Sidechaining is a technique in which you "duck" or lower the volume of one element as another element is playing. The most usual thing you want sidechained in your productions is the bass everytime the kick hits.
Sidechaining between kick and bass is done because of the similar frequency content in both the kick and the bass. When these two clash together, the bottom end sounds like one big mess. This is why "kick holes" (which sounds amazing btw) is necessary.
But sidechaining isn't limited to just these two elements. Some producers like to sidechain all elements to the kick, which gives the whole track that typical "pumping" house type of feel. Others like to not sidechain anything at all.
There are also other techniques to use sidechaining for. For example, you can duck some frequencies in a lead synth everytime the vocals are playing. You can also sidechain a reverb bus to the element that is using the reverb, to get a cleaner mix.
Whatever your production style is, it's really important that you at least know of this technique.
The fruity limiter inside FL Studio can do lots of things. Sidechaining is one of them.
In this example, we will sidechain our bass to our kick.
Start by sending a sidechain signal from the kick channel to the bass channel.
Okay, now we have the sidechain signal going. Let's open up a Fruity limiter on the bass channel.
At the bottom of the Fruity limiter you will see a couple of tabs called LIMIT and COMP. These are the limiter and compression parts of this limiter.
There are lots of knobs and settings that might be a bit confusing, but don't worry about all of them right now.
If you now press play, you probably won't see or hear any difference. This is because we need to set a threshold and a ratio.
Now you will see the ducking begin. Try fiddle around a bit with the THRES and RATIO knob to taste. The feel changes depending on your settings and volumes.
The Attack and Release knobs will change how the sidechaining affect the sound. A faster attack will keep the transients of the element that causes the ducking, and a longer release will create a bigger pump effect.
Make sure not to have the release too short, because this will cause distortion.
This is my favorite. Automation clips can be customized into the smallest details and shaped exactly how you want them. The downside is though that you have to place them out manually in the playlist everytime you want a sound to be sidechained.
We'll keep the same kick + bass example for this one.
Now go into your playlist and place out your patterns. Shape your automation clip how you want it to be shaped. Here's an example:
As you can see, the bass channel is ducking everytime the kick hits. You can shape the ducking exactly down to the smallest details. Let me show you another shape:
That looks a bit weird, I know. It's just to show you how it could look.
Kickstart has been a very popular plugin in the producer community, and for good reasons. You can simplify the process and get amazing results with only one plugin.
There's really not much more to it.
The downside to this method is that if you're making music that doesn't follow the 4-to-the-floor type of beat, you have to fiddle a bit with the settings. Then it becomes almost like the sidechain compression method, since you need a trigger channel that triggers Kickstart.
I hope you found some information worth reading in this posts. Let me just show you the amazing illustration of the kick holes again.