MBR - Explaining the reverb "tone" adjustment

MBR - The "tone" adjustment for reverb.

Natural reverberation occurs when sound bounces off the walls, floor, ceiling, and objects in the room. This reflected sound arrives at the listener's ears slightly later than the direct sound, causing a sort of echo. But, because there are many echoes of the original sound all arriving at closely spaced intervals, it's perceived as reverberation rather than discrete echoes.

Surfaces and objects do not reflect all frequencies equally. Smooth, hard surfaces such as glass or tile are good at reflecting high frequencies, while softer, rougher surfaces such as carpet or upholstery tend to absorb high frequencies rather than reflect them. The BR's reverb Tone control allows you to simulate this. It can boost or cut the high frequencies of the reverb signal by up to 12dB. However, it only affects the signal that's sent to the reverb (ie; the reflected sound, not the direct sound). So, if you have the reverb set to 10, for example, you probably won't hear much difference when you turn the Tone control. If you increase the reverb send value (try 100 for maximum effect), you should find that positive Tone values are bright (like in an empty gymnasium or church), while negative Tone values sound more dull (like in your living room, where carpets, drapes, and furniture absorb the high frequencies).

From "64Guitars"/microredorders.org/forum