The next setting to consider is diffusion. Diffusion is dependent on the ability of the surface to reflect sounds in different directions. In a reverb plugin, this allows you to adjust the smoothness of a reverb. It’s a parameter that varies greatly depending on the reverb plugin used. Some plugins use less CPU when the density is brought down, but often at the expense of realism. However, this can work well for shorter, more percussive elements.
This is how it should be:
In The Air
For the toms let’s try something a little less obvious – a setting that adds ambience, but that doesn’t relate directly to the real world. So-called non-linear reverb programs tend to have unusual characteristics in terms of the way the reverb builds or decays.
Here we have a non-linear program that has a sharp and unnatural decay:
This is often referred to in reverb processors as ‘gated’ reverb as it sounds very similar to the effect of placing a noise-gate (triggered in this case by the level of the toms) across a reverb output (think of Phil Collins’ ‘In The Air Tonight’ for the classic example of this sound). However, some processors allow you to tweak the attack as well:
Non-linear reverb effects can also work well on snares:
The great advantage of these non-linear reverb treatments is that they provide a dense burst of reverb but don’t linger too long and smother other areas of the mix.