The manual do not say there is any speed setting in the dmx chart...
But if the custom fader named "sound" do not set the speed, you can download the file included , with a new version of the fixtre file where the macros are on a new custom fader, wich will allows you to set the speed, i hope.
If it doesn't work, I don't know how to set the speed.
Let me know,
Updated on september 30th