Mastering is about listening and making small adjustments to enhance the mix. There are really 5 different aspects you can play with to make master and I’ll say a little about each.
The biggest effect is when you push things into the limiter. As you hit the threshold as you push gain to make it louder the balance of the mix gets affected. This is what you listen for while you start to push the gain into a limiter. How is the transient of the kick and snare presenting now? What happened to the vocals? Is it louder in the mix now?
What you do with the limiter will inform other processes like what you do with any kind of EQ adjustments you might make. These are the two main processes that affect your master and where it takes the most care. I kind of float back and forth between the two at the beginning of the master, making small adjustments to each. I will tweak these parameters until the master sounds more balanced and at the volume is where you want it to be.
In limiting I recommend spending the most time here. Even though I’m digital I prefer an old school analog limiter emulation with few controls. Just input gain, release time and peak threshold. It’s also nice that on some modern limiters you can do a gain match and hear how the limiter is affecting the mix. This is important because we most frequently perceive things that are louder as better. Often people ruin masters because it’s louder so they think it is better even when they may have accidentally destroyed the balance and dynamics of the mix.
As you push gain into the limiter it will become louder. Push it until it’s as loud as you want without destroying your dynamics. The release time is the place to play around and listen to how it affects the kick and hi end of your track. I tend to prefer longer release times as it tends to smooth things out, though sometimes a really quick release is called for.
Play with these two parameters a lot. Just focus on those two aspects: the gain and the release time until you learn to hear what you want to hear. With practice you’ll be able to dial it in pretty quickly, but always experiment and see which approach excites you. You never know when going counter to your habit will result in interesting and cool sounds.
WIth EQ it’s small moves only unless you really desire to change the entire character of the mix, say for instance make it super lo-fi. So for preserving the character small moves are a must. For this task I prefer a mid side dynamic EQ which is a combo EQ and slight compression. Places of frequent concern are the very low end below 70 to get the sub balance right, around the kick 70-100 hz and the 165-400 hz, the vocal 1600-4000 range and the top end 12k and above.
With a dynamic EQ you can fine tune the kick and low and keep the high end splashy and create a little sense of movement. With a dynamic EQ you get attack and release. I’ll often leave them pretty quick but sometimes will sync it up with the release time of the limiter. They create different effects. See which one you like best for the track you're working on.
Very frequently you need to bring up both the high end and the low end with a shelf. You can also control around the pulse of the beat, bring out the vocal and make sure your cymbals sound musical in the way you want to with eq/compression. Most of this is achieved in the middle of the stereo field.
For the sides, I usually do a low cut filter up to about 70-100 hz to achieve a tightening the low end in the middle center of the mix. If I want to bring up the presence of electric guitars then I might do a small boost in the 700-1500hz area to beef it up. When I want to accentuate the vocal in the middle I might do a small cut at the same frequency I boosted in the middle for the vocal. You may also only want to boost your very high end on the sides and leave the middle alone. This can create a wider sound mix.
With mastering it’s about listening. The concepts are pretty simple and require you hear what is happening when you make this change or that. You have to constantly ask how this change I’m making is affecting the entire mix? What is happening to the vocal, what is happening to kick, the bass, the snare and everything. Playing with these aspects and learning how each time you make a EQ move and how the release time changes what you hear is the key to learning how to master confidently.
This is a lot to take in, so I’ll tackle topics later such as: To Compress or Not To Compress? Why saturation is a whole lot like compression but more colorful, Clipping before the Limiter for loudness and clarity and Stereo Widening, how Delay and Reverb could add an interesting color to your Master, Tape/Viny/Cassette Emulations and other ways you can add a little extra flavor.
Have fun playing with mastering.