General Reverb
From WikiRecording
Reverb (short for Reverberation) is any sound that is not directly being picked up. If you place a microphone in a room you will pick up the direct sound waves going directly forward into the microphone, as well as millions of other sound waves (basically millions of echoes placed so closely together they aren't distinguishable entities to themselves) that bounced off the floor, wall, ceiling, mic stand etc. This is the reverberation. Reverb time is the time it takes a sound in the room to decay by 60db. Reverb consists of various parts. Air and room surfaces absorb high frequencies so reverb time should be shorter for the higher frequencies, alot of reverbs either allow you to put a general HF cut/low pass filter or to adjust reverb time of different frequency ranges
Predelay: is the time before the first reflections. A small room will have virtually none because sound travels roughly a foot per ms so the early reflections will be hitting almost instantly. so a small vocal booth technically might have 3-8ms of predelay. but a large hall might have a long predelay.
Pre-echoes: early distinct echoes before the reverb becomes too diffused to distinguish individuals reflections.
Reflections: these later reflections have bounced off more surfaces and are more diffused yet lower in volume.
The main types of reverb effects or emulators are:
Spring Reverb
Plate reverb
Digital Reverb
Convolution Reverb
