How To OBS Streaming

Keep It Quiet – How to Setup the Expander Filter in OBS

Just like how there are multiple ways to prevent audio from peaking and being distorted, there are multiple ways to keep background sounds from being heard on stream. If you didn’t like how using a noise gate caused your audio to be cut off or interrupted, then consider using the Expander audio filter for more flexibility.

The Expander audio filter also reduces the volume of audio like the Compressor audio filter. The difference between the two is while a compressor is focused on keeping loud sounds from peaking causing distorted audio, the expander is focused on keeping quiet sounds to stay quiet and not be picked up by your microphone.

 Also like the Compressor audio filter the settings are similar.

  • Presets – OBS offers two default settings that adjust the Ratio and the Release for the Expander Audio filter to act as an Expander or closer to a Noise Gate.
    • Expander – Default setting with low ratio and low release.
    • Noise Gate – Default setting with high ratio and high release.
  • Threshold – Anything BELOW the threshold will have the audio be reduced.
  • Ratio – Multiplier of how much the audio will be reduced. I.E. 2:1 ratio means that an sound that produces 6db would be reduced to 3db. A 10:1 ratio means that a sound that produces 6db would be reduced to 0.6db.
  • Attack – The time the expander will take to stop reducing audio when the audio is above the threshold.
  • Release – The time the expander will take to reduce the audio to the set Ratio when audio falls below the threshold.
  • Output Gain – Increase the output level of audio by applying gain. Increasing output gain can result in background audio being louder.
  • Detection – Determines the method of how audio surpasses the threshold for the Expander. RMS is recommended.
    • RMS – Detects average audio level over the last 10 milliseconds reducing chance for audio surpassing the threshold.
    • Peak – Expander reacts to audio peaks resulting in expander to stop reducing audio from sudden loud noises.

Just remember that your goal here is to set a threshold that will keep background noise from being noticed such as loud clicks from the typing of your keyboard to vehicles driving by. Use the audio mixer and see if there are any background noises that gets picked up by your microphone and adjust the threshold so that your voice won’t be affected while your background noises will.

To setup the Expander audio filter in OBS here is what you do

  1. In the Audio Mixer window, for your microphone audio source click on the gear and select Filter.
  2. Click on the + sign and select the Expander filter.
  3. Use one of the presets from the drop-down list or adjust the settings to their desired levels and click the Close button.

The Expander audio filter is meant for your microphone only. I would not recommend using the filter for any audio or video sources that you use in OBS.

If you’re looking for a flexible solution compared to the Noise Gate audio filter, then you should the Expander audio filter to keep any unwanted noise from being picked up when you stream.