Sidebar on distortion: “Distortion or Deafness”

Engineers who make their living with their ears often rely on the discomfort (er, pain?) related to distortion as a mixing cue. A couple of months ago I mentioned a studio that had installed monitors that were distortion-free to 125 dB SPL – care to guess what the chosen mix level was? About 125 dB SPL, until the designer did some “non-linearizing” of the electronics in the monitor system.

My recording engineer friend Carl Beatty often speaks about mixing using “pain” cues. He doesn’t wait for it to hurt, exactly, but he knows, with various monitors, what various types of discomfort “mean,” in terms of how the mix will sound in the real world. He and I both think this is a central part of the success of Yamaha NS10 speakers. There is a hard edge of discomfort with these monitors that sets in at a moderate level and that allows us to derive a sense of edge and intensity that in fact translates into predictable and satisfactory sound quality for end users.

Interestingly, I think the distortion-intensity-discomfort cue is deeply embedded in our psyche. Those readers who are parents know all too well how irritating a baby’s howl is – it cuts to the bone with ferocious intensity, right through everything else going on, yet it isn’t very loud acoustically. Think about it: tiny little vocal cords clipping, generating harmonics right up out of hearing range, driving us bonkers! No wonder humans have survived! The rasp in a voice, the crackle in a trumpet stab, the buzzy edge on a high sustained saxophone wail, are all forms of distortion (er, non-linearity) that are carriers of emotional intensity and need. They are physically stretched limits that musically represent emotional pain or ecstasy.

The onset of distortion, particularly with mechanical systems like speakers, isn’t particularly audible as clipping, but rather as a kind of slight edge and grittiness that seems to say to our inner ear, “Uh, this is beginning to get loud. It may begin to hurt.” The point is that really linear systems don’t get to this until they’re really loud, or the air itself begins to distort. Happily, consumer amps ‘n speakers get to this fairly early in the game. This is also a central element in the argument regarding tube equipment. I suspect it is the onset of this distortion that is the primary determinant of preferred level (now there’s a doctoral thesis topic for any of you who are casting about for such a thing!). So, by inducing distortion at a moderate level, you can save your hearing, your neighborhood, and your musical intensity! And get killer mixes into the bargain!