Microphone Placement on an Acoustic Guitar

Often, owners of home recording studio equipment face the challenges of learning how to use all of the cool toys they just bought. That can be tough. In the big leagues, who they're ultimately competing against, they have the finest microphones, the best sound rooms, and, of course, the best recording engineers and technicians. Often those people come with years and years of experience, and ears that are fine tuned because of it.

How can you get the right sound with less experience? That's not always easy.

First of all, notice that I didn't say, "How can you get a GOOD sound..." I said, "How can you get the right sound..."

This is because you need to divorce yourself from the idea that there are good sounds and bad sounds. Why? Because the context and the artistic intent can vary. Think of the Heavily distorted vocals on "I am the Walrus". Is that a good or a bad sound?

The answer is: "Neither. It is the RIGHT sound for that song."

Once you have that concept in mind, you'll learn that when you put microphones around singers and around instruments, the sound changes depending on where you put the mic and where you point it. There are many standard ways of doing things, but it's best to learn how the sound is changed with different placements, so that you can know which microphone placement to use to get which sound.

Let's consider the humble acoustic guitar.

A long time ago, early in my years of studio work, I had some access to some down time in a studio. I told a guitarist friend of mine to sit on a stool and play. He did, patiently for hours on end.

Meanwhile, I hooked up a single mic, sent it through the system with a flat EQ, and then went into the engineer booth and listened. Then I went back into the sound room and changed the microphone. Then I returned to the booth and listened. Over and over. I tried many different mic placements. Some brought results that I liked more or less, in general, but I knew that I might like to file away the microphone placement in the back of my mind, even on the sounds I didn't like much, because I knew that I might need that sound some day.

I strongly recommend that EVERY budding sound engineer go through this process. Try the mic close, try it distant. Try it over the sound hole, try it over the fretboard. Try miking the body of the guitar from the back. Try it all.

Here are two of my standard mic placements for the acoustic guitar. You'll notice that they sound very different, and they are for different situations.

Overhead:

In many pop, country, and country/pop tunes, the acoustic guitar is important, but not prominent. It has a very thin and bright tone. The strumming provides a rhythmic sparkle to the mix, more than even adding the harmony of the chords. The midrange body of the song is carried by the vocals, the keys, the bass and other instruments.

To get this tone, place the microphone a foot or two above the guitar, and above the guitarist's head, pointing down toward the guitar. The body of the guitar sound will radiate forward out of the sound hole, and, to a certain extent, away from the back of the guitar. The bright, sparkly high end will dance upward into the mic.

The primary drawback of this technique is that the mic tends to pick up the backing tracks that are playing in the guitarist's headphones.

Close miking the body:

If there is only a singer and a guitar, or if the guitar and the voice are the dominant instruments in the arrangement of the song, then you'll want more body to the sound. Place the mic 6-12" inches from the guitar body, with the axis of the microphone pointing at the strings, in a spot in between the end of the fretboard and the sound hole.

Pointing the mic at the sound hole will produce a very boomy, boxy sound, full of low midrange.

The closer the microphone is to the strings, the more crisp highs and deep lows you'll get. Adjust that to get the sound you want.

Summary:

Microphone placement is the hallmark of an experienced recordist. Remember that tweaking the EQ warps the sound more unnaturally, and can add noise to the signal path. If you can get the sound you want in the microphone placement on the guitar, without the use of the EQ (or at least very little), your sound will be cleaner and better!