Music Industry

EQ Explained – The Basics

If we were to ask a thousand up-and-coming producers about the tool they use most, EQ would top the list. But even though its use seems pretty straightforward, a lot of people think too lightly of EQ and what it does. This could lead to wrong decisions when it comes to mixing and a lot of long nights trying to fix the problem. To make sure you don’t lose too much sleep, we’ll explain EQ and why it’s important for you to understand what you’re doing. Welcome to EQ Explained – The Basics.

What Is EQ Or Equalization?

Equalization – or EQ – is one of the most well-known forms of audio processing in music production. It enables you to adjust the volume level of a frequency (or range of frequencies) within a sound, which in turn allows you to cure a sound – or sometimes even entire songs – of its imperfections. This is done by cutting unwanted frequencies and/or boosting others, all to balance out sounds that you feel are lacking.


How Does EQ Work?

For all of you who have worked with a Parametric EQ before, feel free to skip this part. As for the rest, we will explain how EQ works by focusing on Logic’s Channel EQ. This EQ consists of eight individual bands. From left to right, the bands are:

  1. Low Cut Filter (or High Pass Filter)
  2. Low Shelf Filter
  3. Bell Filter 1
  4. Bell Filter 2
  5. Bell Filter 3
  6. Bell Filter 4
  7. High Shelf Filter
  8. High Cut Filter (or Low Pass Filter)

You are in full control of each band, as you can adjust several different parameters for each. The first two, Frequency and Gain/Slope, speak for themselves. Whereas the ‘Frequency’ parameter allows you to set the frequency for each band, the ‘Gain/Slope’ parameter allows you to set either the slope of the filter (Bands 1 and 8) or the amount of gain (Bands 2-7). Q, however, is a little less self-explanatory.

The ‘Q’ parameter allows you to control the range of frequencies that you alter. A low ‘Q’ setting – such as 0.83 – results in a wide bandwidth, which means a large range of frequencies is affected. A high ‘Q’ setting – such as 20.0 – results in a narrow bandwidth and a smaller range of frequencies affected.


How Should I Use EQ?

Now that we know what each button or parameter does, it’s time to dig deeper into how EQ should be used. For this, we’ll divide this chapter into various sections.

An Overview Of Frequencies

Sub Bass
Sub Bass ranges from 20Hz to approximately 60Hz. A nice amount of Sub Bass can give your track a boost in power, but too much will make your low end sound muddy and undefined.

Bass ranges from 60Hz to approximately 250Hz. A lot of Bass may sound nice, but it can also completely overpower the rest of your mix. As always, use with restraint.

Low Mids
Low Mids range from 250Hz to approximately 1500Hz. These frequencies are responsible for the warmth and atmosphere of a sound, but it’s also one of those frequency ranges that plenty of different instruments deal in. To avoid frequency clashes between these instruments, you ought to think twice about boosting this frequency range.

High Mids
High Mids range from 1500Hz to approximately 4kHz. If you use a lot of lead synths, you will have a lot going on in this frequency range. It’s also the sweet spot of the punch of most percussion instruments (excluding kick drums).

Presence ranges from 4kHz to approximately 7kHz. Boosting this frequency range can add to the clarity of the mix and/or specific sounds, but too much can be very tiresome to listen to.

Brilliance/Noise ranges from 7kHz to 20kHz. It is quite similar to Presence in its use, but the higher end of this frequency range is mostly hisses and noise. A small boost may give your mix some breathing space, but too much just means you’re dealing with a lot of high-frequency noise.

NOTE: The above frequency ranges are not set in stone; they are mere guidelines. There can also bit a bit of overlap between these ranges. The same counts for the EQ chart below.

EQ chart 1


Removing Unwanted Frequencies

Every heard ringing in your drums? Or how about resonating frequencies in vocals or instruments? Chances are you want neither. You want all elements to sound crisp and clean and EQ can help you with that. If you want to remove unwanted frequencies, you can make use of a so-called frequency sweep. Here’s what you do:

Step 1: Select one of the Bell Filters. In the case of Logic’s Channel EQ, this means one of the middle four bands (3-6). Set the Frequency to a value in the lower end of the spectrum, such as 250Hz. Set the Gain to approximately +10dB. Apply a high Q setting, such as 30.0.

Step 2: Loop the sound you wish to sweep and play it. While it plays, gradually increase the frequency.

Step 3: Listen closely. You’ll find various frequencies that sound awful as you sweep by them. Once you find one, stop adjusting the frequency. Now lower the amount of gain until you feel that the specific frequency isn’t negatively impacting your sound anymore. Needless to say, the Gain should end up at minus dB. Set ‘Q’ as you see fit.

Step 4: Repeat until you’ve eliminated all unwanted frequencies. Be careful not to overdo it and keep checking if your sound still works well with the rest of the song.


Cleaning Up Your Low End And High End

If the low end of your song isn’t clean or if the high end is hissing at you, you may once again resort to EQ to make it right. This is where the Low Cut Filter and High Cut Filter come into play. These are respectively Band 1 and Band 8 in Logic’s Channel EQ. Whenever we refer to the low end of a song, we mean everything from 16Hz – 60Hz (Sub Bass) and 60Hz – 250Hz (Bass). In the case of the high end, we mean everything from 4kHz – 16kHz, especially 8kHz and over.

The Low Cut Filter – also known as the High Pass Filter – cuts everything below the set frequency. Instead of reducing the frequency by a set amount of dB, the Low Cut Filter cuts more per additional octave below the set frequency. This is why using a Low Cut Filter is best suited for cleaning up your song’s low end, as opposed to a Low Shelf Filter.

While producing, you may notice that some sounds (e.g. pads, synths, FX) can carry quite a lot of low end. Although this could be desirable in some cases, such as breakdown or ambient music, it becomes a bit of a nuisance when you’re trying to mix them into your all-out drop. To make sure you’re actual Sub Bass and Bass stay well-defined, you ought to consider cutting the low frequencies of the sounds that are not meant to supply the actual low end to your track. That way, you’ll end up with a cleaner and clearer mix.

The same principle applies to the use of a High Cut Filter. You cut away frequencies you don’t need (or don’t want), such as excessive high-frequency noise from big synths, FX or even pads. Be careful not to cut too much though. You don’t want your mix too sound like an underwater listening session. All in moderation.


What Are The Pitfalls Of Using EQ (incorrectly)?

Now that you know the basics of EQ and how we can use it, we’re going to keep you from making the same mistakes as tons of other producers before you.

Look At The Bigger Picture
We get that you’re trying to make a bassline or lead synth (or any other sound) smashing by itself. It’s tempting, we know. But the truth is that you’re missing the point of EQ. You could’ve made it the best sound in the world, but if it doesn’t fit your mix, all of the effort was for nothing. Make it your number one priority to EQ in context. After all, EQ is meant to balance your mix. Not to enhance individual sounds. You’ve got other tools for that.

There’s No Such Thing As Magic
You can EQ all you want for hours on end, but it’s not going to help you fix a bad recording. It’s like trying to turn a sub bass sound into a high-frequency synth stab. You can’t boost high frequencies when they aren’t there to begin with. The same principle applies here. EQ doesn’t increase the quality of the recording. You’d be better off just re-recording.

Know When To Stop
It’s easy to get lost in EQing, especially if you’re a born perfectionist. When nothing ever sounds good enough to you, remind yourself that making too many EQ adjustments can work sideways. Every time you boost or cut a frequency, you’re altering the fundamentals of a sound. Because of this, too many alterations can cause it to sound unnatural or even dull. If you do feel that it needs that much EQing, you should just chose a different sound that doesn’t need as many changes.

Automation Is Your Friend
Sometimes, an EQ setting is great for quieter sections, but fails to work magic when all sounds come together. Or vice versa. This is where automation can help you out. Don’t be afraid to use it. Automation’s got your back.

Presets Are Bad. Mkay?
Look. It’s very kind of the EQ builders to supply you with a bunch of presets to make use of. There’s just one tiny, whiny problem. Those presets are made to suit a general use. You don’t want general. You want something custom-made for your own, unique sound. And the only way to get that is to adjust the settings yourself.

You should now know the basics of EQ and which pitfalls to avoid. If you have any questions regarding EQ, tips of your own to share or suggestions on what subject we should explain next, please leave a comment below and we’ll try to help you as best we can. In the meantime, you can read all about Reverb and Compression here.

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  • Reply
    May 29, 2017 at 7:54 am

    Another great blogpost Ruben! Thanks a lot.

  • Reply
    Eva Finch
    November 18, 2017 at 8:45 am

    This is an Ultimate guide about Audio Equalizer. Awesome.
    Thanks Ruben! Keep it up.

  • Reply
    Ivan Milenin
    December 7, 2017 at 12:49 am

    Hi, Ruben. It’s Ivan Milenin again.

    I want to thank you for suggesting me to use the nice balance of the EQ, Reverb, and Compression for the mix down to get crisp and sound great. It really helps me to become better at mixing. For instance, I use the EQ and got rid of the unwanted frequencies. And now I know how it would work when submitting my demo. Thanks for the tip.

    But now I have another problem. I am using Logic Pro X on my iMac Mid 2009 computer, and it was crashing a lot. I receive system overloads and it’s a pain. I tried my hardest to get that software to work, but somehow, it doesn’t seem to respond.

    So I tried a few ways to optimize my CPU on my computer. I increased the buffer size for mixing (hi buffer size for recording can increase latency) to 1024 samples. I tried turning off my wifi, I tried to freeze the software instruments, and I tried to bussing the channel strips with a lot of plugins to an aux track. I also tried to group those channels, to save CPU. But all of these problems seemed to appear as “disk is too slow” or system overload.

    I understand that I may need an external hard drive to save CPU instead, however, I have a 2.0 external drive whereas the USB ports are 2.0. which in this case may slow down my computer. I also have a RAM issue as of a 4GB RAM. I realized that it might be too slow for my DAW to work.

    But that related topic about the EQ is what wonders me: is an EQ a CPU intensive plugin? I frequently used EQs for mixing on my project of a song. Does each EQ on each channel strip could overload my CPU?

    If you haven’t an article about how to optimize any DAW whether is (Logic, Ableton, FL Studio, Reason, etc.), you are more than welcome to write it up.

    I know you can because I believe in you.



    Ivan Yevgenyevich Milenin

    • Reply
      Ruben Meijer
      December 14, 2017 at 4:14 pm

      Hi Ivan,

      EQ is hardly considered a CPU-intensive plug-in. To put it more strongly, EQ very little CPU capacity in my experience. The only kinds of EQ that rob you from (a bit of) CPU power are Linear Phase EQs, because there’s a but more going on in them. Although I’m not a tech expert (or even a tech support guy for that matter), I suspect your iMac may have become a bit too old – and thus too slow – to handle the job. A year or five back, when I still dabbled in music production myself, I owned a MacBook Pro with similar specs, which I think was an early 2011 edition (could be a year or two older than that, I’m not certain). Once it got over a certain age, I got many of the same problems you’re describing: Lots of CPU overloads, “disk is too slow” messages and playback issues.

      You could try asking a friend of yours (with a newer, more powerful mac) if you could open some of your projects on his Mac to see if that fixes the problem. If not, I’m not really sure how much more I can tell you. Really hoping you find out what the problem is, but I know you’ve already done all other possible solutions I’d recommend anyone to start with. I’m afraid purchasing a new mac might prove the only option.

      Hope this helps.

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