Sidechaining is a technique that was made popular in EDM genres that allowed for a signal to be directly affected by another signal from a separate track.
Typically, this was used to lower the volume of the bass whenever the kick drum hit. This is useful for taming two sounds that simultaneously play together and share the same frequency range. Because low-end frequencies carry the most energy, these sounds will clash with each other, creating unpleasant phasing and making the low end less powerful than before.
In FL Studio, there are many ways to achieve this. But the 3 best ways are through Fruity Limiter, Fruity Peak Controller and good ole’ automation.
Starting with Fruity Limiter, add it to the track you want to duck out of the way. So in the example, we went over, you will add this to your bass track. Select your kick track, right click on the bottom arrow of the bass track and select “sidechain to this track.” Now the kick is routed to your bass track without any volume being sent to it. However, when you open up Fruity Limiter on your bass track, you’ll now have the option to select your kick track from the sidechain option at the bottom of the limiter. Set the attack to the beginning to immediately duck the bass. Use short release times to allow the bass to come back in soon after the kick hits. Adjust the threshold, knee and ratio according to how much you want the bass to lower in volume.
You’ll probably notice that completely ducking the bass isn’t the best option. Instead, you’ll want to simply tame the level of the bass so that it sounds “glued” to the kick after it plays. You’ll visually see how much of the bass is ducking, but always use your ears to make your decision.
Fruity Peak Controller will do this without compression. Add Peak Controller to your kick instead of the bass. You’ll have to mute and unmute Peak Controller to hear your kick still playing. Some people will have a “trigger kick” instead of their actual kick. In those instances, you’ll want to leave the kick muted so you don’t hear it playing in the track. Now, select the volume fader of the bass track. Another option would be to add fruity balance or any plugin with a volume knob or slider. Right click on the volume control of your choice on the bass track and select “Link To Controller.” Select Peak Ctrl – Peak under Fruity Peak Controller in the menu. Right-click the volume control on your bass track and copy that setting. Now right click and paste that onto the “Base” knob of Peak Controller. That way your initial peak setting is equal to the level you want the bass to be at when it’s at full volume. Use the volume knob in Peak Controller to adjust how far you want to duck. You’ll notice the volume will duck when you turn the knob to the left and actually increase when you turn to the right. Use the tension and decay knobs to regulate the speed of the ducking.
Last, but not least, is volume automation. This is probably the most tedious of the three options, but it has the most control. The good news is, you can do this directly in the playlist and don’t have to worry about linking or routing anything. Simply right-click the top left corner of the audio track you want to duck. Go to the Automation section and select Volume. If you’re working with MIDI, you can right-click the volume knob, fader or use the Levels Adjustment volume knob in the channel settings and create an automation clip from there. The playlist will create an automation clip where you can draw in the perfect curve for your volume control. Now you copy and paste that automation in the places where the kick hits. This can be time-consuming if you’re using more complicated kick patterns. But in the end, it might be worth the extra effort to be able to draw in your exact volume control.
Personally, I find the first two options more than enough for my style of production. Either way, this should give you plenty of options for sidechaining in your FL Studio projects.