Sonnox Oxford SuprEsser

De-esser plugin

Sonnox Oxford SuprEsser De-esser plugin

Review by George Shilling

New from Sonnox is the Oxford SuprEsser, designed to be “the last word” in De-Essing. A number of plugin designers have recently turned their attention to de-essing, and there are some excellent alternatives, but Sonnox’s new release avails the user of more control parameters than any rival. The busy plugin window features a whizzy real time graph display; there is a ‘More’ button revealing extra parameters, and a further hidden preference menu. Unlike traditional hardware de-essers, the full audio frequency range is selectable, resulting in the possible application of this plugin for all kinds of frequency-conscious or broadband dynamic processing.

The SuprEsser comes as a native-only plugin in VST, Audio Units and RTAS formats. There is no TDM or PowerCore version, nor is there planned to be. Sonnox are at pains to point out that this is not a policy decision signalling the end of TDM or PowerCore support, but merely a technical decision, as the processing used by the SuprEsser is too complex to implement on fixed-point DSP.

Three versions of the plugin are installed, each set up to use varying Kernel sizes. The linear phase filters require a processing time – an ‘Impulse Response Kernel’ to model the filter response. So there is a trade-off between the accuracy of the low frequency processing and the plugin delay. The three different versions of the plugin have different preset kernel sizes, so it is up to the user to choose the appropriate setting. The standard version uses a kernel size of 2048 samples, and it is recommended to use a similar sized buffer to lower the plugin delay. Lowering the buffer too much is claimed to cause problems as the plugin won’t have big enough blocks of audio to process, but in practice I didn’t find a huge problem with lowering the buffer, although a ‘Warning!’ indicator appearing at the top of the plugin.

The standard version is suitable for working on the entire frequency range at 44.1kHz, but for high sample rates the high resolution version is recommended, which exhibits an enormous kernel size of 8192 samples. There is also a ‘low latency’ version which is set for 512 samples. However, this is unsuitable for low frequency accuracy below 400Hz. And the other problem caused by such sophisticated processing is that the SuprEsser uses an enormous amount of CPU power, so depending on your computer and what else is taxing the CPU, one might be limited in the number of instances or which of the three versions you can use, or find that one needs to further increase the buffer… This soon leads to the high resolution version causing the accumulated delay to go beyond the capabilities of the Pro Tools delay compensation engine, although the actual delay is accurately reported in the track delay information.

SuprEsser utilises the excellent Oxford Dynamics processor, adding two linear phase crossover filters to enable complete control of a particular area of the frequency range. The signal is split into the band to be processed and the surrounding bands which are not processed, then these are re-merged with appropriate delay compensation within the plugin, and one can select monitoring of either path (‘Inside’ or ‘Outside’) separately for checking purposes, as well as the intended mixed output.

Despite the processing complexity, it is fairly easy to set the de-esser for normal function thanks to the excellent moving graph display which shows spectrum analysis. ‘Esses’ are pinpointed on the fly with a vertical line and a frequency readout, so watching a few go by will soon show you the range where they are most problematic. A horizontal slider at the bottom allows you to centre the frequency to be targeted, and the band can be narrowed by dragging a point at the top downwards or adjusting the Filter Width setting on the left numerically or by dragging, causing the vertical boundary lines to narrow. This can be set down to 0.2 octaves, or as wide as 10 octaves (full range if centred). Fainter lines show the slope which can also be adjusted from a numerical display on the left of the graph – normally this is set at a remarkable 72dB per octave, which, thanks to the linear phase filtering, causes no problems.

The vertical slider at the right then sets the threshold in conventional fashion. However, the threshold moves dynamically thanks to continuous level tracking, and the resulting de-essing is natural and seems consistent with differing levels of sibilance. There is also an Attack time setting, but for general de-essing, I found no need to fiddle further. The graph can be zoomed in either direction by dragging the mouse logically from one point at the bottom left corner, but it scrolls automatically when setting the frequency, if one is zoomed in. Other bonus items on the display are tall LED-style meters for input and output, with corresponding Trim settings, and a Wet/Dry mix setting. An Access button (‘More’) opens up further setting options, with Hold and Release to accompany the Attack setting, and a Ratio control with unnecessarily odd scaling in degrees. Further, there is Level Tracking On/Off and Damping setting. And here, the Trigger sensor and the Audio modes can be switched from the Band setting to Wide mode, opening up further processing options.

Sonnox have introduced their own Waves-style preset manager with this plugin, allowing users to dial up the same settings across differing platforms if, say tracking in Logic and mixing in Pro Tools. This part of the window is hidden by default, and its view setting is one of the options viewed by clicking the Sonnox logo, where one can also choose the default view (Easy/More), Clip light settings and so on.

Sonnox supply a number of presets as starting points for different situations, and these are provided in the native host’s normal library as well as in the proprietary menu. But you won’t generally need them, such is the ease with which areas can be identified and processed using the graph display. ‘Ess’ and ‘Sh’ sounds are dealt with exceptionally well, and with minimal tweaking, effective de-essing is achieved with no loss of brightness. For other uses such as reducing instrument harshness or resonances, or de-popping, results are very good indeed, and made all the easier with the excellent graph display. The initially daunting interface soon becomes familiar, results are excellent, and the only hesitation in recommending the Sonnox might be the enormous processing overhead and latency.

Pros: Unquestionably the de-esser with the most parameters; Phenomenal control
Cons: No TDM version; Large latency of all versions but especially the HR version

Reproduced with kind permission from Copyright ©

Visit George's website to find more great reviews.