Use ReaEQ in OBS Studio to Remove Mic Hum

This guide provides a step-by-step walkthrough on how to install, configure, and use the free ReaEQ VST plugin within OBS Studio to eliminate background microphone hum. By targeting specific electrical noise frequencies (such as 50 Hz or 60 Hz ground loops) with precision filters, you can clean up your broadcast audio without degrading the natural quality of your voice.

Step 1: Install the ReaPlugs VST Suite

OBS Studio supports VST 2.x plugins. To get ReaEQ, you need to download and install the free ReaPlugs compatibility pack from the official Cockos website.

  1. Download the 64-bit version of the ReaPlugs VST suite.
  2. Run the installer and ensure the plugins are installed to the default Windows VST directory (usually C:\Program Files\VSTPlugins). OBS Studio automatically scans this folder.

Step 2: Add ReaEQ to Your Microphone in OBS

Once installed, you need to apply the plugin as an audio filter on your microphone source inside OBS Studio.

  1. Open OBS Studio.
  2. Go to the Audio Mixer dock, locate your microphone source, and click the three dots (options icon) next to it.
  3. Select Filters.
  4. Click the + (plus) icon in the bottom-left corner of the Filters window and select VST 2.x Plug-in.
  5. Name the filter “ReaEQ” and click OK.
  6. From the drop-down menu labeled Please select a plug-in, choose reaeq-standalone.
  7. Click the Open Plug-in Interface button to open the ReaEQ equalizer window.

Step 3: Identify and Notch Out the Hum Frequency

Microphone hum is usually caused by electromagnetic interference or ground loops from your electrical grid. This occurs at a constant frequency of 60 Hz (primarily in North America) or 50 Hz (primarily in Europe and other regions).

  1. In the ReaEQ interface, locate Band 1 (represented by the red circle labeled “1” on the graph).
  2. Change the Type dropdown for Band 1 from Band to Notch. A notch filter completely cuts out a highly specific frequency while leaving surrounding frequencies untouched.
  3. Set the Frequency (Hz) slider to match your local power grid frequency:
    • Enter 60.0 if you are in North America.
    • Enter 50.0 if you are in Europe, Asia, or other 50 Hz regions.
  4. Adjust the Bandwidth (octave) slider to a very narrow setting, such as 0.05 or 0.1. This ensures that only the hum is removed, preventing your voice from sounding thin or altered.

Step 4: Address Hum Harmonics (Optional)

If the hum is still audible after notch filtering the primary frequency, the noise likely has “harmonics” (multiples of the base frequency). You can use additional bands in ReaEQ to eliminate them.

  1. Select Band 2 in ReaEQ and change its Type to Notch.
  2. Set the Bandwidth (octave) to 0.05.
  3. Set the Frequency (Hz) to the first harmonic:
    • 120.0 Hz (for 60 Hz systems)
    • 100.0 Hz (for 50 Hz systems)
  4. If necessary, repeat this process for Band 3 at the second harmonic (180 Hz for 60 Hz systems, or 150 Hz for 50 Hz systems).

Once configured, close the ReaEQ interface and the OBS Filters window. Your microphone audio will now be free of low-frequency electrical hum in real-time.