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:

www.UnderstandingEQ.com

[Photo by Sancho Papa]

  • ryan

    does a highpass filter need to be the one on the preamp or will one in a plugin work? which one is better?

    • http://www.homestudiocorner.com Joe Gilder

      Doesn’t matter, just don’t use it in both places or you might cut out TOO much low end.

  • Michal

    Does a HPF completely cuts off the frequencies below the threshold? The HPF on Prosonus Eureka only drops frequencies below its predefined threshold of 80Hz by 12dB… Do different High Pass Filters work differently?

    • http://www.homestudiocorner.com Joe Gilder

      It’s a slope. And the “steepness” of the slope can vary from one HPF to the next. Generally 6dB or 12 dB per octave is the normal slope. But yes, a HPF is a continual roll off of the sound. It lower you go, the more the sound gets turned down.

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  • Ernest

    It would be the best lesson I’ve seen so far for a beginner like me to see also in pictures how you treat HPF and LMF in the guitar! and also comparing how it sounds by posting a little sample every time you make a change against the original,raw untreated or bypassed version, but none the less, you have tough me what I did not get in weeks of reading books!
    thank you and I hope one day you make a new revision of my suggestion, great website, I have told my friends about it and they liked it!!!

  • Pierre Cardenas

    This is great. I particularly love how you noted that the key of the song and even the song itself will affect how the guitar sounds. Which does make setting the EQ different from song to song even with the same guitar. I have always believed this to be true but this is one of the first articles in so many I’ve come across that has touched on this. : )

  • jamesgrant

    this is helping me a great deal I'm taking a course in pro tools and have to mix a song with acoustic guitars .my ears are not to good yet on picking up fq.s and i don't quiet under stand the lingo yet but I think I'm getting the idea thanks.

  • jamesgrant

    this is helping me a great deal I'm taking a course in pro tools and have to mix a song with acoustic guitars .my ears are not to good yet on picking up fq.s and i don't quiet under stand the lingo yet but I think I'm getting the idea thanks.

  • Preshan

    Great article!

    I'm still very much an amateur, but I find that often a boost in the mid-range (like around 1.5 kHz) can really help the acoustic cut through a mix a bit clearer, especially when it's a pop kind of mix with other electric tracks etc. Otherwise, all you can hear of the acoustic is the high end “click-click” of the pick against the strings without much warmth or body to the tone.

    This is one of my “trial and error” discoveries, and I'm not sure if I'm completely correct, but it seems to work…!

    • http://www.homestudiocorner.com Joe Gilder

      If it sounds good to you, then it worked! I've not had a lot of luck
      boosting the upper mids on my acoustic, but that could just be due to my
      guitar. :-)

  • Sparqee

    A handy trick I picked up somewhere: if a fast strummed acoustic guitar is being mixed way back as a bright rhythmic element (balancing a tambourine perhaps) then try using a transient plugin to punch up the attack on the guitar. It will perk up in the mix without becoming louder or taking up too much space. I especially like this treatment on 12 string guitars. :)

    • http://www.homestudiocorner.com Joe Gilder

      Very cool.

    • tomakadadooz

      What do you mean by a transient plugin?

      • Sparqee

        Something like UAD Transient Designer, Stillwell Audio's Transient Monster, Sonnox Transmod, etc. Waves has one I think as well as SPL. They are plugin that either accentuate or de-emphasize the attack portion of sounds. A good way to make a snare really crack or bring down the clicky part of a kick, etc.

  • http://twitter.com/bluecavestudios Darryl Gregory

    Great post as usual Joe!

    I may add to this that you also want to listen to the guitar EQ in the mix not just alone – especially when cutting those mids and enhancing those highs – then adjust the EQ while listening in the mix. Adding reverb? that also tends to frak with the EQ in the mix too.

    • http://www.homestudiocorner.com Joe Gilder

      GREAT point, Darryl.

  • DirtyDingo

    in your example at the end of the “low-mid cut” section, are you meaning to leave the HPF at 150 and do a “shallow” cut at 175 for that particular problem? probably a dumb question, just curious.

    • http://www.homestudiocorner.com Joe Gilder

      Not a dumb question at all. I probably could've explained it a little
      better. Yes, you're right. I'm referring to a slight low-mid cut that
      “touches” the high-pass filter.