Ableton Live’s compressor is one of their best stock plugins even though it hasn’t changed much in the two decades or so since the first edition of the DAW came out. In this tutorial I’m going to cover each parameter on the Ableton Live compressor as well as the best settings to use for each.
Before we get into it, note that I did a complete overview on EVERY single one of Ableton’s stock plugins, so refer to that for information and or tips on every single plugin you’ll find in your version of Ableton Live.
Now, let’s get into Ableton Live’s compressor!
Ableton Live Compressor
If you’re not familiar with compressors in general, something I’ve talked about many times on this website, a compressor is a tool to reduce dynamic range in your audio.
Dynamic range is the difference between the quietest and loudest (musical) instances on a track.
Here is an example of a track with TOO much dynamic range:
As you can see, there’s audio which is playing at -20dB at the quietest point and audio which is peaking at -6dB at the loudest point. While dynamic range is a good thing because it’s natural, too much of it makes mixing difficult at best and has your listener constantly turning up and down their volume at worst.
Compressors work to bring down the loudest peaks to be closer to the quietest points in the audio, thereby achieving a more consistent average volume, and Ableton’s stock compressor is no different.
I did a comparison/overview of the different types of audio compressors in the past, but Ableton’s compressor doesn’t fall into any of those categories. If pressed, I’d say it’s somewhere between a VCA compressor and FET style compressor, but it’s their own proprietary design. I will say it works very well, and I still use it amongst other compressors in my mixes.
Let’s go through each of the parameters/settings on the Ableton Live compressor to better understand what they do, how they work, and very importantly where to set them.
For what it’s worth, I put together a complete audio compressor settings chart, so refer to that for more information.
Thresh
The “Thresh” is short for the compressor’s threshold.
Setting this level determines what the minimum volume the track must meet before compression begins. In other words, if you set the threshold too high, your audio won’t be loud enough to trigger the compressor.
Before I recommend any specifics in terms of where to set each parameter, note that these are all generalizations. Grab my free compression cheat sheet which tells you EXACTLY where to set each setting on a compressor depending on what instrument you’re compressing.
Generally when setting the “Thresh” (threshold) on the compressor in Ableton Live, you want to set it at or just above the quietest PRACTICAL point of your audio track. This will ensure that virtually the entire range of that audio will be compressed, albeit it proportionately so that the loudest instances are attenuated more to achieve a more manageable and similar dynamic range.
Note that it’s also a good idea to separate an instrument/track into multiple tracks when it covers a lot of dynamic range all on the same track.
A prime example is a vocal which alternates between quiet and loud points for say the verse and chorus.
The compression settings on the chorus when the vocal gets a lot louder won’t sound good if you set the compressor for the quieter point in the track and vice versa.
In this case, you’re better off splitting the track into two or three tracks to dial in more precise and fitting compression settings for each track individually.
Ratio
The compressor’s ratio refers to the degree to which the volume of the audio is going to be attenuated.
As this diagram demonstrates, turning the ratio up more aggressively pulls down/tames the peaks of your audio:
As you can see, there’s a much bigger difference in how much the volume of the peaks gets turned down between 2:1 and 4:1 versus say 10:1 and 20:1. When you get to 10:1 and beyond, that threshold basically becomes a flat ceiling where any volume which exceeds it get output to roughly the same level.
This is the basis of how limiters work, they create a ceiling which audio cannot exceed, making them a useful tool in the audio mastering process for turning up the overall volume of a song without audio clipping.
I’ll typically use either a 4:1 or 8:1 ratio with the vast majority of my tracks.
In other words with a 4:1 ratio, this means that every 4dB which exceeds the threshold gets reduced down to 1dB.
Likewise, with an 8:1 ratio, every 8dB over the threshold is output to 1dB.
4:1 is a standard or average ratio which works well for most instruments. I like 4:1 because it’s a nice compromise between peak smoothing and acting as a little glue while staying transparent.
I’ll typically use a more aggressive ratio of 8:1 on things which more dynamic range like bass (see bass compression) or vocals (see how to compress vocals) which I want to keep constant/present and up front, respectively.
GR
“GR” refers to gain reduction, and it shows you in release time how many decibels your peaks are being attenuated by.
How much gain reduction I want depends on the instrument, the situation, and of course that track’s dynamic range. In other words, there’s no perfect number here for gain reduction on the peak or on average.
If it’s got a lot of dynamic range like the 14dB I showed earlier, I’m going to want more gain reduction than if I just wanted to smooth out some relatively smaller peaks.
Knee
A compressor’s knee refers to how strictly it adheres to the threshold. The higher this number in decibels, the softer the knee becomes so that compression begins BEFORE the threshold is met, albeit at a lighter ratio.
This is in contrast to say 0dB which is a hard, all or nothing knee where compression is only applied as soon as the signal exceeds the threshold.
Once again, setting the knee depends on the type of dynamic range you’re working with, or better said the complexity of that dynamic range.
If you’ve got a track which peaks at roughly the same level every time like a snare or kick, a hard knee of 0-6dB works very well.
Conversely, a softer knee is much more transparent as it applies that ratio even more proportionately and makes for a smoother engagement of that compression.
I like a softer knee of 36dB or more on tracks with complex dynamics like vocals which are anything but reliable in terms of their peaks.
Attack
The Ableton Live compressor’s attack dictates how soon compression begins once the threshold has been satisfied.
While we obviously want the compression to happen, we want a very short delay so that the peaks of our track can come through for a split second before we drag them down via the compression.
Why?
Because that initial sound we hear of a clip of audio is referred to as its transients. As I explained in my overview of what are transients, these initial high frequency sounds which precede the rest of the sound are important for grabbing the listener’s attention. This draws the listener’s ear to that track and helps to keep it present. If we have too little or no attack, the transients are pulled down with the rest of the audio, and the track gets lost in the mix.
Leaving and maintaining some audio transients helps to create some punch in the mix for that track.
With that in mind, you typically want to leave somewhere between 1-10 milliseconds of attack time to let those transients through. Again, I talk specifics in my free compression cheat sheet, but that’s generally enough time depending on the track to maintain that punch and keep that track present in the mix.
As you might expect, the knee and attack work together to engage the compression. This is a reminder that all compression settings should be adjusted as a unit with the rest of the settings in mind to achieve the best results.
Release
The compressor’s release determines how quickly the compression disengages after the level drops below the threshold.
Setting this to 0 milliseconds, meaning instantly, creates an awkward and abrupt pumping effect which we generally don’t want.
50 milliseconds is a transparent off ramp to release that compression on most tracks, but you should experiment with this to find the sweet spot.
If you’re not sure, try the automatic release feature which works well with especially complex dynamic audio like I mentioned earlier.
Out
“Out” simply refers to the output level of your audio post-compression. The compression causes the gain reduction, meaning the track will sound quieter on the out.
As a result, we need to move this slider up to compensate for the gain reduction and ideally match the volume before the compression to maintain gain staging.
I put together an entire gain staging cheat sheet, but essentially the goal is to maintain roughly -18dB before and after the compressor and any other processing in our chain.
This generally yields the best level to feed into most plugins, not to mention it keeps the overall level of our mix from clipping.
Makeup
Like many compressor’s, the Ableton Live compressor features a “Makeup” gain feature which automatically adds back in the gain which was taken away in the compression process.
As I covered in my makeup gain overview, automatic makeup gain isn’t always preferable or effective in accurately matching the input level. As such, I generally leave this off and manually adjust the slider to match the level I had on the in.
Sidechain
Clicking on the arrow in the top left side of the compressor in Ableton Live brings up the sidechain menu, and clicking “Sidechain” engages this mode.
Sidechain compression refers to compressing the track with the compressor based on the behavior of a DIFFERENT track which you specify in the “Audio From” window:
I put together an entire tutorial on how to use Ableton sidechain compression, so refer to that for more information.
EQ
The EQ feature is also visible when you click the arrow. Clicking on “EQ” allows you to exclude certain frequencies from being compressed.
For instance, if you wanted to exclude everything below 100Hz from the compression, you’d click the high pass filter shape from the EQ filter types and set it at 100Hz.
This would ensure that only everything above 100Hz would be included in the compression and 100Hz and below’s peaks would be untouched.
Generally I don’t use this type of compressor when I only want to compress certain frequencies. In that case I’ll use a multiband compressor.
Dry/Wet
The dry/wet percentage determines the blend between compressed audio and uncompressed audio. While you can in theory use this to lessen the effect of the compression, you’re better off achieving that through the other settings. Plus there are better ways to use parallel compression.
Linear/Logarithmic
Linear results in less foldover or phase issues (extremely rare) in theory whereas logarithmic results in a more transparent compression. I recommend leaving this on logarithmic.
Expand
The “Expand” feature on the Ableton Live compressor allows you to do the opposite of compression, or expanding/increasing the level of your audio as it hits the threshold.
If your audio is a bit too flat in terms of dynamics, this feature will increase the small peaks you do have to create more dynamic range in your track. Note that you’re capped at a 2:1 ratio at max for expansion.
I did an entire overview of compression expansion in mixing, so check that out for more information.
Collapsed/Transfer Curve/Activity View
These three buttons toggle between the different views within the compressor.
Collapsed shows no detailed information in terms of a display outside of the gain reduction and input (relative to the threshold) and output levels.
Transfer Curve shows the bend and hard or softness of the knee.
Lastly, Activity View shows the gain reduction (below the flat line) in real time from second to second as the track plays.
One final time, the best way to know how to set your compressor is to download my free compression cheat sheet which details the exact settings to use (ratio, attack, release, etc.) with a unique chart on every single instrument in your mix.
