Hello!
I suggest that you'll record this instrument in stereo and not mono.
The reason is that the accordion has some panorama Dynamics of the player.
also to get the feel in both sides of the instrument and true color of the sound.
I used A-B Microphone setup to record it, placing two identical Condenser Mics both with an exact same distance from, the center of the instrument ( it is really important to preserve the same distance or else you'll get phaseing in your recording). constantly check for phasing between takes becase the accordion playersa tend to move here and there.
If your still lacking some nice Low - Low-mid sound you can use a dynamic mic facing the center of the instrument.
Bare in mind that you'll have to Edit some " Breathing" Sounds the instrument produces.
Good Luck
Edonedush
