Why is only one USB audio path allowed?

[Guest]

Aggregate devices on a Mac work will all audio interfaces, they do not have to be class compliant.

The best solution is to actually use a hardware clock connection between the devices and then you don't need to turn drift (resample) on at all. This all works perfectly.

I use drift (resample) occasionally for testing and as long as the clocks are not too far out of kilter it seems to handle it well, I'm not sure I would rely on it in a professional setting though. Lots of I/O and a few patchbays seems a better choice.

[MarkOne]

I understand that those clever boys and girls in Redmond did solve this for windows in the form of Direct X

But by the time they did ASIO ruled the world, and it’s much easier to develop your own driver for your own device and only test that combination, rather than the hassle of having to dig into a system level feature you don’t control.