I need to mic my bass amp, and I'm thinking about a Beta 56, Beta 57, or a SM7B. However at all the local music stores they will not allow for me to test them out with a bass amp to see if i like it or not. I dont need a real deep bassy sound...just a crisp and punchy sound (not in need of bottom end)...which of these mics, or any other mics, would be best for that???
We cannot predict which mic you will like the best. We can say that the SM7B will have the best low frequency response of the three models mentioned. The Beta 56 or Beta 57 (inside they are the same) will have a brighter high end.
But keep in mind that selecting a mic is a personal decision, and we cannot tell you which model you will like best. Would you buy a bass without hearing it? The same goes for a microphone.