How to Use Multiband Compression in Audacity

While Audacity does not include a native multiband compressor, you can easily add this functionality by installing third-party VST plugins. This guide walks you through acquiring a compatible multiband compression plugin, enabling it within Audacity’s Plugin Manager, and applying it to your audio tracks for precise dynamic control across specific frequency ranges.

Step 1: Download a Compatible Multiband Compressor Plugin

Audacity supports VST2, VST3, and AU (macOS) plugins. Ensure you download a plugin version that matches your Audacity architecture (usually 64-bit on modern systems). Popular, free options include:

• ReaXcomp (from the Cockos ReaPlugs suite): A highly flexible, lightweight VST multiband compressor.
• TDR Nova (Tokyo Dawn Records): A dynamic equalizer that can function as a powerful multiband compressor via VST/VST3.

Download the installer or DLL/VST3 files from the official developer websites.

Step 2: Install the Plugin Files

• Using an installer: Run the setup file and ensure the VST/VST3 files are directed to your system's standard plugin directory (such as C:\Program Files\Common Files\VST3 on Windows or /Library/Audio/Plug-Ins/VST3 on macOS).
• Using manual files (DLL/VST3): Move the .dll or .vst3 files directly into Audacity’s designated Plug-Ins folder or your system's default VST directory.

Step 3: Enable the Plugin in Audacity

1. Open Audacity.
2. Navigate to the top menu and select Effect > Plugin Manager (or Audio Setup > Manage Plugins depending on your Audacity version).
3. Click Rescan to locate newly added files.
4. Locate your installed plugin (e.g., "ReaXcomp" or "TDR Nova") in the list.
5. Select the plugin, click Enable, and click OK.

Step 4: Apply Multiband Compression to Audio

1. Import or record your audio into Audacity.
2. Select the portion of the audio track you wish to process (or press Ctrl + A / Cmd + A to select the entire track).
3. Click the Effect menu, locate your plugin (often listed under the developer name or a categorized sub-menu), and open it.
4. Set your crossover frequencies to isolate the lows, mids, and highs.
5. Adjust the threshold, ratio, attack, and release settings independently for each band to control dynamic range without affecting the entire frequency spectrum.
6. Use the plugin's preview function to audition the changes in real-time, then click Apply to render the compression onto your Audacity track.