Further Thoughts on Mastering

I have just downloaded Bob Katz's 'The Art of Mastering' and I intend to read through it. Chapters 9 and 10 which deal with dynamics in mastering sound particularly interesting. I have started reading chapter 9 and I already have some observations that I noted down!

Katz recommends avoiding multi-band compressor, unless one wants to change the mix. A multi-band compressor splits the audio information in several bands, so one band will not be affected if another is compressed. For example, in my track, I can use less compression on the high end in Waves's UltraMaximizer, to avoid the aforementioned sibilance. An interesting fact is that TC Electronics was among the first who introduced multi-band processing with their M2000 Effect Processor and, later, with the Finalizer - which I used to master the first version of 'Glass Sky'.

Katz recommends not using bus compression when mixing! which is something I have been doing in the past; recently at work, I started mixing without any bus compression and only adding it at the end, to emulate the mastering stage and make any changes that become apparent to be problematic at a mastering stage.

I also found out that the 'lack of breath' in my final product is caused by hypercompression. Hypercompression leads to lack of dynamics, loss of transient information, track sounding fatiguingly loud at all times, sounds ‘squashed’; the loud bits sounding ‘wimpy’; instruments that are meant to be in the background becoming loud and upfront.

For 'invisible' compression, Bob Katz recommends a light ratio of 1.01 to 1.1 (compression ratios most common used range between 1.5 and 3.0) and a very low threshold; larger ratios can reveal breathing, pumping or other artefacts (for example, in my track, sibilance). Another way of achieving transparent compression is parallel compression, furthered detailed in chapter 10 - which I haven't read yet, but I intend to do soon and put into practice - most probably after Christmas, as I don't have proper monitoring at home. 

References
Katz, B. (2008) Mastering Audio: The Art and the Science. Oxford: Focal Press