The Vocal Channel ProcessorA FLEXIBLE FRONT END FOR THE MOST CRUCIAL SIGNAL PATH 11/01/2005 7:00 AM Eastern
In the pre-DAW world of music recording, a “channel strip” meant one thing to most engineers: one of the many narrow, vertical tactile interfaces offering individual channel control within an analog console. With a microphone preamp, some sort of equalization adjustment and sometimes onboard compression, a channel strip might have comprised the complete line between an audio source and a recording medium. Vocal tracks were often patched to and from complementary outboard processing units before hitting tape; certainly during mix sessions, a vocal track would typically venture far from its console channel strip and into the producer's desk, side rack or machine room for some added flavor.
Today, modern recording engineers are just as likely to think of channel strips as horizontal, all-in-one rack units featuring at least one preamp, equalization, compression/limiting and — sometimes — onboard digital processing and A/D converters. Those built to capture the essence of the human voice are plentiful for good reason: Vocals are important.
(The chart on the following pages highlights a collection of vocal channel processors that were announced in the past year that feature at least a mic preamp, an EQ section and a compressor. Of course, vocal signal chains are regularly recorded without compression and/or EQ, but for our purposes here, the more available features, the better. While each of the following products are well-suited for being a vocal track's sole front end for recording and/or a great processing path for mixdown, each channel strip's capabilities, construction and price varies widely.)
It's no mystery that large-format analog consoles are becoming less common in modern music production environments; consequently, fewer of their respective feature-packed channel strips are available for use. Though many engineers today have a tactile digital controller or simply a mouse for mixing, there has been a recognized need for the front-end sound, just a few channels at a time and without all the real estate.
Thanks in part to the recent influx of all-inclusive, affordable and high-quality channel strips as DAW front ends, increased creative flexibility is feasible for most every recording situation and especially in tracking vocals. Such tracks may involve inexpensive microphones recorded to a low-cost DAW via laptop, or could just as easily be big-budget “pro” productions with a large room and a quiet booth. Whether through console or strip, there's nothing new about skipping a console's multiple gain stages via outboard processors to increase fidelity and lower noise levels.
It seems that vocal sessions can happen anywhere today. A single album project may involve the same vocalist in seven or eight different rooms. It's a fast-paced, on-the-go music production world, and many DAW-dependents benefit greatly by having one comprehensive analog front end that's on the same quality and feature level as a channel from, say, a very non-portable SSL 9000 K.
Constructing a perfect vocal chain is often an involved process for engineers; having everything you need in one box can make it easier for those looking for a signature sound. Particularly in “console-less” all-DAW productions, tracking may be the last time a vocal isn't zeroes and ones, so a vocal channel processor's analog signal path may provide just the right type of desired color.
After 40 years of successfully selling large-format consoles, John Oram — of Oram Pro Audio and Trident Audio Ltd. — recognizes that while sales of big analog desks have dwindled, engineers still seek their most appealing characteristics: superior signal paths. “From my point of view, we wanted to create channel strips that had the same — or greater — sonic performance as a large-format console,” Oram explains. “Obviously, as a console manufacturer, you have to rethink your entire company philosophy because it's quite obvious that the days of spending lots of money on a large-format board is over for many. Yes, digital is brilliant for editing, but now, guys also want the best analog front end to compensate for some of the inadequacies of digital recording.”
CHOOSING A CHANNEL
In shopping for the best vocal channel processor for a specific need and budget, engineers have a wide variety of features from which to choose. These include one or more channels of analog and/or digital circuitry; comprehensive analog and digital I/O; solid-state and/or tube operation; Class-A electronics; preamps of various noise and gain levels; fixed, parametric, semi-parametric or shelving equalization; bandpass filtering; detailed compression control with various ratio, attack, release and band-based parameters; gates; de-essers; enhancers; tape-saturation modeling; and — whew! — I/O level adjustment for the various stages of processing. As a matter of fact, carrying a few vocal channels can be quite the same as lugging around a rackful of outboard gear — sans trouble, back pain and exorbitant freight charges.
Even if an engineer is shopping with a limited budget, offerings with plentiful features abound. For instance, the Drawmer MX60 Front End One — a 1U channel strip offering mic preamp, gate, de-esser, compressor, limiter, 3-band EQ and multiband tube saturation — lists for less than $1,000, as do a variety of other similarly equipped offerings. On the high end of the price and build spectrum, the popular all-tube Manley VoxBox includes a mic preamp, Variable MU compressor/limiter, 3-band/33-frequency EQ and an ELOP-based de-esser/limiter; it's priced at $4,000 and well worth the money for those with the budget.
Reid Mason — director of marketing for PMI Audio Group, distributors for Joemeek and Toft Audio Designs, among others — says that as of late, the needs of DAW users in particular have helped his company's business thrive.
“In terms of features, end-users are looking for new channel strips to have all the basics: mic pre, EQ, compressor — and a de-esser gets extra points,” Mason explains. “But in addition, they want the mic pre to be flattering to their recordings. The EQ not only needs to be flexible and sound great, they want to be able to position it pre- or post-compressor. Accurate metering seems to be universally in-demand, as well. A quality instrument-level input that properly handles high-impedance signals is always a plus. They're not only asking for digital outputs — up to 24-bit/192 kHz — with great converters, but a way to interface it directly with their computer. FireWire seems to be most in-demand, followed closely by USB. An intuitive panel layout gets high marks, allowing the engineer to focus on the artist, not the gear.”
It doesn't seem like a lot to ask for. On second thought, yes it does, especially when you consider that most engineers out there want all of those features to be the best in the store and come in for less than $1k.
ALL-IN-ONE — STILL ONE THING
Although offering considerable sonic flexibility, all-in-one vocal channels are just that: one thing. If engineers fall back on the same channel strip and setting for a variety of sources — especially when tracking lead and background vocals — tracks can tend to have a quality of “sameness” when compared to those whose signals were processed through varied microphones and processing paths.
“I like several of the all-in-one boxes,” comments one prolific professional engineer, who, from fear of being pegged “an elitist old-schooler,” asked to be quoted anonymously. “But with so many of them available, I think that a lot of people don't think about getting a certain sound through better choices and fewer components. They just tweak and twist their signals till it gets there. What they don't realize is that their music could sound much better if they just did their homework.”
Duly noted, but the ideal environment where this engineer most likely cut his teeth is not representative of a growing segment of today's music recording situations. Many commercially successful modern recordings have not necessarily come about because some engineer raided a cabinet of great vintage microphones and had access to racks of classic preamps, equalizers, compressors and limiters during vocal tracking sessions. In many cases, it's likely that only a few microphone and processing choices were available, and all signal paths may have resided completely within one flexible processor — one the engineer considers the best for the artist, the best for the sound.
Strother Bullins is a North Carolina — based freelance writer specializing in the pro audio, music and entertainment industries.
Click here for the chart.
In addition to the tips and techniques offered by our sound reinforcement editor, Steve La Cerra, find out what top front-of-house engineers are using on their artist’s vocal channel.
The only piece of outboard gear that front-of-house engineer Brad Madix uses is the Clair Bros. version of the Lake IO, which he inserts on Shakira’s vocal for EQ. Shakira sings through a Sennheiser mic.
Front-of-house engineer Pete Keppler: “I'm using Digidesign's Pitch program to do a pseudo-[Eventide] H3000. Then I've got two different doublers. One's just a single voice delay with a little bit of pitch modulation. The other one is Eventide Quadravox, which I barely understand, but it sounds cool. I'm using McDSP's Channel G and their multiband compressor, the MC-2000, for guitars and vocals and sub-group compression.” Lead vocalist Davey Havok often twirls his Audix OM7 mic around, as well as cups it. “I would normally hand almost anybody a [Shure] 58 or Beta 58 to start with and see what it sounded like, unless they had something else they were particularly happy with,” Keppler says. “But he'll wrap his hands around the mic and leave very little space to sing into. He knows, he apologized in advance. The first day I mixed the band, one of the first things he said to me was, ‘I cup the mic. I'm really sorry, I just do it. I know it messes with your world and makes it sound worse, but it's an old habit.’ So before I came onboard, Ronnie Kimball [the previous FOH engineer] had found that this mic [the OM7] responded the best and had the least amount of frequency response change and still had a fair amount of gain before feedback. And Audix has been really cool with us. As you can see, most everything on the stage is white; so are the mics. Audix graciously allowed us to powder-coat the mics and then they took them back from us and did their silk-screening of their brand and model number and clear-coated them, and they look great. We use OM5s for the other vocals because, to me, the OM5 sounds very close to a 58.”
In terms of outboard gear, front-of-house engineer Dan Wise carries an ADL 1500 tube compressor on Etheridge's vocals and dbx 160A compressor/limiters on the guitars and bass to keep things even. The goal, he says, is to keep Etheridge's vocal on top. “That's pretty much the whole thing,” Wise says with a smile. “Her band is really good, so it's pretty easy to mix. They mix themselves for the most part. As long as her vocal is on top, I'm happy.”
Fall Out Boy
An Empirical Labs EL8 Distressor compressor is used on Patrick Stump's vocal, via an Audix OM7 microphone, to keep it on top of the mix without having to constantly ride his fader, with an Eventide H3000 also used for just a touch of reverb depth. “Patrick's a really solid singer, so you don't have to do a lot with his voice, but the Distressor has a highpass filter that cuts down the boom and keeps things steady,” Kyle Chirnside, front-of-house engineer, explains. Distressors are also used on backing vocals (also on wired Audix OM7 mics), snapping that portion in line with the lead.
Front-of-house engineer Kevin Madison: "I also split the vocals into the D-Tube DiGiCo valve input section, which, when pushed hard, creates an overdriven effect for vocals. It works very well, sounds great and saves on having to carry any outboard gear.”
According to FOH engineer Ted Keedick, “For rack gear, we have an Eventide H3000, as it delivers a certain vocal effect that is part of my approach. As for the [Summit] DCL-200 dual-compressor/limiter, I use it on backing vocals. I also use an EL8 [Distressor] on my lead vocal.” Avenged Sevenfold is using Shure wireless 58s on lead vocals and Audio-Technica AE6100s on backing vocals.
Front-of-house engineer “Commissioner” Gordon Williams: "Leela likes a lot of vocal up front. I really like tube compressors for Leela's vocal. She has an extremely strong voice, and when she hits something like an 1176 or LA-2A, it just sounds natural.”
Blunt has a signature vocal tone that is altogether powerful and melodic. This is an ideal situation for Hornby, as he can put Blunt's vocal “straight into the microphone and straight out of the speakers — he's just that good,” FOH engineer Mike Hornby says. The engineer says that he rarely uses any effects on Blunt's vocal (only when the room is completely dead), and he only uses a little compressor/limiter when he has to worry about crowd noise level.
Front-of-house engineer Nick Pellicciotto, who has been with Lucinda Williams since her 2004 tour, is the one who put together her vocal chain, which comprises an Audix OM6 microphone, Avalon mic pre, BSS DPR-901 dynamic EQ, back into an insert return on the console to avoid the channel preamps. At the Oakland show, Pellicciotto had a Yamaha PM5D at FOH. Pellicciotto does everything he can to keep things simple, with very little effects inserted. “With a band of this quality, processing would kill whatever they're doing,” Pellicciotto says. “I simply do whatever I can to stay out of the way, to be transparent. I see my role as a balance engineer, though I do work in effects at times. Lucinda has three types of songs. On the ballads, I may pull the kick and bass down a bit so the lows don't wash stuff away. Then on the more bluesy or rootsy numbers, I may change the miking a bit and add some effects to make the drums sound a little more trashy, raucous and not too distinct. Same for guitars. And then the rock numbers get a pretty standard mix. I agree with Mark [Humphreys, monitor engineer] on the need for clarity in her vocal, but these systems have gotten so clean that I often find some murkiness can be helpful. Some graininess and lo-fi feel, especially on the bluesy numbers. And I never really sacrifice the band for her vocal. I'm for everything being audible."
Front-of-house engineer Phil Strong uses TC Electronic D-Twos for delay and an Eventide Eclipse for occasional pitch-bends on Kanye West's vocals, as well as a Summit Audio TLA-50. "The Summit unit allowed me to have the vocals pop through, where they are fat and clear, but still in control," he says. "That's what I needed: a little more color control to help place things in the mix.”
Front-of-house engineer Rick Pope mixes Kay's vocals, which are sung through a Sennheiser 935 wireless mic, through a Manley VoxBox and an Eventide H3000. Save for an occasional nod to a Lexicon PCM81 or 91, all other processing comes through the Yamaha PM1D Version 2 desk.