I wanted to know if you render out the mix and then master it or apply mastering on the project(where all the individual channels are i mean) only. Taking in consideration its mastering at home. Do share any tips/techniques/tricks.
By definition, mastering is what you do to a song recording *after it is finished*.
Mix as though mastering doesn't even exist. Get your song sounding right by mixing it. Once it sounds the way you want it to sound - i.e. *once it is done*, then you can worry about mastering it (setting final playback level, getting to to work on an album, etc.)
Also, what should the average level of the mix be before sending it for mastering? How much headroom should there be?
There will be as much headroom as the mix has in it - i.e. what is there is what is there. The key is to record and mix at natural levels and not just push everything up towards zero in the computer.
This requires an understanding of gain structure - recording at the proper levels, setting proper levels all along the recording and mixing signal path, etc. Study up on that and the levels will work themselves out.
But for some signposts that you're going more or less the right way:
- your individual instrument tracks should typically have an average (non-peak) recorded level of somewhere around -20 to -16dBFS each (give or take), with peaks falling anywhere they happen to fall, as long as they stay somewhere below 0dBFS
- when you mix your tracks, you pull as many faders down as you push faders up (roughly, more or less) - in other words you don't just mix my pushing things up.
- for most typical rock/pop mixes, your final mix should typically *of it's own volition* wind up with pretty much the same kind of numbers as your individual recorded tracks: ~ -20 to -16dBFS average with peaks staying below clipping. If you're doing heavier metal/wall of noise stuff, the final average numbers may be a few of dB higher than that (but don't *have to be*) but the peaks should still come out of the mix anywhere below clipping.
The important, but sometimes hard to understand, thing about all this is those numbers are not so much targets to be shot for or force-fit dialed in, as they are results that should automatically happen on their own.
G.