Most engineers and producers, to allow themselves more options at the mixing stage, record guitars (electric ones in particular) with two or more microphones placed at a different distance from the sound source. Shoegazer bands are particularly famous for using this technique, which indeed can help give the guitar a more roomy and open sound (if the mics are spread across the stereo field), but can also be problematic, because of a little mysterious word called “phase”.
We are about to walk you through a quick and easy experiment you can try at home that will open your eyes about how important phase is!
1. Place two mics in front of your amp: one very close to the cone and another one about 2 feet away.
2. Record an electric guitar part, preferably distorted chords or power chords.
3. After you record, change the two tracks’ settings so that they have roughly the same volume and position them both in the center of the stereo field so that you get a perfectly mono sound.
4. Now insert a short delay plug-in on the track of the closest mic,
5. Play the two tracks back together in a loop with the delay set at 0 ms (no delay) and every few seconds increase it 5 milliseconds at a time.
6. If you have a “phase reverse” button in your DAW, experiment with that as well.
You will notice that every time you change the delay the guitar tone you get will be slightly different. Reversing the phase might have even more drastic results. That is what “phase” does to your recorded guitar sound – or any other sound source for that matter. And that delay trick is used by many producers to get the right tone from a combination of mic sources.