Multiband processing is
the process of splitting the incoming audio signal into frequency
'bands'. For example, a bass band, a mid-range band and a high
band. Once the signal has been split into individual bands,
some form of processing (such as equalization or compression) is
applied to each band. The advantage of this approach is that
the effect can be maximized across the full frequency spectrum of
the input material. For example, in the case of compression,
compressing an entire mix may result in 'pumping' where a loud kick
drum could cause compression of the entire mix. But with
multiband compression, this effect is minimized, because the level
of mid-range and high frequency instruments are not dragged up and
down with the higher volume low band signals.
Although the DADEV
Multicomp is no longer available, it's graphical layout provides a
perfect example of the concept of multiband operation.
The Threshold, Ratio, Attack and Release of the three frequency
bands layered one on top of the other, with 'Low' at the bottom and 'Hi'
at the top.
Each band has an analog style meter showing the
output level or gain reduction.
The cutoff frequencies of the three bands
are controlled by the 'Low Pass' and 'Hi Pass' knobs.
As with many multiband processors, it is
possible to solo or mute individual bands, so that the
parameters of each band can be tuned individually.
There is a final 'Limiter' control to
contain the overall level of the output signal if required.