Our Session has decided to relocate our 12-15 member choir from the loft to standing in a semi-circle around the piano. I'm seeking suggestions for mic placement to obtain a good balance between the vocals and the piano. Thanks
Assuming this is a grand piano, the system has solid gain before feedback, and piano location is not in the coverage pattern of the house speaker system.
Stand mount directional small diaphragm condenser microphones about two foot in front of and two foot above the performers at each end of the semi-circle. Start out with both microphones level and pointed approximately along the arc of the performers. Start out with the piano lid on the half stick and ask the pianist to err on the side of a light touch. Get the choir to sing something they know really well. There will probably be too much piano so shut the lid and try again. If there is still too much piano, stronger singing is the real answer but if that is not possible then enlist a church member that can sew to make a padded drape. The drape will need to cover the entire lid and probably the entire body all the way around, but allow the music stand and light to be in playable positions. Experiment with the drape materials especially the makeup and thickness of the padding and overhang length until it sounds right. We cut up and experimented with an old cover until we came up with what works for us. We generally use one for kids ensembles and dramas so the piano doesn't overpower them. Once the piano level is correct with the drape you may find it sounds too dead if so add a single PZM mic to the underside of the lid positioned over the center of the upper half of the strings. The mic can be readily and securely attached with four to six 3M command adhesive strips. The idea with this mic is to just add back the high frequency information that is being excessively attenuated by the drape. Start with a high pass filter on this mics channel set like 400-500Hz or if yours is not adjustable then engage what you have and roll out the low frequency shelving control on the EQ. A reasonable boost to the high frequency shelving EQ may also be beneficial to capturing the "air" you want without adding back too much overall level. For the record I like hanging Astatic 1600VP microphones for this kind of choir micing and a Crown PZM 6, 12, 30, or 180 for the under lid microphone.