Equalization during mastering is a topic that is rarely addressed and explained.
One only has to look at the very limited number of resources, especially in French, on this theme.
Indeed, an equalizer is an equalizer — but applying equalization on a master is clearly more complicated than it seems at first glance.
To help you avoid the main pitfalls that beginners in mastering often fall into, here are some tips that you can apply almost instantly to the next track you master.
1. Use an Equalizer Suitable for Mastering
This recommendation may seem naive because there isn’t strictly speaking a “mixing equalizer” and a “mastering equalizer”.
Moreover, tools alone do not make the difference: someone who doesn’t know how to equalize at all won’t be able to use an EQ for mastering, regardless of the plugin…
If you are already familiar with a given plugin (perhaps the basic equalizer of your DAW?), stick with that plugin. You are always more effective with tools you know.
However, if you don’t have any particular habits, make sure to use a suitable tool.
If, during mastering, you find the need to equalize very specific aspects of the mix, for example to correct a resonance on a very narrow frequency band, use an equalizer that can achieve that level of precision.
For example, Pro-Q by Fabfilter is a bit pricey but absolutely fantastic because it is very effective.
Be careful though: if you find yourself making a lot of very precise corrections, it’s probably because there is a problem in your mix. Don’t hesitate, if that’s the case, to go back to it to fix the issues you hear.
That said, generally speaking during mastering, we mainly use equalization to balance a track. Typically, to adjust the balance between lows and highs — or to bring a bit of clarity by slightly reducing the low mids if they are a bit muddy.
For this type of use, prefer EQ plugins with musical and broad curves (very low Q factor).
For example, I really like to use the Dangerous Music BAX EQ by Plugin Alliance, which is based on the equalization curves designed by Peter Baxandall in the 1950s:
As for the SlickEQ M by Tokyo Dawn Records, shown at the beginning of the article, it is different but just as effective. Note that a free version with fewer bands is also available.
2. Equalize in 0.5 dB Steps
As I mentioned earlier, if there are frequency issues in the mix, they need to be corrected at the mixing stage. Mastering is there to provide a final polish, a last adjustment of frequencies — particularly by balancing the tracks of the same album with each other.
If you find yourself making corrections of more than 3 dB (decibels), there is likely a problem.
Most of the time, during mastering, we are looking at equalizations of 1 dB, 2 dB, or even a maximum of 3 dB!
So yes, it’s subtle.
But if you remove those corrections of 0.5 or 1 dB, you will notice that the master sounds worse.
Thus, the way you equalize your tracks during mastering is important: prefer adjustments of +0.25 or +0.5 dB at a time, and multiply before/after tests.
For example, if you feel that the lows could be a bit more present, add an EQ around 80 Hz and boost by 0.5 dB. Do a before/after test. Is it better with or without the correction?
If it’s better, try increasing to +1 dB, and repeat the experience… 🙂
3. Master the bass with your EQ
If there is one crucial aspect of equalization for mastering, in my opinion, it is controlling the bass.
If there is too much bass or if it is not clear enough, the track will often feel muddled.
Even if the mids and highs are well mixed.
This is particularly related to a psychoacoustic phenomenon called the “masking effect”, where low frequencies tend to mask high frequencies.
That’s why mastering the bass as best as possible is one of the challenges of mixing and mastering.
To do things right, it is important to first check if the room is balanced in the bass. That means ensuring that the acoustic treatment of modal resonances is effective.
If that’s not the case, and adding bass traps is not possible (we know that home studios rarely resemble real studios), don’t hesitate to rely on a good pair of monitoring headphones like the ATH-M50X.
This will allow you to listen to the bass in your master without the acoustic problems of your room.
Because clearly, if the room is unbalanced in the bass, your master will be unbalanced too.
Now, regarding equalization itself, several approaches can be followed to control the low frequencies.
For example, you can cut the lower part of the bass with a high-pass filter (= low cut). It is indeed quite common to use an EQ to cut around 20-40 Hz, depending on the style of music.
Then, to boost or attenuate the bass, I recommend trying first low shelf EQ filters, which will be more musical than bell filters.
However, if you want to use the latter, make sure that the Q factor is low enough — the idea being to raise or lower the bass transparently.
4. Use Mid/Side Equalization, Ideal for Mastering
You may have heard of it: any stereo signal (thus having a left channel and a right channel) can be “decoded” into a mid/side signal (thus having a channel corresponding to the center of the stereo image and a channel corresponding to the sounds located on the sides).
Mid/side equalization is a common mastering technique.
On EQs that allow it, you will indeed be able to sculpt the signal in detail by balancing the mid and side channels, rather than processing the frequencies globally.
Personally, I love this type of processing for mastering equalization because there are plenty of possible applications. For example, you can:
- add more bass but only on the mid channel for a more precise sound;
- conversely, attenuate the bass on the side channel to tighten the bass by repositioning them in the center of the stereo image;
- or boost the highs on the side channel to add presence to the reverb without making the mid signal aggressive.
Feel free to experiment with this technique, but also take a look at how the presets delivered with your equalization plugin are constructed: this will surely give you some ideas… 🙂
5. Compare Your Master with a Reference Track
The goal of mastering is to provide a finish to the mix and to properly homogenize the entire album, it is often useful to use reference tracks — especially for everything related to equalization.
For my part, I cheat a little bit actually. I make sure my mix is great by comparing it to the sounds of successful commercial albums that I admire.
Sylvia Massy (Tool, System of a Down, Red Hot Chili Peppers…)
Sure, it is possible to judge “broadly” if a track lacks bass or not.
But can we always judge whether to add +1dB or not?
The task can be daunting, especially for beginners…
Also, a simple solution is to compare your master with other reference masters. Typically, commercial tracks of the same music style or better: something that closely resembles your target sound.
Once your reference track(s) is(are) chosen:
- Listen to it
- Listen to your master
- And ask yourself questions like:
- Do I need more bass?
- Should I rebalance the highs?
- Maybe more presence around 10 kHz would be good?
- Are my guitars too forward in the mids? If so, should I perhaps attenuate a bit around 800 Hz?
- etc.
This should guide you towards the frequency corrections that need to be made…
(by the way, don’t forget to adjust the volume of your reference tracks to match the level of your master, otherwise your choices will be less precise)
In conclusion
By applying these 5 main tips, you should feel much more comfortable adjusting your equalizers during mastering.
After all, it’s not that complicated: you just need to ask the right questions. And of course, to constantly compare the sound of your master before and after equalization.
To continue reading about mastering, feel free to check out my plugin recommendations. 😉