We all know what it sounds like to run a sound through the cranked-up amplifiers or overdrive pedals guitarists use; basically, it's the same thing that happens when you overload your microphone inputs while recording and the meters peak too long in the red: The sound gets dirty, fuzzy, grungy and gritty. That is commonly known as distortion, and the same qualities of harmonic saturation that are revered by guitarists can be a bane to recording engineers and home recordists who are simply trying to get a good, clean track recorded.
Bomb Factory's 1176 Peak Limiter is just one plug-in emulation of the revered 1176 compressor, which introduces a subtle, creamy distortion to female vocals and other sources.
Distortion, overdrive and clipping are all variations on the same theme, and the result is a saturated signal that sustains and resonates with overtones and character. To overdrive a sound is to crank up its essence and saturate it with its own harmonic content; a cooking analogy would be stewing something in its own juices. This textural modification of a sound can be horrible or sublime, but careful filtering of distortion to remove or enhance certain frequency ranges can make all the difference between magic and mayhem.
Much has been made about the difference between tube and solid-state gear, analog versus digital, warmth versus accuracy, and the qualities that define good sound and bad. In most cases, those distinctions relate to the degree and qualities of the distortion generated. In a tube microphone preamp, for example, the kind of “warmth” that is most highly valued is a subtle distortion characteristic that softens peaks, clips gently and enhances the character of the microphone or instrument it is transforming to a recordable level. The staggering array of new, handmade boutique tube gear available — as well as great-sounding digital products that are devoted to emulating the quirky funkiness of old-school “warmth” — mean that the right tools are available to anyone who cares to learn how to use them.
LICENSE TO SHRED
Extreme distortion over the years has been the realm mostly of guitarists, who worship harmonic overdrive and saturation with evangelical fervor. Early tube guitar amplifiers made by Mesa Boogie — along with other amps such as the less versatile but no less fearsome Marshall stacks favored by Jimi Hendrix — in many ways put overdriven and sustaining lead guitar sounds on the map in the early '70s (think Carlos Santana). An early innovation on Boogies was a five-band graphic EQ that allowed a remarkable amount of tone shaping, using filters to tame otherwise uncontrollable feedback and saturated tone. When you have a sound that is fat and juicy, a flanger or phaser in the signal path really has something to chew on, resulting in some fine sonic pornography. (See audio examples 1 through 3.)
SPIRIT OF '76
Now with over-the-top use of distortion out of the way, let's turn down from 11 to some more subtle instances of distortion to expand upon. These techniques for adding texture and harmonic content can bring some fresh perspective to the traditional tasks of recording and mixing a song.
On the pristine, superhigh-end, pop-record side of things (Mariah, Celine, other superdivas), many producers and engineers agree that the best compressor to put on a lead vocal is the venerable UA 1176. It's one of the great compressors in the history of music recording, but it stands out is because it imparts a very sweet musical bite to a lead vocal track — particularly to a female voice. That is a subtle but effective use of distortion in a place few might expect to find it, and it is a sort of old-school predecessor to an aural exciter-type of effect; it is worth noting that aural exciter circuits actually add tiny bits of distortion at high-mid frequencies to create an extra sparkle on a sound. (See audio examples 4 through 5.)
There are several digital emulations of the 1176, and most of them capture its enhancing quality fairly well; this effect is worth checking out on just about any midrange-or-higher frequency track that you want to sit up-front.
On the opposite end of the frequency spectrum, one of my favorite compressors to use to record a down-and-dirty DI bass track is the FMR Audio RNC 1776, which is capable of an unusually fast release time that distorts in a way that imparts a wonderfully natural-sounding fatness. (See audio examples 6 through 7.)
Listening to the radio in 2008, our ears are increasingly accustomed to hearing different types of idiosyncratic distortion from tools currently in vogue; extreme settings on the ever-present Antares Auto-Tune plug-in, for example, bring a kind of resonance to a signal by adding a sort of sine-wave power, which bites and cuts. Many mainstream pop records of the last eight or more years use it overtly on vocals, which again underlines how distortion is used in unexpected places. Add a little tasteful overdrive effect to a healthy dose of Auto-Tune, and a simple background voice or strings can become truly enigmatic. Especially in the freewheeling, constantly innovating and rule-breaking worlds of hip-hop, ambient, techno and all forms of deep club music (which in turn influence the larger world of pop music), pushing these various envelopes leads to creative satisfaction. (See audio examples 8 through 10.)
FUZZ ON THE SOFT SIDE
Of course, we can always crank up any mic preamps, compressors, input trims, etc., to the max to achieve some kind of overdrive fuzz, and sometimes that is exactly what's needed for a quick guitar or synth part to sound as grungy as you want it. But the quality of distortion tones varies greatly depending on circuit design and components. Also, distortion aficionados talk about greater levels of detail, including even- or odd-order harmonics, pre-drive highpass or lowpass filters and the characteristics of traditional tube vs. transistor gear. For all of that, once again we return to tools that simulate distortion, which were developed over the years for guitarists.
If you use guitar stompboxes, you typically need to roll off some of the highs in order to keep your distortion tones from fuzzing out too much. Back in the days of stompbox evolution, some very popular fuzz boxes of the '70s, such as the MXR Dist+ and the Electro-Harmonix Big Muff, were trumped by the Pro Co Rat, which introduced a single filter knob. One of my favorite distortion boxes of the '90s was the SansAmp GT, which emulates Marshalls, Fenders and Boogies in one box, with selectable emulations of three types of mic placements in front of a virtual speaker. The SansAmp has a buffered input that will accept a wide range of signal levels, which you can run directly into the board or as an insert effect; its speaker emulations are that close to the real thing.
Nowadays, there are so many emulations of every kind of amplifier/speaker/microphone combination ever recorded that it quickly becomes overwhelming, but if you have access to the great Line 6 emulations or a plug-in like IK Multimedia Amplitube, you might be surprised at how good some of those presets sound on your drum and synth tracks that need a little oomph. (See audio examples 11 through 19.)
One great thing about fuzz-type overdrive distortion is that when you run just about any sound through a very subtle amount of it, you get a lot of tiny fractal edges that make other effects sparkle farther down the signal path. Just a tiny bit of grit on a simple orchestra or jazz instrument gives it a patina that takes a flanger sweep and makes it sparkle. (See audio examples 20 through 21.)
You can find distortion employed everywhere in music. The classic sound of the Hammond Organ relies heavily on the overdrive of the tube amplification in Leslie cabinets, and without that grit, it just doesn't sound like soul music. The African mbira is a thumb piano that benefits greatly from being attached to a resonant gourd with bottle caps nailed to it, which creates a buzzing texture to enhance the mbira's tone. That enharmonic noise component brings to mind another kind of textural distortion, found in the family of instruments loosely categorized as flutes.
Whether we're talking about Mozart or Native American, Indian classical, ancient indigenous wood or bamboo flutes from any continent, flutes by nature employ an intrinsic “noise” component as a result of blowing air over a hole (as opposed to into a sealed mouthpiece like on a trumpet). The richness of a flute's tone is directly related to that nontonal rush of air that is a big chunk of broadband noise, related closer to wind howling or water rushing over a waterfall than to anything flute players do with their fingers to create specific notes.
Synth programmers use similar noise sources to add texture and richness to a patch and as a source for filtering and modulating into something sweet and tasty. Adding harmonic distortion to a flute sound will have a different result than adding more enharmonic noise, but the result may even be more musically pleasing. Overdriving a flute sound will add harmonically saturated overtones that are directly related to the notes of the source material and that can evolve the sound into something that makes your ears perk up. (See audio examples 22 through 25.)
A distorted guitar tone always sounds “louder” than a clean tone, as a result of factors including both nonlinear psychoacoustic perceptive processes and preconceptions of how a distorted guitar tone is created (cranking up an amp), which can make a listener think, “it must be loud to sound like that.” Overdriven sounds evoke both subconscious and cognitive responses in the listener, above and beyond the richness of resulting harmonic saturation. Along the same lines, studio sessions — that may sound great at high volumes through studio monitors pushed to their limits — may sound smaller and tamer in the mastering facility because part of what the artist heard during recording and mixing was aided by distortion occurring in the monitor amplifiers themselves.
During my days working for Bill Laswell in the '90s, I was fortunate to attend many mastering sessions with Howie Weinberg at Masterdisk in NYC. Weinberg had a few surprising tricks up his sleeves in the midst of his hundreds of thousands of dollars' worth of ultrahigh-end mastering EQs, converters and compressors. Sometimes he would run finished mixes through the most seemingly incongruous pieces of gear that he had, a couple of old Pultec EQs — often without any actual EQ settings engaged — to simply warm up mixes that came in sounding too clean, brittle and digital.
Most of us who record, mix and master music witnessed the “limiting wars” of the last decade, in which engineers would limit and compress a final mix to extreme levels, attempting to fit the most perceived loudness into the 16 bits of a commercial CD release and sound as loud as possible over the radio. The downside, of course, is that making everything as loud as possible sacrifices dynamic range, and everything ends up sounding pretty cruddy and — ironically — smaller.
You can achieve superior results by using a plug-in such as McDSP Analog Channel on the master bus. It emulates the subtle and refined distortion characteristics of a high-end mixing console — typically featuring intrinsic soft-clipping and compression elements — and the advantage is that there are musical components to the process far more pleasing to the ear than simply crushing the dynamics of a mix. Much has been made of the difference between “mixing in the box” (bouncing a mix within a DAW down to a stereo master) and summing computer tracks out through a high-end mixing console. By putting Analog Channel or another such plug-in on your DAW's master bus, you can gain some of the subtle but important harmonic saturation of analog summing without the expensive hardware. (See audio examples 26 through 27.)
WARM IT UP, TAPE
Recording to analog tape introduces pleasing, controllable distortion in the form of compression and nonlinear EQ response. Many engineers prefer recording drums, bass and other rhythm instruments to tape precisely for that reason; unfortunately, tape machines, tape and other necessary related tools come at a much higher price than recording the same session digitally, so digital recording often prevails.
I recently dumped the stereo mixes of a rock record that had been recorded and mixed digitally in Pro Tools to analog ½-inch tape as the first step in mastering, to achieve some smoothing and gelling of the mixes. This process imparted some of the very subtle and musical characteristics of recording to analog tape, which include a slight compression and harmonic engagement with the tape itself. Although this subtle use of distortion was never noticeable as such, the result was a richer-sounding mix, smoother on the top and fatter in the low end. McDSP Analog Channel can also achieve similar results with its series of tape-machine emulations. (See audio examples 28 through 29.)
The potential enemy here, when adding varying degrees of harmonic saturation to individual instruments or even an entire mix, is mud. Too much of a good thing can fill up too much space, and excessive layers of rich textures can simply make murky soup. The trick is to use your sonic enhancements tastefully and sparingly, to bring richness to key elements and let them stand out instead of having everything saturated.
I hope this discussion of distortion in its many manifestations will inspire further exploration and fearless experimentation in the wild world of overdrive and harmonic saturation. Keep your heads up for next month's similar venture into delay, reverb and other spatial effects.
Listen to all the related audio examples atremixmag.com.