The truth is, it’s not inaccurate to say “do what the mix tells you (i.e. what the mix needs)”.
The same thing goes for mixing and songwriting (each of which are all very specific artforms, no less so than mastering.)
Mastering, mixing, and songwriting ALL take a lifetime to learn, that is fact! Every day that goes by, you will get better and better, the harder you commit yourself, the sooner you’ll become great.
In order to become a mastering ninja! you’ll need an intimate understanding of Compression and EQ.
When preparing a finished master ready for radio play, which is really the ultimate goal of having a record mastered, People ask how do I make my track sound as loud as that song from that CD and how do I master it so the mix sounds like a professional CD”
You will need to have the ability to objectively look at a piece of music and understand what needs to be done to it.
(i.e., doing what the music is telling you to do)
You can give instruction on the technicalities of how to use various pieces of equipment and what the various controls do, you can explain what types of sounds have fast attacks (or whatever), but actually using it in the proper place in the proper way is up to the user’s ability to:
1. hear what the audio needs;
2. decide which tool is the proper one to use; and use it effectively
Some people seem to just be happy having someone tell them what to do, whether it’s correct and useful information or not!
Someone could tell you some completely useless and false information and people will say “finally! thanks for the help man! good lookin out!”
Please understand this:
There is no “frequency” someone can tell you to boost too.
There is no perfect “compressor setting”.
There is no perfect “level” that can make an instrument sound in the mix.
These are all things the audio will “tell” you it needs!
It is up to you to be able to hear what the audio is saying and it is up to you to know how to “answer it when it speaks.”
If you are mastering your own material, there should be NO CORRECTIVE MEASURES NEEDED with mastering.
But really you should NEVER master your own mixes.
If your hi-hat is too loud, you don’t need to try to correct it in mastering, you just lower the hi-hat in your mix!
If your mix doesn’t sound right and basically like what it should sound like on the album, then you didn’t mix it well.
With regard to both mixing and/or mastering (not everything I am going to mention will apply to both), you can be told things like “don’t over compress, get your levels sounding good, pan your instruments in a balanced way, make sure each instrument has its own space, make the overall album sound consistent, etc”
But it is up to you to know your tools and how to use them!
It is up to you to know what sounds right!
Every day, I see people saying “you should pan this here and use this compressor setting and boost this frequency and roll this off and copy this to another track and use this plugin and this preset and this synth”
That is shit advice!
People say “thanks for the great tips!” because they don’t know any better.
If you want to get some help on your mixing, maybe try posting one of your mixes and ask people to critique it.
Maybe you can get an objective opinion on whether you need to raise the level of your snare!
Or if you have too much reverb on your vocal.
And that should do it.
You’re now on your way to becoming a great recording/mixing/mastering engineer!