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Chapter 13 Space Designer convolution reverb 255
Use Space Designer’s predelay feature
Predelay is the amount of time that elapses between the original signal and the initial early
reections of the reverberation. For a room of any given size and shape, predelay is determined
by the distance between the listener and the walls, ceiling, and oor. Space Designer allows you
to adjust this parameter over a greater range than what would be considered natural.
m To set a suitable predelay time, rotate the Pre-Dly knob.
The ideal predelay setting for dierent sounds depends on the properties of—or more
accurately, the envelope of—the original signal. Percussive signals generally require shorter
predelays than signals where the attack fades in gradually, such as strings. A good rule of thumb
is to use the longest predelay possible before undesirable side eects, such as an audible echo,
begin to materialize.
In practice, an extremely short predelay tends to make it dicult to pinpoint the position of the
signal source. It can also color the sound of the original signal. On the other hand, an excessively
long predelay can be perceived as an unnatural echo. It can also divorce the original signal from
its early reections, leaving an audible gap between the original and reverb signals.
These guidelines are intended to help you design realistic-sounding spaces that are suitable for
various signals. If you want to create unnatural sound stages or otherworldly reverbs and echoes,
experiment with the Pre-Dly parameter.
Change the impulse response start point
Using the IR Start parameter aords a number of other options that can be quite creative,
particularly when combined with the Reverse function. See Space Designer button bar on
page 244.
Note: The IR Start parameter is neither available nor necessary in Synthesized IR mode, because
the Length parameter provides identical functionality.
m Rotate the IR Start knob to shift the playback start point of the impulse response.
This eectively cuts o the beginning of the impulse response, which can be useful for
eliminating level peaks at the start of the impulse response sample.