The last few weeks I’ve been on a mixing kick. We’ve looked at mixing drums and bass. This week we’ll tackle acoustic guitar.

If you have a home studio, there’s a good chance you spend a lot of time doing acoustic guitar/vocal demos. These may develop into full-on rock productions, but a lot of times we start with acoustic guitar and work from there.

Thin vs Boomy

A simple guitar/vocal track should be fairly easy to record and mix, right? Well, oftentimes it proves to be more difficult. While the acoustic guitar is a fairly simple instrument, it can be hard to mix.

Ideally we want a nice, full, rich-sounding acoustic track. A lot of times, though, we end up with a guitar that’s either way too boomy or thin and lifeless. We’ve all been there.

First Things First

Before we can accurately discuss mixing acoustic guitar, we need to make sure we recorded it well to begin with. I talked about this in Home Studio Production, and I linked to a few articles on miking acoustic guitars, like why you should and shouldn’t stereo-mic the acoustic guitar. (You can get your copy of the eBook by signing up to my newsletter.)

I’m writing this article assuming you’ve got a decently-recorded acoustic guitar part to begin with.

EQ-ing the Acoustic

The majority of time spent mixing acoustic guitar will be dialing in the EQ. There’s no magic trick to it. There’s no preset that works every time. In fact, I’ve found that I almost NEVER use the same EQ settings from song to song, even if it’s the same acoustic guitar! The playing style, the key of the song, the pick size, all of these factors create a completely unique guitar part that needs to be EQ’d as such.

My goal here is to get you to think through your approach to EQ-ing acoustic guitar and perhaps offer you a basic approach that you can use every time you go to mix a song with acoustic guitar.

High-Pass Filter

It feels like the high-pass filter (or HPF) is becoming the national anthem of this blog, but I don’t think I can stress it enough. The more low frequency energy you have in your song, the harder it will be to mix.

Acoustic guitars put out a ton of bass frequencies. You may not realize it, but they do. To prove it, take a low-pass filter and sweep it all the way down to 100 Hz, where you’re only listening to everything below 100 Hz.

Hear a bunch of rumble? I thought you would.

There may be the occasional acoustic singer-songwriter track that calls for this low frequency information, but the majority of the time you need to get rid of it.

How much you roll off is a matter of listening. Some acoustic tracks I roll off at 150 Hz. Others I roll off as high as 400 Hz. Even if you only roll off 100 Hz and below, you’ll be doing yourself a favor.

Low-Mid Cut

The low-mids are where the magic happens. It’s where the core tone of the acoustic guitar resides.

However, chances are the guitar will still sound boomy in the mix if you don’t cut some of these low-mids out.

This is probably the part that will take the longest to figure out. Do I do a deep cut with a narrow Q? Or do I do a shallow cut with a wide Q? In other words, do I want to dramatically remove a small group of frequencies? Or do I want to slightly turn down a large range of frequencies?

Great question. Experiment. Some guitars may resonate at 200 Hz, and you’ll need to do a big ‘ol cut right there. Some may just need to be gently turned down between 150 and 350 Hz.

The low-mid cut will also need to “play nicely” with the high-pass filter. Perhaps you tried the high-pass filter at 200 Hz, but it was too thin. However, at 150 Hz it’s too boomy, and you can’t seem to find some middle ground.

Try leaving the HPF at 150 Hz and doing a cut around 175 Hz. This cut will turn down the offending frequencies without completely eliminating them.

Sometimes simply turning frequencies down is more musical than getting rid of them entirely.

High Frequency Shelf

Finally, you may want to add some sparkle to your acoustic guitar. A gentle high frequency shelf can be great for this. Boost it just a little at a time until you achieve just the right amount of “air” without allowing the track to become harsh.

That’s it for EQ for now. If you want to dive in deeper with EQ, check out:

[Photo by Sancho Papa]