It depends. What kind of guitar are you micing?
I'm wrestling with this same thing myself currently. I traditionally like to use 2 SDC mics on an acoustic guitar: one at around the 12th or 14th fret, and another pointed behind the bridge. Between the two, I get a nice bassy sound out of the bridge mic and nice clear sound out of the 12th fret mic. Mixed together at the right ratio, and I get a nice full-range guitar tone to work with.
The problem is that this doesn't always fit into a mix since it has a pretty wide spectrum of frequencies represented. But in a mix where the
acoustic guitar is a featured instrument and not just one of many rhythm instruments, 2 mics might be just the remedy to fill out the sound a bit.
I just got a new drednaught acoustic not too long ago and it's got a huge sound, lots of bass, lots of mids, lots of highs. It's just a huge, bombastic sound when strummed. I'm finding that the bridge mic is a little too much. But I"m not finished experimentng yet.
If you're using an orchestra model or similar guitar, then 2 mics might be a good thing. But with a big, bassy drednaught, it might be too much. Especially if you already have a bass guitar in you ensemble. You might end up competing too much for those low-mid frequencies and creating some sonic mush.
