Photo 1: Tiny adjustments in angle between the guitar and mic dramatically alter your tone.
Miking guitar amps is one of the easiest studio tasks. With decent gear and a solid performance, it can take real effort to screw up. Acoustic guitars are tougher. They have far greater dynamic and frequency ranges, and unlike amps, they have a nasty tendency to move around mid-recording.
There’s plenty of info out there about recording acoustics, but it’s usually presented from the engineer’s perspective: Where do you put the mics after you’ve parked the guitarist in a chair? But what if you’re the poor schmo setting up the mics, sitting in the chair, and pressing record? Let’s look at a single-mic method that almost always works.
Mic choice. To most ears, condenser mics do the best job capturing the full range of acoustic guitar. (Sadly, the inexpensive Shure SM57 that sounds killer on your amp tends to make acoustics sounds harsh and thin.) Ribbon mics can also work great, especially relatively bright-toned ones like the Royer R-121.
Here’s one guitar (a small-bodied 1941 Martin 00-17) recorded through four different mics: a Neumann TLM 103 (a large-diaphragm condenser), an Ear Trumpet Edna (a small-diaphragm condenser), a Royer R-121 ribbon, and a Shure SM57 dynamic. These are raw recordings, with no EQ, compression, or effects. Draw your own conclusions.
Sadly, ribbon and condenser mics cost more than dynamic mics. The most coveted models can cost thousands. But as with guitars, you can find Asian knockoffs that yield surprisingly good results at a fraction of the price.
Small-diaphragm condensers are probably the most popular option among engineers, though countless classic recordings have been made with large-diaphragm models. Some say small diaphragm mics are better at capturing airy highs. Try before you buy.
Mic position. If you’ve ever recorded an acoustic, you probably realized that aiming the mic at the soundhole yields boomy, bottom-heavy tones. Instead, aim for the junction of the body and neck, around the 14th fret. This spot tends to provide a good balance of highs and lows, though the perfect position may vary between guitars, players, and parts. Even tiny adjustments of angle and distance can dramatically alter the sound.
That’s why I always record acoustic guitar while wearing headphones—it’s the only way to accurately gauge how slight position changes alter your tone. Careful, though—if the headphone cable brushes the guitar body, you’ll hear it through the mic. (I usually secure the cable under my butt—sorry if that’s TMI.) Also, listening on phones tends to yield tighter performances in band tracks. (Hint: Focus on the drummer’s hi-hat.)
The pivot principle. Six to eight inches between guitar and mic is a good starting distance. From there, pivot your body and guitar to varying angles in relation to the mic while listening on headphones (Photo 1). You’ll hear subtle differences in phasing and bass-to-treble balance, and one spot will probably sound best. If you’re overdubbing onto other tracks, listen to them while finding your position—certain balances work better in context. With practice, you may find yourself “playing to the mic” the way skilled singers do, altering your position slightly to bring out the best sound for each section.
Consider the space. Many engineers emphasize the importance of capturing room ambience when recording acoustic guitar. But those folks are working in rooms designed for recording. If you’re in a funky home studio, a tight, close-miked sound may be your best bet. If your mic has switchable pickup patterns, the cardioid setting (which deemphasizes room reflections from the back and the sides) is probably a good call.
But even a closely positioned cardioid mic picks up the room, so experiment with different spots in your recording space. (If you’re working alone, you may be glued to a chair within reach of your computer keyboard.) Many players and engineers swear by recording on a hardwood floor.