An Engine Driving I/O Innovation
The Hi-Tech Audio digital festival matrix for multiple consoles and much more.

January 12, 2011, by Mark Frink

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At typical multi-band concert festivals, various consoles must be mixed, merged or switched to the loudspeaker controllers and crossovers at the main mix position, with some acts bringing their own desks, while other artists’ engineers use consoles provided by the vendor.

The traditional approach has been to use a master “production console” to mix the other desks, along with other festival production inputs.

Alternatively, something like a Midas XL88 8 x 8 matrix mixer is combined with a separate small production console.

In the first case a less expensive desk mixes several high-quality large format consoles.

In the second case, a purpose-designed high-quality matrix accommodates just four stereo sources and feeds up to eight outputs.

Both ways, the mixing happens in the analog domain, and connections from digital consoles to digital processing suffer from round-trip conversions to analog.

Today analog consoles are the exception, and mainstream crossovers are digital.

Further, typical concert mixers supply four channels - left, right, subs and front fill - instead of simple stereo.

It’s detrimental to modern festival productions to require multi-channel digital consoles to go through an analog bottleneck that forces additional A/D and D/A conversions in addition to accommodating a limited number of console inputs.

Yamaha DME64N and Apogee Big Ben in digital festival console matrix rack.

Let’s look at a solution by Louis Adamo of Hi-Tech Audio that’s designed to handle multiple analog and digital consoles - even those of different sample rates - using a Yamaha DME (digital mix engine) to provide a 32 x 24 matrix that can handle the demands of modern festivals while maintaining sonic quality.

Starting with one console two decades ago, Hi-Tech Audio of San Francisco has grown to become a premiere live sound console company, specializing in the sale and rental of digital consoles worldwide and with dealerships including Yamaha, DiGiCo and Avid.

They’re familiar with the needs of touring vendors through long-term relationships they maintain with industry leaders, and provide a breadth of knowledge acquired from extensive experience with a wide variety of consoles and the hundreds of audio engineers who use them.

Flexible I/O, Multiple Choices
Several customers expressed an interest in a high-quality all-digital multiple console signal path for festival situations.

Adamo chose the Yamaha DME64 not only because he is known as “Mr. Yamaha digital console,” but also because the product uniquely offers a large and flexible I/O count in a single integrated package.

Other solutions are possible, but they would have to be built from 8 x 8 sub-chassis and integrated. In addition, operating at a 96 kHz sample rate helps win arguments about sound quality.

The DME Festival Matrix is based around the modern mixing concept of four output channels from each console designed to feed the left and right mains, plus the subwoofers (often driven from an independent auxiliary send) as well as a mono front fill send that can be needed to compensate for the lack of stage volume from typical IEM stages.

With the guidance from Yamaha wizard Steve Seable, Adamo programmed the DME64 using DME Designer software to build a 32-input (eight console) by 24-output channels matrix.

Pick A Card
The DME64 has four MY card slots. Two slots employ Yamaha MY8AE96 cards to provide four sets of quad channels of AES digital for 96 kHz consoles, such as a PM5D-RH or a DM2000.

The third slot uses a MY8AE96-S card, which incorporates sample conversion allowing two 48 kHz consoles, such as an Avid Profile or a DiGiCo D5, to feed the DME64 (again, which runs at 96 kHz).

The DME64 is also packaged with an Apogee Big Ben digital word clock to synchronize it with digital consoles and digital loudspeaker processors.

Rear of rack panel detail with digital I/O, word clock distribution, and analog I/O below.

Two of the Big Ben’s outputs are used in a “divide by 2” mode to provide a 48 kHz clock source to the 48 kHz desks and improve their sample rate conversion.

The fourth slot of the DME64 uses an MY8ADDA 8-channel analog I/O card to accept two analog consoles, while also providing eight analog outputs for ancillary feeds such as video, press mult and hearing impaired systems with parametric EQ available.

The first two MY cards provide sixteen 96 kHz outputs, typically to drive the Dolby Lake processors or other loudspeaker system controllers digitally, maintaining a digital path throughout the system. The DME64 also has delays available to any of the outputs, if needed.

A tablet PC is incorporated to control and monitor audio, as the DME64 has minimal front-panel instrumentation.

The 4RU DME64 is housed in a 12RU rack along with the Big Ben and an APC UPS, and there are drawers to hold the console looms and tablet PC, plus a rugged illuminated switch panel connected to the DME64’s GPI EuroBlock connectors to control changeovers between up to eight consoles.

Rear panels provide XLRs for digital and audio I/O as well as BNCs for shipping word clock to other digital equipment.

Rave Reviews
The DME64 Festival Matrix is in its second year. Delicate Productions has now deployed it twice for KROQ’s “Almost Acoustic Christmas” at the Gibson Universal Amphitheater and for their annual summer “Weenie Roast” at Irvine Meadows Amphitheater.

Rat Sound Systems used it for the Christian Fish Fest at Irvine.

Adamo’s favorite quote came from its maiden voyage at the 2009 Weenie Roast. Delicate was using two PM5DRH consoles and a DM1000 production console, all running at 96 kHz and feeding the Dolby Lake processors for their Martin Audio Longbow line arrays. Head system tech Bryan Bazilsky finished running pink noise through the system and shut it down to listen for noise floor.

“The venue was very quiet but we could hear some noise. We muted the PA and it was still there,” Bazilsky says. “Figuring it might be the side fills, we asked for them to be muted and it was still there.

After some running around the stage listening we discovered the source. It was the ambient sound of the fans on the two moving lights that were located one each side next to the sidefills. Pretty darn quiet!”

The most ringing endorsement so far is the fact that after using the Festival Matrix for Fish Fest, Jon Monson of Rat Sound requested it for the main stage at Coachella coming up this spring.

Screen shot of the DME.

The DME system was also deployed again last month by Delicate Productions for Christmas festivals in southern California, including the KISS FM “Jingle Ball” at the Honda Center in Anaheim, the KLOS Christmas Show at the Nokia Theater, and the KROQ “Almost Acoustic Christmas” at the Gibson.

Feedback from all these events was unanimously positive. The combination of an all-digital path from console to processors all tied together with the Apogee Big Ben word clock clearly provides a sonic advantage.

Andy Turner, who mixed My Chemical Romance on one of the provided Yamaha PM5D consoles at the Gibson, described the sound as “clean, accurate and punchy, with great subs. I thought the rig sounded amazing.” It looks like there’s a new standard for concert festivals.

Finally, it’s worth noting that for almost half the price, a smaller matrix for merging two digital consoles and a pair of analog desks can be made using a Yamaha DME24N.

Mark Frink is editorial director of Live Sound International.



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An Engine Driving I/O Innovation
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