Waves Audio PS22 Stereo Maker User Guide

Table of Contents

Acknowledgment .......................................................... 2

Section 1: How to use PS22 & DLA................................ 3

Section 2: In-depth topics ........................................... 26

Introduction .................................................................................... 3

Chapter 1........................................... Essential overview ................ 6

Chapter 2 ............................................................. PS-Split .............. 13

Chapter 3...................................... Using PS22 with DLA.............. 18

Chapter 4............................................................ Tutorial.............. 20

Chapter 5....................... Setup library and applications.............. 23

A word about Phase.............. 26

Using PS with Waves S1 .............. 26

Using PS with Waves TrueVerb.............. 26

Stereo inputs.............. 27

Spreading non-central mono sounds.............. 28

Subjective comments and hints.............. 29

Processing Aims.............. 29

Sweeps, Spread statistics, and coloration .............. 30

Mono compatibility.............. 30

A workaround when mono compatibility is critical .............. 31

When is a mono input mono?.............. 31

The technical bit.............. 32

Stereo Monitoring.............. 33

PS-Spread as an audio phase scrambler—A specialist use .............. 34

Q10 Pseudostereo effects .............. 35

Factory Presets ............................................................ 36

Setup Library Notes ..................................................... 42

PS22-DLA product team: Michael Gerzon, Meir Shashua, Seva, Yoel

Users Guide written by: Michael Gerzon, Seva, Meir Shashua

PS22 Plug-In Manual

Acknowledgment

Michael Gerzon, the inventor of the PS22 process, died in May 1996, only a few months before releasing this product. Michael invested years of mathematical research, as well as audio engineering into this new type of process. Although the basic process underlying PS22 was previously incorporated into some commercial products, PS22 is the first time this process has been made available as a precision tool for pro audio engineers.

Michael did live to see the last stages of development of PS22, and was very pleased with what he saw and heard.

This Users Guide was drafted by Michael, and is a vivid example to the devotion this man had into creating excellent audio processing tools, and educating for their correct use and understanding. This is especially evident reading the text in Section 2: In-depth topics, which is almost untouched from Michael’s original draft.

Process licensed from Trifield Productions Limited, US Patent 5671287

PS22 Plug-In Manual

Introduction

PS22 StereoMaker is a set of tools for creating convincing stereo results from mono source material as well as a set of true stereo-in/stereo-out processing tools for synthesizing a richer stereo effect from existing stereo material.

It is far more than merely another “pseudostereo” effect. It is a mixdown and remastering tool capable of producing subtle or dramatic stereo effects of a kind and quality previously impossible - something that will become an essential tool in everyday stereo production of all kinds.

The idea of synthesizing a fake stereo effect from mono sources is a very old one, but the results have usually been disappointing and very often virtually unlistenable, giving unpleasant and unconvincing results. StereoMaker’s tools are unique, and have been designed after decades of research to avoid the problems of previous processes.

Several aspects distinguish StereoMaker tools from previous pseudostereo effects:

(i) tonal neutrality. All StereoMaker processing preserves the original frequency response. Any tonal

alteration should be the result of intentional equalization desired by a user, not an accidental byproduct of stereo processing. StereoMaker is designed to leave the tonal quality of the original source unaltered.

(ii) Very low phasiness. The unique patented StereoMaker processing produces sounds of low phasiness,

giving a highly listenable sound. Ordinary stereo pans sounds to different positions with low interchannel phase difference. Previous pseudostereo processing caused large interchannel phase differences which produced a vague and phasey sound which was not pleasant to listen to for extended periods.

(iii) Stereo-in/stereo-out processing. While StereoMaker processing can be applied to central mono

sounds to produce a stereo spread effect, StereoMaker is unique in actually working with full stereo inputs, spreading each input stereo sound source around its position in the original stereo stage. This means StereoMaker can be used to enhance the spread of each sound image within a stereo mix, or with panned mono sound. StereoMaker thickens the stereo width of any stereo sound source around its original position. This gives much more flexibility in composing rich stereo mixes than processes that only give a blanket spread to central mono sounds.

(iv) Wide spread effect. While StereoMaker is fully adjustable to achieve subtle narrow degrees of spread if

desired, it is unique in the extreme of wideness of effect it can achieve. StereoMaker allows very extreme left-

right stereo to be achieved which nevertheless sounds convincing and real. Conventional pseudostereo is often sufficiently subtle that stereo effects are quite difficult to hear other than when doing straight A/Bcomparisons with the original mono.

PS22 Plug-In Manual

(v) intuitive user controls and interface. All synthesis of stereo from mono inevitably involves an artistic judgment as to where sounds should appear from in the stereo stage, since there is no position informa

tion in the original mono. StereoMaker provides a range of user controls that allows the stereo effect to be composed in an intuitive manner, offering not just control of the degree of spread and spaciousness, but also positioning of dominant sounds within the stage. A graphical display shows stereo positioning as a function of frequency.

(vi) No unwanted processing side effects. StereoMaker aims at avoiding any sound alterations other than

those needed to create a convincing stereoism. As such, it has no conflict with other kinds of processing such as EQ or reverb. In particular, StereoMaker is not a reverb or echo effect, so that the original artistic decisions in the monosound are not being modified. StereoMaker may be used with EQ tools such as Waves Q10 or with room simulation tools such as Waves TrueVerb for more creative effects - the user’s choice of the nature of each effect is preserved.

PS22 StereoMaker is a toolkit of three separate processes, packaged as two plug-ins, which may be used separately or in various combinations. The three processes are all stereo-in/stereo out, and are each optimized to achieve different kinds of results. Their stereo sound is very different from each other, and you will soon discover which kind of process is suited to different artistic or creative needs. None of the processes is a substitute for the others - they are all different.

The three processes are: PS-Spread, PS-Split, and DLA. All the PS processes share the low phasiness, and stereo compatibility features as described above. Each of the two master plug-ins have at least two component plug-ins, which will be described in this chapter. The DLA ‘family’ of plug-ins comes with the PS package, and is designed to be used in conjunction with the PS processes in specific ways.

PS22 StereoMaker plug-in

This master plug-in has three components: PS22-Spread, PS22-Split, and PS22-XSplit.

PS-Spread creates a smooth spreading of sounds across the stereo stage. It not only has low phasiness and the capability of spreading around any stereo position, but it also offers adjustment of additional bass spread enhancement for an exceptionally spacious effect. The (10) version has only 10 sweeps, and therefore uses less DSP. All the PS plug-ins are based on the controls of the PS-Spread, so you should read

Chapter 2: PS-Spread before reading about any other component’s controls.

PS-Split completely splits sounds across the stereo stage. Visually speaking, the graphic representation of the PSSplit looks like a square wave swinging between left and right, where the PS-Spread effect looks like a sine wave. The resulting effect is a dramatic left-right split. Best results are normally achieved when PS-Split is followed with one of the DLA-X process (or a reverb effect), but it can be used without them.

PS-XSplit is almost the same as PS-Split followed by DLA-XL built into a single interface. The DLA-X and PS-Split processes complement each other to create a more natural, yet having the two processes combined into one user interface and linking some controls, it is much easier for you to achieve optimal results.

PS22 Plug-In Manual

There are two variations of this plug-in: PS22-Spread and PS22-Spread(10).

more spectacular stereo effect, as explained below. By

DLA plug-in

In the DLA plug-in are 6 components, two of which are not part of the PS process, but are small plug-ins to compensate for the delay in the C1 and L1 plug-ins. See the DLA chapter for more detail on these components.

The DLA-X process family is based on short time stereo cross feed delays (not an echo effect). DLA-X is the basic effect; DLA-XL controls the amount of cross feed separately for the high and low frequencies, and DLA-XLB has an optional longer delay of low frequencies. While DLA-X processors can be useful used on mono input sources, it is most effective on stereo inputs, and especially when used in cascade with either PS-Spread or PS-Split can give spectacular and dramatic results.

The DLA-X and PS processes complement each other. When used on mono input sources DLA-X tends to produce a comb-filter coloration side effect as a result of the interaction between the delayed and original sound. On the other hand, PS-Split (and for a lesser extent PS-Spread) will split the spectrum of a central sound so that distinct frequency bands will exist only in one of the two stereo channels, this has a different kind of coloration side effect.

When DLA-X and PS plug-ins are used together, the DLA-X cross-feeds the missing frequency bands from one channel to the other, but since each channel has different frequency bands, the interaction between the delayed and original signal is avoided. A similar, but more complex effect takes place on stereo input.

Note that following PS-Split by a stereo compatible reverb will achieve similar results, so using DLA-X is not needed in this case.

PS-Split is the tool to use when you wish to split input mono sounds into two almost completely separate stereo positions, e.g. for a dramatic left-right split. It is capable of extreme and dramatic stereo separation effects. Best results are normally achieved when used in conjunction with one of the DLA-X plug-ins, but it can also be used either on its own or with a reverb effects unit.

All three effects are fully user-adjustable from zero effect up to a high degree of effect — as much or as little reprocessing of stereo effect as you want or need. The quality as well as amount of the stereo effect is also fully under user control.

The PS22-Spread component has the basic set of controls common to all 3 PS components. In the PS-Split component chapter, only the additional controls will be discussed. Therefore, we’ll describe each control of the PS22Spread in detail.

PS22 Plug-In Manual

Chapter 1 - Essential overview

Controls

These fall into two groups: Input and Spread.

Input Controls

Gain From 0.0 to -24.0dB. Adjusts input level so that potential output clipping problems can be avoided.

Width Adjusts the width of an input signal all the way from mono (width 0.00) to original stereo (width

1.00). Used to adjust the degree of stereo retained from the input signal before the PS22 spreading effect. This lets you collapse the input signal to avoid making a signal too wide with the PS process.

Rotation In degrees from -45.0 to +45.0. Exactly like the S1’s Rotation control, adjusting the centering of the input

stereo signal without affecting level-balance. Useful for centering off-center input material or for panning mono material to the left or right.

Channel polarity and channel swap buttons. These are intended to correct errors in the input stereo signal. The +/

- buttons adjust the polarities of the individual channels. Normally, both should be set to “ + “, but if the input stereo is out of phase, the button on one channel should be set to “ + “ and the other to “ - “. You should not normally set both buttons to “ - “ unless you understand why are you are doing this. The <-> (channel swap) button swaps left and right channels at the input if the stereo channels have accidentally been reversed or where it is desired to reverse the input stereo effect.

PS22 Plug-In Manual

Spread controls

These controls affect the way sound images are spread and will be described in terms of what they do to a central mono input sound. The effect for other stereo input sounds will be described in more detail later in the manual.

They are divided into two groups. The top line of controls under the graphical display are and the bottom line of controls are

Spread statistics controls.

Spread envelope controls,

Spread envelope controls

These control the total degree of spreading as a function of frequency.

Spread Adjusts the degree of spreading from 0 (no spreading) to 1.2 (ultra wide spread). A spread of 1

fills the sound stage between the two stereo loudspeakers. By using Spread together with the input Width control, and the MS metering (see details below) you can adjust the overall stereo content of your output signal so it is not exaggerated.

Freq In Hertz (Hz). This adjusts the frequency at which bass spread starts acting. A good starting

value is 630 Hz, although the range covers from 32 Hz to 16kHz.

LFspread This provides additional adjustment of spread at bass frequencies. The degree of spread is the

same as at high frequencies if LFspread is 1.0, the bass is wider and more spacious if larger values of LFspread such as 2.0 are used, and the bass becomes more mono and centered in the stereo stage if a smaller degree of LFspread approaching 0.0 is used.

Spread statistics controls

These four controls adjust the precise way the input sound is panned to and fro between left and right as a function of frequency. The panning is shown on the display graphic.

Sweeps This control is the number of sweeps between left and right across the entire audio frequency range.

In other words, how many bands the audio is divided into. The value ranges from 2 to 22 [or 2 to 10 in the PS-Spread(10)], . For 2 it sweeps from left to right and then back to left again as one goes from low to high frequencies, up to 22 sweeps. (Note that at some control settings, some of the sweeps to-and fro may be outside the graphic display frequency range).

PS22 Plug-In Manual

FCenter In Hz. This control adjusts the center frequency around which the density of sweeps to-and fro

can be increased or decreased by the FDensity control. This allows the maximum degree of toand-fro processing to be concentrated mostly in a given frequency range if desired.

FDensity This controls weather to increase or decrease the density of sweeps around the FCenter frequency. When

set to 0, the to-and-fro sweeps are fairly uniformly distributed across the audio frequency range. For positive values of FDensity, the to-and-fro sweeps are more dense near the FCenter frequency and less dense far away from it. For negative values of FDensity, the to-and-fro sweeps are spaced wider apart near FCenter frequency, and more dense at the bass and treble ends of the audio range.

Twea k For a given setting of the other controls, this control allows the user to tweak how particular

frequencies are panned within the spread stereo stage. When varied between -1 and +1, each individual frequency will be panned trough all the possible positions between left and right. It is usually the most useful control when trying to achieve a balanced spread sound stage between left and right loudspeakers.

Important note for when Sweeps = 2. FCenter and FDensity controls do not work for 2 Sweeps, and Tweak then only has the effect of reversing the left and right aspects of spreading when set outside the range -0.5 to + 0.5. The main controls for altering spreading effect with 2 Sweeps are provided by the three spread envelope controls Freq, Spread and LFspread. The effect of FCenter, FDensity and Tweak becomes more evident when Sweeps is 3 or higher.

Graphic display

The graphic display of PS-Spread displays the way stereo position of a central mono input source is varied at the output as a function of frequency. Also shown in light blue is the overall spread envelope, i.e. the degree of spreading as a function of frequency. The vertical grid lines show left, center and right stereo positions. If the stereo position is shown beyond the left or right lines, this corresponds to signals having an antiphase relationship between the two stereo channels.

The graph also has two cursors. The solid-square Density cursor (shown upper left in graphic) controls FCenter frequency vertically and FDensity horizontally. Pressing the option key while dragging vertically changes the Tweak instead of the FCenter value. -

PS22 Plug-In Manual

The open-square Spread cursor (shown lower right in graphic, with four arrows) controls the Spread horizontally and the transition Frequency of the spread envelope vertically, Pressing the option key while dragging horizontally changes the LFspread instead of the Spread value.

Either of these grab markers may be selected and dragged by clicking on them with a mouse and dragging them to new values.

When you drag the Spread cursor, the graph is redrawn in real time to indicate the relative spread of high and low frequencies, and the transition frequency.

The graphic display also shows the Rotation and Width of the input control settings as light blue lines for the left and right, and a light blue pointer (an upside-down “V”) in the middle, showing the center of the signal (see graphic below). These three markers are the Input Stereo cursors.

You can drag these Rotation and Width lines directly in the graph, or on the faders on the left of the graph. In both the graph and the faders,

horizontal mousing controls the Rotation, vertical mousing controls Width.

It is important to have these lines displayed so that you can see when you might be getting “too wide” with the output. The light gray vertical lines that go from top to bottom on the graph show the normal Left and Right pan positions. Anything outside these lines is

anti-phase, which, although it might sound great, may have mono-compatibility problems, or might be fatiguing for long listening periods. Therefore, by putting the Rotation and Width display on the same graph, you can see if excessive width might be caused by the PS process.

If you have a very wide stereo input, it is advisable to reduce the Width somewhat before applying the Spread. By using the graph and the MS meters, you have a lot of information that can help create a highly-listenable and creative sound. The MS meters are discussed in the next section.

PS22 Plug-In Manual

Metering

On the right side of the PS22 window are the bar level meters. The meters always indicate the current output of PS22. Above the meters is a clip light. If a clip occurs, the Clip Box above the dB meters will indicate “clip” until the meters are reset.

The clip indicator light is always active, including during non real time (NRT) file based Processing. This is a great advantage in determining whether a clip occurred during the NRT Process of a file.

Below the level meters are digital values showing the highest peak encountered. To reset these peak level values and the clip indicator, just click anywhere inside the level meters.

Although the PS22 processing is designed not to change the energy levels of incoming sounds, it does alter both the phase and the stereo positioning of different sound components in the input signal. This can cause the output peak levels to be higher than in the input stereo signal. In some very extreme cases, peak levels can be increased by 9 dB or more - although this is very rare, and figures of 2 or 3 dB are more common. If the output meters indicate clipping as a result, you are advised to reduce input gain to avoid clipping.

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LR and MS display modes

The PS22 meters have two modes of display: LR, and MS. The LR mode is the standard Left and Right level meters. Using the MS mode is explained below. The MS mode only affects what the meters display, and has no effect on the output. The mode may be selected by clicking on the L-and-R/M-and-S button above the meters.

Uses of MS meter mode

MS metering mode displays the levels of two signals, M representing the amount of mono present, and S representing the side signal, i.e. the signal representing the differences between the two stereo channels. The greater the degree of stereoism present, the higher the S signal when compared to the M signal.

Judging effect of spreading

On mono inputs, MS metering can be useful in indicating the degree of stereoism produced by a given degree of spread processing. Generally speaking, the widest spatial effect will be obtained when M and S levels are roughly equal, with a narrower effect if S level is smaller than the M level. If the S level is typically larger than the M level, this may indicate an excessive degree of spread processing that could sound fatiguing on extended listening or could lead to mono compatibility problems.

Diagnosing stereo input problems

In general, spread processing will only be successful if applied to input stereo signals that are in phase and not excessively wide. The MS metering on PS22 can be used to help diagnose problems with the input stereo signal.

Without processing, i.e. with zero spread, and width at 1 and rotation at 0, the MS meter mode can be used to judge whether the input stereo material is in phase. If it is, the M level will generally be significantly higher than the S.

If, without processing, the S level is generally higher than the M level, this indicates one of two possibilities:

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(1) the most likely, that the input channels are out of phase, for example due to an analog-domain wiring error in

balanced cables somewhere in the stereo signal chain, an incorrect setting of a phase switch, or possible an incorrectly wired microphone capsule in a stereo pair of microphones. Correct this by altering one only of the two input polarity buttons to read “ - “ rather than “ + “. Monitor the output to verify that changing the polarity does indeed improve the sharpness of stereo images, particularly for sounds at the center of the stereo stage.

(2) in unusual cases (such as certain specialist one-point stereo microphone recording techniques such as MS or

“Blumlein figure-of-eight” when presented with a very wide sound source stage, or if previous excessive width or spread adjustment has been used) it is possible that the S meter can read higher than the M

without a channel polarity error due to excessive width. In this case, center stage sounds WILL be in phase, and the phase switches should NOT be used.

If the input stereo is in-phase but very wide according to the levels indicated on the S meter, then the effect of PS processing may sound excessive, and you may find it useful to use the width control to narrow the stereo input image first.

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Chapter 2 - PS-Split

The PS22 PS-Split and XSplit components are designed primarily to take a mono input and to spread different frequencies to and fro around the central position. Each frequency is panned to a different position within the stereo stage, as shown on-screen.

PS-Split differs from PS-Spread mainly in that the PS-Spread has “sine-wave” panning, and the Split has “square wave” panning, where most frequencies are either panned sharply to the left or right position, with very few frequencies in-between. It is called PS-Split because it in effect splits the frequency components of a mono sound between just two positions in the stereo stage. PS-Split is preferred in cases where a very dramatic stereo effect is wanted.

Split and XSplit both have a Shape control that alters the “waveform” of the splitting of the signal. For instance, it can vary from a smooth panning similar to the Spread, or to a “square wave”, with almost all sounds being panned completely apart with very fast transitions between these bands.

PS-Split and XSplit have identical controls to PS-Spread, except for these changes:

1 — There is no LFspread control (the low frequency spread is always set to 0).

2 — Freq now adjusts that frequency below which spread is pulled towards 0. The range of the frequency

control is still 32 Hz to 16kHz.

3 — The Sweeps range is from 2 to 10.

4 — The Shape control.

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Shape control ranges from 0.00 to 1.25. When Shape=0.00, it is more of a triangle waveform. Shape=0.15, the shape is the same as the sine-wave shape of the Spread. Shape=1.00, the shape is square-wave. Shape=1.25, the shape is a HyperSquare that has some ‘overshoots’.

The Shape control make the PS-Split similar to a variable PS22-Spread(10), so for sound design applications where you might want a larger degree of stereoism, the Split version gives you more flexibility, although the number of Sweeps is limited due to DSP requirements.

Adjusting the Shape control is almost completely by subjective choice, and should be used “to taste”.

Split and XSplit are generally used for taking a mono input and creating a strongly separated stereo image from it, but can be used with stereo inputs as well. The Spread (or Split with lower values of Shape) are generally recommended for stereo inputs, but there are no rules, just suggestions!

PS-XSplit plug-in

The XSplit also has a DLA-XL “built-in”, and doesn’t require the external plug-in, unless you need the XLB, which you can simply use inserted after the Split component.

The DLA-XL is fully integrated into the logic of XSplit and takes in account the internal settings of the XSplit parameters when computing it’s own settings. Two additional controls are given to the user: Delay and Xfeed.

Delay is exactly the cross feed delay as in DLA-XL. Xfeed is different from the DLA-XL control in that it takes in account the current setting of Spread. When Xfeed =

1.0 the amount of cross feed fully compensates for the current degree of Spread, Xfeed<1.0 means the Spread is partly compensated. Normally the recommended setting is Xfeed=0.5.

The settings of the low frequency transition and Xfeed are set internally according to the Spread transition frequency.

Here is why the Xfeed and LF settings have an “auto” compensation, and it’s important.

The best Xfeed gain should be equal to or less than the Spread value (when Shape is 1.0, a “square wave”). Therefore, you can set XFeed to a value, then when varying Spread, XSplit will automatically “track” the crossfeed gain for you. XFeed also compensates for varying shapes.

For setting the Xfeed gain when using separate plug-ins (like Spread and DLA-X) see the next chapter, with DLA.

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Using PS22

+ 32 hidden pages