How to Phase Align Two Microphones On One Guitar Amp

I've been asked many times the way to achieve a great guitar sound. Surprisingly, there are few factors in attaining this objective. It all begins with a great guitarist performing a great instrument. All the sound engineer is required to do is capture the sound onto a recording device. Sound easy? Well, actually it is. It is not uncommon for an engineer to use two different microphones on one guitar amp. This will often yield a tonal characteristic that isn't possible with just one mic. What can often occur when using this technique is phasing. Sometimes the phasing can be minimal and thus desirable, but most often will result in a smaller more diminutive sound. I'm going to discuss a technique that I use to eliminate phasing when the two mics are summed to create one unified sound.

Instructions

Difficulty: Moderately Challenging

Things You’ll Need:

• Guitar
• Guitar Amplifier
• Two Microphones
• Digital Audio Workstation (ProTools, Sonar, Nuendo, Cubase, etc)
• A/D Conversion Interface

1. Set up the amplifier in with the two microphones pointed at the speaker cone. These two microphones will later be summed to create one sound.
2. Assign each microphone its own respective track within your recording set-up.
3. Press the record button on your DAW.
   
   With your guitar in hand, play a quick palm-muted strum. We're not going for guitar acrobatics, here. We're just trying to record a fast, clean transient into the system.
4. Now zoom-in closely to view the two juxtaposed waveforms. You will notice that they will not be perfectly aligned. In this case what has been achieved is phasing. It will sound incongruent and loose. What we want to do is manually nudge either of the two mics to be aligned with the other. It may only be 'off' by a few milliseconds. So, just grab the cursor or grabber tool and spot in into place. Voila! Perfect phase coherency between the two microphones. You will now have that giant guitar sound you've always dreamed of.