Sound 2 Light is an add-on to Freestyle, created by remco_k, which as the name says , makes an audio interface to FreeStyler.
It processes an audio signal into a beat triggered signal which can be used control various FreeStyler functions.
More info can be found here on the original page. See: Sound to Light Interface

Sound 2 Light is by default installed with FreeStyler and can be opened here.


If not installed then it can downloaded here. http://www.digiplay.nl/fs, where also more information can be found.

Sound2Light is a plugin which takes an analog input signal and convert it to a beat / program control signal for FreeStyler.
As this uses an analog input signal there are some considerations which are to be taken into account to get a god performance.
Lousy input, lousy output.

Considerations.
There are more input possibilities and one of them is the microphone input on the PC.
This is probably the worst signal to use as this pickup and noises signal which nothing to do with the beat we want detect.
So this input signal are in general to be avoided as input signal.
The better one is a line signal from the mixer to the PC.

Audio signal considerations.