Lexicon MX500 Owner's Manual page 30

Effects Descriptions
Mid RT and Decay
Controls the amount of time the reverb can be heard. Higher settings increase reverber-
ation times which are usually associated with larger acoustical environments, but can
decrease intelligibility. Lower settings shorten reverb times and should be used when a
smaller apparent space or a more subtle effect is desired.
Diffusion
Controls the initial echo density. High settings of Diffusion result in high initial echo
density, and low settings cause low initial density. In a real-world situation, irregular
walls cause high diffusion, while large flat walls cause low diffusion. For drums and
percussion, try using higher Diffusion settings.
Shape & Spread
In the Hall reverbs, Shape and Spread work together to control the overall ambience
of the reverberation. Shape determines the contour of the reverberation envelope.
With Shape all the way down, reverberation builds explosively, and decays quickly. As
Shape is advanced, reverberation builds up more slowly and sustains for the time set
by Spread. With Shape in the middle, the build-up and sustain of the reverberation
envelope emulates a large concert hall (assuming that Spread is at least halfway up,
and that Size is 30 meters or larger). Low Spread settings result in a rapid onset of
reverberation at the beginning of the envelope, with little or no sustain. Higher settings
spread out both the buildup and sustain.
Size
Size sets the build-up rate of diffusion after the initial period (which is controlled
by Diffusion). The Size control changes reverb sound from very large to very small.
Generally, set this control to the approximate size of the acoustic space being created,
before adjusting anything else. The size in meters is roughly equal to the longest
dimension of the space. Audio is temporarily muted when Size is changed.
RT High Cut
Rt HC sets the frequency above which a 6dB/octave low-pass filter attenuates the rever-
berated signal. It does not attenuate the reflections. High frequencies are often rolled
off with this parameter, resulting in more natural-sounding reverberation. Setting a
low frequency for this parameter can actually shorten the reverb time, as it damps the
audio as it recirculates.
Liveliness
Adjusts the amount of high frequency content in the reverberation tails. Higher settings
increase high frequency response, creating brighter reverbs; lower settings create darker
reverbs with more bass frequency emphasis.
Bass Boost
Bass Boost boosts or cuts frequencies below Crossover. The amount of boost or cut
required is highly dependent on the material being processed.
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