I've heard various conflicting suggestions about where to put a microphone to best pick up a mandolin's sound. Chris and I decided to do a blind test to see what we liked. We recorded chris' mandolin ten different ways, then listened to them (under random aliases) to pick the sound we liked best. Then, running out of time, we recorded my mandolin four ways (excluding ones that we'd not really liked earlier). The pictures below show the different positions we tried for the microphone .
All microphones were parallel to the ground. Microphone (I) was from the back. For chris's mandolin, we tried it plugged in as (J).
Don't listen to the below yet if you would like to see for yourself  which position you prefer in an unbiased way. Otherwise:
|position||chris||jeff melody||jeff chords|
Our preferences for chris's mandolin: G, E. For mine: A, B, E, G. We have pretty different mandolins, but somewhere between A and G, pointing angled at the fingerboard around the 15th fret, might be a good place to use in general.
 A shure sm57 instrument mic, with a cheap foam windscreen, running through a spirit folio mixer into a macbook pro. (Update 2011-09-11: The mic was in each case as close as it could be without us bumping it, which was about an inch.) For the test with chris's mandolin plugged in, we ran through a berhinger DI100 active di box with one 20db pad enabled into the same mixer with phantom power on. The hum is unfortunate, and I think comes from the mixer not doing a good job with phantom power, but I should investigate. The recordings here are all level-matched with mp3gain, but while we were doing the testing we hadn't done this. So we might have been biased some by louder recordings.
 In randomized order, these were the recordings:
chris: c-1, c-2, c-3, c-4, c-5, c-6, c-7, c-8, c-9, c-10
jeff melody: jm-1, jm-2, jm-3, jm-4
jeff rhythm: jr-1, jr-2, jr-3, jr-4
Rank your preferences and then check out the key.