Foo Fighters singer Dave Grohl, possibly requesting “Fresh Pots!” during tracking sessions for Wasting Light.

Tame your track with dynamics processing

BY MICHAEL COOPER

EVERY PRODUCER worth his or her salt will tell you that the success or failure of a noninstrumental recording hinges primarily on producing a riveting lead vocal track. While recording a great performance is the critical first step in the process, the mix engineer must work his specialized techniques on the raw track afterward to take it to the next level and rock everyone’s world. Simply slapping a compressor and equalizer on an insert is rarely enough. Wowing your audience takes some wizardry.

In this multi-part series, I’ll show you how to sprinkle fairy dust on the singer’s track to create a magic moment. Before it can cast its spell, however, a bewitching vocal must first be made to sit properly in the mix so that it sounds powerful but doesn’t overwhelm the band. In this first installment, I’ll show you how to use dynamics processing to do just that.

Mind Your Signal Chain In most cases, you’ll want to place dynamics processing on the vocal track before any EQ so that the compressor doesn’t limit the effect of your tonal adjustments. (In an upcoming installment, I’ll reveal a cool trick that takes the opposite tack.) Post-EQ placement would arbitrarily condition the compressor to dip levels when the singer hits a part of his or her range that has EQ boost applied, which may not be what you want. Use dynamics processing first to rein in the track’s levels. Then apply EQ to shape its tone.

De-Ess First Sibilance (a whistling sound that can occur when the vocalist sings lyrics containing an s, f, or t) can create very transient and large signal peaks (up to 20dB!) that leap out of a mix and distract. Most soft-knee compressors are too slow and nondiscriminating to catch these ephemeral, high-frequency peaks. But even though they’re always late to the party, their gain reduction function can still be whipsawed by sibilance after-the-fact. That’s why it’s important to place a de-esser (dynamics processing tailored toward taming sibilance) on a sibilant vocal before any compressor you use to create density or control average levels.

To quash sibilance, you usually need to use a limiter or hard-knee compressor that employs peak-detection circuitry. The limiter must offer a sky-high ratio of 20:1 to 50:1, lightning-fast 50µsec (0.05ms) attack time and a release time of 40 to 60ms. It should also allow access to its sidechain.

To de-ess the vocal track, first copy it and insert an equalizer on the copy. Using a shelving filter, boost the equalizer to the max (even 24dB is okay) above 5kHz. Cut below 5kHz as much as possible. Bus the heavily-EQ’d track copy into the sidechain for a limiter placed on the original vocal track. Now the limiter will “hear” a screechy version of the vocal with highs cranked and lows removed, making it ultra-sensitive to any sibilance. Set the limiter’s threshold so that gain reduction occurs when whistling fricatives sound but not when sustained vowel sounds are voiced.

Fig. 1 iZotope Alloy’s de-esser module is highly effective and simple to operate.

If this setup sounds like too much work, don’t fret. Several purpose-built de-esser plug-ins do most of the heavy lifting for you. iZotope Alloy (see Figure 1) provides the most effective and best-sounding de-esser I’ve heard in plug-in form and doesn’t require copying your track or complicated sidechain routing. Simply adjust the frequency band you want Alloy to treat (in Multiband mode) and tweak the attack, release, and threshold controls. Goodbye, sibilance!

Squeeze Next After de-essing (if necessary), use a soft-knee compressor to reduce peaks so that the vocal doesn’t pop out in the mix and dwarf other elements. Putting a lid on peaks also allows you to raise the overall level of the vocal without clipping. That prevents softer phrases from being buried or sounding weak. The overall effect is one of increased size, loudness, and density.

Opto-electronic compressors generally offer the most natural and transparent sound for treating vocals. The best plug-ins I’ve heard that emulate opto compressors are the Waves CLA-2A and -3A and the Softube Tube-Tech CL 1B (see Figure 2). All three plugs have an uncanny ability to perfectly seat a highly dynamic vocal track in a mix without making it sound quashed. And their operation is so simple, an amoeba could swing it.

Fig. 2 Softube’s Tube-Tech CL 1B plug-in models the high-end opto tube compressor of the same name and sounds outstanding on lead vocals.

A vocal track that exhibits wildly fluctuating levels may need especially heavy compression to force it into submission. In this case, you’ll get much better-sounding results by chaining two compressors in series instead of making one compressor do all the work. Set the first compressor’s threshold high enough that it reacts to only the strongest peaks. This allows the second compressor to focus on smoothing average levels and creating density. The compressors each perform softer action than a sole compressor would need to in order to get the job done, resulting in a more transparent and natural sound.

Set a Limit If compression doesn’t fully rein in vocals running amok, place a brickwall limiter at the end of your track’s signal chain as a last resort. The Waves L1 plug-in and McDSP 4040 Retro Limiter plug-ins are very effective for this purpose (see Figure 3). But tread lightly—too much brickwall limiting will defenestrate nuance and depth and introduce audible distortion.

Fig. 3 The McDSP 4040 Retro Limiter is a great choice for taming runaway vocals.

Only the Beginning Now that your vocal track’s dynamics have been deftly controlled, the next step is to craft a captivating tone. I’ll discuss some tips for doing that in next month’s segment, along with strategies for fine-tuning the vocal to make every lyric have maximum impact.