Bitrness Effects - Alesis ModFX Bitrman Reference Manual

Bitrness Effects

Because of the unique digital signal processing used inside the
Bitrman, Alesis engineers were able to include a family of effects
that take effects processing to a whole new level. These effects
process the input in unique, striking ways that have to be heard to
be understood. So, we put them under the common control
[BITRNESS], and you can select any of these following effects
using the Bitrness rocker switch.
What is Comb Filtering?
A comb filter is a kind of equalizer with several steep notches or
nodes in its frequency response. If you've ever mixed a slightly-
delayed signal with an original, you've heard a comb filter. The
[BITRNESS] control sweeps this comb filter across the frequency
band so you can lock it in any part of the spectrum you want. As
you turn the knob, the notches also spread apart from each other.
Unlike the other effects, however, when the Bitrman is in
COMB mode, the filter is always in the path—the [BITRNESS]
control affects the frequency of the filter only, not the amount of
filtering applied to the signal.
What is Decimation?
The Decimator is a unique kind of distortion/modulation that can
twist any input signal into something else entirely...i.e., decimate it.
It adds weird multi-frequency nonharmonic aliasing distortions to
the signal, somewhat like Ring Modulation (see below), but more
as a distortion effect than a harmonic effect. But while the
[DISTORT] feature sounds like overdriven electronics,
DECIMATOR sounds like digital satellite or cell phone distortion.
The [BITRNESS] control increases the amount of decimation; at
high settings there are so many distortions the original signal
disappears into the effect.
Using the Bitrman
Tec hn ic a lly, th e
D ECIMATO R lo wer s th e
s ig na l' s s am p ling fr eq ue n cy
witho ut lo we r in g th e
a ntia lia sing filter . This
m ea ns th at m irr or r e flec tio ns
o f th e o rigin al fre q ue nc y
( "a lias e s") a re c re a te d in th e
s ig na l, ad din g cr un c h an d
b uz z. Try this with a d rum
m ac hine fo r a s pe cia l effe c t.
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