In OBS Studio we have the ability to add filters to our Sources, Scenes and even our Audio Devices. The following filters are available in OBS Studio 23.0.0:
You can add them by right-click your desired Scene, Source or Device and selecting "Filters" (for Audio Devices, click on the gear icon next to your device). But let me explain what the different filters allow you to do.
The Image Mask/Blend filter gives us the option to use the Color or Alpha Channel of an Image as a Mask or to Blend an Image (multiply, addition, subtraction) over your Scene or Source. This can be used to give your webcam a round border for example:
The crop filter should explain itself but in short it lets you cut off the top/left/right/bottom of your source/scene to only show the parts you want.
Again, the name says it all. You can change the contrast, brightness and gamma of your source and even provide a color overlay.
The scroll filter gives us the ability to give our text for example a scrolling effect, left-to-right and top-to-bottom. Negative and positive values will change the direction in which your source will scroll and you can limit the height and width if necessary.
Both the Color Key and Chroma Key filter can be used to remove a certain color of your source and make it transparent. This can be used for green screens and similar stuff. They behave slightly differently, so you will need to experiment and see which works best for your personal use case.
This filter allows you to apply a LUT to your video sources.
The sharpen filter should explain itself as well, if you feel your webcam input for example is a bit blurred and you want to improve the overall sharpness a bit, add the filter and test with different values.
A compressor is very useful if your source (typically a microphone) is set for a normal level but can sometimes spike much louder, such as impromptu shouting or getting into a heated discussion. It will automatically lower the source's volume to reduce the likelihood of it peaking above 0dB, which can cause clipping and distortion, and then turn it back up once the volume is back to normal.
In short, a compressor makes loud sounds quieter and typically would be placed at or near the beginning of your filter chain.
Note. A source can still exceed 0dB with a compressor if your input level is too loud, your ratio/threshold are set incorrectly or you apply too much output gain. To ensure you do not exceed 0dB you can use a Limiter at the end of your filter chain.
Sidechain compression, also known as Ducking, can be used to make room for your voice when speaking over-top of music and games by lowering your desktop audio when you speak.
The following sidechain compression settings are recommended as a place to start. Adjust the threshold to control the strength of the ducking, attack/release control how quickly the volume changes.
An expander can be used to reduce background noise such as computer fans, mouse/keyboard clicks, breathing and unwanted mouth noises. An expander reduces the level of an audio signal by applying gain reduction, similar to a compressor but below the threshold instead of above it.
An expander can be used in place of a gate for noise reduction, they can produce a smoother open and close due to having an adjustable ratio whereas a gate is a fixed.
In short, an expander makes quiet sounds quieter and typically would be placed near the end of your filter chain, after any compression/other effects but before a Limiter.
Gain should generally be applied at the source before it reaches OBS, but if needed the gain filter can help with very quiet audio sources to increase the output volume.
Used to correct phase cancellation issues.
Limiters are used to prevent an audio signal from peaking above 0dB which can cause clipping and distortion. A limiter is a special type of compressor with a very fast attack and a very high ratio.
When using a Limiter it should be the last filter in your chain.
The Noise Gate allows you to cut off all background noise while you are not talking. Select a close threshold above the noise volume and an open threshold slightly below your voice input to get good results.
The Noise Suppression filter can be used to remove mild background noise or white noise that may be in any of your audio sources. While this is generally not effective at large amounts of background noise (i.e. in a loud room) it can be quite effective at reducing things like PC fan noise or other environmental noises.
0 is off. The further you move the slider to the left, the 'stronger' the filter will be, and the more sounds it will filter out. Keep in mind that this can distort other sounds (like your voice).
OBS Studio supports many VST2.x plugins. Adding a VST plugin is as simple as adding any other audio filter, but there are some limitations. VST1.x, VST3.x, MIDI control/input in VST plugins, and shell VST plugins are not supported at this time. We have not tested all plugins, and some VST plugins may cause crashes. Make sure you save and back up any settings to avoid loss of data when experimenting with VST.
Lastly, always keep an eye on CPU usage, some VST plugins can be very CPU hungry!
OBS Studio will search for plugins in the following locations:
A short list of free plugins that were used to develop and test the VST support in OBS Studio can be found below. Your experiences may differ, but these are the ones we know have been tested to work in our environments:
Untested, but highly reviewed:
In the future more filters will be added to OBS Studio, so always keep an eye out for the next update of the software.
Original guide by Jack0r, updates/edits by Fenrir and the #obs-dev team