Serial Compression – The Ultimate Guide

Serial compression is a technique used by mixing engineers all over. Integrating this technique into your own music can yield a more natural sound as opposed to just using one compressor. Let’s talk about what serial compression is and when to use it and how to use it (with settings).

What is Serial Compression?

First let’s identify what serial compression is.

Serial compression means using two or more compressors on the same track typically one after another to compress your signal.

Why use more than one compressor? By splitting the workload between two compressors, you get more transparent results so you don’t hear the compressor working but you get the effect you want.

Each compressor can treat the audio dynamics differently and works toward a specific purpose.

I oftentimes like using two compressors in a row to get better control over the signal, particularly on more dynamic tracks like bass (see how to compress bass) or vocals (check out my recommended compressor settings for vocals).

I demonstrated this in my post answering how many compressors to use on vocals.

How to Use Serial Compression

The first compressor in serial compression is usually an 1176 modeling FET style compressor to tame the peaks and compress the dynamic range. This can handle a heavier workload than what we’re using next in the chain.

As such, the settings are more aggressive because I’m trying to get a more even signal achieve more cohesion and energy in that track:

A FET style compressor (see types of audio compressors) like the Waves CLA-76 or the Arturia Comp FET-76 works well here for getting a handle on tracks with a lot of dynamic range like bass or vocals.

Because we’re using serial compression with another compressor next in the chain, we don’t have to run this TOO hard. I’m looking for gain reduction of about 5dB or so on the loudest peaks.

This sets things up nicely for our second compressor. I’ll usually reach for an optical/opto compressor here. You generally don’t run these compressors quite as hard and they yield very transparent results.

I like the CLA-2A from Waves as a simple opto style compressor. Just set the input (peak reduction on the right) for how much gain reduction you want, and your makeup gain with the gain dial on the left.

Here I’m just looking for a bit of glue to my already compressed signal, maybe 1-2dB of gain reduction on the peaks here to smooth it out just a touch more:

After my second compressor, I’ll typically insert any other processing the track calls for. When all is said and done, I might put one final compressor (typically an opto again) at the end of the chain to add one final touch of glue after any additional processing.

That’s basically how serial compression works. Hit those peaks hard on your first compressor, then ease things up to glue the remainder together.

This gives you an effectively and consistently compressed signal without the artifacts that you’d get if you had to run just one compressor harder to do both jobs.

Serial Compression Tips

• Serial compression means using two compressors typically back to back in your insert signal chain on a track or bus.
• Using two compressors back to back like this allows you to divide the workload between two compressors with lighter settings rather than driving one compressor harder. This yields more transparent results to where you don’t hear the negative elements of the compression working.
• Try a FET style, 1176 modeled compressor first in the chain, aiming for about 5-7dB of gain reduction on the loudest peaks. This gives you a more even signal to feed into the next compressor.
• Follow this up with a transparent, optical compressor to act as a bit of glue and smooth out the signal further. Go for 1-2dB of gain reduction on the loudest peaks.
• Add any other additional processing on that track and end the signal chain with one final optical compressor with settings similar to the last one if you need to create a bit more cohesion from your track’s dynamics.