We’ve been doing a deeper dive on all of the components of our audio compressor settings chart recently, so let’s take a quick look the threshold setting. Let’s look at what the compression threshold is, what it does, and where to set it.
What is the Compression Threshold
The compression threshold setting dictates starting at what volume the compressor will engage.
Note that this input volume is the level which is being fed into the compressor at that point in the signal chain.
If you set the threshold, then later add a plugin before the compressor in the signal chain, that input volume will change along with the compression.
Keep this in mind whenever you add another plugin before the compression as you’ll need to reset the threshold.
Also note that the more volume which exceeds the threshold, the more the signal will be compressed at the compressor ratio which you set.
With an average 4:1 ratio, 8dB over your threshold (so -12dB peaks with a -20dB threshold, for example), those 8dB would be reduced to 2dB.
Where to Set Your Compression Threshold
Where to set your compressor’s threshold is always going to vary depending on what result you want.
For instance, if you want to absolutely squash a track, maybe setting it up for some parallel compression like your drum bus, you want to set your threshold really low so that virtually everything gets compressed. You might not want to bottom it out so that it’s compressing room noise, but certainly to the quietest element of the track.
You’ll want to pair this low threshold with a high ratio, as well, as the idea with parallel compression is to essentially make anything which surpasses the threshold the same volume on the output.
For more conventional compression, you might just want to tame the highest peaks, setting your threshold accordingly for a few of dB in gain reduction.
It’s also important to remember that everything works together on the compressor; setting the threshold low won’t have much of an impact if you set the ratio too low or the attack too high.
Ultimately where you want to set your compression threshold really depends on how dynamic your audio is, and how dynamic you want to keep it post compression. Generally I like to aim for anywhere between 3-10dB of gain reduction, but it’s a case by case basis depending how much I want to rein in the dynamics.
I’ve put together a number of tutorials on how to compress most elements of your mix. Here’s a sample:
- Compressor Settings for Vocals
- How to Compress Bass Guitar
- Piano Compression Guide
- Compression on Acoustic Guitar
- Snare Compression
You can also check out the compression category to get the full list and all the latest tutorials on using compression.