Serial Compression

If using more than one compressor sounds hedonistic to you, think again. It’s a real technique, with real benefits, and it’s called serial compression

We all know about parallel compression, blending a heavily compressed signal with an unprocessed one… but serial compression is a different animal. It uses multiple compressors placed in a chain. The principles were first used in mastering, with the Shadow Hills compressor being a good example, but we’re using it in a mixing context here. So how is serial compression different to just whacking a single compressor onto a channel in your mix? Now for the second compressor placed after the first. This will be slower, and designed to add character – a classic buss or desk compressor could be great at this point. Now dial in some gentler settings: slower attack and release, lower threshold and a gentler ratio should bring the whole vocal into line and also give the sound a bit of personality. Here’s a raw vocal track ready for some compression. The obvious first step is to throw a compressor on there and dial in some appropriate settings. That’s fine, but we can go one better. Instead, let’s start again with serial compression. This time, we add the compressor with one intention in mind: to scalp the topmost peaks off the waveform only – almost like a limiter or a clipper. This means we can choose a compressor that’s better for that specific task. In essence, serial compression is comparable to the effect of sub-group or mastering compression, but allows even more control to be taken during the mixing/ sound-design process. Serial compression won’t

on every track, but it’s a good technique to have at the ready when you need to get the right response, reining in unruly material. We’ve used a vocal for this example because they can be especially tricky to knock into shape. Let’s tackle the peaks – whack the attack and release down to a minimum, activate Lookahead to make sure it clamps right down. The ratio and threshold should be fairly high, as we’re trying to affect just the highest peaks, and hit them hard. With the fast timing and high ratio, be very aware of distorting the peaks too much as the waveform starts to get shaved off at the tops. The ordering of the two compressors isn’t set in stone. Placing the peak-clipper first as we’ve done will help reduce pumping, for example. But why stop at two compressors – here’s the same vocal balanced with four stages of compression, ranging from very fast timing and high ratio/threshold settings, to slow timing and low ratio/threshold settings. Admittedly, this is overkill for our specific vocal, but we have to admit that it sounds better than it did before!