Hi!
I just started to use Cubase Elements and I am not yet equipped very well.
So I want to record drums with three mics. I have an interface with two inputs and I have a USB-mic. However, I can’t get Cubase to use them simultaneously for the recording. Does this work at all and if yes, what do I do? 
Thanks!
eckertone
You might try ASIO4ALL. That’s what they say. I have no personal experience with it, or USB mics. ASIO4ALL apparently supports multiple ASIO drivers. There was a time when I seriously considered it, but I figured I could get by with one ASIO driver at a time. Another possibility: some interfaces can be chained, one sends to the other, which passes it along to the DAW, but you probably don’t have that option.
ASIO4ALL is definitely what you need. Just be leary of clock drift. That means that your tracks may drift off time the longer they record.
I had this issue running two different Tascam interfaces until i clocked one to the other over SPDIF.
YMMV.
T