Live Sound

Technology Breakthroughs In Concert Sound

THESE ARE THE GOOD OLD DAYS 5/01/2005 8:00 AM Eastern

Many of today's high-tech products have complicated our lives and have made decisions regarding inventory an endless nightmare of guesswork, yet it's easy to forget how stone-age we were not so long ago. During the past 10 years, concert sound technology has dramatically improved. To quote The Postman, “Stuff's getting better.” A major sound company owner recently remarked, “The equipment is so good today that it really comes down to people who can run it to its potential.” Major advancements in concert sound quality in the past decade include line arrays, computer-based acoustical analysis, network protocols, DSP system control, in-ear monitors, digital mixers and all categories of wireless from mics and receivers to tablet controllers.

photo: Steve Jennings

Line arrays are last year's Hummer. Originally perceived as enormously cool, line arrays offer obvious benefits in many venues but don't translate for every trip. Meanwhile, computer applications — such as control of DSP and amps, array wizards, predictive software and measurement programs — help fine-tune systems to where they rival the sonic quality of studio monitors, allowing engineers to transparently communicate mixes to near perfection. In-ear monitors have revolutionized stage monitoring, and wireless is a necessity. The digital live console is the equivalent of next year's hybrid car: As our world changes and the available models improve, the benefits become clearer. The upshot of a decade of progress? Often, it's now easier to succeed with arena or shed shows than in smaller, traditional venues.

Any discussion of dramatic technological improvements would be incomplete without a grateful acknowledgement to an array of pioneers such as Sterne and Perkins; Forsythe and Meyer; Heil and Adams; Henricksen and Button; Gamble and Brooke; Martin and Andrews; Yuill-Thornton and DeLoria; McCarthy and Berkow; Pearson and Borthwick; Harmala and Olsen; and Garcia and Harvey, to name a few.

LINE 'EM UP
During the past decade, we've seen heated reaction to L-Acoustics' V-DOSC modular line array speaker system, with other manufacturers rushing to imitate them, criticize them or both. Many forget that Apogee was the first to introduce a modular line array cabinet. Or was it Clair Bros.? Engineers for touring and large-scale events responded to line array products for their benefits: smaller systems producing more coherent sound and projecting further, often eliminating the need for delay clusters. Widely recognized for superior sound quality, line array designs are extremely popular, even where venue size and geometry dictate that conventional systems might work better. Demand for line arrays in smaller venues has spawned a constant stream of generational compact designs that are smaller, lighter and can bend vertically at greater angles. Manufacturers from all points of the compass have had good results.

Well-designed systems, when used properly — ample cabinets with correct array designs in appropriate installations — will provide superior sound. Without getting into all of the physics, there's not much about line array behavior that really conforms to the theory behind line sources. A line array's height determines the lowest frequency where it still maintains pattern control. It takes a 15-foot array to get good control to 300 Hz. A four-box array may only provide pattern control above 800 Hz. The 3dB instead of 6dB attenuation per doubling of distance claimed for line sources is not found below these frequencies, with a possible result being high frequencies ripping to the back of the venue (where the front-of-house console is often located). When the lows are pushed to keep up, there's a puddle of mud onstage. In some cases, a smaller number of well-designed modular speakers in a traditional array may be a better solution.

BOX OF PLENTY
Typical speaker system design has grown from straightforward left/right arrays with delay speakers used for only the largest outdoor gigs to a fairly complex set of zones, similar to traditional theatrical designs. In addition to delay or under-balcony speakers, small front-of-stage fills and two-way front-fills near the subwoofers at each side of the stage are normal. It's therefore common to employ several DSP processors, originally meant as stereo three-way crossovers, to be used as 2×6 matrix processors in the FOH drive rack to optimize multizone systems by adjusting delay and EQ. Further development of this zone control in larger systems includes split processing of arrays into two and three sections, subtly equalized and gain-shaded to better accomplish consistent coverage throughout the listening area.

These past 10 years saw the rise of DSP products for speaker optimization. Remember when a “drive rack” was a rack of analog gear that processed signal feeds to the amps? A dozen years ago, Yamaha's D2040 defined the DSP product class — and the company is still selling them. Suddenly, not only gain and crossover could be secured, but features such as signal limiting, time alignment, parametric equalization and precise EQ for constant directivity horns could be locked down, significantly increasing a speaker designer's ability to create a great-sounding turnkey system.

High-end concert rigs are attended by system engineers who can now use a combination of computer applications and DSP presets to provide a system that needs little additional adjustment by the band's mix engineer. The traditional graphic EQ placed across the FOH mix bus is virtually obsolete, though it's still comforting to reach over and grab a frequency slider or two.

DSP control over a network is increasingly common. TC Electronic's EQ Stations connect over Ethernet, and Lake Technology's processors can only be adjusted from a networked computer or tablet, as they offer little front panel control. “WiFi” technology borrowed from consumer computer networking has made wireless remote control affordable with off-the-shelf solutions, making it possible for the engineer to tweak each zone of a large system while standing in its coverage and listening to it. Those two-person, walkie-talkie adjustments are a thing of the past.

One benefit of the need for quality system adjustment? With FOH engineers often recording gigs while mixing a show, proper adjustment of the system is key to getting board tapes that translate well on playback. And with sales of live concert product — whether as immediate post-show or later releases — becoming more common, the responsibilities and skill of the house mixer is increasingly more important.

THE SOFTWARE SIDE
Ten years ago, SIA Software's Smaart software put powerful speaker measurement within the reach of anyone with a laptop. Device Control is a great feature that allows users to control outboard DSP from within Smaart while taking measurements. SIA Software has also created the SmaartLive Controller, which allows SmaartLive measurements to be seen from within the Lake Controller application.

During the years, we've also seen the evolution of Meyer's SIM audio analysis platform, the high-end product for speaker measurement and optimization that pre-dates Smaart. The newest version, SIM3, is joined by Galileo, a 6×16 DSP processor that interfaces with SIM3 to integrate system signals with room mics for FFT measurement, plus an Ethernet port for remote control and monitoring of Meyer self-powered speakers.

If the console is digital, then it's easy to see why digital I/O for outboard DSP is the new standard. In the coming digital convergence, signals are converted to digital once at the mic preamps onstage and stay that way through all mixing and processing until they get to amplifier inputs. The next evolution is for speaker DSP to move inside the mix engine, but until digital console technology becomes widespread, outboard DSP will remain a crucial product category.

JBL's VerTec speakers have entered the digital convergence with the DrivePack, a piggyback Crown amp module with integral dbx DSP that networks using Harman Professional's HiQnet network for control and monitoring. Digital pioneer Stanley Miller (Neil Diamond's FOH engineer) had CobraNet PIP cards installed in 70 Crown MA-5000 amps to provide stock delay, crossover and EQ for the 2001 Three Cord Opera tour's VerTec speakers. On the 2002 Peter Gabriel Up tour, AudioTek chief engineer Scott Harmala similarly implemented a digital drive, using an XTA 226 in the drive rack to send the signal from the FOH Yamaha PM1D to QSC amp racks over RAVE via fiber optics. In both cases, digital I/O for the DSP made it possible.

THE GOLDEN AGE OF WIRELESS
HDTV's disappointing adoption by consumers is an omen of continued uncertainty for entertainment wireless users. In most areas, the transition to DTV will not meet its original end-of-2006 goal and both analog and digital transmissions will continue, ensuring increased congestion in the largest cities. Operators have been able to fight back with improved antenna combiners and superior designs (like the helical). Manufacturers have added intelligence features to their newest products, such as built-in frequency scanning and remote battery monitoring. If you're on a five-year plan, now might be the best time to upgrade as the status quo is likely to continue until 2010, when DTV acceptance by consumers might have saturated the market enough that analog broadcasts in some areas finally cease. For years, the marketing come-on was “sounds just like a wired mic,” but today's improvements to companding circuits and front-end RF design have actually started to lend truth to these comparisons for some of the newer products.

In-ear monitors have revolutionized stage monitoring and, in the process, extended older performers' careers by years. IEMs give each musician a precisely customized headphone mix while quieting the roar of wedge-based competitive monitoring. They've also created the need for higher levels of performance from monitor engineers who can no longer “set it and forget it,” but now must make a record every night, with a special mix for each musician. As an additional bonus, IEM usage has reduced onstage volume levels, thus simplifying the job of the FOH “make CD sales from my board mixes” engineer.

MOORE'S LAW AND MORE
Though digital live consoles are not for everyone (yet), they're indispensable for TV awards shows, a boon to multi-act festival tours and a friend to Broadway audio mixers. They're also becoming favored for other applications as more engineers learn to get around on a new control surface. As our industry changes, additional benefits of digital desks become clearer: Beyond repeatable mixes, libraries for all types of settings and the Holy Grail of being able to restore the desk with the push of a button, there's also new products like personal monitor control for musicians and plug-ins for live sound. In fact, at last month's Musikmesse show, Drawmer unveiled Tour Buss, the first plug-ins designed specifically for sound reinforcement: a dynamics suite for Digidesign's VENUE console.

Multitrack technology is becoming a more common part of the live milieu. Once confined mostly to racks of DA-88s or a PCM-3348 capturing direct console outputs at the house position for a live CD or DVD release, robust high-resolution disk recorders — ranging from a full Pro Tools rig to MOTU's Traveler FireWire interface(s) feeding a laptop or Tascam's new rackmount X-48 48-track deck — open new possibilities in the live environment. With the continued fall in digital storage costs (now less than $1/GB) and inexpensive multitracking options, it's almost obligatory to feed a split of the inputs to a hard disk recorder so that the show can be played back without the band, allowing the engineer to tweak both the system and each scene of a performance in the absence of the musicians. This “virtual band” approach makes practicing the show's mix each day before the band arrives a reality.

Don't get me wrong, I miss a few of those great old products, but mostly, it's the music that makes the show.



Mark Frink is Mix's live sound editor.

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