A fundamental question about pre-delay....

[144dB]

Hey all,

 

I was going to mock up a fancy diagram, but I think I can ask this question with a simple word-based example. This has always eluded me about pre-delay on reverbs, etc.

 

Let's say that you record the words "Doh - Re - Mi" into a DAW or recorder.

 

If you slap a reverb on it with no pre-delay, all of the words, syllables, consonants, vowels, etc. will get reverberation.

 

If I now put a 50 millisecond pre-delay on that reverb, does "Doh" get reverberated in full but 50 milliseconds late, or does "oh" get reverberated and the "D" get dropped altogether?

 

In other words, does pre-delay delay the reverberation of the full passage, or does it delay the onset of the reverb, which then omits certain elements of the sound (for example, the attack transients only)?

 

I suppose I could set up a quick experiment to confirm, but I'm sure the board will have the answer.

 

Thanks in advance.

[MikeRivers]

The reverb always does what it does, it just starts later. So, yes, all of your syllables get the same reverb as with no pre-delay, just a little later.

 

Pre-delay, which may be built into many reverb 'programs', represents the time it takes for a sound to get from the source to the first reflecting surface, which starts the reverberation. In practice, it prevents the reverbation from covering up the first part of a sound.

[Phil O'Keefe]

Predelay only effects the reverb... if you add 50ms of predelay, the reverb will come in 50ms after the sound that triggered it. Every syllable will still trigger the reverb, just like it would with no predelay - but with predelay added, the onset of the reverb will occur slightly after whatever triggered it.

[philboking]

It's good for staging the 3rd dimension of panning: depth

Each millisecond of predelay moves the source away from the listener by about a foot.

As long as you don't get too crazy with it... Delays aren't perceived as such if you stay under 20 or 30 milliseconds.

 

I should correct this a bit: predelay by itself won't add depth on a reverb since it is mixed with the dry (and undelayed) source signal. But a fixed delay in a given track can do it.

[144dB]

Thanks guys. I did a quick experiment with a snare sample, and your feedback is all correct. It's funny how you can't always hear the delay (for example, the initial crack of the snare), given the relatively low level of reverb that is typically used. But it does provide breathing room for the original sound, and I'm going to experiment with this more in my mixes.

[Phil O'Keefe]

Thanks guys. I did a quick experiment with a snare sample, and your feedback is all correct. It's funny how you can't always hear the delay (for example, the initial crack of the snare), given the relatively low level of reverb that is typically used. But it does provide breathing room for the original sound, and I'm going to experiment with this more in my mixes.

 

Predelay is a really useful tool. Don't forget to also play with the early reflection parameters in your reverb plugin too - they can also be very useful; reverb doesn't hit "full bore" from the onset. You hear those initial early reflections first, then the reverb blooms and develops from there.