Operation, Signal processing overview, 3 operation – Sonnox Oxford SuprEsser User Manual
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3 OPERATION
3 Operation
3.1 SignalProcessingOverview
Basic SuprEsser signal flow
The Oxford SuprEsser contains a pair of mutually opposing filters — by default one is a
narrow bandpass filter, the other is the complementary narrow band-reject filter. This
results in one signal path containing just the contents of the band of interest, and another
signal path containing the input signal with this band entirely removed; when mixed back
together in equal ratios, you get the original signal.
The bandpass signal is usually fed to the compressor, both to the sidechain and to the
main signal path, so that it is just this signal that triggers gain reduction, and it is just this
signal that is affected by any gain reduction.
The bandpass/reject filters will switch automatically to other EQ types when conditions
warrant it, giving a total of four EQ types. For example, when the ‘Width’ control narrows
the bandpass filter to its minimum, a High-Q notch filter is invoked that provides a much
better reduction of a very narrow band of frequencies. When either side of the band
window touches the end stops (20Hz or 20kHz), the bandpass filters change to LF-Cut or
HF-Cut as necessary.