I got a UMIK-2 today, and when I measure an externally generated frequency sweep using RTA, I get a large SPL difference between using the miniDSP ASIO driver and the ASIO4ALL driver. Is there some setting I'm missing that would account for this?
I'm not sure if there have been any changes since I received a prototype UMIK-2, but when I use the miniDSP ASIO driver the UMIK-2 inputs are generically labelled CH1 and CH2, REW doesn't know they are coming from a UMIK-2 so it doesn't apply the sensitivity info. If that has changed and the names include "UMIK-2" then another possibility is the input volume controls on the miniDSP driver. There are two, one labelled master and the other labelled for the two channels. The one labelled master make changes that are not reflected in the Windows input volume control, so REW can't see them and can't account for them. That needs to be left at max (0 dB).