Yesterday I walked you through an overview of how I EQ acoustic guitar, now let’s take a quick look at compression.

Since most of my EQ choices tend to be cuts rather than boosts, I like to compress after the EQ nine times out of ten. As I mentioned in Intro to Compression, compression does one of two things: it turns down louder signals and turns up quieter ones.

This is an oversimplification of compression, but that’s still the way I think about it when I reach for a compressor on any track. I ask myself, “What will this compressor do to the tone of this track? And will that get me closer or further away from the sound I want?”

For example, when you compress drums, like the overhead mics for example, the compressor will turn down the drum hits (the loud parts) and turn up the “ring” of the drums and also the sound of the room (the quiet parts).

Know what to expect from the compressor before you start twisting knobs. If you have somewhat of a plan, it’ll be easier to determine if you need compression and how much to use.

Compressing Acoustic Guitar

I don’t compress acoustic guitar very often. Most of my music has the acoustic guitar very up front in the mix, and I’ve never been happy with the way a compressor handles that. I usually run my mix through the SSL Buss Compressor plug-in, which tends to be all the compression I need for many acoustic guitar tracks.

However, there are times I’ve compressed acoustic, and there are reasons you should, too. As always, let your ears guide you.

Well, what can you expect when you compress an acoustic guitar?

If you asked 10 engineers how and why to compress acoustic guitar, you’d get 10 different answers. I encourage you to share your thoughts in the comments section.

Here are my 3 main reasons to compress acoustic guitar:

1. Louder transients – Generally speaking, the sound of the pick or even finger on the strings is usually pretty quiet in comparison to the overall volume of the guitar. In some songs, however, bringing out that pick/finger noise can give the guitar a more percussive sound.

By compressing the guitar, you can achieve a very choppy, rhythmic tone. When the pick hits the strings, there’s a lot of high-frequency information there. Compressing this will accent those high frequencies.

2. More harmonic content – Acoustic guitars, like pianos, are chock full of harmonics. When you play a single note on the guitar, you hear a few more “ghost” notes ringing out in the higher registers. These are harmonics, or harmonic frequencies. Obviously, the more notes you play, the more harmonic content you’ll hear.

This is what can make an acoustic guitar sound full. In a mix, though, the harmonics may simply be too quiet to hear, and you’ll lose some of that fullness. With a little compression, though, you can bring out the harmonics, bringing them to a level where they can still be heard over the other instruments in the mix.

3. More sustain – Just like an electric guitarist uses a compressor pedal to increase sustain, so will using a compressor on an acoustic guitar. Since compression turns up the quieter parts, you’ll hear the notes ring out longer, giving the illusion of more sustain.

Use Caution

Don’t compress the guitar just because you can. I’ve done this, and after hours of wrestling with the compressor, I realize the track simply sounds better without compression. That’s why it’s important to have a plan, to know what sound you’re going for.

While compression has its benefits, it also tends to bring up the amount of room noise in the track. In a pro studio this isn’t a big deal. In a home studio, however, where you’ve got a computer and hard drives whirring in the background, too much compression could make for a noisy track.

What are your thoughts? Do you agree? Disagree? I love a good debate. I always end up learning something. Leave a comment!

[Photo by CTD 2005]