This month we’ll see how blending sound from two mics can add color and distinction to an electric guitar recording—or ruin it.
But first, a few clips inspired by reader comments. I recorded last month’s audio examples with the mic’s element aimed directly at the grille, just at varying positions on the near/far and center/edge axes. But several folks mentioned orienting the mic at a bias—say, at a 45 degree angle relative to the grille. How does that alter the tone?
Hear for yourself: I recorded an audio clip four ways (Pic. 1) through a Shure SM57.A. Center position, 1" from grille
B. Center position, 45 degree angle, 1" from grille
C. Midway to speaker edge, 1" from grille
D. Midway to speaker edge, 3" from grille
No surprise that clip B sounds darker than clip A—the element points away from the bright speaker center. Now compare clip B to clip C, where the element is aimed to the same spot, but with its barrel perpendicular to the grille. Clip C has a touch more low-end warmth. That’s the proximity effect—the mic’s tendency to pump up lows when positioned close. The mic is a couple of inches further from the grille in clip D, nixing some of the proximity effect and producing something quite similar to clip B.
Angling a close mic in relation to the grille slightly lessens the proximity effect, which sometimes yields clearer tones.
Key point: Angling the mic reduces proximity effect. (It probably makes total geometric sense if, unlike me, you know your ass from your hypotenuse.) The technique is especially useful for minimizing leakage on live stages or when tracking multiple instruments.
The birth of big. There’s a great illicitly circulated Led Zeppelin studio outtake (sadly not on the official Outtakes collection). While Jimmy Page plays the “Heartbreaker” solo, we hear an engineer bringing up two mics. First is a close mic, dry and claustrophobic. Then we hear a spooky, resonant room mic. Then we hear the two together, slightly panned in stereo. It’s like witnessing the birth of modern rock guitar tone, but without messy placentas and stuff.
Exploitation of ambient space is a big part of Zeppelin’s magic. Jimmy Page realized that the emotional impact of a riff wasn’t merely about the player’s notes and guitar tone—space itself could impart majesty and mystery.
But before you set up 47 mics, consider this: Each new mic adds something, but takes something else away.
Positioning a second mic at varying distances from a close mic emphasizes different frequencies while attenuating others.
Double trouble. Whenever you blend mics, phasing comes into play, because the sound reaches each mic at a slightly different time (see Pic. 2). Like a phase shifter pedal, which combines your dry signal with a slightly delayed signal, some frequencies resonate more strongly while others are cancelled. The result can add cool texture and dimension, or just make parts sound thin and diffuse.
I recorded a quick clean-toned example with the SM57 right on the speaker, with a Neumann TLM 103 condenser alongside, and then at increasing distances from the amp. In the audio clips, you hear the 57 alone for six seconds before the 103 switches on. It’s dramatic!