My question was supposed to sound more along the lines of tips for getting my mix into the desired integrated LUFS/RMS/fundamental frequency sweet spot. My conundrum is that I have my mix sounding the way I want with each track having presence and sitting well in the mix with enough headroom for mastering. Unfortunately, I still feel that my RMS should be around 2/3 dBFS higher before I master to prevent over-limiting over-compressing there.
I was looking for tips/techniques for this.
Thank you for the reply though, I'm still learning lots about music production and every insight helps!
When you have a mix with a certain RMS and peak content you may or may not be in a position that you can gain all input tracks in the whole project a little or 50% on each side of the compressors, to achieve these extra dBs. The issue is most commonly though that the mix signal is at this point already rather fatigued by peak reduction, which means that when you push the mix even more it will simply become numb. This particular issue is most commonly due to wrong compression on the input track level earlier on.
So, the issue is wrong use of compression on the first compression stage. So for instance the vocals might need a FET compressor first that deals with the very dynamic issues as little as possible but much enough, a Tube compressor afterwards that rounds off the remaining transients (the louder the transients are the harder the compression, because the ratio increases with gain reduction) and some RMS based compression afterwards (opto type) that ensures it does not jump around too much in RMS. So this is 3 different types of compression FET, Tube, Opto on a single sound source that effectively deals with the dynamics. When you with very good accuracy apply the compression on all sound sources tailored around the dynamic issues in the first stage, you have a mix that has a very good signal and RMS level on each track in the first stage of compression. So that means with this type of compression quality at the very core of the content, you can now bring up the RMS levels by adding additional stages of compression, for instance side-chained compression, parallel compression (incl. two stage compression), multiband compression and some rather gentle peak limiting at the end. The combination gives you a full waveform with the right loudness and dynamic characteristics.
So the art of compression is to a great extent about applying the right types of compression in the right order on the tracks early enough. Different sound sources vary in their dynamic characteristics, vocals for instance can jump around in their dynamics quite a lot and hence need to be very well controlled with compression. It is also important that the various compressor types act on the content in the right dosages, for instance you do not want mostly fast compression of the content, because that means the mix becomes hard in the punch. Instead you want more of Tube type compression that softens the sound sources a lot, which means the mix becomes softer also. And then you want also the FET compression that kind of stabilizes the dynamics, so that they are easier to control with other types of compressors afterwards.
The overall issue is hence that when the dynamics are not treated according to what is necessary to create certain dynamic characteristics, then later on when you deal with more mix level compression you might face some issues when you are applying additional compression. That is why the first stage of compression is the most important.
So bring up the RMS levels by having compressors act on the content at different times in different ways. In this way the waveform is not as much altered, so it becomes a more natural and more smooth type of compression.
