Broadcast & Mobile: One Shot, No Worries
Direct Stream Digital for Jazz Broadcast and Archiving

By Steve Harvey

There are no second chances in live audio. Nowhere is that more true than at KUVO 89.3 FM in Denver, Colorado. The all-jazz station, one of only a handful in the country, not only broadcasts a significant number of live performances each month but also archives the sessions to Direct Stream Digital (DSD), the highest resolution digital format currently available.

DIGITALLY ASSEMBLED

Photo #1: Mike Pappas

“We put out a compilation disc every year,” elaborates chief engineer Mike Pappas.(see Photo #1) “And because we’ve been using DSD now since 1999, we are probably going to do our first Super Audio Compact Disc release next year.” Super Audio CD (SACD) utilizes the 1-bit, 2.8224 MHz sampling rate DSD encoding scheme jointly developed by Sony and Philips. DSD audio production tools are still relatively few, and far between. Pappas reports that KUVO recently purchased a Genex GX8500 digital hard disk recorder to more easily facilitate DSD recording at the station. “And Ed Meitner (founder of EMM Labs) is building us a set of eight-track DSD converters for it.”

KUVO’s Logitek Numix digital console, Harris digital microwave and Nautel FM 10 transmitter with digital exciter are no less revealing than the DSD archive format. “The whole path in the plant is digital,” confirms Pappas, who championed the station’s digital upgrade began in 1999. Consequently, he and his engineering team have assembled an equipment inventory of the highest quality for their live broadcast and recording.

“We use Grace Design 801R preamps, which are remote controlled, so they are in the other room and everything coming to us at the mixer is at line level,” he explains. No EQ is applied on the Mackie d8b and processing is kept to a minimum. “We don’t use any compression or limiting except at the master processor for the on-air system, which is an Omnia FM (Veris) with look-ahead limiter option.”

SOOOO CLEAN

Pappas chose the Omnia for its low distortion. “We aren’t particularly loud but, man, are we clean! Distortion adds up to ear fatigue, and that’s why listeners tune to other stations.”

KUVO is a public radio station and during pledge drives may broadcast as many as eight live shows in a week. “So there’s a pretty wide variability in what we do and how we accomplish it, how we set the room up, what mikes we choose and how we mic it,” Pappas notes.

While bands of twenty-five or more pieces are not unusual, a more typical session is likely to be a trio setup. “If we’re looking at a trio, we’re typically using Sennheiser MKH 800s on the piano. We use them in the broad cardioid pattern. We typically place the microphones about eight inches or so above the strings and move them around until we get the right balance.”

For drums, says Pappas, “we use two Sennheiser MKH20 omnis as overheads, with the optional pressure rings, which give you about a 2dB bump at 15kHz acoustically, so you don’t have to use any electrical equalization—that just gives us a little shimmer. Then we use a Schoeps CMC 5 with the MK 2 capsule, and we place that low on the beater side of the kick drum and move it around until we get a good balance between the snare, the kick and the floor tom.”

Pappas uses a Beyer M 201 dynamic hyper-cardioid on bass. “We usually place that about six inches in front of the f-hole on the acoustic bass and then take a DI feed off from the pickup through a Whirlwind passive DI box. The DI gives a little more snap to the bass and helps bring it out in the mix just a little bit.”

The thousand square foot ft.(93.msq) performance space and recording studio typically accommodates an invited audience of fifteen to fifty subscribers. “Our usual selection for audience microphones is a pair of Neumann KM 184s on a stereo bar in a classic ORTF 110-degree configuration.”

A/D OUTPUT

The output of the Mackie is fed into an EMM Labs’ A/D converter. “That converter does both our DSD conversion for us and gives us a 24-bit super-bitmapped, triangularly dithered output which we feed into our digital plant.” The Meitner also feeds a Z-System router, allowing the engineers to drive DAT machines or other peripherals.

“We run an Alesis ADAT as a multi-track backup in case at some later point, when we decide to use a cut, we decide that we want to change some of the balance,” Pappas notes. “But we’ve gotten so good in the last couple of years that on the last CD I think I remixed only one tune.”

Photo #2: KUVO’s Control Room View

Unusually for a broadcast setup, Pappas and his engineers use a Telex RTS 4000 series IFB system during live dates. “It allows us to cue my assistant engineers, who are in the room on headphones with an IFB pack, so that when things run amok you’ve got a prayer of fixing them. Once you’re on the air there’s no turning back.”

Also unusual is the station’s choice of monitors: “We’re using DAS Model 6 Nearfield monitors in the control room, driven by a Spectron Class D digital switching amplifier, but I think we’re probably one of only about four broadcasters on the whole planet that uses Genelec (1029A) monitors.

The Genelecs, located in the station’s production studios (see Photo #2), were found to minimize ear fatigue. Pappas reports, “And on top of it they absolutely sound wonderful. Plus, if we have a problem in the air chain I hear it from the on-air people before I get forty calls, because they’re listening on a system that is significantly better than most of our home listeners.”

QUALITY CONTROL

To ensure that shows run trouble free, KUVO has worked hard to achieve total reliability and constancy. “We’re very particular about doing full line checks long before we even think about going on the air, so every microphone is tested. All of our cables are made by Cardas Audio in Oregon. They’re expensive but they’re built like tanks.

“I have a piano tuner who understands how I want the piano to sound and how I want it tuned, so I have a consistent piano sound. Our drum setup took us two years of experimenting to get that mic configuration. It’s very consistent in terms of how it sounds; the same with the bass.”

Pappas concludes, “Once you hit air, it’s all got to be perfect, it’s all got to work and it’s got to be consistent. I think the years I spent doing live television drilled that into my head.

“We’re not doing it live-to-tape, where we can stop, back up and start over again. Everything that we do has to work the first time out of the gate. Take two is not an option.”

January/February 2002 Live Sound International