How to Use Pre-Delay

A guide to mixing music - Part 67

Now that you've chosen the best reverb presets, the time has come to tinker with the parameters so you can adjust them to best fit your needs. In this article, we'll focus on a very important reverb parameter: pre-delay.

Keep your distance

For those of you who don't know what I'm talking about, here's the short version: pre-delay is the parameter that determines the elapsed time between the direct and reverberated sound, usually expressed in milliseconds. Do note however that, depending on the plug-in, this setting adjusts the time between the source signal and the reverb as a whole or only between the source and the diffused sound field. But there's no need to rack your brains about it, since this difference will have only a very slight impact on the end result.

Why is pre-delay so important during mixdown? Well, among other things, pre-delay provides information to the listener about the size of the room. Thus, a long pre-delay suggests a large room while a shorter pre-delay hints at a smaller space.

On the other hand, this setting directly affects the sensation of distance between the listener and the signal producing the reverb. But be careful, contrary to what you might think, the longer the pre-delay time, the closer the signal seems to be. Although it seems a bit counterintuitive, if you think about it, it's pretty logical. Indeed, if a sound is emitted close to you, the time difference between direct and reverberated sound is bigger because it obviously takes more time for sound to reach the walls, be reflected and get back to you. So, to make an element of the mix seem farther away, make its reverb pre-delay shorter and if you want to make it seem closer, make the pre-delay longer.

Here are some warnings regarding the use of this parameter. First of all, a pre-delay above 50ms will harm the natural character of the reverb. Which isn't necessarily a bad thing, but you should keep it in mind. On the other hand, a very short pre-delay can have disastrous results, like the loss of intelligibility (which can be extremely disturbing for vocals) or the alteration of the timbre, considering that the mix of direct and reverberated sound can lead to comb filtering (something I already I told you about here.

Also note that a pre-delay time set according to he tempo of the song will help the reverb blend into the mix more naturally, since it breathes in rhythm with the groove of the song. This is especially true for purely rhythmic elements, like drums, percussion, bass or even rhythm guitars, but also for rap vocals, for instance.

Next week we'll tackle another parameter that is just as crucial, namely reverb time.