We are in need of a condenser type mic to use for several things. (1) We have a stage (25' by 25') that needs mic'd for plays. (2) 3-vocalist that are spaced about 2'-3' apart. (3) Piano and woodwinds, sax, flute. I know that is a general field to cover. Would the SM81 be a good choice for that?
Yes, the SM81 would be a superb choice.
1. Make certain the vocalists do not hold the SM81; it is designed for stand mount use.
2. Consider mounting the SM81 with an A53M shock mount to reduce vibrational noise.
3. The SM81 requires phantom power from the mixing board; make certain the board has phantom.
Also consider the new KSM27 in the same price range.
In a lower price range, consider the SM94 and PG81.