The guitar - Mic choices, patterns, and placements
Ok, here we go, pinched sciatic nerve be damned!!
Miking an acoustic guitar
Many acoustic guitars today have built in pickups, and it's gonna hafta be your choice whether you add that to the mix or not - that's a whole 'nother subject. Before you reach for a mic, you hafta decide a few things:
Is it a solo guitar, strictly as a backdrop for vocal, or is it one part of a group mix (where there'll be other instruments like drums and bass and electric guitars going on)? Does it need to be recorded in stereo or is mono ok? Is it gonna wind up being in your face, or buried in the mix?
Solo Guitar or Background For Vocal?
If it's a great sounding guitar, and you have a good room, you want to use the best mics you have and record in stereo. You can use omnis, or a pair of good cardioids in an X/Y configuration (capsules almost touching, angle of about 110 degrees between the two mics) and about two feet out from the instrument.
A dynamic or condenser mic will work fine as long as the mic has a fairly smooth response. Smaller condenser mics are usually more accurate, but if it's not a killer instrument, don't be afraid to try large diaphragm mics to get a more flattering sound. The mics should be pretty closly matched otherwise the stereo image can shift as you play different notes.
If the sound ain't working for you, that's the time to move in closer and see if you can find spots nearer the guiitar that produce a better tone (even if it's just for that song). Try to get as close as possible to the final sound you want BEFORE you reach for eq and/or effects.
After you get the tone damn near perfect from placement and selection, then do a little touchup with the eq to nail it. (If you hafta boost or cut more than 4 dB in any frequency range, you either haven't got the placement right yet, or it's a really crappy guitar.)
Acoustic Guitar as a Rock Track With a Band
You need a tone that's gonna cut thru the other instruments and if there's gonna be drums, bass, electric guitars going at the same time, record the guitar on the thin side (some bass cut and treble boost). Make it brighter than you normally like it, and don't worry about how it sounds soloed - it's how it sounds when it's all mixed that will count. I usually mic in close (about 6 to 8"), from slightly below, looking up directly at the bridge. Roll off the bass below 100 Hz, and boost around 2 to 4 kHz (move the frequency around to where it sounds bright, but not shrill).
The Singer/Songwriter Syndrome
The singer also want to play guitar at the same time, and you want some decent separations between the vocals and the guitar. One trick is to use a X/Y stereo pair of small cardioids down low, aimed at the guitar, hile you position a large diaphragm mic at the singers forehead, tilted just slightly forward, toward his/her nose.
Some Points To Ponder
These techniques should work for banjo, mandolin, 12 string, uke, and other small stringed instruments. But sometimes they don't always work as planned. If you're not hearing the sound you want, try moving the mic around, even to the point of miking the side of the instrument instead of the front. Violins, cellos, and upright basses are a whole special category which will be discussed later.
A good trick is to stick your finger in one ear and move around till you find a spot that sounds good, then put the mic there for starters. Remember that each guitar is different, each mic is different, each room is different, and sometimes just going up or down a 1/2 step will change everything. Starting from the outside edge of the "nearfield" is a great starting point.
Some Mics To Try First:
Dynamics: Shure SM57 - Sennheiser 421 - Beyer
M201
Ribbons: Beyers, RCA, any ribbon mic.
Small Condensers: Oktava MC012, Marshall 603S, AT 4041, Neumann KM184, any small cardioid or omni condenser mic.
Large Condensers: These mics add a great deal of color to the sound, so "try" anything you happen to own. It may work great or shitty - you never know.
End of the first part - more to come!