Two mics on a snare drum is better than one
Ok, we have to be honest here. This is one of our biggest pet peeves. Not because we haven't seen this done correctly but, because mostly we have not. We see it done by people who have absolutely no idea of the physics behind what they are doing. They do it because they have seen it done or because someone told them it was a good idea.
There is a cost and a trade off of everything we do and we are always better off if we don't complicate things. Our preference is of course to tune the snare drum. One microphone is enough if the snare is properly tuned.
The same physics of loudspeakers also applies to microphones as well. After all they are pretty much moving coils in a magnetic field, one at the beginning and one at the end. Yes this is very simplistic, we know, but, bear with us, needed to prove a point. If you know you can get wave interference with one then why not the other? Well, the answer is you can.
We used MAPP online to demonstrate this. We can't show two mics on a source but, we can show two sources on a mic. That is technically the same thing when combined to show what we are talking about.
The next time you think about putting two mics on anything remember this picture. Please notice the reduced decibel levels between two thousand and sixteen kilohertz. With two microphones there is phase cancellation that only very exaggerated equalization will correct, and is completely unnecessary.