What Depth is doing
The Depth module takes the delay's repeats and feeds them into a diffusion and spatial processor. Instead of hard, countable echoes you get something that dissolves: the repeats smear into atmosphere.
That is the useful distinction. A delay puts a copy of the vocal somewhere later in time. Depth stops you noticing that it is a copy.
The five engines
| Engine | Character | Reach for it when |
|---|---|---|
| Room | Early reflections, subtle ambience | The delay needs to feel like it is in the same space as the vocal, not a different one |
| Hall | Deeper sense of space, significant depth | You want obvious space and the arrangement has room for it |
| Plate | Brighter, crisper reflections, noticeable length | The vocal needs to stay forward and bright while the repeats still spread |
| Huge | Enormous spatial depth, momentum and glue | You want the track to feel bigger, not just wetter |
| Ether | Shimmer-style, long angelic evolving tails | You want drama, or a pad that was not played |
Ether deserves its own note. It is a shimmer algorithm: the tails rise and evolve rather than simply decaying, which makes it the most dramatic of the five and the easiest to overdo. Used heavily it is an effect the listener notices. Used subtly, low SPACE, it puts a beautiful shine underneath an instrument that nobody can point at.
The habit worth breaking
Most people reach for Hall, hear "bigger", and stop.
In a dense arrangement that is usually the wrong call. Hall and Huge fill space, and in a busy mix the space is already full, so the result is a vocal that sounds further away rather than deeper. Room and Plate are the ones that work in crowded mixes, because they add dimension without occupying much room.
The test: solo the vocal with the delay and it will sound wonderful on any engine. Put the mix back in and ask whether the vocal moved back. If it did, go smaller.
SPACE and LENGTH
Two controls decide how much of any engine you get.
SPACE sets the amount. It has a threshold worth knowing: above 50 percent the repeats go soft enough that the sound stops being a delay with reverb on it and becomes a hybrid, somewhere between a delay and a reverb. That is a genuinely different effect, not just more of the same. Below 50 percent you hear repeats with space around them; above it, you hear a texture.
LENGTH stretches or shortens the space to fit the song. A long tail on a fast song is mud, and the fix is usually LENGTH rather than turning SPACE down.
Depth changes how much feedback you need
This is the part that catches people.
Every engine adds perceived sustain. A feedback setting that sounded right on Room will sound like far too much on Huge or Ether, because the tail is now carrying on long after the repeats themselves have stopped.
So when you switch engines, revisit FDBK. Going bigger almost always means going down. Ether and Huge with high feedback is also the combination most likely to run away entirely, for the reasons in why the delay sometimes runs away.
One more interaction: gating happens before the Depth module. That means SPACE will smooth out an aggressive hard gate, which is the trick for very long delays that still need to stay clean.
A starting point
If you are not sure, start here and adjust:
- Dense mix, vocal needs to sit forward: Plate, SPACE around 25 percent, short LENGTH.
- Sparse arrangement, want obvious depth: Hall, SPACE 40 to 60 percent.
- Want the track to feel bigger overall: Huge, low SPACE, and pull FDBK back from wherever you had it.
- Want drama or a pad: Ether, and start lower than feels right.
- Want it to sound like one space, not two: Room.