A while back I was pondering mixing live shows, as I strangely so often find myself doing, and I began to analyze the varying aspects of dynamics in live reverberant fields.
Is there something more legitimate than personal preference that would add credibility to using compression?
The studio humans and mastering labs use a ton of it, but comparatively, we live engineers use fairly little. I know it works well to control the variations in a band’s playing, and also helps with smoothing the sound, but is there yet another advantage of compression that is not so readily apparent?
On the surface it’s quite obvious that compression can be used on bass to reduce the differential between the louder and softer notes resulting in a more consistent sound. Same with vocals, and I put compressors on guitars as well.
I even take it further and run kick and snare into a subgroup that has a bit of compression on it to keep the two a bit more locked-in, volume-wise, to each other.
So what got me started (again) on this train of thought?
Not long ago I was listening to a super punchy horn-loaded sound system. Boom, crack, boom, crack, as the drums jump out at me - and they do sound cool.
But I also know from experience that the reverb decay time from the loud “on to” super punchy sounds blurs the intelligibility of everything else that immediately follows.
So if an uncompressed snare is 10 dB “on-top” of the mix, then the correspondingly loud roar of the room-reverb-decay-level from that snare will hurt overall intelligibility long after the original snare hit has been heard and ended.
Conversely, that means that if the instruments are all compressed to a fairly narrow volume range, they then would stay at an even level consistently above the room reverberation rather than the loud sounds setting off room reverberations louder than the following softer sounds.
What I’m getting at is that controlling the differential between the loudest and softest sounds not only improves intelligibility by reducing volume inconsistencies, it’s also helpful in dealing with reverberant room acoustics.
The sacrifice? The loss of some of that “slam-hit eye-blinking” impact.
But hey, the upside is your mix will sound a bit more like an album, the audience will be able to hear the various instruments and vocals, especially in reverberant rooms, and you’ll be able to get more overall volume from the PA with less clip lights flashing.
Just a thought…
Dave Rat heads up Rat Sound Systems Inc., based in Southern California, and has also been a mix engineer for more than 30 years.