Acoustic Guitar Techniques

Recording The Acoustic Guitar

While the acoustic guitar remains one of the most simple instruments by design, it also remains one of the hardest to get a great sound on in the studio. It's really not brain surgery, but knowing some of the basic laws of physics doesn't hurt. Unfortunately, I skipped school that day and didn't learn my physics, so I had to learn how to get a great acoustic guitar sound one mistake at a time. After making those mistakes, I sat down and formulated these laws which are considered to be the Ten Commandments of recording the acoustic guitar (by me anyway).

For the sake of argument I'm going to assume that if you're reading this, you own a 4 track, or an 8 track recorder, a fairly small console, some basic outboard equipment, and you don't own any $2,000 microphones. If you own 13 foot long console and a 48 track digital machine, you can skip this article because you probably know what I'm about to tell you.

Rule 1 • A condensor mic will almost always sound better than a dynamic mic for acoustic guitars. There are several condensor mics that are currently on the market in the $350 price range that sound great on acoustics.

Rule 2 • New strings will always sound better for recording than old.

Rule 3 • Skinny strings sound brighter than fat ones (can you believe I get paid to write crap like this?!)

Rule 4 • The sound you get has a great deal to do with the dynamics of the player.

Rule 5 • Get down on your knees and position your ear as if it were the microphone while somebody else is playing the guitar. Move your ear around to find "sweet spots". You'll learn more from that, than you will by reading this article. Don't try it with an electric guitar!

Rule 6 • If you have somebody that is assisting you on the session, have them move the mic around what you think will be the sweet spot while the player is practicing the part he or she is about to lay down. Have your assistant wear headphones so you can communicate with him while the moving of the mic is taking place.

Rule 7 • A limiter/compressor will almost always help you get a better sound.

Rule 8 • Don't believe everything you read. I only have seven commandments, not ten.

Let's get right to it. If the sound you want to get is a country/pop, strummed sound similar to the Eagles "Lyin' Eyes", here's the formula: Place the microphone about 6 to 8 inches from the guitar's sound hole, but angle the mic toward the area where the fretboard and the sound hole meet. If you point the mic directly into the sound hole, it will be very full - probably much too full, and very boomy. Use a compressor/limiter to knock down any peaks (3:1 ratio), and set the threshold a little lower to give it a slightly "squashed" or tighter sound. Set the threshold higher to just limit the peaks and give a more open sound. You may need to EQ out some boominess. If so, try rolling off some bottom (100Hz), or cutting a couple of db at 300Hz. To add some "silk" on the top end, try something in the 8-10K range, but be careful, to much will add noise to the track. Positioning the mic so it angles toward the pick will give more attack-less sweetness.

For that John Cougar Mellenkamp sound, try medium gauge strings, a little more compression, and try adding a little EQ around the mids - lets say 700Hz-1.2K. That will give you a sound that is a little more "woodsy" (a highly technical term).

"Ya, well what about Melissa Ethridge," you say. Try this on for size. Use a guitar with a built-in pick up and a microphone to boot. You will undoubtedly get some phase anomalies, but that's part of the sound. Experiment with moving the mic closer and farther. That will affect the phase relationship of the two sound sources. Sooner or later, you'll hit on something that will put a smile on your face. You can pan the two signals left and right to get a broad stereo sound, but make sure that if you check the sound in mono, that there's still some signal left. Keep an eagle ear on Mr. Phase, he can be a tricky bugger.

And now ladies and gentlemen, for the most often heard acoustic guitar sound at the 1993 Grammys it's that Eric Clapton classical/gut string guitar! Piece of cake. Once again, use a condensor mic, but place it about ten inches away from the guitar. As a matter of fact, try placing it about 3 to 4 inches up the neck, but aim it at the players picking fingers. This angle will reduce boominess by virtue of the mic's cardioid polar pattern producing a natural roll off when it's aimed off-axis, while simultaneously delivering the attack of the fingers. Try and say that three times in a row! The added distance will pick up some of the guitar body's resonance. A compressor/limiter is a must for this case because of unexpected peaks. A 4:1 ratio is a good place to start, but set the threshold fairly high so that the most of the guitar's natural dynamics are left in tact.

When mixing acoustics guitars for rock or alternative tracks, you will usually have an electric guitar or two in the track as well. My personal preference is to pan the acoustic and electric across from each other. Send one full left, and the other full right. You'll quickly discover that the electric will overpower the acoustic and the most effective way to even them out is to compress the acoustic a little bit more than what you may have already done going to tape so you can bring the acoustic's level up high enough to compete with the electric.

Another simple but effective trick is to have the acoustic and electric guitars play parts that counter each other rhythmically (giving them each their own space), and have them each play in a different octave. That will give you a full sounding track that remains open and airy at the same time. You can also make an acoustic guitar sound bigger or more rock-like by panning the original to one side and a delayed signal (short delays are best) of the same guitar to the other side. That effect can be taken one step further by using the pitch change option on your delay to "de-tune" one of the guitars just a pinch (one cent is a good place to start). The delay will provide the brain with the psychoacoustic information it needs to perceive the guitar as bigger, while the pitch change will make it appear "fatter."

Funny how fatter is always better in the world of recording, but not in the case of the human body. Just a tangential observation must be time to go.