The SM-58 is considered by most musicians to be the defacto standard for live vocals. It is also omni-directional, which means it can pick up sound from multiple directions instead of just straight on. It has a bassier sound (which some might call "warmer") and that is apparent when you also record with it. More often than not, if used in a live or a recording situation, you'll be rolling off some of the bottom end of your voice on the board and perhaps boosting the mids and the highs a bit to compensate. It is a very smooth sounding microphone, hence the vocal appeal.

With instruments, in this case a guitar, the recorded bottom end will be more pronounced whether live or for recording. If you are using a dreadnaught sized guitar you'll likely want to limit the bass response from a microphone (since the dreadnaught itself should provide ample bass) and hence the reason for using a 58 as an ambient microphone rather than for close-up mic-ing.

The 57 on the other hand is a more uni-directional microphone and has a stronger detection of midrange and higher frequencies (than bass) which is why you often see it used with bands mic-ing instruments like drums, cymbals, saxophones, acoustic guitars. It adds very little bass "coloring" to the overall sound, and enhances the sounds of midrange and trebley sounding instruments. Both the 57 and 58 are virtually indestructable as well, hence their popularity.

If you don't want to spring for a condensor, then the 57 would be your best bet - for now.

But, if you dig the sound of what you start recording, and figure down the road you might want to hear even better and truer quality recordings, you'll end up buying a condensor anyway and will have spent twice on microphones. A decent condensor will yield a truer, more accurate representation of the sound of the instrument (or your voice) WITHOUT adding the additional "coloring" that a 57 or 58 might. In the long run, for the extra 40 or 50 dollars it might cost you, the condensor makes more sense, provided your pocket book can handle it.


And Mick is right. Once you start down this road, it will never end. You'll be constantly broke or squeezed for cash, and loving every minute of it. (You will learn to love Kraft Dinner and peanut butter sandwiches and wear the same clothes in your closet for years.)