As for the CM-200A vocal mic, put on the foam windscreen, allowing a little airspace between the windscreen and the mic grille. Sing with lips touching the windscreen to reduce breath pops and increase gain before feedback.
Roll off some bass (low-frequency EQ) on each instrument until the sound is natural. Same for the CM-200A if you want a little cleaner sound.
Some bluegrass bands are miking the entire group with a single cardioid mic, such as the Crown CM-700. For details see this article.
If feedback is a problem with the acoustic guitar, you could search for acoustic guitar pickups in Google. Good luck!
I would like to record a bluegrass group live. Is the PZM mic a smart move. Also would like to use the same mic in a PA system. Any ideas?
Reply: By "recording live," do you mean recording a live performance with monitor speakers on stage? If so, a PZM on the floor would pick up too much monitor sound. It would be better to get a 4-track recorder, record the house mixer signal on two tracks, and record two PZMs at the Front-of-House position on the other two tracks. Each PZM should be on a 2-ft. x 2-ft square plexiglass panel, with the panels touching on one edge to form a V. Aim the point of the V at the group. Or tape the PZMs to the ceiling.
Mix the four tracks after the concert. The house-mixer tracks provide clarity, while the PZMs add bass and room acoustics.
If you plan to record your group playing all at once in a studio or in your house, a PZM or two could work well. You could tape two of them (for stereo) on a wall at mouth height about 3 feet apart. Gather the group close around the mics, and
record. Listen to the playback, then move each band member toward or away from the mics until you get a good balance.
Since a PZM has a half-omnidirectional pickup pattern which can cause feedback, it is not recommend for PA except in a kick drum.
Crown's best-sounding PZM models are the PZM-6D and PZM-30D. They sound the same. The PZM-6D is smaller and lighter, making it easier to tape onto walls and ceilings.