Seems Like Old Times
Catching up with the "new" rig

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Sometimes opportunity knocks twice. Recently, my company got to return to the Georgia Dome in Atlanta, where a couple of years ago we first premiered NEXO GEO T loudspeakers and CAMCO power amplifiers in the U.S. (See November 2003 issue of Live Sound).

Two years have passed, and the system has more than met our expectations in terms of its rigging, small size and weight, and output and coverage capabilities. The loudspeakers themselves haven’t changed, but the controller has gone from the model NX241 to the NX242, with several software upgrades issued as well.

This time out, we were providing sound reinforcement in the same cavernous dome for a corporate event by Herbalife, marking the company’s 25th anniversary and hosting thousands of company representatives from around the world. SSE Hire Ltd. of London is the contractor for all Herbalife shows, and also provides language translation services in conjunction with RJ Steventon and Mike Devlin at American Translation Services. By the way, for this event wireless bodypack receivers were distributed to roughly two-thirds of the audience so they could listen to live translation in 27 languages.

My friend Chris Beale, director of SSE Hire, was instrumental in the development of the GEO T loudspeakers, and he was also responsible for my interest in them. In Atlanta, we teamed up with NEXO USA to provide enough loudspeakers for this show, and it’s the largest GEO rig in the U.S. to date. Doug Fowler was also on-hand to provide expert coordination in the interfacing of loads of cabinets, amplifiers and cable from our respective warehouses.

An interesting side note: All audience coverage (to about half of the dome or 35,000-plus people) was generated by just three columns of loudspeakers and NO delays. The design by Chris called for a left-center-right (LCR) configuration, starting with a center column of 26 GEO 4805 Tangent Array modules and two GEO 2815 Tangent Array modules. Left and right loudspeakers each included lines of 18 boxes –16 4805’s and two 2815’s.

The theory behind this design approach is that most of us mix with the main instruments and vocals center panned. The stereo field is only used for special effects, which make up a small part of any show (except maybe The Wall.)

The other big issue is that with a conventional two-column hang: most of the audience is hearing one side over the other. Due to the distances involved, the farther column arrives out of phase and at a reduced level to the nearer column. And particularly in a venue of this size, point-source provides the least generation of secondary reflections. A good reason to avoid delay loudspeakers if possible.

Because the program for this show was predominantly voice (mono), with some secondary live band and recorded tracks, it made sense to give each section of the audience it’s own “power alley.” For more on this, see my original “groundbreaking” article (which almost got me killed!) on why line arrays don’t work if your seats are off stage or in the null between hangs.

GETTING PREDICTIONS
Using the NEXO predictive software program, GEOSOFT, coverage was predicted and optimized as much as possible beforewe started setting up the rig, with plots showing even coverage (within 3 dB) from the main floor to the upper portion of the third balcony, about 350 feet. And at front of house during the show, our handy SPL meter recorded an “easy” 108 dB during concert acts.

GEOSOFT also showed that we would get consistent sound pressure levels throughout all seating – side to side, up and down. Using a small laser, we were able to aim the columns up into the highest seats with pinpoint accuracy. Our trim height was 97 feet, and no, this is not a typo (Hard-hats off to the Georgia Dome riggers! These folks must all be trig majors to float that much in space using the simple old triangle.)

NEXO CD18 cardioid, dual-18-inch-loaded subwoofers were stacked in two columns of three high and placed under large video screens off stage left and right. An additional 16 were spread out under the stage equidistant from each other. Every other sub had a GCS G2 (15-inch cone driver with horn) on top for nearfill to the folks at the downstage edge.

All amps were CAMCO V6, generating roughly 250,000 watts. Improvements with the NEXO controller software these past two years ago have helped us attain a more seamless blend between the subs and flown boxes. While I happen to think that the NEXO bass signature is second to none, the top boxes always sounded like, well, top boxes.

More specifically, the bass always seemed to becoming from the ground and everything else was coming from upstairs. This is not un-typical of line arrays, but there’s always room for improvement. (Are you reading this, Starbucks?) The latest software update (installed on-sight hot off the lap top) moved us more toward that “the wall of sound” we’ve been lusting for.

SCHIZOPHRENIC CHANNELS
Herbalife regular Nick Pain mixed the proceedings on a Midas H3000 console, while I cued 40 schizophrenic channels of audio from video on a Midas Verona. (Why can’t “vidiots” decide which machine they’reusing BEFORE the director calls “roll video”?)

The awards gala featured some obscure singer/piano player who goes by the name of Sir Elton John. He played a full 90 minute set with his five-piece band, which includes John Mahon’s huge percussion rig and additional keyboardist Guy Babylon’s rig, Bob Birch on bass plus legendary Davey Johnstone on guitar, and Nigel Ollson on drums. (If you’re guessing I dug this performance, you are correct!)

During Sir Elton’s set, ably mixed by Matt Herr with an all-Clair Bros. front end and monitor rig, I stayed at FOH to watch PSU voltages and other boring stuff. The crew scaled the heights and said the sound was clear all the way up to the nosebleed seats along with some massive bass even at the roofline. (Thanks to Rob and Adam for snapping some great shots from up there.) Three encores, and it was off to the airport for a show the next day in my hometown Chicago.

Gary Gand has been designing and mixing sound for 30 years and is the owner of Gand Music and Sound in Northfield, Illinois, just north of Chicago.

Source: Live Sound International, September 2005.