Acoustic guitars are beautiful-sounding instruments that play a wide variety of roles in many musical genres and often benefit from the essential mixing process of EQ. When it comes to EQing acoustic guitars, there are no simple step-by-step instructions; every mix is unique. However, there are certain considerations we should take into account when EQing acoustic guitars, which is what this article is all about.
Before we go any further, I should state that there are no hard rules with EQ or any other mixing process. The tips mentioned in this article are simply suggestions and techniques worth considering when EQing acoustic guitar. There are no procedures that work 100% of the time, and every mix is unique in its own needs.
Here are 11 pro tips for EQing acoustic guitar:
- Consider the role of the acoustic guitar in the mix
- Consider how the acoustic guitar was recorded
- Consider the genre
- EQing acoustic guitar in the context of the mix
- Adding “air” in the top-end
- Boosting body
- Cutting “boxiness”
- EQing against competition with the vocal
- Eliminating low-end rumble
- Affecting depth with EQ
- Mirrored EQ in doubled acoustic guitars
Let's discuss each of these tips in more detail to give you important considerations when EQing acoustic guitar in your mixes.
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Consider The Role Of The Acoustic Guitar In The Mix
The first question we should ask ourselves when deciding how to EQ an acoustic guitar (if we decide to at all) is, what is the role of the acoustic guitar in the mix?
Is it a solo acoustic guitar performance?
Is it a singer-songwriter performance with just vocals and guitar? Are there additional supporting elements in the song?
Is the acoustic guitar part of a much larger ensemble?
Does the guitar play a key role in the song, or is it more so for colour?
Does the performance have huge, open chords, gentle fingerpicking, or lead lines? Does it combine different playing styles throughout?
Understanding the role of the guitar in the song and the production at large will help us make informed EQ decisions.
In sparser mixes where the guitar plays a larger role, we may opt for gentle EQ to boost character and reduce frequency masking, if we EQ it at all. Conversely, in denser mixes where the guitar plays a supporting role, it may be necessary to apply rather aggressive EQ to make it fit perfectly into the mix.
Without giving any specific EQ moves (remember that every acoustic guitar performance, song and mix are different), it's paramount to consider the role of the guitar in your mix.
Consider How The Acoustic Guitar Was Recorded
Knowing how the acoustic guitar was recorded will give us invaluable details to help make informed EQ decisions.
Let's begin this discussion with whether the guitar was recorded with a microphone or a pickup.
Pickups generally sound much less natural than microphones and often require EQ to shape their audio into a more natural-sounding guitar. Of course, some pickups are better than others, and it's important to use our ears when making any decisions.
Microphones tend to offer a more natural sound than pickups, though they're more sensitive to the acoustic environment. In general (and within reason), the further the mic is from the guitar, the more natural the sound will be and the more the room acoustics will affect the mic signal.
So we should also be made aware, if possible, of the acoustic environment where the guitar was recorded.
If the acoustic guitar were recorded by itself or within its own iso-booth, we wouldn't be concerned with having to address bleed from other sources with EQ.
However, if the acoustic guitar was recorded in a room with other instruments or vocals playing simultaneously, we may consider using EQ to reduce bleed in certain frequency bands. More specifically, we should aim to cut the frequencies of the most distracting non-guitar elements while boosting the characteristic bands of the guitar, if at all.
If the acoustic guitar were recorded by itself in an acoustically-treated iso-booth, there likely wouldn't be any issues of resonance frequencies to be fixed with EQ. If the acoustic guitar was recorded in a specific room for colouration and natural reverb, we might want to enhance or pull back certain aspects of the environment.
Sometimes we must record in less-than-ideal environments, where resonances (buildups of unnatural-sounding frequencies) will require cutting with notch filters.
Beyond the transducer (pickup vs microphone) and acoustic environment, we should also consider whether any processes were printed to the audio. Was there an EQ already inline that treated the guitar before it was recorded? Having this knowledge can help us determine whether we want any more equalization on the guitar.
Finally, knowing the guitar itself can be useful if we have a memory for the differences in tone between different instruments. Extending this point further, knowing whether the strings were new or old, whether the strings were plucked with the fingers or a pick, what the tuning was, etcetera can all be worthwhile to help give us more information before EQing.
Consider The Genre
It's true that every mix is different, which is why I'm hesitant ever to give specific action steps for EQing acoustic guitar (or any other instrument). However, certain mixing techniques are common across different songs within particular genres. Therefore, it's worth considering the genre when it comes to processing acoustic guitar (including EQ).
As an example, modern country and pop have a more polished mixing approach, and if the acoustic guitar plays a main role in the mix, you can bet that broad EQ moves can help it shine through. Conversely, if the acoustic guitar plays a supportive role, you may want to EQ it more aggressively to fit in the mix.
Conversely, in some indie music and singer-songwriter records that benefit from a rawer mix, perhaps the acoustic guitar should only have a touch of EQ, if at all.
The point here is not to give you specific instructions (again, every mix is different). Rather, it's to encourage you to think of the genre in question and study it if you need to gather knowledge on what can be expected of the acoustic.
When mixing anything, it's worth asking for a few reference tracks on which you can base your mixing decisions. If you're producing your own music, it will be on you to choose a fitting reference mix to base your on. Being able to A/B against a reference mix will help us fit the acoustic guitar into the mix appropriately, which often includes the use of EQ.
EQing Acoustic Guitar In The Context Of The Mix
A mix is about combining every element together into a cohesive listening experience. To many beginners, it's tempting to forget the holistic balance of a mix and focus on perfecting the individual elements. However, that's not an effective strategy for achieving great-sounding mixes.
Of course, if there are issues that need addressing (low-end rumble and resonances, for example), it is beneficial to EQ an acoustic guitar solo. Though when it comes to mixing, it's nearly always best to EQ our tracks in the context of the holistic mix. The acoustic guitar is no different.
Note that this concept applies to mixing. When recording, it's always advisable to get every track sounding as good as possible. What I mean to write here is that a great mix is often made of parts that sound imperfect on their own. The combination of these imperfect tracks makes up a great mix with proper separation, dynamics and clarity.
If EQ is necessary, adjust the parameters while the acoustic guitar is playing back with the rest of the mix. Adjust until you believe the guitar sound better in the context of the mix. Be sure to A/B the EQ processing by turning the EQ on and off. Bypass it for a few seconds and turn it back on again. Repeat the process a few times and make an objective decision about whether the EQ improves the mix or not.
If the EQ improves the mix, move on. If it doesn't, consider adjusting parameters and repeating the process, listening critically to how the acoustic guitar interacts with the rest of the elements. In some cases, EQ will not help the mix, and it's likely best to scrap it altogether and move on.
In sparser mixes, we may want to have the entire frequency spectrum of the acoustic guitar present in the mix, perhaps with little tweaks throughout to boost the body and cut “boxiness”. Conversely, if the mix is super crowded, there are instances where the acoustic guitar may be EQ so drastically that we only hear the strumming and a hint of its harmony.
Adding “Air” In The Top-end
If the acoustic guitar deserves a bit of brightness in the mix, we can boost around 8 kHz and again above 10 kHz.
These gentle bell/peak filter boosts can help give a sense of brilliance and life to an acoustic guitar without necessarily altering its tone. It's a great, subtle way of making an acoustic guitar more present, especially if it plays a big role in the mix.
The mid-range frequencies are perhaps the most important to get right in a mix. This often means carving space for individual elements in denser mixes.
When it comes to the low-mids, we may need to high-pass acoustic guitars rather aggressively to make way for the bass and kick.
If an aggressive HPF doesn't sound good, but the guitar is masking the bass, it's worth trying a cut in the 150 – 250 Hz range to help clean up the competition.
To build back some of the body lost by HPF and low-end cutting, try a boost in the 250 – 350 Hz range to help give some more weight to the acoustic guitar.
Before opting for EQ, ask yourself whether the acoustic guitar needs a lot of body in the mix. It's sometimes the case that the acoustic guitar is an important part of the song and demands solid body frequencies. Other times, the acoustic's supporting role in the mix means we can cut in this range to make room for more “important” elements in the low-end and low-mids.
If the acoustic guitar is too “boxy”, try taming/cutting frequencies in the 600 – 1,000 Hz range. This is common when recording through pickups or close mics.
Listen critically to the mix as a whole when taming the “boxiness” of an acoustic guitar and ensure you aren't hollowing out the mix in doing so.
EQing Against Competition With The Vocal
In the case that the acoustic guitar(s) and vocals are clashing, a wide cut in the 2 – 6 kHz range can help make space for the vocal.
Again, it's important to listen critically. Be as objective as possible when dealing with frequency masking, especially when the acoustic guitar and vocal are key elements in the mix.
Eliminating Low-end Rumble
Eliminating low-end rumble is an essential task in most mixes.
Low-end rumble refers to low-end frequency content that doesn't provide any musical information. It's the noise that muddies up the bass elements of the mix and eats away at precious headroom. In addition to the typical culprits of mechanical noise (footsteps, ventilation, touching the mic or mic stand, traffic, etc.), I also typically group low-frequency electromagnetic interference in with low-end rumble.
This low-frequency information isn't needed and is best eliminated altogether. This job is best accomplished with an EQ's high-pass filter.
We can start with an HPF cutoff frequency of 20 Hz (the lower limit of human hearing) and work our way upward until the guitar becomes noticeably thin in the context of the mix. From there, we should back up about 15-20% and set the filter.
As we continue mixing, it may very well be the case that the low-end of the acoustic guitar interacts poorly with the mix's low-end elements, notably the bass guitar and kick drum. In this case, increasing the high-pass filter's cutoff frequency is often beneficial to a point where the bass and kick can be heard more clearly.
Use your ears when setting high-pass filters, as there's more than meets the eye (knowing the cutoff frequency).
Firstly, we have the psychoacoustic phenomenon known as the “missing fundamental”, which states that our brains can effectively fill in the fundamental information of a musical instrument (the note being played) when presented with only the harmonics of that instrument (and the specific notes being played). This means that we can still comprehend the low-end information of an acoustic guitar even if it's high-pass above its low-end frequencies.
Secondly, EQ causes inherent phase shifting. At low frequencies, such phase shifting can lead to constructive and destructive phase relationships between the acoustic guitar and the other bass elements, especially at and below the cutoff frequency. Beware of such phase relationships, as they'll affect the overall mix in addition to the attenuation caused by the high-pass filter.
Affecting Depth With EQ
EQ can be used to affect the perceived depth of an acoustic guitar (and other elements) in the context of the mix.
As sound waves travel naturally, the high frequencies are attenuated at a faster rate. Higher-frequency (shorter-wavelength) sound waves lose energy faster due to friction as they cause the air molecules to vibrate. This is part of the physics of sound.
In addition to the distance factor, closer sounds are often heard as having more pronounced transients (the initial attack of a sound). The transient spikes of a sound or musical instrument contain a lot of timbral information in the upper harmonics of the sound. By reducing the high-end with EQ, we can effectively dampen the transient harmonics and give the illusion of a sound being further away.
So when it comes to mixing, we can use EQ to attenuate some of the high-end of an acoustic guitar to give it the effect of being further back in the mix. Conversely, we can pull the acoustic guitar closer to the front by boosting some of its high-end.
Shelving filters are great for this.
For a more aggressive approach, we can also use low-pass filters to make acoustic guitars sound duller and push them toward the back of the mix.
Mirrored EQ In Doubled Acoustic Guitars
When dealing with doubled acoustic guitars or guitars recorded with stereo miking techniques, we may want to enhance their perceived width in the mix.
While hard panning can get us great results, we can take the stereo width a step further by introducing mirrored EQ. Let's discuss how.
We'll call the doubled guitars guitar A and guitar B. Panning these guitars to opposite sides of the stereo spectrum will give us some width due to the differences between the two panned audio signals.
To increase the sense of width, it can help to boost a sonically-pleasing frequency in guitar A and cut that same frequency in guitar B. Find another sonically-pleasing frequency in guitar B and cut that frequency in guitar A. This mirrored EQ can help improve separation and give each guitar its space in the mix.
I should note that whenever we're dealing with increasing the perceived width of a mix, we should always A/B our stereo mix against a summed-to-mono mix. Width is caused by the differences between the left and right channels of a stereo mix. If there are significant phase differences between these two channels, there will be poor mono compatibility.
Many playback systems, including some public address systems, smartphones, computers and television, play audio back in mono. Our mixes must also sound as good as possible in these systems. Therefore, checking mono compatibility by periodically summing the mix to mono is an important habit to develop.
Other EQ Tips For Common Elements
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- Top 11 Best Tips For EQing Kick Drums
- Top 11 Best Tips For EQing Snare Drums
- Top 7 Best Tips For EQing Drum Overheads
- Top 11 Best Tips For EQing Pianos & Keyboards
- Top 11 Best Tips For EQing The Mix Bus