Sidechain compression is when you have two sounds linked, and one sound is being muted by the other sound.
For example when you side chain the melody to the kickdrum, when the kick drum is played the melody will be muted slightly. (depending on the compressor threshold and ratio settings)
What is the Difference?
If the audio compressor has a slow reaction time and high threshold, this can cause heavy compression.
If the audio compression has a fast reaction time and a small threshold, this can make light compression.
What is the Best Sidechain Compression Tip?
Light side chain compression is the preferred compression method with professional audio engineers.
Enable Sidechain and choose an input
In Ableton specifically, if you are using the default compression on a track you can just enable the ‘sidechain’. Next you can choose the source sound you want to sidechain or ‘duck the sound lower’ when the other sound is being played. So for example a good method is to always sidechain your melodies to the kick drum. To do this you just choose in the ‘audio from’ change that from ‘no input’ and choose your drums.
A threshold between -3 to -25 is the area you should be staying in. You can also crank up the ration from 2, to 5, 10 or 15 and this helps. If you do this also add a little ‘knee'(+3db) into it as well.
This is very important, for a quick sound like drums you want this to be a quick release around 1ms. For a crash sound or bang you want that to be a little more softer to that should be around 5ms + or more.
If you have a nice melody this should be in the range of 3ms to 6 ms. If you are mastering drums then an ideal attack would be around 1 or 2ms.
5 Best Different Types of Compression and How to Use Them
1. Multiband Compression/Limiting
Multiband compression allows one to affect the dynamic range of multiple frequency ranges independently of one another. Want to tame the beater of a kick drum without altering the low end? No problem. Simply choose a frequency range, and then set threshold, attack and release like you would on a normal compressor.
Practical applications: Master bus for clearing up problem areas like low-mid buildup, or on lead vocals to tame harshness in the 5-10k range.
Recommended plugins: FabFilter Pro-MB, iZotope Ozone 6, Waves L3-LL Multimaximizer
2. Lookahead Compression
Lookahead compression essentially analyzes an input signal and applies compression before the signal is audible, allowing one to tame transients in a unique way. Lookahead compression can be achieved with a standard compressor by duplicating the signal onto another track in your DAW, moving the audio back in time, placing a compressor on the original signal, and using the duplicated audio as the sidechain input.
Practical applications: Really anything with prominent, fast transients but especially effective on snare drum and vocals.
Recommended plugins: Softube FET compressor, Waves C1 Compressor with Sidechain
3. Brickwall Limiting
[Disclaimer] Learn how to mix before simply applying a brickwall limiter to the master bus of all your productions.
Although arguably the catalyst for the Loudness War, which stripped certain popular music of dynamics for over a decade, brickwall limiting certainly has its place in music production, live sound reinforcement and broadcast. Set the ceiling, and your signal will never go above it. Alter the threshold to bring the lower amplitude of the dynamic range closer to the top, allowing one to reach professional-level RMS without understanding professional-level mixing skills. [see disclaimer!]
Practical applications: Pre-mastering if used properly and mastering. Use on sub-auxiliary tracks to achieve higher RMS values before even hitting the master bus. Can be used on individual tracks to tame transients or shape tone just like a traditional compressor.
Recommended plugins: FabFilter Pro-L, Waves L2, PSP Xenon
4. Sidechain Compression or Ducking
A staple of the EDM production toolkit, the sound of a side-chained synthesizer and kick drum is instantly recognizable. Essentially, it involves using one signal to apply compression upon a another. There are plenty of online tutorials for this process, but the applications below may be ones you’re less familiar with.
Practical applications: Use the signal of vocals to duck drums or guitars to allow the vocal to sit more prominently in the mix, use a sample to replace or augment originally recorded cymbals, use a cowbell or tick sample rather than the kick to duck synth (due to the faster attack of the tick sound.)
Recommended plugins: Softube CL1B or Valley People Dyna-mite, Waves H-Comp or API 2500
5. Parallel Compression
Parallel compression (sometimes referred to as New York compression) is great for keeping the original, natural sound of a recording, while still enjoying the benefits of a compressed signal. Simply route your signal to an auxiliary track (via the sends, not output) apply compression, and blend in the aux track to taste. Be aware of delay compensation settings in your DAW to avoid unwanted phase issues.
Practical Applications: Very popular on drums or signals with harsh transients. Also great on the master bus for achieving a boost in RMS.
Recommended plugins: Certain plugins like Cytomic’s The Glue or FabFilter’s Pro-L allow for a dry/wet blend which can achieve similar results to parallel, but any of your favorite compressors can achieve great results if used properly.