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| WaveWarp 2.0 Component
      
Reverbs:
Functional Description
Bank of six parallel comb filters with built-in low-pass elements,
for use as a reverberator
according to the design in
[Moorer2]
(based on the ideas of Schroeder).
Algorithm
A verbatim implementation of
a parallel bank of six filters of
the type shown in Fig. 5 of
[Moorer2].
The transfer function, T(z), of each is given by:
| T(z) = z-m /(1 -g2 z-m -g1g2 z-(m+1)) |
where the delay, m, and gains, g1 and g2, for each filter
are adjusted via the Parameter Window, as summarised in the
following table.
| Parameter | Purpose |
|---|
| "Reverb time" slider |
Adjusts the overall reverberation time of the
bank of comb filters. From the value of this slider, denoted T (in seconds),
the quantity denoted g in
[Moorer2]
is given by: g = 1 - 0.366/T, according to the
approximate curve-fit in Fig. 13 of
[Moorer2] .
The six delays, m, and low-pass gains, g1, are interploated
from the data listed in
Table 2 of [Moorer2],
which was obtained from a series of
optimizations
designed to match the model filter frequency reponse with measured data.
Finally, the six comb gains, g2, are obtained from the
value of g given above, and the six low-pass gains, g1, according to
the following formula
(from [Moorer2]): g2= g (1-g1).
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The delays are implemented using circular buffers.
For more information on
room acoustics and
reverberation, see, for example:
[Roa] p. 477-492,
[Moore] p. 370-394,
[Ros]p. 459-493,
[Be] p. 172-222,
[Zo] p. 181-205,
plus various articles in
[AES8]
and
[AES16].
Signal Implementations
| Audio signals | Control signals | Description |
|---|
| Single input single output mono-mono | n/a | The mono audio input is filtered and sent to the mono audio output. |
| Single input single output mono-stereo | n/a | The mono audio input is filtered and sent (in duplicate) to the stereo output channels. |
| Single input single output stereo-mono | n/a | The stereo audio input channels are averaged, then filtered and sent to the mono audio output. |
| Single input single output stereo-stereo | n/a | The stereo audio input channels are are averaged, then filtered and sent (in duplicate) to the stereo output channels. |
Related components:
Example DrawingBoards illustrating usage:
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