I used a combination of techniques to ultimately correct this, but the one which had the biggest impact was to put a limiter (Waves L1) in the signal chain before the compressor. Coupled with the fact they were on syncopated beats of the bar (especially the synth stab which was on the 3rd 8th note), this was likely what was causing the un-rhythmic pumping of the compressor. My assumption was that at fast attack settings, the uneven peaks of both instruments were causing the compressor to trigger inconsistent amounts of gain reduction. The synth stab used a fairly heavy chorus effect which caused the individual notes to peak at varying levels in the waveform. Notice the highlighted uneven peaks caused by the synth stab sounds (red) and snare hits (blue). I bounced the uncompressed track to an audio file so I could get a look at the waveform (see below)… (From further experience since this, I’ve come to learn that un-rhythmic movement of the gain reduction needle like this usually always results in uneven, pumping compression). While originally working on this I also noticed that the virtual ‘needle’ in The Glue jumped around unevenly, not moving with the rhythm of the track. The pumping of the compressor is evident from the uneven level of the offbeat open hi-hats.
the same track plus ‘The Glue’ with similar fast attack settings to what I used originally used… If I moved the attack back to 0.01ms, it caught all the transients, but also resulted in a fairly un-musical pumping effect. Initially I used a slowish attack setting of 0.3ms, but I was finding a lot of transients were slipping through and causing digital clipping when the level was raised. My ‘goto’ compressor for bus compression is Cytomic’s ‘The Glue’, so first step was to insert an instance of this over the master mix. What I basically wanted to achieve with bus compression was to maintain the general sound and dynamic as much as possible, while making the overall level more ‘competitive’. It centered around my track ‘ Push On‘… when I’d completed mixing of this track, I was really happy with the sound… the bass line was strong and solid, and the snare and synth ‘stab’ sounds both had a nice punchy and aggressive dynamic. My experience in this process was one which helped me discover, and then cement this approach of progressive compression. I discussed in my last post on this topic the importance of applying compression in a staged and progressive manner through the entire sequencing and mixing process, rather than leaving all the work to a couple of plugins at the point of final ‘mastering’. This is my second instalment on bus compression, and the story of how I discovered what has since become my default effects chain for master bus compression.