Sidechain compression is arguably the most essential mixing technique in electronic dance music. That signature pumping effect, where pads, basses, and synths duck in time with the kick drum, is what gives EDM its rhythmic pulse and energy. Whether you are making house, techno, trance, or dubstep, understanding sidechain compression will transform how your mixes feel and move.
What Is Sidechain Compression?
In standard compression, the compressor reduces the volume of a signal based on that same signal's level. Sidechain compression works differently. Instead of using the signal itself as the trigger, you feed a separate signal, usually the kick drum, into the compressor's sidechain input. When the kick hits, the compressor clamps down on whatever audio is passing through it, creating that characteristic ducking effect.
This technique serves two purposes. First, it creates rhythmic movement that locks your mix to the groove. Second, it provides frequency separation between the kick and bass, ensuring the low end stays clean without static EQ cuts.
Setting Up Traditional Sidechain Compression
The classic approach uses a compressor plugin on the track you want to duck, with the kick routed to the compressor's sidechain input. Start with these settings as a baseline: set the ratio to 4:1 or higher, the attack as fast as possible, the threshold low enough that every kick triggers compression, and the release between 100 and 300 milliseconds depending on your tempo.
The release time is the most critical parameter. It controls how quickly the signal comes back up after the kick hits. Too short and the ducking is barely noticeable. Too long and the signal stays ducked through the next beat, killing your groove. Aim for the signal to fully recover just before the next kick hits for that smooth pumping feel.
Volume Shaping Plugins: The Modern Approach
Many producers have moved away from traditional sidechain compressors in favor of volume shaping tools like LFOTool, Kickstart, Trackspacer, or Shaperbox. These plugins let you draw custom volume curves that trigger in sync with your DAW's tempo, removing the need to route a sidechain signal entirely.
The advantages are significant. You get perfectly consistent ducking on every beat, complete visual control over the shape of the curve, and the ability to create complex rhythmic patterns that would be difficult to achieve with a compressor. For most EDM production, these tools have become the standard approach.
How Much Ducking Is Enough?
The amount of gain reduction depends on the genre and the effect you want. For subtle, transparent mixing, aim for 3 to 6 dB of ducking. This is enough to keep the kick and bass separated without an obvious pumping effect. For classic progressive house or trance pumping, go heavier with 8 to 12 dB of ducking. For extreme French house or electro-style effects, you might push past 15 dB for dramatic, audible pumping.
What to Sidechain
The bass is the most obvious candidate for sidechaining, but the technique works on many elements. Pads and chords benefit enormously from sidechain compression, creating space for the kick while adding rhythmic movement. Reverb and delay sends can be sidechained to prevent wash and buildup on kick hits. Even entire mix buses can be lightly sidechained to give the kick priority across the full frequency spectrum.
The only elements you typically do not sidechain are the kick itself, hi-hats, and lead elements that need to stay consistent in volume.
Multiband Sidechaining for Precision
Standard sidechain compression affects the entire frequency range of the signal, which is not always desirable. Multiband sidechaining lets you duck only the low frequencies of a bass synth when the kick hits, leaving the upper harmonics untouched. This gives you clean low-end separation without affecting the brightness and presence of the bass sound.
Many modern plugins support this out of the box. Set the sidechain to affect only the band below 150 to 200 Hz, and you will get transparent, professional-sounding separation that does not sacrifice your bass tone.
Common Mistakes to Avoid
Over-sidechaining is the most frequent mistake. When every element in your mix pumps aggressively, the track loses its dynamics and becomes fatiguing. Be selective about what you sidechain and how much ducking you apply. Another common error is using sidechain compression as a substitute for proper arrangement and frequency management. If your kick and bass are clashing, sidechaining can help, but proper layering, EQ, and arrangement should be addressed first. Finally, watch out for sidechain artifacts like clicking or pumping that sounds unmusical. Adjust your attack and release times until the ducking feels smooth and natural.
Putting It All Together
Sidechain compression is not just a mixing technique. It is a creative tool that defines the feel and energy of electronic music. Start with the basics, a compressor or volume shaper ducking the bass with the kick, and expand from there as your ears develop. The goal is always to serve the groove. When sidechain compression is done right, you do not hear it as an effect. You feel it as movement.
