The SM81 has been a small diaphragm condenser "old standby" for a while now. In my opinion it is one of the best small condenser's on the market, even though it's not one of the most expensive. You need to hook this up with an XLR cable to a mixer or preamp that can give it phantom power. This mic has a switchable low-end roll-off filter. You can set it to bypass, have a gradual roll-off starting at about 120Hz, or a sharper, faster roll-off that seems to start around 70Hz. This mic has a cardioid pickup pattern, which is great for isolating your sound source without too much ambience if you are close miking something. One of the best things about this mic is how totally even the frequency response is. Usually with small diaphragms you tend to get hyped highs and upper mids, which can sometimes sound kind of harsh. On top of that, the bass end tends to not be very well established. Not so with the SM81! For some reason the bass comes through really great on this mic, and the highs don't really seem to get tinny. That's great news since you are still getting the very fast transients and sensitivity of most other small condensers. One thing about this mic I don't like is the relatively low SPL it can handle before breaking up a little bit. Just don't stick it too close to a drum head!

OVERALL OPINION

I have been using this mic for years now. Some of my favorite applications are background vocals, small string ensembles and choirs, and snare drum bottoms. The SM81 is often my first choice mic for those applications. At less than $500, this mic is definitely a fantastic value. Add to that the fact that Shure mics are built like tanks (I've dropped mine more than once and it still works great), and you have a great mic and a great deal. I recommend it.