Mixing is an essential part of the music production process, and the only way to a professional-sounding song is a well-balanced mix.
Beyond a great volume balance, one of the best tools in any engineer’s toolkit is EQ. With EQ know-how, you can enhance the strengths and reduce the weaknesses in each element to give your overall mix a cleaner, clearer, and more exciting sound.
Of course, with the power of EQ comes great responsibility. It’s easy to take all the guts out of your mix by scooping out too much of the low-mids or make your mix unbearable to listen to with the introduction of too many highs.
In this guide, we’re going to break down 5 essential EQ techniques you can use to clean up your mix.
1. Clean Up the Low-End
Getting a big low-end in your mix often entails getting other things out of the way. Each component of your song is going to interact with the others, so if you have a large build-up of low-end in other instruments, such as your vocals, guitars, or synth pads, you’ll more than likely run into issues with phasing or muddiness in your low-end.
You can remedy low-end issues with a simple parametric EQ move.
Start by loading up your parametric EQ of choice and get rid of the sub frequency content in elements it has no business being in. Doing so will open up space in your mix’s bottom end, giving the low-frequency instruments that need it, such as the kick and bass, room to breathe.
Take heed, however.
Cutting too much low-end out of your other instruments can make your mix sound thin and wimpy. Amateur engineers often go overboard with high-pass filters and wonder why they have hollow and lifeless mixes.
This technique is best used in moderation.
ONLY cut out low-end frequencies if you hear a problem with them. For example, if your vocals are boomy and interfering with your bass, your first move should be applying a high-pass filter up to around 80-100Hz. Male vocals often utilize frequency content from 100Hz and up, while female vocals can typically do without 100-150Hz or so.
However, if you have a high synth lead in a sparse mix, it might actually benefit from a little overlap in the bottom end.
While there are no rules for applying high-pass filters, I recommend using gradual slopes if possible (anywhere from 6-18dB per octave). This will help keep the divide between your high and mid-range instruments more organic.
In the end, it’s important to remember that there are no magic numbers for high-passing, so dismiss any article that tells you so. It will ALWAYS depend on what’s happening in your mix and how you want to fill out the frequency content.
2. Can’t Hear It? Scratch It
Okay, this technique is a bit more complex than that, but it’s EXTREMELY important, so listen up.
Plugins and hardware units have a wider range of “hearing” than humans.
Human beings can only hear from around 20Hz to 20kHz. There are times when you might have an ultra-low portion of your sub bass triggering the limiter on your master bus prematurely. The worst part is that you might not even be able to hear it.
When I’m mastering a song, I often like to start with a linear phase EQ, such as the AVA Mastering EQ Without getting too deep into the science, the important thing to note about linear phase EQs is that they don’t create phase shift at the filter crossover points, giving you the most transparent results possible.
The goal with this technique is to ONLY remove the frequency content you are unable to hear.
I often like to bring the high-pass filter to a point where I can hear it making an impact, then dial it back a few Hz. Natural slopes anywhere from 6-18dB per octave will work best.
Now, for the most important part.
Only perform this technique on a system that is capable of accurately reproducing this ultra-low frequency content. If you’re using a monitor system, note that most monitors can only produce down to around 30Hz at best, meaning you’ll have to integrate a sub into your setup for this to work.
However, if your room isn’t tuned for a sub, it could do you more harm than good. In that case, I recommend getting a good pair of mixing headphones that can produce low-end, as it takes your room out of the equation.
The goal here is to give yourself more headroom and focus in your sound. When you A/B this move, you shouldn’t hear a drastic difference. If you do, dial it back.
3. Use Dynamic EQ
Your average EQ plugins will apply static adjustments, meaning if you cut 250Hz by 6dB, no matter what part of the track is playing, that specific element will have a big cut at 250Hz the entire song unless you automate it.
Music is a lot like the weather — it changes constantly. As your song progresses through the different sections, it may call for different EQ settings. Some sections might be loud and boomy, while other might be soft and subtle.
The bassist might strike a note really hard, triggering a big bump at 120Hz in one section of the song, though might not be giving enough 120Hz in some sections.
So, if you were to hear that unwanted bump at 120Hz and cut it by 3dB using a static EQ, that section would sound great, though the rest of the track would sound thin, leaving you thinking, “why in the world can’t I get my bass to sound good?”
The answer is dynamic EQ.
While a bit more complex than what I’m about to make them out to be, the most prevalent use of dynamic EQs is to tame the loudest parts of a frequency in a given track. Here are a few common uses of dynamic EQ:
- Taming Shrillness in Vocals – If a singer sounds great throughout the track, though sounds shrill when they start hitting the higher notes in the chorus, you could employ dynamic EQ to tame the high chorus notes without ruining the rest of the performance.
- Reducing Out-of-Control Bass Notes – Every bass guitar sounds different, and there are some basses that even the best players can’t fully control. A bass might just be built with a crazy resonance whenever the player strikes the low-E string. If that bass node only pops up intermittently throughout the song, you can use dynamic EQ to tame it.
- Mastering – Dynamic EQ is an excellent tool for mastering and can offer a wonderful way to tame any last instances of boominess, boxiness, or harshness that pop up in your mix before you send it out into the world.
While there are plenty of great dynamic EQ plugins out there, one of my absolute favorites is Neutron 4 from iZotope.
4. Tame Resonances
There are undoubtedly be times when you’re mixing when you notice a harsh or unwanted resonance.
Resonances are buildups of frequency content at specific points in the frequency spectrum. Getting rid of resonances can be super simple or super challenging depending on the amount of resonance you’re dealing with.
In the track above, I was hearing a resonance at around 5kHz in a guitar part. Everything else was pretty evened out without much bottom-end or ultra high-end, which you would expect from a funky guitar part like this.
I determined I was hearing a resonance that I didn’t like, so I boosted the frequency with a narrow Q value to find exactly where it was most prominent.
Sharp resonances, especially in the high-mids or highs, will sound like whistling.
However, there are times when resonances don’t present themselves as obviously as this. If I can hear something sounds off, though I’m not sure where it’s coming from, I’ll go “fishing” for the bad frequencies.
Fishing is the process of taking a bell filter with a narrow Q value and boosting it drastically so you have a high and narrow band. Then, slowly sweep it throughout the spectrum while the audio is playing and listen for the frequency(s) that bother you.
Once you find those frequencies, reduce the level below 0dB and adjust the Q value until you get a natural sound. A/B it to make sure it sounds better than what you had before.
The important thing here is NOT to overuse this technique.
Many beginner engineers find out about frequency fishing and start applying it to every slightly annoying frequency they here.
The truth is, any piece of audio will sound annoying when you boost it by 20dB using a narrow Q value.
If you get done EQing and realize that your audio has five or more ultra-narrow notches, you should go back to the drawing board. If you have the ability, consider re-recording that part of your track.
5. Avoid the Solo Button
EQ can be an audio-shaping tool during the production process, but when it comes to mixing, EQ is meant to help your elements fit together cohesively. In order to get your tracks sounding balanced with one another, you have to mix them in context.
I get it, avoiding the solo button can be hard.
Not only does it make it more difficult to hear EQ issues, but it can also make it more difficult to hear what you’re doing altogether.
The problem is that the minute you solo a track, you strip it from the context of the overall mix. You’ve likely heard this over and over again if you’ve ever read an article or watched a video on EQ but NO ONE will ever hear your elements in solo.
It doesn’t matter if that guitar track sounds killer on its own. If it muddies up your mix, it needs work.
I often find that when EQ’d properly, my tracks in solo sound awful. The guitars sound thin, the vocals have too much presence from 1-3kHz, and the band-passed synths feel like they need to be opened up. However, when put together, they fit like a dream.
Avoid the solo button and I guarantee your mixes will improve tenfold.
EQ Your Way to the Perfect Mix
EQ is one of the most powerful tools you’ll have access to in your DAW, and with the proper application, you can create a polished and professional mix.
From employing high-pass filters in context to giving your mix air with careful top-end boosts, you can turn your track into a radio-ready piece of art.
If you’re ready to take your mixing skills to the next level, make sure to check out our FLTips Academy, which offers more than 320 hours of lessons and training to help you become the best writer, producer, and mixing/mastering engineer that you can be!