How to Sidechain a Delay (Ducking): Loud Echoes, Clear Vocals

The short answer: sidechaining a delay (also called ducking) means putting a compressor on the delay return and triggering it from the dry vocal. While the singer is singing, the compressor pushes the echoes down; the moment they stop, the echoes swell back up into the gap. You get big, long, obvious delays that never blur the words, which is how modern records sound so wet and so clear at the same time. Start with a ratio of 4:1 to 6:1, a fast attack, a release of 100 to 250 ms, and 4 to 8 dB of gain reduction while the vocal plays.

I duck almost every vocal delay and many vocal reverbs in my own mixes (Sony, Universal, Ultra, Dim Mak). It's one of the highest-impact, least-known moves in vocal mixing.

How it's routed

Order on the return: delay first, then an EQ (high-pass around 250 to 400 Hz, low-pass around 5 to 8 kHz), then the sidechained compressor last so it controls the whole echo signal.

Step by step in your DAW

Ableton Live: on the delay return, add Compressor after the delay. Open its sidechain section, enable it, and set Audio From to the vocal track. Lower the threshold until you see 4 to 8 dB of gain reduction while the vocal plays.

Logic Pro: on the delay aux, insert Compressor after the delay. At the top right of the plugin window, set Side Chain to the vocal track (or its bus). Pull the threshold down until the echoes duck under the vocal.

FL Studio: route the vocal's mixer track to the delay's mixer track using "Sidechain to this track" (right-click the arrow at the bottom of the mixer strip). On the delay track, add Fruity Limiter in compressor mode after the delay, and set its sidechain input to the vocal's number.

Some delay plugins have a built-in ducking control that does the same thing in one knob. If yours does, try it first.

Starting settings

• Ratio: 4:1 to 6:1. Higher is more obvious; lower is subtler.
• Attack: fast (1 to 10 ms), so echoes duck the instant the vocal starts.
• Release: 100 to 250 ms. Tune it to the tempo so echoes swell back in with the groove; a beat or an eighth note from the delay time calculator is a good starting point.
• Gain reduction: 4 to 8 dB while singing. Then raise the delay send louder than feels normal. That's the payoff.

The same trick for reverb

Ducking a vocal reverb from the dry vocal keeps long, lush tails from masking the words. Combine it with tempo-synced pre-delay and the vocal stays dry and upfront while the space blooms in every pause. Ducking also lets you get away with more width from stereo delays, but always check the result in mono.

Where it fits

Ducked delays are part of the space stage of a vocal chain. The delay times themselves (dotted eighth, quarter, slapback) are covered in how to use delay on vocals and the dotted eighth delay guide.

Quick answers

What does it mean to sidechain a delay? A compressor on the delay return is triggered by the dry vocal, so the echoes get quieter while the vocal plays and louder in the gaps.

Why duck a delay? So you can use louder, longer delays without them blurring the words. It keeps vocals clear and wet at the same time.

What compressor settings should I use for ducking? Around 4:1 to 6:1 ratio, fast attack, 100 to 250 ms release, and 4 to 8 dB of gain reduction while the vocal is active.

Can I sidechain a reverb the same way? Yes. Same routing on the reverb return, triggered by the dry vocal. It's one of the cleanest ways to use big vocal reverbs.