Equalizing an acoustic guitar is more complicated than it seems, especially for beginner home studio owners. The recording can seem quite simple, but when trying to integrate an acoustic guitar track into your mix, one often realizes a number of rather difficult problems to correct with an EQ, unpleasant resonances in the bass, noises of the hand on the strings.
When you clicked to read this article, maybe you were looking for some standard EQ settings to apply to your acoustic guitar recordings. Here we will find some of advices and tips in order to guide you in the control of your equalizers on this very precise instrument.
Perhaps you could imagine finding advice like “cut the treble at 8000 Hz with a low pass filter” or “boost the mids by 4 dB at 320 Hz”. This is what we regularly find on the net and it is logical, when you are an amateur home studioist, to look for the right way to do it to use a particular effect.
However, especially in the case of EQs, I wouldn’t help you much if I gave you just that kind of advice. Quite simply because it all depends on the basic!
Say you have a very dark jumbo guitar that you recorded with a bass-enhancing microphone. In this case, it’s likely that you end up with too much bass and need to cut it down. Now imagine that you are recording with a very bright parlor guitar and a microphone with attenuated bass frequency response: in this case your sound may lack density, and you may need to boost the bass with a filter in.
Likewise, the EQ that you are going to do on your acoustic guitar will always depend on the musical style: if you are recording a guitar / vocals piece, the guitar will be emphasized much more than if it is simply used as accompaniment in a piece. In short, you will understand it through these examples: there is no magic EQ setting for the acoustic guitar.
However, in order to equalize this instrument properly, it is important to learn to hear what is happening in certain frequency bands – so that you can correct problems when you hear them. And this is precisely what we will see in this article.
Frequency bands to know to equalize an acoustic guitar
Here are the frequency bands that we will specifically talk about. You can download the diagram in printable PDF format by clicking here.
<50 – 80 Hz: Background noise
Quite often on acoustic guitar recordings, the lower frequencies contain what I call to simplify “background noise”.
That is to say, energy linked to sounds that are simply not the ones we want to record at the base.
It could be for example:
- electrical background noise linked to the preamplifier power supply;
- purring of devices in the room (air conditioning, computer, etc.);
- noise from the street next door;
- low vibrations linked to the instrument but which one does not wish to capture;
It is therefore generally a good practice to attenuate or cut the corresponding frequencies, to prevent this sound energy from taking up too much space in the mix or even affecting the definition of your bass line or your bass drum.
Usually this materializes as a high pass filter positioned between 50 and 80 Hz, for example with a slope of 18 dB per octave. But you can of course experiment.
Be careful not to go too high, however, since the fundamental frequency of the lowest string on a guitar (E 2 ) is 82.41 Hz.
70 – 100 Hz: Density
Now that we’ve got the background noise out of the way, we can focus on the frequencies that are more important to the guitar.
On the 70 to 100 Hz band, we will generally find energy which contributes to the density of the recording.
That is, the ability of your guitar track to pack a punch, to be punchy and powerful enough.
If these frequencies are under-represented, your guitar will sound quite weak, quite fragile – in this case feel free to use your EQ and boost a few dB.
If on the contrary this frequency band has too much energy, you will hear marked resonances and your track will contribute to making the low frequencies of your mix muddled.
Note also that if your acoustic guitar is just the accompaniment and does not have a primary role in the song, you may not need to emphasize this frequency band too much, because it is rather the bass and the kick drum that will be emphasized at this level.
100 – 350 Hz: The Complicated Zone
Yes, a bit like the equalization of the voice, properly adjusting an EQ on an acoustic guitar track is not always easy.
This frequency band going from 100 to 350 Hz is often complicated to equalize because there is a lot going on there. It is therefore important to succeed in adjusting it without affecting the balance of the recording.
First, note that the quality of the recording is essential to minimize the EQ settings that need to be applied at this level.
Indeed, we are right at the level of the fundamental frequencies of the acoustic guitar (which goes from 82.41 Hz to 329.63 Hz in normal tuning) – and we also find different resonances of the instrument emitted at the level of the rosette. .
It is therefore important to position your microphone correctly when recording to have the cleanest sound possible.
Often this said, you will need to attenuate at least some frequencies between 100 and 250 Hz to control the resonances and make the acoustic guitar track less “boomy” as English speakers say, that is to say less thick. in the bass and low-mids.
On the higher part of the frequency band, say between 200 and 350 Hz, it is more the body of the instrument that you will find.
If your sound seems too thin, too fragile, it may be worth boosting those frequencies. Be careful, however, you will find that the sound quickly becomes muddy (“muddy”) and messy. Feel free to listen to the rest of the mix along with your acoustic guitar track when working on these particular frequencies.
400 – 800 Hz: “Cardboard” frequencies
As with many instruments, this frequency band generates a “cardboard box” sound when emphasized too much, making the midrange particularly messy.
Note, moreover, that these problems can spread up to around 2 kHz, thus taking on a more nasal, more metallic appearance. The choice of strings is therefore necessarily important!
However, as a general rule, unless you notice a major problem of this type, it is not really necessary to equalize this frequency band if the recording was done well.
Keep in mind to identify the type of sound I am talking about, take an acoustic guitar track and an EQ and boost it to +12 dB around 500 Hz. Take the time to listen to the sound produced.
2 – 6 kHz: Clarity
The frequency band from 2000 to 6000 Hz is generally the easiest to control.
It is on this one that you will mainly find the snapping and cutting aspect of the strings.
Much like vocals, if you want to put the guitar in front of the mix and boost the impact, adding 2 or 3 dB to these frequencies should point you in the right direction.
If on the other hand your guitar is too aggressive or too cold, on the contrary, do not hesitate to attenuate them a little with a bell filter.
Note in passing that generally, it is rather the voice that we will prioritize on these frequencies: if this is the case in your mix, avoid also boosting the acoustic guitar on these.
> 8 kHz: Air
Finally, there is a nice and rather easy technique to put in place to add shine and give space to your acoustic guitar recordings – we often talk about “adding air”.
You just need to take a high-shelf filter or why not a bell filter, but personally I’m less of a fan and gently raise the treble above 8 kHz. It’s up to you to identify the cutoff frequency.
Instantly, the sound becomes more open.
Be careful, however: the effect is often very appreciable, but the risk of overdoing it is real. A few decibels are sufficient most of the time.
Some general tips for the equalization of the acoustic guitar
Certainly, it is important, even essential, to have a good understanding of the main frequency bands associated with the acoustic guitar in order to be able to equalize its tracks.
However, in addition, here are some more general tips that will also help you manipulate your EQs with this instrument.
Equalize as soon as you record. But be careful, don’t take this chapter title too literally. I do not recommend that you equalize your recordings on take. What I do want to emphasize, however, is that the way you record your acoustic guitar affects the amount and complexity of the EQ you are going to do next. In the first paragraphs of the article, I used the guitar type as an example: if you want a bright sound, avoid using a dark guitar. And vice versa.
Also, don’t forget to change the strings before any serious recording session – the older the strings, the duller the sound. So put on new strings and enjoy a clearer and more qualitative sound, which will require less equalization to be pleasant.
Of course, the choice of microphones and the sound recording technique used strongly influence the frequency distribution of sound energy: read my article on acoustic guitar recording and try out different recording methods. to find the one that best suits the sound you are looking for.
The better the recording, the less you will need to use an equalizer when mixing. Sometimes you won’t even need an EQ!
Equalize as a group
If you have several similar acoustic guitar tracks for example to distribute them left and right in terms of panning, feel free to group them in a buss to treat them in a similar way. Buss is a group of tracks.
Indeed, we sometimes have the reflex to say to ourselves that to do better, it is better to be more meticulous and equalize each track independently. In reality, this is often a waste of time but is also a source of errors, which can make your mix wobbly. So simplify the approach and group your acoustic guitar tracks before adding plugins.
Control the resonances
We said a little earlier that certain resonances linked to the instrument could appear in the lower mids.
However, the entire frequency spectrum is potentially subject to resonances: these can indeed come from the selected microphone, from the electrical network or from the acoustics of the room.
It is therefore important, if you hear this kind of problem in your sound recordings and especially if it comes out in the mix, to attenuate them with a bell filter with a high Q factor.
Sometimes a reduction of a few dB is enough, but in some cases you have to go heavier and get something different.
Attenuate before amplifying
Finally, a last piece of advice that applies to the equalization of acoustic guitar as well as to any other instrument: before amplifying any frequency bands, start by cutting off those that are causing the problem.
Indeed, if you tone down the most problematic aspects of the sound, in theory you will only be left with what sounds good. In doing so, you will no longer need or much less to amplify the rest of the frequency spectrum.
There you are, now you are a specialist in the equalization of acoustic guitars! At least, you have all the information to train yourself to recognize the impact of equalization on a particular frequency band with regard to the acoustic guitar.
So don’t hesitate to apply all the tips in this article the next time you equalize a track on this instrument! And check How much does it cost to restring a guitar out!