I'm using MuLab to create audiovisual sessions for "mind machine" type devices. There are several light control protocols, a 2-channel protocol uses a 19.2kHz signal on each channel, a 6-channel protocol using several different high frequencies on each channel and yet another that directly uses audio to drive the lights.
The first two are easy and I have written Mux presets to handle them very nicely. For some purposes I am using MuLab in preference to dedicated AVS software.
The last requires 7.1 audio - it appears to the computer as USB 7.1 Audio device, with two channels providing sound and the other six controlling R/G/B LEDs, left and right.
It can be done by exporting stereo pairs and putting it together in Audacity (not really a practical option as it makes testing and tweaking a painful multistep process) but I have not found a way to do it with MuLab.
Using ASIO4ALL I am able to use 7.1 on my PC's integrated VIA chipset, however the USB device, based on CMedia 106/XEAR 3D uses a proprietary driver that is not known to ASIO4ALL. Generic drivers cannot be used with the device.
No worries. Problem solved. After a bit of fiddling and comparing the devices in Control Panel/Device Manager and Sound ASIO4ALL detected the device correctly and it all works beautifully.
Should anyone wish to do similar, assuming the output device is working correctly, it's just a matter of adding additional Audio Outs to the session mux (or any other instrument/effect mux and/or adding additional Masters if many tracks/devices are to be routed to particular channels.
How cool it is to write music and have 3/4 of it rendered in lights!