1. Equalizing with Frequency Specific Distortion
2. Equalizing with Frequency Specific Compression
3. Equalizing with Analog Emulations
4. What is Linear Phase Equalization?
5. Left and Right Channel Equalization
6. Mid and Side-Channel Equalization
7. Dynamic Equalization
In many ways, distortion can be used as a form of equalization - especially when that distortion is easily controlled and can be made frequency specific. For example, an exciter will create high order harmonics, in turn amplifying the high-frequency range - resulting in a brighter master.
So when you’re setting out to equalize your master, keep in mind that other forms of processing, although not exactly equalizers, will affect the amplitude of various frequencies in your spectrum, much like an EQ.
Compression and equalization are thought of as very distinct and separate forms of processing, but they overlap in more ways than you might think. If you want to attenuate an aspect of your frequency spectrum, you can either cut it with an EQ, or you could compress it.
Say that 200Hz is too prevalent and is causing a muddy-sounding master - using an equalizer I can dip it by a few dB - or I could use a multi-band compressor to target those frequencies and set the threshold to only cut it when it’s too prevalent.
Analog emulations are somewhat different from your traditional digital equalizers - they create unique and distinct curves, as well as introduce phase changes that are specific to the gear they emulate. For this reason, the sound they impart on a master is indicative of classic hardware processing.
When we observe the frequency spectrum, we can see that each analog emulator imparts unique slopes and Q values, as well as phase changes different than regular digital EQs. If you’re using one of these emulations during mastering, you’ll need to use your ear even more than normal, since you can immediately see the changes you’re making.
In a linear phase eq, the filters used in the equalizer are all delayed by a set and equal amount - resulting in the retention of the original phase of the signal. Linear phase can cause something called pre-ringing or smearing of the transients by how this latency is compensated.
Typically the higher the latency, the worse this pre-ringing effect, so keep this in mind when equalizing a master. Typically a low-latency setting is best since this retains the phase without significant latency.
When mastering, you can affect your left and right channel separately to both control the signal in a unique way, and to expand or narrow the stereo image. If you amplify both the left and right channels at slightly different frequencies, you’ll cause some mild but noticeable stereo expansion.
Mastering with this setup makes you think about your signal a little differently - instead of processing the totality of the stereo signal, separating the two lets you bring out or attenuate very specific details.
Solo just the right or left to get a better understanding of what’s on each channel.
When mastering, you can convert your stereo signal into mid and side - this lets you control your stereo width by altering the relationship between the mid and side channels. For example, you can find the dry vocal in the mid, and boost it, or increase the reverb on the side.
Granted, what’s on the mid or side images will depend on the mix, but typically you’ll find more dry and powerful signals in the mid, and more of the temporal effects like reverb and delay on the side.
Dynamic equalization is similar to multi-band compression on expansion in that you get to control both the dynamics and the frequency response. When mastering this is a great way to make your boost or cut amplitude specific or only occur when the signal is loud enough to trigger it.
For example, I could amplify my kick frequencies by 2dB with a bell filter, or maybe instead, I could amplify it 1dB, and leave the remaining 1dB up to when the kick is present. Dynamic equalization, especially when combined with left-right, and mid-side equalization opens up a lot of possibilities.