@MixMeister
With WDM, there is an extra management layer (Windows) which means you can use the device with any app within Windows (and multiple apps simultaneously) as the expense of performance and channel count/routing options.
ASIO effectively accesses the device directly, with Qu this provides more channels and better performance regarding latency.
Generally speaking, WDM is good for playback and stereo recording/streaming or when the app does not support ASIO.
ASIO is better for use with DAW’s and other professional audio and video apps.
The bit crusher noise you mention can be caused by issues with the computer where it is either not suitable or has not been setup for realtime audio.
This can affect both ASIO and WDM connections and I would suggest getting to the route of this before anything else.
There is a thread discussing it here – https://community.allen-heath.com/forums/topic/digital-noise-when-streaming-audio-via-usb-b
And an article with info on optimising your computer here – https://support.allen-heath.com/hc/en-gb/articles/4404321552401-Qu-Troubleshooting-issues-with-the-USB-B-interface
But of course you can contact us directly about it by submitting a ticket using support.allen-heath.com – every situation and setup is slightly different so there’s not really a one size fits all solution.
Thanks,
Keith.