Mic placement is one of the most crucial steps to recording your electric guitar’s sound. All of the different steps are crucial to getting the best result, but mic placement seems to be one that is often neglected. The most widely used microphone for electric guitar amps is the Shure SM57 dynamic microphone.
Just about every studio will use them at some point, and they are affordable enough for the home recording artist as well. Its sound complements the guitar’s sound nicely, on just about any type of music, and with both clean and distorted tones.
Setting the Amplifier Volume
I will assume that you have already set up your guitar to be ready to record. If not, read my article Preparation Before Recording. Before we place the microphone, we need to get the amp set correctly. Adjust the equalizer on the amp so that it sounds the way you like it (or the way the guitar player likes it, if you are just the engineer.) This is very important. If the guitar player does not hear ‘his sound’ coming out of the amp then he will not be as happy with it, and it can affect the playing quality. So make sure he has ‘his sound’ first, and you can make changes with EQ later in the mix.
Next, adjust the volume of the amp so that the speakers get some good volume and start to visibly move. This is where the speakers themselves contribute the most to the sound. Just be sure you are not pushing them too far.
Finding the Sweet Spot
If the amplifier has more than one speaker, determine which one sounds best. There’s no good way to do this, so just stick your head down there and hear what each one sounds like. Just be quick about it so you don’t go deaf. Its going to be loud down there at this point, and your ears can only handle that amount of noise for about three minutes. When you have selected the best speaker, throw on a good pair of isolating reference headphones so you can hear what the mic hears and less of the surrounding noise.
Start sweeping the microphone around the cone and listen to the differences in sound based on the part of the cone it is placed in front of. The edge of the cone is more bassy and not as loud, where the very center is very shrill and trebly, as shown on wellmixed.com. The sweet spot is going to be somewhere in between those points. Just keep listening and moving the mic around until you find it.