The tone of an acoustic guitar can significantly be altered for a brighter or warmer tone via EQ, but just as importantly we can correct issues with our acoustic via EQ. This acoustic EQ guide will cover all scenarios.
Acoustic EQ Guide
Before we get into the acoustic EQ moves I recommend, I want to share my acoustic guitar frequency chart to give a better idea of what characteristics the tone has on the acoustic at different frequency points:
Understanding this gives us a better idea of what is going on where as we cut and boost.
Now with that in mind, here is my recommended acoustic EQ profile, showing where to cut and boost at each frequency point:
While you can simply apply these moves to whatever your EQ of choice is (I’m using FabFilter’s Pro-Q 3 above), whenever I do an EQ cheat sheet, I always like to go over the moves in greater depth to explain WHY I’m recommending the moves I’m recommending.
High Pass at 70Hz
High pass filters remove everything BELOW a certain frequency.
Virtually every EQ I use in my mix features a high pass filter as this is an effective way to:
- Remove unflattering noise (both room and electrical/hardware related) from your track, creating a cleaner mix.
- Remove inaudible noise to give your mix more headroom.
- Create space for the low end mix elements which need this frequency real estate to themselves like the kick and bass, creating a more focused and powerful sounding mix.
It’s just a matter of WHERE to high pass from track to track, instrument to instrument. In the case of acoustic EQ, we saw from the aforementioned acoustic guitar frequency chart that the lowest fundamental note in standard tuning on the acoustic is 82Hz.
With that in mind, we can high pass to remove everything below that without worry that it will negatively affect the sound.
I like 70Hz as a general rule as depending on the EQ slope of the filter, this will keep those lowest notes unaffected. Use a 24dB/oct slope at 70Hz and let’s move on.
Cut/Boost at 200-300Hz for Boomy/Thin Sound
200-300Hz is a key frequency range on the acoustic EQ for a number of reasons.
This is the upper end of the fundamental frequency range of the notes themselves (meaning the peak frequencies the notes vibrate at), not to mention the earliest overtones (meaning the first octave up from the fundamental notes).
If your acoustic is too boomy, a dynamic EQ cut in the 200-300Hz range helps to tame that. As an aside, boomy guitar is typically the product of improper microphone placement, specifically miking the sound hole. Incidentally, check out my overview on how to mic an acoustic guitar for tips on getting the best sound going in.
Conversely, if the guitar is too bright and can benefit from some warmth and body, a small dynamic boost in the 200-300Hz range will help balance out the tone.
One last thing to mention which is not featured as part of the graphic above – just north of 300Hz, try a dynamic cut in the 400-600Hz to clean up some of the mud to add some clarity by way of subtractive EQ.
Boost at 3.5k for Clarity
I just mentioned adding clarity by way of cutting the mud with that 400-600Hz range.
If you still don’t have the clarity you want by way of subtraction, try a small boost in the 3.5k region to bring out the brighter side of the guitar.
Don’t boost TOO much as this will thin out or harshen the tone, but a small boost will give you a touch of brightness your tone might be lacking.
Boost at 10k for Punch
Transient punch is the high frequency percussive tone which precedes the rest of the tone by a few milliseconds.
The nature and origin of this tone will vary from instrument to instrument – in the case of acoustic guitar it’s the sound of the strings themselves. I’m not referring to the palpable notes associated with the strings, just the percussive sound of finger or pick on the strings as you strum, pick, etc.
This helps the acoustic guitar assert itself in the mix as that initial punch draws the listener’s ear to the subsequent rest of the tone.
All this to say, if you want the acoustic guitar to assert itself a bit more in the mix even if you’ve already got the level set right where you want it, try a small acoustic EQ boost around 8-10k to bring out more of the percussive sound of the strings to get that acoustic sitting better in the mix.
Low Pass at 20k
Like virtually any instrument or track in your mix, low passing isn’t nearly as impactful or important as high passing. That said, you can conservatively low pass at 20k without giving it a second thought or affecting the tone, transients, etc.
While this won’t have an appreciable effect on your mix’s headroom, adding this up over dozens of tracks in your mix can buy you a little mixing headroom which in turn allows you to achieve a (better sounding) louder mix.
Acoustic EQ Tips
- Acoustic EQ can help clean up noise, create space for other tracks, and ultimately yield a more balanced tone for your acoustic guitar.
- Begin with a high pass at 70Hz with a 24dB/oct slope to filter out inaudible and unwanted noise, creating invaluable space in your mix’s low end.
- Dynamically cut or boost in the 200-300Hz region to control a boomy tone or add warmth and body, respectively.
- Use a dynamic EQ cut in the 400-600Hz region to add clarity and clean up the mud from reflections and unflattering tones in that area.
- Add clarity via a small boost at 3.5k.
- Try a small 1dB wide boost from 8-10k to bring out more of the percussive sound of the strings themselves to add transient punch and help the acoustic guitar sit better in the mix.
- Roll off 20k and above with a low pass filter to add a modicum of headroom without affecting or detracting from the tone.
Speaking of the acoustic guitar, check out my many acoustic guitar tutorials like my acoustic guitar and vocal EQ guide for stripped down mixes which focus on just these two elements to make up the entire mix.
