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Blue Cat's Liny EQ User Manual
Blue Cat's Liny EQ User Manual
Blue Cat's Liny EQ - Low Latency Linear Phase Equalizer Plug-in (VST, Audio Unit, AAX, VST3)
"Linear phase equalization, without the latency."
MacOSUniversal BinaryWindows Vista or newerWindows x64 (64-bit)VSTVST3AAX64-bit AAXAudio Unit


Blue Cat's Liny EQ is an 8 bands linear phase equalizer with very low latency and comprehensive visual feedback: thanks to its highly optimized linear phase kernel, it processes the signal without phase distortion, with an unusually short latency (less than 3 milliseconds).

Liny EQ's wide range of gain (+-40dB) and multiple filter shapes make it very flexible for a graphic EQ, letting you create unique EQ curves. The dual channels version offers independent settings for the left/right or mid/side channels, with flexible linking capabilities for an optimal workflow.

The highly customizable user interface includes a first class spectrum analyzer and spectrogram viewer. It lets you choose the best layout and display options to adapt the plug-in to your own workflow.

Thanks to its ability to update the EQ curve continuously using MIDI or automation and its additionnal "Mix" control, dynamic equalization tasks can be performed easily when used together with any of our control generation plug-ins.

Blue Cat's Liny EQ - Single channel EQ, with spectrum display. Blue Cat's Liny EQ - Selecting a greyscale spectrogram, with simultaneous dual channels display and control. Blue Cat's Liny EQ - For maximum precision when used with large screens, the user interface can be widened.

Typical applications: Low latency linear phase equalization, mastering, mixing, spectral correction, stereo widening or narrowing.

System Requirements


  • An Intel or Apple Silicon processor.
  • Mac OS 10.9 or newer.
  • Any VST / Audio Unit / AAX compatible application (64-bit) .


  • An SSE2-enabled processor (Pentium 4 or newer).
  • Microsoft Windows Vista, Windows 7, 8 or 10.
  • Any VST / AAX compatible host software (32 or 64 bit).

For more information about supported platforms, see our Knowledge Base.

Demo Limitations:

  • Limited number of instances of the plug-in per session.
  • The plug-in is regularly bypassed for a few milliseconds.


The plug-ins versions cannot be run standalone: they require a host application (see the System Requirements chapter for more information). Depending on which host application you use, you might need to install the plug-ins in different locations.

Before installing one of the plug-in versions, you should close all your host applications.



All versions of the plug-in provide an installation program. Follow the steps of the wizard to install the software on your machine. During the installation you will be asked where you want the software to be installed. For the VST version, you should install the plug-in inside the VST plug-ins folder used by your host application(s). The default path set in the installer should work for most applications, but you should check your host software documentation to know where it looks for VST plug-ins. For other plug-in types, you should just use the standard path.

Some applications will not automatically rescan the new plug-ins, so you might have to force a refresh of the plug-ins list.


When a new version of the software is released, just launch the new installer: it will update the current installation.


To uninstall the software, simply launch the "Uninstall" program that is available in the start menu or in the configuration panel. It will take care of removing all files from your computer.



On Mac the plug-ins are available as drive images with an installer. After download, double click on the dmg file to open it. You can then double click on the installer (.pkg file) to install the package.

Note for Mac OS 10.15 Catalina or newer: you may have to right click on the installer and select "Open" instead of double clicking on the file to launch the installation if your computer is not connected to the Internet.


When a new version of the software is released, just launch the new installer: it will update the current installation.


To uninstall the software, simply remove the component(s) from their install location (move them to the trash):

  • AAX plug-ins are installed in the /Library/Application Support/Avid/Audio/Plug-Ins/ folder
  • Audio Units (AU) are installed in the /Library/Audio/Plug-Ins/Components/ folder
  • RTAS Plug-ins are installed in the /Library/Application Support/Digidesign/Plug-Ins/ folder
  • VST plug-ins are installed in the /Library/Audio/Plug-Ins/VST folder
  • VST3 plug-ins are installed in the /Library/Audio/Plug-Ins/VST3 folder

If you want to completely remove all settings and configuration files, you can also remove these additional directories that may have been created on your computer:

  • ~/Library/Preferences/Blue Cat Audio/[Plug-in name and TYPE], where TYPE is VST, AU, RTAS or AAX: global preferences.
  • ~/Library/Preferences/Blue Cat Audio/[Plug-in name]: license information
  • ~/Documents/Blue Cat Audio/[Plug-in name]: user data, such as presets, additional skins and user-created plug-in data.

Please be aware that these directories may contain user data that you have created. Remove these directories only if you do not want to reuse this data later.

First Launch

Blue Cat Audio plug-ins cannot be run standalone, they require a host application (see the System Requirements chapter for more information). Some host applications will require you to scan the plug-ins before they are available in the application.

If the plug-in is not available in the application, please check that it has been installed in the appropriate directory (with no host application running), and that the host application has scanned it.

Using Blue Cat's Liny EQ


Blue Cat's Liny EQ is versatile linear phase graphic equalizer with very low latency and minimal pre-ringing artefacts.

Graphic EQ

With a graphic EQ, you can change the gain of a pre-selected set of frequencies that cannot be modified. In this particular plug-in, the EQ offers several shapes to increase the flexibilty and overcome the limitations that are usually found on such EQs. It is thus possible to create almost any EQ shape without the need for more control.

Linear Phase

A linear phase EQ is a special type of EQ that does not affect the phase of the signal by introducing a phase shift in the signal that is proportional to the frequency, as opposed to " minimum phase" EQs. It means that it usually sounds more transparent because it does not change the shape of the signal with random phase shift accross the spectrum. It's one of the reasons why such EQs are preferred at the mastering stage.


Linear phase EQs all bring additional latency to your signal chain, because they add a constant delay to all frequencies (you can see this as a way to compensate the phase shift). This can become a problem when the latency becomes high, because your Digital Audio Workstation (DAW) will react with a noticeable delay.

In the case of this plug-in, this is not an issue since the latency has been greatly reduced: it is less than 3 milliseconds (128 samples at 44.1 kHz) thanks to a specially optimized filter kernel. You can thus enjoy your linear phase EQ without the latency!


One of the downsides of linear phase equalizers is a "pre-ringing" effect that can be heard on transients: because of the way digital linear phase EQs affect the phase, some frequencies may be shifted to the "and" and happen before a transient occurs (a kind of "back to the future" effect). This audible artefact sounds rather unnatural.

The good news is that this effect is highly reduced with Blue Cat's Liny EQ and its very low latency kernel. Even if you tweek low frequencies, pre-ringing should be barely noticeable.


Blue Cat's Liny EQ offers mid/side processing capability. With this feature you can process the mid (center) and side (sides) channels instead of the usual left and right channels.

Concept Origin: Mid/Side Recording

Mid/Side recording is a famous recording technique that is preferred in some cases to the traditional left/right recording. Searching for "mid side recording" on the web will give you many tutorials about this technique.

The result of such a recording is a pair of mid/side (M/S) channels instead of classic left/right (L/R) channels in an audio stream. The mid channel is also often called "Mono" and side "Stereo": the mid channel contains the signal that is in the center of the stereo mix, and the side channel contains the rest (everything that is on the sides of the mix):

(The triangles above represent the listener's head)

From Mid/Side Recording to Processing

The relationship between L/R and M/S channel can be computed so that you can transform any Mid/Side recording to standard listenable left/right stereo stream. The reverse operation is also possible, which means that you can artificially separate mid/side information from your usual L/R stereo tracks. That's what is done by our mid/side processing plug-ins.

Processing separately the mid/side channels instead of left/right channels offers more control over the stereo character of a sound. Reducing the volume of the side channel makes it sound more "mono" and vice versa.

Mid/Side and EQ

Applied to EQ, this lets you control how "stereo" a range of frequencies may sound. It offers a much more flexible and intuitive way of managing the stereo distribution of spectrum than the usual left/right technique: processing separately both channels does not alter the L/R balance of the output signal but changes the ratio between the stereo and mono signals instead. It is thus much easier to control: you can choose to either "stereoize" or "monoize" parts of the spectrum.

The User Interface

Note: The main toolbar, menus and basic features available with all our plug-ins are detailed in the Blue Cat Audio Plug-ins Basics section.

Blue Cat's Liny EQ is bundled with several skins that have similar layouts and exactly the same capabilities. The default skin is described below.


The plug-in comes in two versions: single channel (one set of controls is available and affects both the left and right channels for stereo instances), and dual channels (two sets of controls are provided, with left/right or mid/side operation).

Both versions are very similar, except that the dual channels plug-in offers more controls, so we will focus on the user interface of the dual channels plug-in.

  1. Layout type for channel controls below the graph: single, dual column or dual row. You can choose if you want only one channel at a time, or both channels displayed in a column or a row (Dual version only).
  2. Show/Hide EQ controls.
  3. Show/Hide graph.
  4. Show/Hide output level meters (#12).
  5. Select the display size to adapt the user interface to your screen.
  6. Freeze display: freezes the spectrum or spectrogram display if active.
  7. Mid/Side switch: when activated, channel 1 represents the mid (center, or mono) signal and channel 2 the side (or stereo) signal. When off, channel 1 is the left channel and channel 2 is the right channel (Dual version only).
  8. Link channels: when active, controls for both channels are linked together, according to the options selected with #9 and #10 (Dual version only).
  9. Absolute/Relative link: in absolute mode the values of the controls for both channels are identical, whereas in relative mode only controls variations are reported to the other channel (letting you setup a different EQ on each channel, and then apply linked modifications for example).
  10. Normal/Mirror link: in mirror mode, the gain value for both channels are reversed. It is very handy when you want to use the EQ as a balance between channels (Dual version only).
  11. Display range: select the range for the EQ (affects both the controls and the display).
  12. Output level meters: display the peak level at the output of the EQ.
  13. EQ response curve and controls: the response curve of the EQ is displayed on the graph (decibels as a function of frequency), and overlayed controls are available to ste the gain for each band. Controls can be hidden using #15.
  14. Spectrum analysis display: depending on the options chosen with #16 and #17, a spectrogram or spectrum curve may be displayed behind the EQ curve.
  15. Select for which channels you want to display the controls over the EQ reponse graph.
  16. Select for which channels you want the analysis curves to be displayed.
  17. Select audio analysis display type (instant spectrum curves, greyscale or color spectrogram).
  18. Main gain controls for each channel.
  19. Auto gain control for each channel. When "auto gain" is selected, the EQ automatically sets the output gain to compensate the maximum peaks set on the EQ, so that the signal's maximum boost is kept at 0 dB.
  20. Click on the channel name or the arrow to switch controls for the other channel, when single display mode is selected with #1 (Dual version only).
  21. Normal or Notch shape for the current channel: see the various EQ modes and shapes in the next chapter for more information.
  22. Smooth or Sharp mode for the current channel: see the various EQ modes in the next chapter for more information.
  23. Mix Control for the current channel: this control acts as a dry/wet balance. You can use it to reduce the amount of EQ applied.
  24. Main EQ controls: boost or cut frequency ranges from bass to treble.

Spectrum and Spectogram

Two modes are available for output spectrum display (post-EQ). In spectrum mode, curves representing the instant spectrum of both channels is displayed (blue is channel 1 and red is channel 2):

In spectrogram mode, the evolution of the spectrum over time is displayed as a color (or greyscale) map. In color mode, louder parts of the spectrum are visible as bright red spots, whereas quieter parts will show in dark blue/black. In greyscale mode, the brighter also means the louder:

The various elements of the user interface (knobs, sliders, buttons...) are simple and intuitive to operate, but more information about how to interact with them is available in the "Plug-ins Basics" chapter of this manual.


Operating the EQ is straightforward: just moving the knobs/sliders or the controls on the graph will boost and cut the frequencies the way you want. There are however a few tricks that may be useful when operating this particular EQ.

Choose your EQ shape

Blue Cat's Liny EQ offers four types of EQ shapes that can be selected using the mode and shape switches. The final curve is built using these shapes, based on the boosts/cuts that you have chosen.

Influence of the mode and shape parameters on final EQ curve

Shape: Normal

With this shape, boosts and cuts have the same bandwith for the same frequency. This results in an unmodified spectrum if two EQs in series are setup with opposite settings. Boosts and cuts are simply symmetric.

Shape: Notch

With this shape, boosts have a larger bandwith than cuts for the same frequency. It lets you produce slightly sharper cuts in the spectrum, and wider boosts.

Mode: Smooth

Smooth mode produces smoother bell-shaped curves, but may create unwanted steps when buikding complex EQ curves.

Mode: Sharp

Create sharper triangle-shaped curves, and reduce the step effect for complex EQ curves.

Select the most suitable layout

The plug-in offers multiple layout options and skins, so you may want to choose your favorite layout for each situation.

For example if you need to save screen real estate and prefer operating in "blind" mode (with your ears only), you can reduce the user interface to its minimal configuration:

Tiny user interface preset

You can browse the factory presets to try several predefined configurations and tweak the plug-in to find your own.

Select the most suitable range

The plug-in lets you select the boost/cut range for the controls and curve display. You should select the range that suits your particular situation: for drastic EQ changes (sound design, track tweaking), you can choose up to 40 dB. On the other hand, for mastering, you will usually need more subtle changes, so using the 10 dB range will give you more precision and avoid "going too far".

Display the spectrogram of each channel separately

In the dual channel version, by selecting the channels below the main graph, you can display each channel separately, or a mix of both channels. Checking individual channels is particularly useful when applying diffrent EQ curves on both channels.

You may still want to keep an eye on the overall spectral balance by selecting both channels, so that the average level is displayed.

Using the "Mix" control

The " Mix" control can be very useful while tweaking the EQ: as a first step, you will usually want to hear the effect of the EQ to clearly define your favorite equalization. Once the result can be heard, you can then reduce the mix parameter to make the changes more subtle, and reduce the effect of the EQ.

On the other hand, when you are experimenting and looking for the best EQ settings, you can start with the mix control set to 50%: while tweaking the curve, you can increase or decrease the mix control to check wether more or less equalization sounds better or worse, without having to change boosts and cuts for all bands.

Dynamic EQ / Side Chain

All the parameters of the plug-in support automation and MIDI control. So, when used in combination with our MIDI and automation generation plug-ins, this plug-in can easily be transformed into a dynamic EQ, with linear phase!

A typical example is to use the Blue Cat's DP Meter Pro plug-in to generate a MIDI envelope that follows the input signal and assign it to the Mix parameter of the Liny EQ plug-in, once your EQ has been set. This way, the amplitude of a track (that can be different from the track being EQ'ed) will control how much EQ is applied.

This advanced side chaining principle can also be applied to individual bands gain values, to dynamically control each band separately (potentially with different tracks as well).

You can read more about such techniques in the Tutorials section of our website.

Blue Cat Audio Plug-Ins Basics

This chapter describes the basic features that are common to all our plug-ins. If you are already familiar with our products, you can skip this part.

User Interface Basics

About Skins

Like all Blue Cat Audio plug-ins, Blue Cat's Liny EQ uses a skinnable user interface. It means that the appearance and behavior of the user interface can be entirely customized.

Especially with third party skins, the experience may be quite different from the one offered by the default skins that we provide. However, our plug-ins and our skinning engine have several standard features that will be available whatever your favorite skin.

More information about custom skins can be found in the skins section.

The Main Toolbar

In most skins, an optional toolbar at the top of the user interface gives you access to the main options and settings of the plug-in:

Smooth Bypass

On the left, the power button can be used to smoothly bypass the plug-in.

Presets Area

At the center of the toolbar, you can see the current preset area (the "Default Settings" box). It displays the name of the current preset, with a "*" at the end if it has been modified since loaded.

The arrows on the left and right let you navigate thru the (factory and user) presets available for the plug-in.

Clicking on the preset name opens the presets menu which lets you manage the presets of the plug-in.

Using the knob on the bottom right of this area, you can reduce the opacity of the window, and make it transparent (the actual result may depend on the host application). Additional messages may appear in the area next to this knob, depending on the plug-in.

Some plug-ins may also propose you to manually select the audio I/O inside the plug-in (bottom left of the presets area), regardless of the host configuration. It can be useful for example to save CPU by selecting mono to stereo configurations (instead of full stereo sometimes chosen by default by the host), or add extra channels to manage side chain internally, when the host does not provides any side chain input. Please note that this does not change the number of I/O seen by the host application.


The icons in the toolbar give you access the to the following commands that are detailed in the next paragraph:

Icon Name Function
Menu Open the main menu
Control Settings Display the controls settings menu (to manage automation and MIDI control, as described here).
Undo Undo
Redo Redo
Manual User Manual
About About
Zoom Scale the user interface (from 70% to 200%).

The Main Menu

The main menu is available from the main toolbar, or if you right click anywhere on the background of the plug-in:

  • Presets: opens the presets menu to manage presets.
  • Preset Skin: opens the skins menu to choose the skin for the current preset and manage alternative skins for the software.
  • Undo/Redo: undo or redo the latest modifications. This includes all changes made to the current preset settings such as MIDI or automation preferences.
  • Presets Settings: open the presets settings window. It lets you change the skin, MIDI and automation settings for the current preset.
  • Global Settings: open the global settings window. It lets you change the skin, MIDI and automation settings that are used by default in all instances of the plug-in (if not overridden by the current preset).
  • User Manual: open this user manual.
  • Check for Updates: opens up our website to let you check if any update for this software is available.
  • Get More Skins: get more skins for this software.
  • Legal Information: browse licensing and misc legal documents.
  • About: displays the “about” dialog box.



Here are a few examples of typical controls you will encounter in the user interface of our plug-ins:

slider slider knob button Text control

Interacting with Controls

You can interact with the controls of the plug-in interface either with the mouse or the keyboard.

Setting the keyboard focus on a control (so that it responds to key strokes) may be automatic (when you pass the mouse over it it gets focus) or manual (you have to click on the control to set the focus on it). Note that all host applications behave differently regarding keyboard handling. In some applications you may not be able to use all keys described later in this manual to interact with our plug-ins. It is usually made obvious to you to know the active surfaces of the skin (the places where you can click with the mouse): the mouse cursor usually changes when you can do something on a control. In the default skins delivered with the plug-in, the cursor changes to a small hand or an arrow to tell you when your mouse is over an active control.


Various mouse movements will let you interact with the controls:

Mouse Interaction Action
Left Click Acquire focus and start dragging or push (button)
Left Click + Alt Key Set the value to default
Left Double Click Acquire focus and launch the “fine tuning” edit box (except button):
Right Click Set the value to default
Mouse Wheel Increment or decrement the position (focus required)
Mouse Drag Change the control position depending on mouse movement (except button)


All control widgets support the following keys (note that some of them are caught by the host and thus never forwarded to the control. For example in Steinberg Cubase SX you cannot use the arrow keys to control the plug-in):

Keys Common to All Controls

Key Action
Up Arrow Small increment of the position (up or right)
Down Arrow Small increment of the position (down or left)
Left Arrow Same as Down Arrow
Right Arrow Same as Up Arrow
Page Up Large increment of the position (up or right)
Page Down Large decrement of the position (down or left)
+ Small increment of the value of the control
- Small decrement of the value of the control
d Set to default value (same as mouse right click)
e Opens the 'fine tuning' window to precisely set the parameter:
SHIFT When the key is down, the fine tuning mode is on, and you can modify the value with better precision when moving the mouse, the mouse wheel or using the keyboard. Just release the key to get back to the normal mode.

Keys Specific to Buttons

Key Action
Enter Pushes the button


To get started with the plug-in and discover its capabilities, a couple of factory presets are provided. You can also save your own presets and recall them later for other projects. Our plug-ins propose a full-featured preset manager to let you save, browse, organize and recall its presets.

The Presets Menu

The presets menu can be opened from the main menu or the main toolbar. It displays the list of presets available for the plug-in as well as commands to load, save or organize presets:

  • Factory Presets: shows the list of factory presets delivered with the plug-in.
  • "Folder A" to "User Preset Z": user presets and categories.
  • MIDI Program Change: activate MIDI Program Change support (see below).
  • Load: load preset from file.
  • Save: save current state to last loaded user preset.
  • Save As: save current preset to a file.
  • Copy copy preset to the system clipboard.
  • Paste paste preset from the system clipboard, if available.
  • Save As User Default: save the current state as the default preset. This preset is used every time a new instance of the plug-in is created.
  • Clear User Default: reset the default preset to its factory state: this makes the plug-in forgets the custom settings you might have saved as a default preset.

More about Presets

There are two types of presets: factory presets (read only) that are provided with the plug-in, and user presets that can be created and stored by the user.

The user presets are stored in a subdirectory of the documents folders of your profile ("Documents" on Mac, and "My Documents" on Windows): Blue Cat Audio/[Plug-in Name]/Presets. Each preset is stored as an individual file. You can create folders and subfolders in the Presets directory to classify your presets, as shown in the example below:

If you save a preset named "Default" in the root Presets directory, it will override the factory default preset (that's what "Save As Default" does). To restore the factory default preset, you can just remove this file or use the "Reset Default" command.

MIDI Program Change

It is possible to load presets remotely using MIDI "Bank Select" and "Program Change" messages. To enable this feature, select a MIDI channel to receive the events from in the MIDI Program Change menu item from the presets menu:

This setting is saved for each plug-in istance with your session but not in presets (except for the default preset, using the "Save as User Default command"). Once activated, the plug-in menu will display the bank number followed by the preset number for each preset:

Every root folder is considered as a new bank, starting with the factory presets (bank 0). Program and bank numbers may change while you add folders and presets, so you should be careful when naming them if bank and program numbers matter to you. It is recommended to use folders to make this task simpler. As a side note, sub folders do not define additional banks (all presets contained in sub folders are associated with the current bank.

As specified by MIDI, bank select messages are not used until a program is actually selected.

MIDI Implementation note: the software supports all types of Bank Select methods. You can use either MIDI CC 0 or MIDI CC 32 to select banks. If both are used simultaneously, they are combined together so that you can use more banks (in this case CC0 is LSB and CC32 is MSB, and actual bank number is 128*CC0+CC32).

MIDI and Automation Control

Blue Cat's Liny EQ can also be remotely controlled via MIDI using MIDI CC ("Control Change") messages or automation curves, if your host application supports it. It is possible to customize the channel, control numbers, range and response curve used for each parameter in the settings panel available from the main menu (see the Plug-in Settings chapter for more details).

MIDI and Automation Settings Menu

The main menu

Most skins also provide the ability to change MIDI and automation settings directly in the main user interface. Clicking on the control settings icon in the main toolbar opens the following menu:

  • Show Control Settings: show direct access to individual control settings for each parameter in the user interface (see next paragraph).
  • Lock Control Settings: lock the current controls settings for MIDI and automation so that they remain unchanged when loading presets.
  • Use Global Control Settings: ignore the current MIDI/automation settings and use the global settings instead.
  • Control Settings Window: display the control settings window, to change control settings for all parameters.
  • Save As Global Control Settings: save the current settings as global settings (used by default, when no specific MIDI/Automation setting has been set for the cuirrent preset).

Individual Control Settings

When this feature is activated using the "Show Control Settings" item in the MIDI and Automation Settings menu, dropdown menu buttons appears next to the main controls displayed by the plug-in:

Clicking on this button shows the MIDI/Automation settings menu:

  • MIDI Learn: launches MIDI learn mode for the control: touch your MIDI controller and the control will learn from it the MIDI channel and CC number. To end the learn mode, reopen this menu and deselect the option.
  • MIDI Unlearn: deactivates MIDI control for this parameter.
  • Control Settings: launches the advanced settings panel described below. This controls the settings for the current preset.
  • All Control Settings: display the control settings window, with access to all parameters.

Advanced MIDI and Automation Settings

You can completely customize the way the plug-in is controlled by automation and MIDI. For a global view of all parameters at a time, you can use the Plug-in Settings window for the current preset which is available from the main menu.

MIDI Settings:

  • Enable MIDI: enable/disable the MIDI control of the parameter.
  • Channel: MIDI Channel for the parameter control. If set to 0, the plug-ins will accept Control Change Messages from all MIDI Channels (MIDI Omni mode).
  • CC: Control Change Number.
  • Learn: click on this button to activate the MIDI learn functionality. When it is activated, you can move your MIDI controller, and the plug-in will automatically set the MIDI Channel and CC Number.

MIDI and automation settings:

  • Response: response curve of the MIDI or automation control: from very fast to slow control.
  • Min: minimal value of the parameter when MIDI controlled or automated.
  • Max: Maximum value of the parameter when MIDI controlled or automated.

Note: if the Min value is higher than the Max value, the response curve will be reversed: increasing the control value will decrease the parameter value.

Note: if you double click on the parameter text control boxes for the max and min values, a “fine tuning” edit box will appear and let you change the min and max values with more precision:


Check our online tutorial for more screenshots and more examples of our plug-ins user interfaces.

Blue Cat's Liny EQ Parameters

All parameters described below can be automated and controlled via MIDI if your host application supports it. You can precisely define this behavior in the settings panels described later in this manual.

All parameters (except bypass and stereo mode) are duplicated for each channel in the dual channels version.





Bypass the effect.

Stereo Mode


Stereo processing mode (Dual channels version only).



Main gain.

120Hz, 330Hz, 640Hz, 1.2kHz, 2.5kHz, 5kHz, 10kHz, 16kHz


Gain for each frequency band.


'Normal' or 'Notch'

Shape of the filters. When set to 'Normal', boosting and then cutting an EQ band by the same amount cancel each other. In Notch mode frequency cuts are narrower than boosts (for a notch filtering effect).


'Smooth' or 'Sharp'

Interpolation mode between bands. 'Smooth' produces smoother bell-shaped curves, whereas 'sharp' produces sharper and flatter curves.



Amount of EQ. Reducing this value will reduce the amount of EQ applied.



Enable/Disable audio analysis.

Plug-in Settings

In addition to the controls offered in the main user interface, Blue Cat's Liny EQ has various settings that let you fine tune the behavior of the plug-in. You can choose to change these settings either for the current preset or globally for all instances of the plug-in.

The Global Settings Window

The settings available in this window apply to all instances of the plug-in, for all presets, if not overridden in the presets settings. Consider these settings as “default” settings.


You can change the default skin for all instances of the plug-in: write the skin file path in the text edit box or click on the button to open a file chooser dialog. If you have several instances of the plug-in opened in your session, you will have to re-open the user interfaces of these plug-ins to see the skin change.

The output data refresh rate can also be customized for all instances of the plug-in. It controls the refresh rate of non-audio data produced by the plug-in (parameters, curves...). It also controls the refresh rate of output MIDI CC messages or output automation data. The higher the refresh rate, the better precision, but also the higher cpu usage (some host applications may also have trouble recording MIDI data at high refresh rates). The default value is 50 Hz.

Global Control Input Settings (MIDI and Automation)

The plug-in offers a couple of settings that affect the way it is controlled by MIDI messages or automation. While the first settings only apply to MIDI control, the "Control Response", "Min" and "Max" settings apply to both automation and MIDI control.

For each parameter you can define a default MIDI channel and CC number. You can then control the plug-in with an external MIDI controller or one of our plug-ins that generate MIDI messages.

The settings below are available for each plug-in parameter.

MIDI Settings:

  • Enable MIDI: enable/disable the MIDI control of the parameter.
  • Channel: MIDI Channel for the parameter control. If set to 0, the plug-ins will accept Control Change Messages from all MIDI Channels (MIDI Omni mode).
  • CC: Control Change Number.
  • Learn: click on this button to activate the MIDI learn functionality. When it is activated, you can move your MIDI controller, and the plug-in will automatically set the MIDI Channel and CC Number.

MIDI and automation settings:

  • Response: response curve of the MIDI or automation control: from very fast to slow control.
  • Min: minimal value of the parameter when MIDI controlled or automated.
  • Max: Maximum value of the parameter when MIDI controlled or automated.

(generic screen shot, does not correspond to the actual plug-in parameters)

Note: if the Min value is higher than the Max value, the response curve will be reversed: increasing the control value will decrease the parameter value.

Note: if you double click on the parameter text control boxes for the max and min values, a “fine tuning” edit box will appear and let you change the min and max values with more precision:

"Send MIDI events when parameters values change": activate this option when using a control surface that accepts MIDI events as input. MIDI messages will be sent to the output of the plug-in when the user change the parameters values in the user interface, to keep the software and the controller in sync. MIDI is only sent for parameters that are activated for MIDI control.

The Current Preset Settings Window

In this window you can change the settings for the current preset of the current instance of the plug-in only.

Preset Skin

You can choose to use the global skin setting or to change the skin for the current preset. This way you can have different skins for different instances of the plug-in in the same session in order to differentiate them.

Preset Control Input Settings (MIDI and Automation)

Use the global settings or override them for the current preset. The parameters are the same as for the global input settings.

(generic screen shot, does not correspond to the actual plug-in parameters)

About Skins

Blue Cat's Liny EQ integrates Blue Cat's skinning engine that allows you to customize the user interface. You can download alternate skins for your plug-in at the following address:

If you don't find a skin that fits your need or if you want a custom one, you can choose to create your own skin.

Choosing the Skin

There are two ways to select the skin of your plug-in: you can change the default (or 'global') skin, or change the skin for the current preset only (either in the preset settings page or from the main menu). The global skin applies to all plug-in instances (choose this one if you want to use the skin used by default, regardless of the session or preset), whereas the current preset skin only applies to the current preset of the current plug-in instance (use this one if you want to change only the skin for the current session/preset).

Note: in some host applications, the plug-in window won't resize automatically when you choose a skin with a different size. In this case, just close the window and re-open it: it will be displayed with the right size.

The Skins Menu

The skins menu can be opened from the main menu. It displays the list of skins available for the plug-in as well as commands to manage the skin used by default when no preset skin has been selected:

  • First Section - Factory Skins: shows the list of factory skins delivered with the plug-in ("Default" and "Light" in this example).
  • Second Section - User Skins: shows the list of user skins that have been installed in the Documents Skins folder for the plug-in (see below).
  • Use Global Skin: use the global skin for the current preset/session (unloads any custom skin previously selected for the current preset).
  • Load: opens a file browser dialog to manually select the skin from the file system.
  • Save As Global Skin: use the current preset skin as the global skin (loaded by default if no preset skin has been defined).

Installing User Skins

To select user skins directly from the skins menu, install them in the "Skins" directory available in the plug-in's documents folder:

[Your Documents Folder]/Blue Cat Audio/[Plugin Name]/Skins/

The skin engine will scan this folder for new skins (xml files) and display them in the menu. The skin files should be in the root skins folder or in a subdirectory inside this folder: subdirectories are not scanned recursively.

Other Methods to Select Skins

You can also select the skins in the settings panels available from the main menu:

The global skin (used by default if no preset skin has been selected) can be changed in the global settings pane. The current preset skin can be changed in the preset settings page .

Create a Custom Skin

You can create custom skins for your plug-in in order to adapt it to your exact needs. You can change its look and feel and make it completely integrated in your virtual studio!

Just read the Blue Cat's Skinning Language manual and download the samples for the tutorial on You can get ready to create your own skins in a few minutes. You can then share your skins on our website.


This manual only covers the main aspects of Blue Cat's Liny EQ. Our website offers many additional resources for your Blue Cat's Liny EQ plug-in. It is constantly updated, so keep an eye on it!


As you can see in the history log below, we care about constantly updating our products in order to give you the latest technology available. Please visit our website often to check if Blue Cat's Liny EQ has been updated, or subscribe to our Newsletter to be informed of the latest news about our products.

Note: minor version updates are available from the same location as the original full version download (link received by email upon purchase). The demo version publicly available on our website will not let you register.

You can also follow us on twitter, facebook and instagram for almost real time updates notification, and subscribe to our YouTube channel to watch the latest videos about our software.

Versions History

V5.21 (2022/12/12)

  • Added Apple Silicon support for AAX Plug-in Format.
  • Fixed VST3 version not always loading properly in Ableton Live 11.
  • Improved VST parameter value display in some host applications.
  • Added an option in global & preset input settings to send MIDI events when MIDI-enabled parameters are modified in the plug-in (to update control surfaces accordingly).
  • Improved undo management and automation when using the mouse wheel to move knobs.
  • AAX: Fixed erratic mouse behavior in Pro Tools on Mac.
  • Mac: installers and plug-ins have been notarized to avoid security warnings on Mac OS Catalina and newer.

V5.2 (2021/10/19)

New Features and Improvements:
  • Refreshed GUI design, with improved usability and touchscreen support.
  • The GUI can now be zoomed from 70% to 200%.
  • New high resolution graphics for knobs.
  • Now supports retina displays on Mac (high resolution).
  • Last loaded preset is now remembered in session and displayed in the presets menu.
  • Plug-in state can now be reverted to the last loaded preset.
  • Improved MIDI & automation control settings with lock, reset and "save as global setting" capabilities.
  • MIDI Program Change preference is now saved into session instead of global preferences, so each instance can now use different MIDI channels. It is also saved in the user default preset.
  • VST3: added program change support for VST3 plug-in format.
  • Mac: faster GUI rendering on recent Mac OS systems (up to 8x faster).
  • Spectrum analysis is now performed in the background and does not affect audio performance.
  • Level meters, spectrum analyzers and tuner stop processing when the user interface is closed, reducing CPU usage.
  • Reduced disk footprint.
  • Full Unicode Support.
  • Mac: new installer.
  • Updated demo limitations: up to 5 instances allowed, bypass time changed to half a second, and bypass parameter is not affected anymore.
  • VST: the user interface is now properly resized in Cubase on Windows.
  • VST3: fixed random crashes in Ableton Live 11 when inserting the plug-in.
  • Mac: Fixed keyboard not responding in registration panel in some host applications (LUNA, Garage Band...).
  • Mac: Fixed demo version that could hang Logic when reloading projects using the plug-in.
  • Mac Audio Unit: fixed plug-in listing in some host applications (Plogue Bidule).
  • Native Apple Silicon (M1 processor) support.
  • Now compatible with Mac OS Catalina, Big Sur and Newer.
  • Dropped support for Windows XP and Mac OS X 10.8 and earlier.
  • Dropped 32-bit support on Mac.
  • Dropped support for legacy RTAS and DirectX plug-ins formats.
  • Fully compatible with previous versions of the plug-in (except for VST3 on Mac, as explained below).

Warning: because of a bug of the initial VST3 release, this new version may not work with existing sessions that used the VST3 format. See this blog post for more details and how to fix it.

V5.1 (2016/03/03)

  • VST3 plug-in format support.
  • Custom skins can be selected directly from the main menu.
  • Presets can now be selected using MIDI Program change and bank select messages (optional).
  • Last loaded preset can now be saved directly from the presets menu without having to select the file.

V5.02 (2014/01/09)

New Features:
  • Audio Suite support for offline processing in Pro Tools (AAX).
  • Copy/paste the plug-in's current state from the presets menu using the system clipboard.
  • Reduced the plug-in's memory usage.
  • Windows VST Installer now remembers where the plug-in was initially installed to simplify upgrades.
  • (Mac) plug-in version number is now available when using "Get Info" in the Finder.
  • (Mac) Improved display of Audio Unit parameters in most host applications.
Bug Fixes:
  • Fixed window frame not showing with Cubase 7.5 (32-bit) on Mac.
  • (Mac) About window does not show up first in the corner of the screen anymore.
  • (Win) Alt-Click on a control now resets the value to default in Pro Tools, as expected.
  • Fixed version number reported to host application for VST and Audio Unit versions.

V5.01 (2013/06/21)

  • 64-bit AAX support for Pro Tools 11.

V5.0 (2013/05/23)

New Features:
  • Brand new, fully customizable user interface:
    • New look and feel.
    • Show/hide what you need.
    • New EQ curve display.
    • New instant spectrum curves display.
    • New color or greyscale overlayed spectrogram view.
    • New output peak levels meters.
    • Multiple display sizes.
    • Improved readability.
    • Animated transitions.
  • New "mix" parameter for instant dry/wet control or side chain dynamic equalization.
  • New interpolation mode for up to four different EQ shapes.
  • Now includes both single and dual channels versions and superseds the three plug-ins previously included in the Blue Cat's Liny EQ Pack bundle.
  • Spectrum and spectrogram displays can be frozen to capture spectral snapshots
  • New integrated presets manager:
    • Load/save presets from the plug-in's user interface.
    • Organize presets with folders.
    • Customize the default preset.
    • Exchange presets easily.
  • Automation range and response curve can now be customized for each parameter (in and out).
  • Automation and MIDI settings (channel, MIDI learn etc.) are now accessible from the main user interface.
  • AAX plug-in format is now also supported on Windows (Pro Tools 10.2 required).
  • Different EQ shapes can now be selected for each channel.
  • New presets to get started faster.
  • The windows installer now automatically detects the most appropriate VST install path.
  • License is now shared between plug-ins types (register only once for all formats).
  • Improved value display in fine edit window.
  • Improved parameters display on control surfaces.
Optimizations and Performance Improvements:
  • Improved parameters precision (now stored as 64-bit).
  • More compact presets format (uses less space and loads faster).
  • Smaller binaries on Mac (dropped PowerPC support).
Bug Fixes:
  • (RTAS) Fixed parameters control with EUCON control surfaces in Pro Tools.
  • Fixed user interface issues in Final Cut Pro X.
  • Fixed user interface display issues in Wavelab on Mac.
  • Fixed keyboard stealing issue in Digital Performer 7 on Mac.
  • Fixed copy/paste keyboard shortcut issues in the registration panel on Mac.
Note: this new version can be installed side by side with the previous version for backward compatibility reasons. Installing this new version won't break your previous projects.

V4.11 (2011/02/10)

  • Fixed keyboard focus stealing issue in Pro Tools and several other host applications.
  • 64-bit Mac VST support.

V4.1 (2010/05/04)

  • RTAS plugin format support for Pro Tools (Mac and Windows).
  • 64-bit applications support for Windows DX and VST under Windows x64.
  • Mac AU 64-bit format support (compatible with 64-bit Logic 9.1 on Snow Leopard)
  • Space bar does not trigger plug-in buttons anymore (avoids conflict with transport control in most applications).
  • Demo version now displays a nag screen only once per session, and only when opening the user interface of the plug-in.
  • Fixed MIDI learn issues.
  • Fixed issue with EQ curve type that was sometimes not properly recalled.
  • Mac: fixed user interface crashes in some hosts under Snow Leopard.
  • Mac: fixed keyboard/mouse focus issues in some hosts.
  • Mac: fixed multiple screens issue.
  • Mac-AU: fixed settings lost issue when doing offline rendering in some applications.

V4.01 (2009/05/05)

Mac VST update: fixed incompatibility issues with Cubase 5 on Mac.

V4.0 (2009/03/09)

  • Mac Audio Unit support.
  • Mac VST Support.
  • New user interface design.
  • The plugin now offers two types of EQ curves.
  • EQ range is now customizable.
  • Undo/Redo support.
  • Preset import/export in a host independent format.
  • Window opacity control for plugin transparency.
  • New Windows installer.
  • New documentation.
  • This version is installed as a new plugin because of the new parameters. You can keep the previous version and this one side by side.

V3.0 (2006/11/29)

  • Advanced MIDI control with customizable parameters curve response and MIDI learn.
  • Now supports Blue Cat's Skinnning language 1.2.4 with several skins per session.
  • Parameters can be fine tuned when the shift key is down, which offers a .1 dB gain resolution.
  • CPU efficiency improvement: no processing occurs when input is silent.
  • Settings window now loads faster.
  • (Bug fix): in some plug-in adapters (such as FxPansion's VST to RTAS adapter) the GUI did not display properly when first loaded.
  • (Bug fix): when reinstalling the software in another directory, the "skin not found" message was displayed.
  • Warning: because it now supports MIDI events, the DirectX plug-in may appear in the "Synth" or "DXi" category instead of "effects" in some hosts (such as Cakewalk Sonar). If it does not appear in you host, you might want to use our DXi Manager to de-activate MIDI features.
  • Warning: this new version breaks the presets compatibility.

V2.0 (2006/06/19)

  • New skinnable user interface, with several skins included.
  • Blue Cat's Skinning Language 1.1 support, for an easy user interface customization.
  • User manual available from the user interface.
  • (Bug fix): no more constant -3dB offset on global gain.
  • (Bug fix): the VST version now reports the latency to the host.

V1.2 (2005/06/17)

Brand new GUI.

V1.1 (2005/05/17)

  • Right clicking on a slider now sets the default value of the parameter
  • (Bug fix): smooth update mechanism did not work properly on very fast variations

V1.0 (2005/04/19)

First release.

Thanks again for choosing our software!

See you soon on!