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]

  • umidorland

    I did some re-mixing of my acoustic guitar track and recognise aspects of your explanations. 🙂 I also applied the EQ techniques, because when I recorded, indeed the low frequencies were resonating like a tanker. Every time I record something, I use consumer hardware to check whether it still sounds good, because high-end monitors and interfaces give away a more clean sound in any case, as I have tested. And this time, the guitar sounds very clean, barely any resonating. However, for some reason when I record the guitar, it’s quite soft, so I used a compressor to makes it louder as a whole. Are there any ways I can get a louder sound from recording though the mics already? Because for some reason, and I don’t know why. It’s very soft by default. I do use an auto sense fucntion on my Roland Studio Capture, but would it be better to turn the knobs after that myself and listen some more?

    • I don’t think soft is a problem. Just turn it up in your system after it’s recorded. Don’t need a compressor for that.

  • What about in a live context? Does it make sense to have a compression in a live acoustic rig?

    • Hmm…I think the sound guy at our church compresses acoustics. So….yes? 🙂

  • gave me a new perspective to see compression.

  • david blayne

    very good post.

  • Purecountry70

    awesome post  Joe, I never realized how inportant compression  was on an acoustic guitar, from now on on every track before I compress I need to know who and how much, thanks again     Bill McDonald

    • Exactly. The less you do things “by default” the more in control of your mix you’ll be.

  • my experience to..using compression typically makes it worse? it’s like you said, there is no exact formula..tweak,tweak, and tweak some more.

  • Rico Kiko

    Hi , my question , which is possibly impossible to answer , is about mixing a solo Flamenco guitar , sometimes you have only percussion to add to it .
    I have heard that compression is nearly always used, and as to the EQ, another section here that I read, well yes its different for every guitar and player , also a certain amount of ambient type reverb is often in play, but are there any real rules ? or real Do’s( or don’ts) like is the EQ always subtractive rather than additive, is a parametric better than a graphic , where would be a good starting point , from an amature point of view , or are all the answers going to start “It depends…..”

    • I wish I could give you a formula for a perfect guitar sound, but there really are far too many variables to give you EXACTLY what you need to do. Don’t use a graphic EQ. That doesn’t give you enough control. Other than that, focus on getting the best sound with the microphone(s) FIRST, then use EQ to shape the sound a little more. Then use compression IF NEEDED.

      • Rico Kiko

        Thanks for your quick reply , I know it is difficult to answer as the sound you want is kinda personal as well e.g. I might be happy with a sound , but you might not. Also I do a mix and then the next day i listen and think its just awful and redo everything and this goes on a while …
        I always have a problems with reverb , either too much then not enough , cant seem to get it right at all parts of the song. The only thing I discovered was copying a digital mono recording onto another track (meaning Trk 1 and trk 2 identical)
        the idea was to mix one a bit bassy and the other a bit trebly but instead I moved one track just a few clicks forward , and set the pan trk 1 75%left and trk 2 75%right,It really seemed to give a big depth to the sound have you ever came across this technique?

        I will keep reading the info you have here and experimenting as best I can , good info site you have by the way , thanks.

  • Hello Joe, I use always some compression in live performances and in general because it helps me control the feedback problem of the acoustic guitar.
    In my opinion, this is the biggest problem with these guitars, especially when you do not like also cover his soundhole.
    I would appreciate very much your opinion and any help to this regard.
    Emilio.

    • I would think compression would make the feedback problem WORSE, since it brings up the quiet parts of the guitar…

  • MichaelHe

    Hi, I'm new here on HSC and I read a lot of the articles… I wonder why no one mensions multiband compression…

    Ex. on a acoustis guitar where there are so many frequences going on, it's hard to comp because all sorts of frequency bands is tricking the comp…
    A nice subtle 4 band compressor can be very nice on many instruments and even on vocals as well.. It can really lay things very steady in the mix, and all the high frequences on a acc. guitar can me nicelly compressed without effecting some of the low-mid you have maybe lowered and so on…

    To much multiband compressed make a mix sound doll, but used right, it can make a loss mix be very nice and steady…. My tip :o)

    • Great suggestion! There's not a lot on here about multi-band compressors
      because I simply don't use them. I found it was too easy to make it sound
      bad. 🙂

      • MichaelHe

        You are right, it can very easilly sound bad… If you just put on multiband compressors you can very easilly put together a nice and steady mix, but it will easilly be doll, flat and lifeless…

        But used subtle and on the right instruments it's a very nice tool…

        I can recomment Waves C4… It's great because it has a automatic gain adjust… So when you push down the treshold and the compression kicks in, the output gain is always the same… So you don't have to think about the levelmix if you want to give an instrument some more compression… You just turn the treshold down until it sound right, and the level is still the same.. very nice :o))

        Try it out if you have the C4 in your bundle…
        I use it alot on ex. background vocals, because you can get many vocals to be steady compared to eachother nomatter what they are singing… So when you've mix the bgv to level-match eachother it just stays like this all the way through the song with very little automation :o)

  • Sparqee

    I used to have a 12 string. I found that the most significant difference in how I mixed it was that it never needed reverb, even in an exposed place in the mix. If I'd ever learned to keep the thing in tune while I was playing I would have kept it. 😉

  • Nacho

    What would be your approach (also when EQing) for a 12-string acoustic? Given the high frequency information there, I guess you'd do it differently

  • Sparqee

    Transient designers (yes, again) can come in handy if someone is flat picking an acoustic with somewhat inconsistent results. Some times I want a finger picked guitar sound but I can't finger pick to save my life, so I use a flat pick and then pull down the transients with a plugin. It of course doesn't sound like finger picking but it can approximate the mood. I find a transient designer far more applicable here than say a compressor with fast attack.