Tips on Recording Acoustic Guitars (Microphones)

I’m trying to record my band and need some advice on recording an acoustic guitar.

What’s a good mic for acoustic guitar?
Where exactly do you place the mic?
Do you use compression or EQ?

It depends upon the sound your going for. I find that using a single AKG 451 mounted between the sound hole and the upper part of the neck (higher frets) works really well. This is really for recording mono which is easier to mix back into the band.

You can also record in stereo by placing another mic between the bridge and the sound hole. I put one finger in my ear and listen while the guitarist is playing to find the starting point. You’ll usually find a spot that doesn’t sound too boomy. The 451 is fairly flat when it comes to frequency response and has a 75hz high pass filter that removes most of the low rumble. On some guitars it may take out too many lows so you may want to just EQ some of them out.

I also like using the using two audio technica AT3032 omnidirectional mics placed in the same position. They have a really big sound but you need to make sure that the room isn’t to lively and that the early reflections are not too much. If

this is for radio or tv make sure to check what it sounds like in mono before committing to disk. You may need to take out some of the 500 to 2k frequencies but it will really depend on the guitar, and guitarist.

I’ve used two small lavalier condensers mounted on the sound hole itself. It’s the only way to go. You have to make sure the guitarist doesn’t hit the soundboard because they’re fairly sensitive. As far as checking for mono do you mean turn off one of the mics? I’m recording an ovation that has a pickup and preamp already in the guitar. You can convert to mono by turn the pan pots (panners) on your mixing board to the center position. This will place everything in the center so you can hear what happens to the sound.

If you’ve already have a preamp then record it along with the microphones onto a different track. Then mix it to what you think sounds the best. I usually have it about -6 to -9dB below the microphones. The pickups don’t sound as natural to me as a microphone but they do add some definition to the sound.

You can also mount a roland gk-2ah guitar pickup on a acoustic guitar. that way you can play a gr33 or gr20 guitar synth. I used the double sided tape and mounted about 1/4″ or so from the bridge. It really adds depth to the sound. try putting a choir, bell like sound, or even another guitar sound but about -15dB or so below the real instrument. I’ve only tried it on my yamaha acoustic that has metal strings. I haven’t tried it on a nylon string guitar. Sounds really cool.

I usually use two condenser mics in the XY configuration. I use one of those atlas two microphone mounts where you have two mic mounts that can be repositioned. I align the mics at a 90° difference/angle to one another on the atlas mic mount. Depending on the mic you’ll have to get the 90° angle as close as possible. I use a protractor. Check both the vertical and horizontal angles, look at it from the side as well as the top.

I then place the mic about 12″ in front of and towards the bottom part of the guitar’s sound hole. Using the XY mic pair gives the guitar a depth of soundfield that a single mic just can’t do. You can change the density of the stereo field by panning the pan pots on the mics at mix down. Instead of having them and hard right and hard left you can pan them more towards the center. The stereo image completely collapses when both the left and right pan pots are centered.

As far as using an EQ I try to avoid it but there are times that the low frequency cut found on many of the condenser mics just doesn’t remove all or the problematic low frequencies. Then I use a low cut filter.

My favorite Mics to use for miking an acoustic guitar are: the AKG C-414, AKG C-1000, and the Neumann KM 184. I’ve even used the Behringer B-5 and Nady CM-90 condenser mics got pretty good results. They are not really in the same league as the Neumann or AKG mic though. But if you can afford the more costly mics you can try the cheap condensers. As far as preamps I like, but don’t own, a universal audio M610 mic preamp. The dbx 376 and 786 mic preamps and even their mini pre works pretty well.

Most importantly is to use your ears and search to find the best spot to place the mic. I run the stereo pair of mic into the headphones and then have the guitarist play and then position the mics. This is the best way to get things started. You should then record to tape (hard disk) and then check the mix. Also pan both mics to the center and hear how it sounds If it becomes really thin sounding then the XY placement is not aligned properly or there is some other problem.