening of the MIT Media Lab Europe in Dublin. Upon walking in, Bono approached MIT doctoral student Joseph Pompei and said "Where's the audio spotlight?" Pompei impressed not only the members of U2, but also everyone present. And now, he's set to impress the world with his invention, the Audio Spotlight.

The Audio Spotlight is to sound what the spotlight and laser are to light. Instead of filling a room with sound as a traditional loudspeaker would, the Audio Spotlight allows sound to be channelled through a narrow beam, allowing only those in its path to hear it while "lighting up" backdrops with an audible array of sounds - imagine replacing the lighting in Bad with swirling sounds and you begin to get the idea.

@U2 was fortunate enough to sit down recently with Dr. Pompei in his Watertown office to talk about his invention and the way in which he became involved with U2.

Pompei said the Audio Spotlight was something that "really excited them [U2] - to mimic the kind of effects that you do with lights, only with sounds - so his [Edge's] guitar can fly by your face, for example." Or imagine the sound of an airplane taking off in the middle of Beautiful Day as a wave of sound, instead of a wall of sound. These effects would add spatial quality or some audio motion to the live show, in the same way a spotlight can shine on only Bono or on the entire audience.

The way the Audio Spotlight works is by using ultrasound to direct the sound through the speaker and to the listener. The sound can be directed to a specific area so it can only be heard in that location. Pompei demonstrated this at the MIT Media Lab using a John Coltrane saxophone solo. "I had his saxophone flying around the room and whizzing by people's faces... they were blown away by it."

Dr. Pompei has been meeting with members of U2 since then to explore how the Audio Spotlight can be used in a concert environment. "They are rather innovative thinking-wise. We actually went out to the Staples Center in L.A. with some of our sound equipment so that we could do a proper acoustic assessment of the space and understand what it would take to get an Audio Spotlight to work in that kind of environment," Pompei said. He feels that about a dozen speakers would suffice in an environment like that, acting like theatrical spotlights.

"You could synchronise it with the lights themselves, and the lighting designers are already well versed and well trained to choreograph lighting, so they can think in the same terms of lighting as they do with sound."

Even though Pompei would not confirm the Audio Spotlight will be part of U2's plans for their next tour, they are listed on his web page as a client. Pompei did sound optimistic that it could be available when the tour starts, "Might be. We'll see. It's possible." Willie Williams, U2's long-time tour and lighting designer told @U2 that he's heard of the Audio Spotlight. "Edge mentioned the Holosonics idea some time ago, though there are no firm plans to use it on the next tour."

At age sixteen, Pompei became the youngest sound engineer at the Bose Corporation, and at the age of twenty-one had the desire to explore the notion of directing sound. According to Pompei, "I don't think they [Bose] were all that interested in what a twenty-one year old had to say about the future of audio technology." So, he enrolled at Northwestern University and studied psychoacoustics and auditory physiology. After investigating underwater SONAR research done by the Navy in the 1960s, he stumbled upon something from the 1980s. "And there were a couple of papers from the early 1980s about a couple of Japanese companies who were trying to do this in air - and make a loudspeaker out of it. Now when I saw those, I got very excited because I said, 'Hey - maybe this is really possible.'" Pompei noticed where the Japanese researchers went wrong in their math, and realised that he was well on his way to an invention that will change the way people experience sound.

He then landed at the Massachusetts Institute of Technology's Media Lab for his doctorate, and successfully developed his first prototype. After realising that his invention worked, he said, "I was psyched. I was a little bit dazed at first. I remember the first time I turned on the most modern prototype, it was about seven or eight in the morning and I had been up all night. I was a little bit groggy and I shouldn't have been working with electronics at that hour. But I was. I remember turning it on and expecting a very faint sort of sound. So I turned it on and just hear this loud-like tone come out. And I shut it off right away because I thought it might be broken, because it shouldn't have been as loud as it was. And I didn't think it was going to work as well. So then I kind of checked everything and turned it on again and kind of played with it and, lo and behold, it was actually doing what it was supposed to do."

Now, a few years later, with the Audio Spotlight being used in museums and trade shows around the world, Pompei is excited about the opportunity to move the technology into the concert arena. He'd be happy to see anybody using the technology, although when pressed for specific artists he admitted, "I wouldn't mind if Jimi Hendrix was still around using audio spotlights."

For now, it looks like U2 will be the poster child for this technology. And with the impending tales of upcoming tours and concert dates it might not be long before it is your face that Edge's guitar is whizzing by.