The Microphone vs. the Ear
Dave Moulton
May 1993
Why Recordings Don't Sound Quite Like the Real Thing and Some Things You Can Do About It. An informal introduction to the realities of psychoacoustics.
So, clearly, the ear is far more complex than the microphone and we can't reasonably expect the microphone to deliver anywhere near the kind of information that the ear does. So what? How can we make use of this insight?
The first thing has to do with microphone placement and directionality. While the ear manages to separate our sense of room reflections from the direct sound of the instrument, the microphone can't separate the two at all, so you have to place it closer to the instrument than your ears think is reasonable . This reduces the relative loudness of the room reflections picked up by the microphone. Of course, this presents other problems. If we get really close to the instrument (within a couple of inches, say) the microphone no longer can hear the
whole instrument, and the timbre of the instrument will no longer be what it normally sounds like to you (go ahead -- just listen to a violin from 1" above the bow, near the bridge, for instance, or stick your head inside a kick drum, and you'll see just how dramatically different sounds from those perspectives are). Another solution is to use a directional (cardioid) microphone, which will tend to reduce the relative loudness of room reflections. Then you may be able to back the microphone away from the sound enough to hear it more reasonably and accurately.
The next thing has to do with interference between microphones. Again, our ears (and brain) have numerous ways to process the information coming from two different points. The mixing console has no such capability. This means that it is fairly important to keep interference between microphones under control. The standard procedure here is called the "Rule of Threes," which simply means that when you are miking two different (but of similar loudness) instruments with two microphones, you place microphones so that the distance from each microphone to the
source you don't want it to pick up is at least three times greater than the distance from that mic to its intended source. If the sources have different levels (a kick drum vs. a flute, for instance), the Rule of Threes doesn't work very well.
The third thing you can do, odd as it sounds, is learn to "listen like a microphone." Learn to listen to the sound of the room (listen in between the notes, to everything
but the music), and learn to detect the colorations the room is causing. This takes practice, and it can be really distracting from your musical efforts, but it may be worth the effort if you really get into trying to record great sounds (especially while working on really arcane crafts like sampling).
The fourth thing, of course, is to use stereo. From this article, it should be fairly clear
why stereo works: it at least begins to fill in some of the richness of details that our ears and auditory system crave. The simplest way to use stereo, of course, is to simply use two good microphones placed a couple of feet apart. You will have to give up some other things if you do this, but it may be worth it. There are numerous other techniques too, but they are beyond the scope of this article. Maybe next time . . .
Finally, of course, you have to just
try to be aware of what is going on. As this article has tried to suggest, don't make the casual assumption that a microphone is like an ear, because it really isn't. It "hears" in fundamentally different ways than ears do, and that is a major part of the reason that recordings sound different than the real thing. The microphone fails to pick up information that we routinely and unconsciously make use of all the time, without being aware of it. We only notice when those things are gone. So, it is important that we make sure we've managed to include enough of what the ear really expects to make the recording compelling. That is done by intuition, by using your ears, by modifying the sound (by mic placement, by equalization, by reverberation, or whatever) until you can say to yourself, "Yeah, that really
is an acoustic guitar!." That essence, that feeling, that sense of reality is what the goal of recording is really all about.
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