Apple Logic Express 7 - Manual (Page 63)

Chapter 9 Reverb 63
Density
This parameter controls the density of the diffuse reverb. Ordinarily, you want the
signal to be as dense as possible. However, less Density means the plug-in eats up less
computing power. Moreover, in rare instances, too great a Density can color the sound,
which you can fix simply by reducing the Density knob value. Conversely, if you select a
Density value that is too low, the reverb tail will sound grainy.
Diffusion
Diffusion sets the diffusion of the reverb tail. Sometimes, the terms “diffusion” and
“density” are confused. The density is the average number of reflections in a given
period of time. The diffusion is the amount of irregularity of the density. High values of
diffusion represent a regular density, with few alterations in level, times, and panorama
position. At low diffusion values, the reflection’s density becomes more irregular and
grainy. The stereo spectrum changes, too.
Note: The Diffusion parameter is only available if you activate the 001/011 button in the
plug-in header.
Reverbtime
Reverbtime is commonly considered as the amount of time it takes for the level of a
reverb signal to drop by 60 dB. This is why the reverb time is often indicated as RT60.
Most natural rooms have a reverb time somewhere in the range of one to three
seconds, a value which absorbent surfaces and furniture reduces. Large empty halls or
churches have reverb times of up to eight seconds, some cavernous or cathedral-like
venues even beyond that.
High Cut
Uneven or absorbent surfaces (wallpaper, wood paneling, carpets, and so on) tend to
reflect lower frequencies better than higher frequencies. The High Cut filter replicates
this effect. If you set the High Cut filter so that it is wide open, the reverb will sound as if
it is reflecting off stone or glass.
Spread
This parameter controls the stereo image of the reverb. At 0%, the plug-in generates a
monaural reverb, at 100%, the stereo base is artificially expanded—which, of course,
makes the reverb sound monumental, but collapses in monaural playback.