In (seemingly perpetually) thinking about and discussing rewriting Imperfect Sound Forever, the issue of side-chaining came up in relation to the last Flying Lotus album, which, from a superficial reading of the signifiers (Aphex Twin does jazz, perhaps?), ought to be right up my street but which I can barely stand to listen to.
I was batting emails back and forth with Graham Sutton regarding the loudness war thing again, and asked about side-chaining. This is what he said: “Side-chaining a compressor to key its gain reduction from a secondary external input is pretty standard stuff – it actually dates back to the 1930s. Doug Shearer first developed the idea while working at MGM Studios at the birth of film sound. Originally it was developed to ‘De-ess’ sibilant voices which were problematic to record as they could easily overload the electronics of the day.”
What that first bit means, is that side-chaining as a technique works by tying a compressor on one element in a mix to a separate element; so when the second element comes in, the first one goes away (it’s almost literally pulled to the side, and thus out of prominence in the mix). If this sounds complicated, you’ll probably recognise its basic effect from what’s referred to as “ducking” on the radio: i.e. when the DJ starts talking and the music gets turned down. It’s not someone with fast fingers twitching a volume knob; a side-chained compressor takes care of the work.
In dance music “side-chaining” is normally applied to a kick drum in order to get that pumping, beat-driven sound. In order to get the kick drum as prominent as possible while still keeping the mix as loud as it can be, every time the drum hits, the rest of the mix effectively moves to the side in order to make room. This results in a weird “sucking” sound as basslines, synthesizers, guitars, vocals, and everything else gets squished aside to let the kick drum through.
Graham expanded: “SSL were the first to introduce desks that featured built-in side-chaining compressors, as opposed to external units, at the turn of the 80s. Techniques like ducking bass by kicks became pretty common. By the 90s/00s side-chaining was everywhere club music wise – the whole track now being pumped by the kick more and more as the years drew on.”
Apparently, and I’m pretty sure my ears concur, Flying Lotus makes plenty of use of side-chaining in order to get his tracks as loud and pumping as possible, in a Daft Punk style. Which is a totally OK artistic choice to make. Except that, for me, the type of music that Flying Lotus is applying this technique to doesn’t suit it; one track of vocodered vocals and a minimal synth line being squeezed aside to make room for a kick drum is one thing, but layers and layers of harps and jazzy trumpets and Squarepusher-esque bass runs and distracted digital effects squishing sideways, even if stuff isn’t clipped, and the overall volume never dipping away from intense, means that even sub-2-minute tracks become really, really difficult for me to listen to all the way through (never mind a 45-minute album). Even if the grooves are otherwise awesome (and they often are).