Sonnox Oxford SuprEsser User Manual

Contents

1 Introduction 4

2 MainFeatures 6

3 Operation 7

3.1 Signal Processing Overview . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7

3.2 Resolution, Kernel Sizes, and Delays . . . . . . . . . . . . . . . . . . . . . . . 9

3.2.1 Delay Compensation and Audio Buffer Sizes . . . . . . . . . . . . . . 11

3.2.2 Over-Taxing the Host . . . . . . . . . . . . . . . . . . . . . . . . . . . 12

3.3 Advanced Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13

3.3.1 Trigger and Gain-Ducking Modes . . . . . . . . . . . . . . . . . . . . . 13

3.3.2 Automatic Level Tracking . . . . . . . . . . . . . . . . . . . . . . . . . 16

3.3.3 Bandpass Filter Modes . . . . . . . . . . . . . . . . . . . . . . . . . . 18

4 DescriptionofControls 19

4.1 Basic Screen Controls . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19

4.1.1 Touch Pad Controls . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20

4.1.2 Options Menu . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21

4.1.3 Input Monitor Section . . . . . . . . . . . . . . . . . . . . . . . . . . . 22

4.1.4 Listen Section . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22

4.1.5 FILTERS Section . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23

4.1.6 DYNAMICS Section . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24

4.1.7 OUTPUT MONITOR Section . . . . . . . . . . . . . . . . . . . . . . . 26

4.2 Advanced Screen Controls . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27

4.3 Graphical Screen Controls . . . . . . . . . . . . . . . . . . . . . . . . . . . . 32

4.3.1 Explanation of Controls . . . . . . . . . . . . . . . . . . . . . . . . . . 33

5 OxfordSuprEsserDS (AAX DSP) 35

6 Specifications 36

6.1 SuprEsser DS – Pro Tools | HDX & S3L – Instances per chip . . . . . . . . . . 38

7 PresetManagerToolbar 39

8 SupportedPlatforms 40

9 SystemRequirements 40

10 CopyrightandAcknowledgements 41

1 Introduction

1 INTRODUCTION

The Sonnox Oxford SuprEsser was designed primarily to be the last word in ‘de-essing’

applications. While we worked on creating the best possible de-essed sound, we found

that we needed more control than was available on conventional De-Essers. Most

de-essing work can be carried out in ‘simple’ mode but sometimes, to do the job properly,

it is necessary to utilise all the controls of the underlying engine — a full-blown dynamic

EQ, or frequency- conscious compressor.

Thus a new concept was born — a simple and intuitive De-Esser, plus access to a much

more sophisticated frequency-specific compressor, giving complete control over

aggressive frequencies wherever they may be in the audio spectrum. With the Oxford

SuprEsser you can take out unwanted frequency peaks as and when they occur — unlike

applying a fixed EQ to the whole channel.

As a De-Esser, the Oxford SuprEsser is designed for the treatment of sibilance and

fricatives in vocals, and the treatment of unwanted whistles and ’spirant’ artefacts

associated with wind instruments. However, it can equally be applied to removing

low-end plosives and thuds from over-close vocal work, without affecting nearby

components in the frequency spectrum, keeping the low-end intact. For the most natural

sounding results, the Oxford SuprEsser de- esses only the frequency band you select —

so you won’t end up with an over-de-essed lisp- like voice with all the high frequencies

gone!

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1 INTRODUCTION

Detailed visual feedback is provided by a highly intuitive graphical display, allowing quick

identification of the frequencies that need treatment, and where to set the threshold. The

threshold level and peak-hold level of the user-definable band are shown on the graph,

alongside the FFT (Fast Fourier Transform) display of the narrow band signal, which

includes retention of the peak level and the frequency containing the most energy.

At the heart of the Oxford SuprEsser is an enhanced version of the compressor section of

the Sonnox Oxford Dynamics plug-in, which is renowned amongst professional users for

its consistent delivery of the precise and transparent control of peak signals. Around this

is built a pair of crossover filters to make the compressor react only to the defined

frequency band. These linear-phase filters are modelled on the filters from the Sonnox

Oxford EQ, making the Oxford SuprEsser useful for precise mastering as well as mixing

work.

Three listen modes allow the user to listen to the Mix, the output of the bandpass filter

(Inside), or the output of the band-reject filter (Outside).

Careful thought has been put into making the Oxford SuprEsser extremely easy and quick

to use. The screenshot on the title page shows the plug-in as it appears when first

activated. Once the frequency band has been defined, simply lower the threshold fader

until the gain reduction meter starts to kick in. The plug-in then automatically tracks the

general signal level and the threshold follows accordingly, so that it gives the same

relative amount of gain reduction as the signal level rises or falls. This is perfect for vocals

where, for example, a vocalist is louder in the chorus than the verse, but you want to

apply the same relative amount of de-essing, but don’t want to over de-ess in the chorus.

This Auto-Level-Tracking mode lets the Oxford SuprEsser do all the hard work. It can also

be switched off for a fixed threshold.

In its default mode of operation, the Oxford SuprEsser feeds the defined Band signal to

the compressor to affect only this narrow-band signal. The result is that the compressor

reacts only to specific frequency components when they reach a specific threshold, and

applies compression only to these specific frequency components, leaving the rest of the

spectrum untouched. Audio Wide mode can also be selected to allow full-band

compression reacting to only specific frequencies, or any combination of Band and Wide

defining when the compressor reacts, and what it compresses.

The Oxford SuprEsser comes complete with many presets to act as good starting points;

alternatively, the advanced section provides full access to all controls for precise

correction, or even creative use.

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2 MAIN FEATURES

2 MainFeatures

• Highly featured professional De-Esser

• Linear-phase Dynamic EQ

• Transparently controls aggressive frequencies

• Automatic level-tracking follows energy level (eliminating the need to automate

threshold)

• Large intuitive graphic display makes finding frequencies very easy

• Full spectrum operation (20Hz–20kHz)

• Three different ‘Listen’ modes

• Very easy to use

• Advanced mode for ultimate control of the Dynamic EQ

• Many creative as well as corrective uses

• Presets provide good starting points

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3 Operation

3.1 SignalProcessingOverview

3 OPERATION

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.

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3.1 SignalProcessingOverview 3 OPERATION

AdvancedModeSignalFlow

In addition to the four EQ types, there are four different compressor modes that are

concerned with which signal is passed to the sidechain and which signal is passed to the

main input of the compressor. See Section 2.3 Advanced Operational Modes for more

information on this.

The following diagram provides a more complete signal flow to illustrate the elements

required for advanced modes of operation:

Advanced SuprEsser signal flow

The ‘Wet/Dry’ control is a frequently requested feature that allows you to add back the

uncompressed signal to a highly compressed signal to add in some punch. As you can

see from the diagram above, the Wet/Dry blend control is implemented inside the

dynamics module, and therefore only operates as expected when you are listening to the

‘Mix’, or ‘Inside’.

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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

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3.2 Resolution, KernelSizes, andDelays 3 OPERATION

region of 4116 to 12308 samples. See the section below for information on reducing the

delay.

OxfordSuprEsserLL/LowLatency

This small kernel version has a kernel size of 512 samples.This version gives superior

performance in terms of having a small delay, and thus is more suitable for live de-essing

work at low sample rates, and for the tracking phase of a project, where you are laying

down new tracks from midi instruments, and you don’t want a significant delay between

what you are playing and what you are hearing. The smaller kernel size means the

resolution at low frequencies will be poor, and so cannot be used much below 400Hz.

Depending on your audio buffer size, the delay or latency will be somewhere in the region

of 276 to 3072 samples. See the section below for information on reducing the

delay.

OxfordSuprEsserDS (AAX DSP)

This version has an even smaller kernel size of 128 samples, in order to further reduce the

processing delay. Due to this, the filter range has been reduced to 1 kHz minimum, in

order to prevent poor low frequency performance from producing unexpected

results.

For further information, see Section 5.

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3.2 Resolution, KernelSizes, andDelays 3 OPERATION

3.2.1 DelayCompensationandAudioBufferSizes

The plug-in delay produced by the Oxford SuprEsser depends both on the kernel

size/resolution and the audio block size.

The block size is the size of the sample buffers passed to the plug-in by the host, and is

usually specified in your audio hardware preferences/configuration/setup page. The

reason that the plug-in delay depends on the block size is that the plug-in must

accumulate a whole kernel sized block of samples before it can process them.

In order to ensure the minimum plug-in delay, make sure the block/buffer size is the same

as or greater than the kernel size/resolution setting!

For example, if the kernel size is set to 512, ie. you are using the Low Latency version,

and if your block/buffer size is 512 or 1024, this will ensure that the plug-in produces the

minimum delay of 276 samples.

If you use a smaller block size than the kernel size, the overall delay of the plug-in will go

up, not down. For example, if the block size is 256, then the Low Latency version will

produce a delay of 532 samples.

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3.2 Resolution, KernelSizes, andDelays 3 OPERATION

3.2.2 Over-TaxingtheHost

The Oxford SuprEsser uses a process called convolution to implement filtering, a process

that is expensive on CPU resources. When using very large kernel sizes, in combination

with small audio buffer sizes, it is possible for the plug-in to take longer than an entire

audio block to complete processing, with the result that (from a monitoring point of view)

the playback breaks up. This can manifest as obvious clicks and pops, or more subtly as

occasional quiet clicks.

Note:

If you experience clicks, keep in mind that these are monitoring only. They will not be

present when bouncing down your mix.

If you experience clicks, increasing your audio buffer size will resolve the issue. Once

again, the best buffer size for the Oxford SuprEsser is the same as the kernel size (or

resolution). Generally speaking, the only reason for small audio buffer sizes is for tracking,

or live working requirements.

The plug-in issues a red warning label next to the Sonnox button when you are using a

combination of small buffer size and large kernel size that we have found to generally

result in clicks. This is not a reliable indicator, however; it completely depends on your

system CPU speed, sample rate, and other factors.

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3.3 AdvancedOperation 3 OPERATION

3.3 AdvancedOperation

3.3.1 TriggerandGain-DuckingModes

There are four major operational modes selectable via the TRIGGER and AUDIO buttons

in the Advanced Mode (MORE:) section, as described below:

Mode: Signalto:

Trigger Audio Comp SideChain

Band Band Filtered

signal

Band Wide Delayed in-

put signal

Wide Band Filtered

signal

Wide Wide Delayed in-

put signal

Filtered

signal

Filtered

signal

Delayed in-

put signal

Delayed in-

put signal

Result

Gain ducking occurs only in the narrow band,

triggered by the narrow band.

Gain ducking of (wide) input signal, triggered by

narrow band signal. Equivalent to compressor in

side chain EQ mode.

Gain ducking occurs only in the narrow band of the

spectrum, triggered by the wide input signal.

Equivalent to compressor with no side chain EQ.

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