be sure it;s a microphone, and not some
goofy piezoelectric or magnetic pickup.
[actually i would like to hear someone
report on what a piezo pickup does. i would
expect lots of clanging and flapping noises
to be carried to it through the wood, and
not very much actual reed sound..]
the location of a mic inside the accordion is
critical
if it;s a lot closer to some reeds than others,
those notes will be a lot louder
you need to back off from the reeds so that
the relative distance from the mic to each
reed is close to the same
if you try doing that in a 3 row, you find out
you can;t get one mic far enough away, because
when you close the accordion, the right and
left hand reed blocks are too close together.