There comes a time when even rock bands use acoustic guitars, either in live performances or in recording. Knowing how to mic one will help you out!
First, choose your mics. A lot of people don’t have a studio locker full of microphones, so you may well be limited in your choice. Most musicians have access to a dynamic mic. A Shure SM57 can work well on acoustic guitar especially for getting the mids to punch through a mix. If you’re forced to use a dynamic mic, don’t get too close to the guitar or you’ll get something called a ‘proximity effect’ (or ‘bass boost’ to you and me), which can sound pretty overpowering. A lot of times, bass frequencies will be cut from an acoustic guitar with EQ unless it’s a very sparse arrangement.
If you can use a condenser mic instead of a dynamic, so much the better. Condensers are usually better at picking up the high end detail of an acoustic guitar.
Just about the worst place you can mic an acoustic guitar is on the sound hole. That’s pretty much the muddiest, boomiest place. What seems to work well and is a tried and tested method, is miking the point where the neck joins the body, or around the twelfth fret, moving the mic about 8 to 12 inches away.
The area between the bridge and the end of the guitar is also a lot better balanced tonally than the sound hole area. A mic here should be pointed at the body about 10 inches away. Using a combination of this technique and the neck join technique above can give you a great sounding stereo image – just pan the mics hard right and left. This will leave a nice space in the middle for vocals or lead instruments.
- Wear headphones and move a mic around the guitar whilst the guitarist plays so you can hear where the mic sounds best. Bear in mind what other instruments are in the arrangement whilst you do this – you may not be able to get a great mix if the acoustic is really bass heavy.
- To pick up more detail, try miking higher up the fret board. The closer the mic is the more fret noise you’ll pick up.
- Acoustic guitars rarely sound amazing just out of the jack (if they have one). If the acoustic has a DI, try combining that with a miked signal for some more tonal options.
- If you have a compressor on hand, use a ratio of about 5:1 and set to a slow attack to let the string attack transients through before the compressor clamps down to give the guitar a percussive sound. Use a faster attack if you need to tame picking/strumming.