How to mic a guitar

I'm going to answer your question.  Any way you want to.
   Now.  For the wasting of letters in the alphabet part.  What kind of guitar?  In what environment? With what microphone? What preamp? For rhythm or lead? Primary instrument or backing? Picking or strumming? Fingerpicking or pick? Taylor?  Fender? Gibson? 6? 12? 8? With percussive attack or without? Stereo or mono (mono)? Electric or... surely you get the point.  There are far too many variables for that to be a valid question, but I've asked it too.  So now I'll tell you what I've learned from experienced engineers and from doing it wrong a thousand times.

Rules:

1. Know where this guitar recording will be in the mix.  The only true wisdom I can give you on this is ...If the instrument will be accompanied only by a vocal or is all alone, or rather is the primary instrument...then your microphone(s) should be closer to the instrument than in other cases.  It will have more character as a result.  How close depends on a lot of things but I have learned that farther away than you think is almost always a better choice than too close.  I don't care what anybody says (nor should you care what I say...more on that in a minute) but I recorded guitars too close for a number of years and battled string noise, pick attack, percussive elements, transients far more than is necessary.  Which leads me to this:

2. The place where you hear the guitar sounding the way you want it to sound on the record IS the right place.  Here's a trouble spot that will arise:  If the guitar player is in charge of this desire then you will need to hear the guitar from where his head is...or as close to that noggin as you can get which will cause other issues.  If any other human being on the planet is in charge then this location will move to out in front of the guitar because that's the way everyone else hears the instrument.  Height matters.  If you're 6 foot 3 and like the guitar sound when you're standing better than when you're leaning over...don't put the mic 3 feet off the ground.  Put it up at 6' 3"...  If you're recording a guitar in a band setting where it plays an equal role in the body of the song you'll need to back away a bit to give it some room to blend with everything else.  Depending on the microphone you're using all of these decisions could cause you to be 9 inches from the fret board or 8 feet away.  I will not tell you what is right but here's some food for thought.  The time that it takes sound to travel from each instrument to it's respective microphone will dictate how "real" this recording sounds.  It will also lend to perceived timing of the instrumentalists and if they are all playing at once but not everyone's microphone (or DI signal) is the same distance from the instrument then the perceived sound will not match what you heard live in that setting.  Another unusual phenomenon occurs because every band member hears a different mix of the song based on their location within the playing space.  You really should decide on a listening point for the body of music and sculpt the recording to emulate this location.  All of this only if "real" is a thing you're after.  Even if you're not after "realism" you probably will struggle with seemingly troubled timing if the distance/time is not somewhat equal.  SO...if everybody in the band is playing into a microphone at about 3 feet away then believe it or not that direct bass line you recorded will be arriving at the recorder faster than everybody else and "things" will happen that make you scratch your head.  If one guys mic is 10 feet away and someone else's is 3 inches...it becomes very apparent that something is amiss and very few people figure out what it is.  It's time and distance.  Being different distances gives the expected perception of varying distance from the listener.  If you want the vocal closer to the listener then put the singer closer to the mic.  Where do you want the guitar in relationship to the listener and the rest of the band?  That's your bible as far as distance from the microphone goes.  Walk around, move your noggin, listen for balanced tone and peculiarities/smooth spots...beware of bass blasts if it's an acoustic, beware of transients that ping your ears no matter what it is and Put the Mic there.

3.  How many microphones?  It's always going to come back to your intention.  Bluegrass band sitting in a line...Blumlein pair maybe.  James Taylor doing his thing on the next legendary ballad he's gonna write...one well placed mic and perhaps a room mic or two (that whole stereo/mono thing again).  Any backing guitar...One.  And the type of mic is going to make more decisions for us.  After you find that perfect location and have a mic there it's time to listen again.  That mic you chose just changed things...It's not your ears.  If it's a cardioid microphone you're possibly still too close because it's hearing is superimposed...hyper-cardioid is more-so.  If you've chosen an omni mic you have my blessings on the next record because obviously you're a discriminating listener and you're a whacko...who records with omni's (I do)...but you may be able or need to move that mic closer to the source.  It's picking up everything in the room and it doesn't have trouble with proximity affect so it's the most forgiving tool when it comes to close mic'ing.  Ribbons are awesome for lots of things...signal is sometimes an issue but good Lord they love amplified instruments and they'll work on a lot of acoustics.  If your player is gently stroking the strings and you must strain to hear their softest notes a ribbon is probably not the right microphone.  Read up on suggested microphones elsewhere but some of my favorites include the Audio Technica 4022 (omni), the AT 4041 (cardioid), the AKG C414 (try all the patterns), the AEA R84, the Royer 121 and of course the SM-57.  Never underestimate the SM-57.

4.  Where should this guitar be recorded?  Again...what's the goal?  If' it's an important player in the mix then start thinking about the space that will surround the track.  If you record everything in a nice, "lively" room that provides it's own "reverb" or "ambience" then you may avoid destroying your whole project with some crappy reverb plugin, which we would all appreciate.  If you are going to HAVE to add depth with an electronic device (try delay instead of verb) or absolutely cannot find a good room to record in (though I'm sure there's one in your house) then a quiet room is best, largest room you can find unless it's fabulously engineered to trap bass and diffuse/absorb higher freqencies etc.  Read up on room treatments as well and do what you can...don't mortgage the house for it.  The most important thing that will happen during this recording will be the performance:  If the performance is magnificent you can fail at everything else and it's still going to be legendary.  If the performance is mediocre (as mine usually are) then you need to get some things right.  Really right.  Concrete walls suck.  Drywall sucks most of the time.  Being in exactly the center of the room is a no-no.  Too close to a corner is usually a bad idea.  Do some more research, I've rambled too long already but bottom line: record where the instrument sounds as close as it can to your desired end result.  The less you have to do the track to get where you're going the better the track will be.  Staircases and bathrooms may provide a fantastic place to put a second mic which can be blended in with the source mic to give your track depth.  Be creative.  Break the rules.  Steal ideas from stories you read about smart engineers and musicians.  It's an art form you know.

5.  Preamps, Interfaces, Formats etc...  Get the best things you can afford.  Read lots of reviews.  I like and trust most of the Sound On Sound reviews I read.  Your salesman at that one place you shop will actually have information.  I'm not a MAC guy so I don't have a lot of input on the MAC only stuff but obviously the Universal Audio gear is very good stuff.  I like the the AEA RPQ-500 and the MAAG PreQ4.  If I could afford to I'd have several UA pre's, a Manley Slam and a Grace design product.  I can't so I use what I can afford.  The RPQ-500 is extremely versatile, has crap tons of clean gain and once you start to understand the 140Khz bell curve that is the Curve Shape device...you'll benefit from it's existence.  $650.  Not cheap but well worth the money.  Interfaces for windows: I like the Focusrite stuff.  I like the pre's in them etc.  I've used a lot of things.  A/D conversion is where the meat is and once again, if I could afford something of professional studio quality that's what I'd have.  Most of the trusted brands have produced a great interface that is capable of high quality conversion with reasonable preamps and options.  Do your own homework and get the one you think is the prettiest or take out a loan.  All of these things will affect your recording to some extent.  Weakest link, ya know...but don't lose sleep over it.  Do what you can do and do the best with it you are capable of.  You can record something of higher quality than Neil Young's Harvest Moon album.  Bit Depth, Resolution...talk to Bob Katz.  HIGH.  24 bit is great.  32 is better.  I don't trust floating parameters...some people do.  96hz is great, 192 is better, 384 is available...another blog altogether.  The question for me is back to the performance again...Pink Floyd wasn't recording on a device that can capture sound at unimaginable frequency ranges that the cheapest interface on the market today can...Will your recording defy human hearing to the extent that we should debate 24/96 over 32/384?

6.  When in doubt...too many mics is a good thing.  Choose and change your mind as the mix progresses.  Don't do it just to be doing it...but if you're truly uncertain about what you're hearing put up the extra mics.

Last note.  You must record the guitar wrong several hundred times before you get it right.  That's just a law around here.  Get started.  Try something new.  Surprise us.  Surprise yourself.  Don't take my advice at all.  Don't take anyone's if you so choose.  At least lay awake at night and develop a theory about what "should" work and go from there.  If it fails, move on.  I tried a ribbon in front of the sound hole on an acoustic for a time, null point of the figure 8 pointed right into the nucleus of that low frequency train wreck and the did some fancy mix tricks to pioneer a sound that had never been achieved before.  It didn't work of course (well it worked sort of), but the point is...there are still new ideas out there running around.  Catch one.  Let us know how it works out.  Enjoy making music.  Have a plan.  Research and develop.

Hope this answered something for someone.
I'm out.

Jefferson Fox
maker of many mistakes