If we were to ask a thousand up-and-coming producers what 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. With EQ, you can 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 so they work well with one another.
How Does EQ Work?
If who’ve worked with a Parametric EQ before, you can freely to skip this part. But since you're still here, let us explain how EQ works by focusing on Logic’s Channel EQ, which closely resembles FL Studio’s built-in Parametric EQ (and the native EQs of other DAWs). This particular 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 it’s affecting a large range of frequencies. 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 you 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 EQ Frequencies
Sub Bass
Sub bass ranges from 20Hz to approximately 60Hz. An appropriate amount of sub bass can give your track a boost in low-end power, but too much will make your low end sound muddy and undefined.
Bass
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. This frequency range is responsible for the warmth and atmosphere of a sound, but there are a lot of instruments that occupy this space. To avoid frequency clashes between these instruments, you'll need to thoroughly consider which sounds to boost and by how much.
High Mids
High mids range from 1500Hz to approximately 4kHz. If you're using 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
Presence ranges from 4kHz to approximately 7kHz. Boosting this frequency range can add clarity of the mix or specific sounds, but too much can make an entire track tiresome to listen to.
Brilliance or Noise
Brilliance or 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 a bit of breathing space, but too much means you’re drowning the track in 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.
Removing Unwanted Frequencies
Every heard ringing in your drums? Or how about resonating frequencies in vocals or instruments? You want all elements to sound crisp and clean, and EQ can help you with that. If you want to pinpoint and 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 apply the frequency sweep to and play it. While it plays, gradually increase the frequency.
Step 3: Listen closely. You may find various frequencies that sound awful or ear-piercing 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 so to counteract the initial frequency overdose. Set Q as you see fit.
Step 4: Repeat until you’ve eliminated all unwanted frequencies. Be careful not to overdo it, as the sound may begin to sound very unnatural and plastic. 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 sounds such as pads, synths and FX can carry quite a lot of low end. Although this could be desirable in some cases, such as with breakdowns or ambient music, it becomes a bit of a nuisance when you’re trying to mix those sounds into a drop with all bass, bells and whistles. To make sure your actual sub bass and bass stay well-defined, you can consider cutting the low frequencies of the sounds that are not meant to supply the actual low end of 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 to sound like an underwater listening session. Moderation is key.
