Resolution, kernel sizes, and delays, 2 resolution, kernel sizes, and delays – Sonnox Oxford SuprEsser User Manual
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3.2 Resolution, Kernel Sizes, and Delays
3 OPERATION
3.2 Resolution, Kernel Sizes, and Delays
The linear-phase filters used by the Oxford SuprEsser require an ‘Impulse Response
Kernel’ to model the response of the internal Oxford Filters. The size of this kernel (as
measured in samples) determines both the plug-in delay and the accuracy of the model,
which in turn affects the performance, especially at lower frequencies.
Large kernels
Better performance at low frequencies, but longer overall plug-in delays
Small kernels
Adequate performance at high frequencies, and shorter plug-in delays
While small kernels are adequate for high frequency work such as de-essing, the
performance at low frequencies will cause poorly defined filter slopes, and poor
separation of ‘Inside’ from ‘Outside’.
We have found that host applications are generally not able to readily adjust their delay
compensation engines if the kernel size is adjusted dynamically at run time. The Native
Oxford SuprEsser is therefore released as three separate plug-ins; each with a different
fixed kernel size.
Oxford SuprEsser
This is the standard version, and has a kernel size of 2048 samples. This is suitable for
work across the entire frequency range at 44.1kHz sample rate, and thus is the standard
plug-in to reach for, especially for the mixing stage of a project. Depending on your audio
buffer size, the delay or latency will be somewhere in the region of 1044 to 3092 samples.
See the section below for information on reducing the delay.
Oxford SuprEsser HR/HighRes
This is the large kernel version, with a kernel size of 8192 samples. This version gives
superior resolution at the lowest frequencies, and thus is particularly suitable for low
frequency mastering work. Remembering that, as you increase the sample rate, the
resolution at the low end will be correspondingly reduced, this version is particularly
suitable for use at higher sample rates, especially 176.4kHz or 192kHz. This version will
have a very significant delay that can be beyond the ability of Pro Tools HD to
automatically compensate for. The true delay is reported correctly in the track delay
information, and depending on your audio buffer size, the delay will be somewhere in the