Guidelines for miking the mandolin and mandola.
As is the case with all acoustic instruments, recording a mandolin/mandola is always a compromise between getting the full timbre of the instrument and isolation from other instruments or unwanted reverberation.
If there are good acoustics and no other disturbing sound sources, one or two precise and highly detailed omni mics would be ideal. 4041-SP Large Diaphragm Mics
or 4006A Omnidirectional Microphones
will ensure that you do not lose any vital information. Try aiming an omni at the sweet spot, which is often where the neck meets the body: this position will give you a good blend of strings, fingers, and wood. Also try placing two omnis at 30 – 40 cm (12 – 16 in) distance to create a nice stereo image.
If more isolation is needed, one or two cardioids or wide cardioids is a good solution. Two cardioids can be placed in XY configuration at the sweet spot.