I need to buy a good inexpensive mic for a 5 string bass. I checked a musical acoustics book and according to it the low "B" rings at a frequency of 30Hz. Does this mean I need a mic with a low freq. of 30 or below?? Or if I have a mic like the SM57 with a low end of 40Hz will that work good too?
Miking is an art, not a science. The SM57 will pick up the low B, but whether you like the sound or not is your decision. As an alternative, consider the model KSM27.
Read more about miking at: Educational Articles - Online booklets and bulletins