The Secret Weapon to Professional Sound

Whether you're working on music, film, broadcast, or video post-production, a multi-band compressor is a powerful tool for achieving professional-quality results. Use it to control the dynamics of specific frequency ranges, which can be incredibly useful for improving the clarity, punch, and overall sound of your audio.  

Typical multi-band compressors require careful management of dozens of finicky controls. Harrison’s Multi Band Compressor takes a different approach: Each band’s attack, release, and other parameters are calculated by the plugin to get the best possible sound. Internal processing ensures that the combined signal is phase-accurate and has a flat pass-band. The result is a much more natural sound, allowing you to tame problematic frequency ranges without wrecking your instrument’s character. And it works with surprisingly few controls: locate the problem frequencies, choose how much correction to apply, and you’re done!

For artistic effects, there’s a dedicated sidechain input, sidechain eq, and ‘expander’ mode. Enable those features to get traditional pumping and gating effects, or even unusual cross-band effects: drive your low-end compression from a high-pass filtered sidechain, or vice versa.

 

Features:  

• Intelligent algorithm controlling 4 bands of compression.
• Band Solo and Auto-Solo features to help dial in the desired frequency ranges.
• RTA analyzer display helps to locate problem frequency ranges.

• Capable of up to 12dB reduction in each band.
• Sidechain “key” input with dedicated EQ.  
• Ultra low latency processing, suitable for “live” use.

 

Intelligent algorithm:

The intelligent algorithm in the Multi Band Compressor is a powerful tool that will  giving your mix that classic ‘glue’ effect that makes your sound cohesive and balanced. With this powerful tool, you can achieve excellent results that will make your mix sound clear, professional, and amazing.lets you shape the sound of your mix with ease and precision. Whether you need to tame harsh frequencies, enhance the low end, or add some sparkle to the highs, this intelligent algorithm will do the job with minimal effort. so that you can achieve excellent results that will make your mix sound balanced, clear, and professional.

 

Controls:

Graph

The main display graph provides control over the four band frequencies and depths.

Click anywhere inside the bands and start dragging to change frequency and depth of that band. Using the scroll wheel you can adjust just the depth to really dial-in the exact amount you want!

 

RTA Controls:

The main display also features a high precision, high-speed RTA analyzer (“Spectrum Graph”, or “Scrolling Graph”) , which you can engage to be PRE or POST EQ changes. It also features a Decay knob, which allows you to control the decay rate of the display, and a trim control.  

NOTE:  the RTA requires considerable CPU resources and should be disabled when not in use.

 

Harrison’s Multi Band Compressor gives you the flexibility to control the dynamics of your audio in each frequency band. You can reduce up to 12dB of gain in each band, allowing you to tame the peaks, smooth the transients, and enhance the details of your mix. Whether you want to compress the low end, expand the high end, or anything in between, Harrison’s Multi Band Compressor will help you create a rich, full, and balanced sound.

 

Input Threshold Controls:

The main input meter, and threshold slider (on the left) controls how much material is passed into the plugin (-60dB - 0dB).  Moving the threshold slider down (a lower threshold) will increase the overall compression effect.

In addition to that, each band has its own input meter and threshold to let you have fine-grain control over how much material each band is working on (-15dB to +15dB).

Moving the individual thresholds down (lower threshold) will increase the compression effect for that band.

 

Band Bypass and Band Solo Controls:

Every band can be bypassed and removed from processing by clicking on its associated ‘IN’ button.

Every band can also be solo’d so you can hear the material the band is working on.

 

Band Frequency and Band Depth Controls:

The band frequency control controls the low frequency of the band’s bandwidth.  Adjusting a band’s start frequency might affect the width of bands adjacent to it.  The available frequency settings are:

Band 1) 20hz

Band 2) 50 - 400hz

Band 3) 145hz  - 2.5kHz

Band 4) 1kHz - 8kHz

 

Attack, Release, Knee, and Makeup Gain:

• Attack (200μs - 20ms)
  • The ‘Attack’ knob controls how long it takes the signal above the threshold to reach full compression.
• Release (20ms - 200ms)
  • The ‘Release’ knob controls how long it takes the signal, once it falls below the threshold, to return to an uncompressed state.
• Knee (3dB - 24dB)
  • The ‘knee’ control defines how far the signal must exceed the threshold to achieve full compression.  A smaller knee setting will result in more aggressive compression.
• Makeup Gain (0dB - 12dB)
  • The ‘Makeup Gain’ control allows you to apply additional gain to the output signal, to ‘make up’ for the attenuation applied by the compression.

 

Expander:

The ‘Expander’ control switches the main operation of the compressor from a multi-band Compressor into a multi-band Expander. 

In Expander mode,  the gain reduction curve is applied when the signal falls below the band’s threshold. 

 

Key Input:

The “Ext. Key” control allows you to use a sidechain as the signal driving the compressor.

If Key Input is enabled, then:

• The main input meter and threshold will be referenced to the KEY (sidechain) input, not the main input.
• When a band is soloed (using auto-solo) then you will hear the main signal input, not the sidechain.
• The sidechain EQ is applied to the key input signal.

 

Sidechain EQ:

The sidechain EQ is a single-band equalizer.  By setting the shape of the band ( high/low-pass filter, bell, or high/low shelf )  you can modify the signal that drives compression in each of the 4 bands.  For example, you can use the filter to remove all high frequencies from the sidechain.

 

Connecting the External “Key” input

Dynamic effects ( like Compressors, Gates, and Expanders ) measure the volume of an audio channel, and then apply a change (either louder or softer) to the main signal. The signal that is “measured” is called the key signal.  Most commonly, a compressor uses its own input as the key signal.  But some processors allow you to feed a separate signal into the key detector

Each DAW has a different method for connecting a track to the AVA sidechain key input, and each format ( AAX, VST3, AU, and VST2 ) treat the additional sidechain input separately.

It is beyond the scope of this manual to describe each DAW’s method to connect the sidechain input.  Our product demonstration video describes how to make the connections in Mixbus (VST), Studio One (VST3), and ProTools (AAX).

 

Stereo and Multichannel operation

When used in multichannel mode ( stereo or surround ), dynamic processors must have the ability to apply gain-reduction to all of the channels simultaneously: this prevents the stereo (or sorround) “image” from shifting when one channel is affected differently than the others.

The Multi Band Compressor calculates the “maximum” gain reduction that would be applied to any channel, and it applies that amount of reduction to all of the channels in the plugin.

 

Usage Notes

Taming Uneven Frequency Ranges

To address issues like uneven bass notes or harsh sibilance,  you can; and then apply gentle compression to even-out the level of that frequency range.

• Suggested settings:
  • Use the provided RTA to recognize the problem area, and adjust the band frequencies to encompass the problem area.
  • Set a mimumum threshold (-15) on the problem band.
  • Start with the “knee” setting at max, to apply gentle compression.
  • Attack/Release knobs should be left near the default values.
  • Now lower the master threshold, and/or decrease the “knee” until the desired effect is achieved.

If necessary, you can use an EQ after multi-band processing to make-up any lost volume in the affected range.  Or, if you have individual tracks available, it is sometimes better to increase the input level of those troublesome tracks into the multi-band processor.

 

Maximizing Loudness

Multi-band processing is an effective tool for maximizing the loudness of a mix.  By compressing each band separately, you can avoid artifacts caused when one frequency range is driving the gain reduction, when other ranges should not be processed so heavily.

• Suggested settings:
  • Use the provided RTA to recognize the ranges of your song: low bass, low mid, high mid, and high frequency ranges.
  • Adjust the band frequencies to encompass each of the ranges.
  • Attack/Release knobs should be left near the default values.
  • Start with the knee setting at its minimum, to apply hard compression limiting.
  • Now lower the master threshold to achieve the desired amount of compression, and increase the “knee” knob to avoid artifacts, until the desired effect is achieved.

Use the “makeup gain” knob to maximize the volume after the individual bands have been processed.

 

Artistic Effects (pumping)

Many DAWs provide the ability to feed the sidechain “key” input from a different track source.  For example,  in electronic dance music it is common to compress the synth and/or bass track from the kick-drum.  This creates a tempo-synced breathing sound that swells before each beat.  This is a useful mixing technique for any dance-music style.

If you are working with drum loops without a separate kick track, you can use the sidechain EQ to focus the effect on the desired instrument.  For example:  to trigger the gain reduction on the kick drum, you can low-pass-filter the key signal so only the bass drum is triggering gain reduction.

By adjusting the depth and threshold of each band, you can cause useful effects:  like compressing only the lowest register of the bass, when the kick drum sounds.

Note:  when you are using an external key,  the same signal is sent to all 4 bands (the key is not filtered into 4 separate bands).  This allows you to focus the key signal on a range (like bass) but affect a different range ( like mids or highs ).

Increase the “release” knob until the effect accentuates the pulse of the song.

Enabling the Expander mode will create the inverse effect:  you can gate the keys or bass to sound during the kick drum, and get quieter between notes.  This can result in a more stocatto sound.

 

Ultra-low latency processing

Ultra-low latency processing is a must-have for any pro or aspiring audio engineer who wants to record, edit, or play back audio in a live setting. Feel the difference of real-time audio processing, with no annoying delays or lags that can spoil your performance, creativity, and quality of your audio. Take advantage of ultra-low latency processing and make your mix sound amazing.

 

Additional Features

At the top-right corner of the plugin window are the Momentary Bypass 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. 

 

Settings

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

 

Control Behaviors & Shortcuts

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

Sliders/Knobs

 

Labels

 

Combo Boxes (Drop-down menus)

 

Band Controls

 

Graph Rulers

 

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}

This will set the environment variable for that particular terminal session only, so it will be reset once the session is ended. If you don’t want to run this command every time you launch your DAW, you can set the environment variable in your profile script so that it automatically gets set every time you login.

 

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 (http://www.openssl.org/)

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!