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USer Guide - Studio Legacy EQ

Sonic legacy that you can now enjoy in your own studio


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The Legacy EQ is a plugin that recreates the sound and feel of our classic MPC digital equalizer: a versatile and musical EQ that was originally designed as an analog circuit with digital control, and later became a digital staple in high-end post-production and film studios around the world. The Legacy EQ lets you shape your mix with smooth and precise control: each band has a limited and carefully chosen range that matches the original analog knob, and the Q factor is optimized to give you the best results for each frequency. Whether you need to add some sparkle, warmth, punch, or clarity to your tracks, the Legacy EQ will help you achieve professional sound quality with ease.



  • Comprehensive main display
  • 5 flexible and powerful parametric parametric EQ bands
  • Choose the shape, Q, and gain with EQ band controls
  • 6 EQ Band Shapes each with their own sound
  • 2 filters with selectable shapes
  • Get a detailed and accurate view with High-precision RTA analyzers


Comprehensive main display


Shape your sound with the AVA LegacyQ’s main display graph. You can drag a band’s icon to set its frequency and gain. You can use the mouse-wheel or 2-finger drag to change the band’s Q. The main display also shows you a high-quality, fast RTA analyzer that you can switch to be PRE or POST EQ. You can adjust the speed and trim of the display to suit your signal. The AVA LegacyQ will make your mix sound better by giving you a clear and easy way to control your EQ.


The LegacyQ controls can be divided into 3 categories: EQ Graph, RTA controls and Band/Filter controls. 


The EQ Graph provides a visual display of the EQ curves and also allows for direct hands-on control of the bands and filters. 


Just below the graph are the RTA controls. These are used to adjust various RTA settings such as toggling the RTA on/off and selecting the RTA Type.


The Band and Filter control sections are displayed across the lower portion of the plugin window. These sections provide more in-depth control over the corresponding bands on the graph.


There is also a knob to control the EQ’s output trim on the right, between the graph and control sections.  

RTA Controls

The RTA (real-time analyzer) offers a visual representation of the spectral characteristics of the audio signal being processed. The RTA display is calculated using a Discrete Fourier Transform, which provides high resolution data even in lower frequency ranges.


The first button on the left, labeled “ANALYZER” toggles the RTA on or off. 


You’ll notice that turning the RTA on will enable the RTA Range ruler on the right side of the graph. This shows the level of the RTA measurements on the graph and can also be used to adjust the RTA Trim or Zoom (See RTA Trim section below for details). 


The Post button sets the input signal to the RTA from Pre-EQ to Post-EQ when toggled on. If you want the RTA measurements to be affected by your EQ adjustments, you should enable this option.

The Decay knob controls how long RTA measurements are displayed before they ramp back down to zero. If the RTA display is changing too rapidly to be useful, you should increase the Decay value. Likewise, if the display appears to be “frozen”, try decreasing the Decay as this might be the result of an excessively high Decay value. 

The Length knob is only available in Scroll mode and essentially controls the scroll speed of the spectrum data. If the display is scrolling too quickly or if you would like to see more of the spectrum’s history, you should increase the Length value. 

The Type dropdown menu selects between the 4 modes of operation:  Graph, Scroll, Bar, or Lightning

For multi-channel configurations, the Channel Mode dropdown menu will allow you to select individual channels for the RTA to listen to. This option defaults to “Sum” mode, which sums all the available channels together for the RTA to read from. The Channel Mode selector will be disabled if the channel configuration is mono. 

NOTE: Summing multi-channel audio may produce misleading RTA measurements due to the potential phase difference between signals. Selecting an individual channel for the RTA channel mode will provide the most accurate RTA measurements.


RTA Trim

The Trim of the RTA’s input signal can be adjusted on all RTA types by clicking the ruler to the right of the display and dragging it up or down. This can be used to increase or decrease the RTA’s sensitivity to the signal being fed to it.

When the RTA is in Bar or Scroll mode, the ruler will display the levels of brightness that correspond to each intensity value along the vertical axis. The levels of brightness displayed on the ruler will change accordingly when the Trim is adjusted.  

In Graph and Lightning modes, the scale of the vertical axis can be zoomed by right-clicking the ruler and dragging up or down. 

The RTA Trim / Zoom can be reset to their default states by Alt-clicking or double-clicking this ruler. 


RTA Modes


In Graph mode, energy is represented by the vertical position of the RTA across the horizontal frequency spectrum. High-energy points can be easily recognized as “peaks” in the RTA graph.



In Scroll mode, the RTA is displayed as a vertically-scrolling spectrogram, providing you with additional time to recognize and target certain spectral characteristics of the audio signal.


In Bar mode, the distribution of energy is represented by the brightness level of the vertical bands that flash across the spectrum.



In Lightning mode, the RTA is displayed as a horizontal curve which is the calculated average of the actual curve. Bright flashes occur along the spectrum in areas where the peaks are greatest above average.

EQ Band & Filter Controls

In addition to using the EQ graph, the individual band and filter parameters can also be adjusted by the corresponding controls below the graph. These allow you to toggle bands on or off and adjust the shape, frequency, Q, and gain. The square button at the top left of each control section toggles the respective band or filter on or off. 


The dropdown menus at the top right can be used to select the EQ shape for the corresponding bands. The shape and pole (slope) options for the bands and filters are listed below.

Bands 1-5:

  • Low Pass (6, 12 dB/octave)
  • High Pass (6, 12 dB/octave)
  • Low Shelf (12 dB/octave)
  • High Shelf (12 dB/octave)
  • Bell
  • Notch (infinite “cut” at the selected frequency, with adjustable Q width)
  • Search (filters all frequencies above & below the center frequency to help locate specific sounds)

Filters A & B:

  • High/Low Pass (6, 12, 24, 36, 48 dB/octave)
  • Low/High Shelf (12, 24, 36, 48 dB/octave)
  • Wide Notch (4 closely-spaced notches;  this allows easier tuning of the notch frequency, because it affects a wider frequency range than a typical notch ) 

Frequency, Q, and Gain

The frequency, Q, and gain for each band/filter can be adjusted using the corresponding knobs and labels in the control sections. Each of these parameters can be adjusted either by turning its knob or by typing the desired value directly into the control label. For ease of use, these will accept bare numbers such as “500” or numbers with units such as “500Hz”, “1k”, “1kHz”, “20dB”, etc. 


All knobs and labels can be reset to their default values by Alt-clicking or double-clicking them.


Note that some of these parameters may be disabled for certain shapes. For example, selecting a Low Pass shape on a band will disable its Q and gain controls since those parameters do not apply to that particular shape. 


Control Behaviors & Shortcuts

Various mouse & keyboard shortcuts can be used to perform certain actions on the following controls:


Band Controls

Action Shortcut
Reset Gain to default Double-click
Reset Frequency, Gain and Q to default Alt-click
Adjust Q

Right-click & drag 

Shift-click & drag

Scroll mouse wheel

Temporarily put in Search mode Hold down Control while adjusting or hovering over a band
Fine adjust Frequency and Gain Command-click & drag (OSX Only)

Graph Rulers

Action Shortcut
Reset Pan & Zoom or Trim



Fine adjust Pan or Trim

Shift + Left-click & drag

Control + Left-click & drag (Windows only)

Command + Left-click & drag (OSX only) 

Fine adjust Zoom

Shift + Right-click & drag

Control + Right-click & drag (Windows only)

Command + Right-click & drag (OSX only)

Adjust Pan Scroll mouse wheel
Adjust Zoom Shift + Scroll mouse wheel

Combo Boxes (Drop-down menus)

Action Shortcut
Reset to default Alt-click
Scroll through menu items without opening menu Scroll mouse wheel
Select next/previous item (menu must already be open) Keyboard arrows
Close menu (if open) ESC


Action Shortcut
Reset to default Alt-click
Fine adjust

Shift-click & drag

Control-click & drag (Windows only)

Command-click & drag (OSX only)

Adjust value Scroll mouse wheel
Close editor (discarding changes) ESC
Close editor (submitting changes) Enter


Action Shortcut
Reset to default



Fine adjust

Shift-click & drag

Control-click & drag

Command-click & drag (OSX only)

Adjust value Scroll mouse wheel

Additional Features


At the top-right corner of the plugin window are the Momentary Byass and Settings buttons.

Momentary Bypass

The Momentary Bypass button bypasses the plugin for as long as it's held. This is useful for auditioning A/B comparisons quickly. 



The Settings button reveals a pop-up menu where the window size and theme can be adjusted. It also contains a link to the plugin manual and version info at the bottom.


System Requirements

Your system must meet the following requirements in order to run Harrison plugins:

  • Windows 7 or higher
  • Mac OS 10.9 or higher
  • Linux GCC 5 compatible systems
  • OpenGL 3.2 or higher
  • libcurl-gnutls on Linux

macOS M1/ARM Support: This plug-in is provided as a universal binary for macOS and features native M1 support.

Note for Pro Tools users: Pro Tools 11 or higher is required on Mac, 10.3.5 or higher is required on Windows.

Additional requirements on Windows

Harrison plugins require the “Windows C++ Universal Runtime” to be installed on your computer.  Universal runtime is part of the system’s core libraries on Windows 10. On Windows versions Vista to 8.1,  it will be automatically installed via Windows Update. It is also possible to install the runtime manually, but that is outside the scope of this manual.

Note for Linux Users

If you’re experiencing issues with the plugin’s graphics or the GUI isn’t showing up correctly on Linux, make sure your system’s graphics driver supports the minimum required OpenGL version of 3.2 or higher. To check this, run glxinfo | grep Max in a terminal window and make sure that the value listed for the OpenGL core profile version string is at least 3.2 or greater.


If your core profile version meets this requirement but you are still experiencing graphics issues like the ones mentioned above, it is likely that your system is reporting an OpenGL version lower than 3.2 to ensure backwards compatibility with deprecated OpenGL functions. To work around this, you can force the system to report an OpenGL version of 3.2 or higher by setting this environment variable: MESA_GL_VERSION_OVERRIDE=3.2


You can use this as a prefix when opening your DAW from a terminal command like so:


MESA_GL_VERSION_OVERRIDE=3.2 {command_to_launch_program}


Installation & Licensing

Licensing on macOS & Windows

This plugin is licensed through iLok on macOS and Windows. Visit iLok, Licensing and Activation for guidance on activating your Harrison plug-in. 

Licensing on Linux

This product includes software developed by the OpenSSL Project for use in the OpenSSL Toolkit (

In DEMO mode, after using the plugin for a certain amount of time, it will display a message:

This message will come up periodically unless a license is provided. You can purchase a license directly from Harrison’s web store or from an authorized plugin reseller. Once you’ve purchased a license, install it by entering your license key into the designated field on this screen. Continue to the next section for detailed instructions on how to obtain your license key. 

Obtaining your License Key

After you purchase a license, you will receive a license key that will look something like this:

{your  name}*AVA-BF*DC-138971-151520-1|gGLbnvCZJe386ULohzfQN6cIsoZ71n7c+AUg==|

This license key is required to install your license and activate the full version of the plugin. The way to obtain your license key varies depending on where you purchased the license from.

If you purchased the license from Harrison’s web store, you will receive an email with a link to download a text file containing your license key. If you purchased the license from a reseller, you will receive an email containing the license key text.


Licensing your Plugin

When prompted by the plugin, copy and paste your license key into the designated text input field. This will automatically install your license and register it with the plugin.

Once installed, Harrison’s license files are simple text (.txt) files which are stored in the user’s HOME folder. The HOME folder is the folder that contains your Desktop, Downloads and other folders. The location of your HOME folder is different for each operating system:

  • Linux: /home/{your username}

You may keep a copy of this file for your own use. The license is a per-user license and you may install the license file on all of your computers. To install the file on a new computer, simply save the file to a USB key or other transferable disk; then transfer the license file to the new computer’s HOME folder. The license file has your name encrypted in it, so you should not share it with other people. Your name will appear on the top of the plugin’s control panel to indicate that it is licensed to you.

The plugin will automatically detect your license key as long as the license file is stored in the HOME folder of the computer you are using. After transferring the license file to a new computer, it may be necessary to close and re-open your DAW in order for the plugin to detect the license.

If you don’t want to keep your license in your HOME folder for whatever reason, you may also store it in the following alternative location:  ~/.config/harrisonconsoles

Finding the plugin in your DAW 

DAW operations vary tremendously. Generally speaking, to use the plugin you must follow these steps:

  1. Install the plugins, using the provided plugin installer application.
  2. Follow your DAW’s instructions to “scan” for new plugins.

Please refer to your DAW manual to see which plugin formats (AAX, AU, VST, or VST3) are supported by your workstation.

Most plugin formats require that plugins are installed to a specific location on the system. In these cases, the installer will place the plugins in the default locations.

For VST format, on Windows, it is normally expected that the user defines the location of VST plugins, and tells the workstation where to find the plugins. The default location for VST plugins is C:\Program Files\Steinberg\VST.  The plugin installer will save the VST (.dll) files to that location if a custom VST path is not provided by the OS.  If you are having trouble, you should verify that the path is included in your DAW VST scan paths.


Thank you for purchasing this Harrison plugin!

Harrison has been making products for the audio engineering industry since 1975. We continue to make these products, with intense dedication, from our Nashville, Tennessee factory.  

As the audio industry has changed through the decades, Harrison has too. Originally launched to provide mixing consoles for music recording studios, the Harrison brand has extended to provide products for live broadcast, live sound, theater installations, post-production, film dubbing stages, and bedroom studios. We’ve lived through the launch of the commercial music industry, the maturation of analog, the digital revolution, the establishment of the internet, and now the acceptance of computers as the de-facto platform for the audio industry. In our pursuit of audio excellence, we’ve developed our own analog circuits, digital I/O solutions, digital DSP engines, control surfaces, audio workstations, and nearly every aspect of pro-audio technology.

“If you asked a hundred engineers, mixers and producers to define the “perfect console” you would probably get a hundred answers. The answers, however, would all contain the same salient points.”
“The “perfect console” would have totally transparent sound, capturing the true musical quality of all performances. It would have unlimited features, facilities, and functions. It would perform all required tasks with a minimum of operator effort. It would be totally reliable and require no preventive or corrective maintenance…
You can spend the rest of your life looking for the “perfect console”. You’ll never find it. You will find, however, that we have what you need.”- quote attributed to Dave Harrison;  Harrison MR20 brochure; circa 1982

True-er words were never spoken; indeed every year there are many products and technologies that seem tantalizingly necessary for audio excellence. Our lasting experience has proven that simple, straightforward, well-engineered, and great-sounding tools are the only necessity.

These plugins represent the pinnacle of Harrison’s engineering practices for digital audio sound & workflow. We sincerely hope that you enjoy using these tools as much as we enjoyed creating them. Your continued support is greatly appreciated!