| Re: digital S/PDIF vs. analogue output to receiver/sub with REW
Hi Blue,
Well, the intention of the soundcard cal is to remove any shortcomings of the measurement system only. Since the receiver is part of the "device under test," including it as part of the loopback test will allow it to contribute to the calibration corrections. If there is a component of the cal file that is caused by the receiver, it will be accommodated for in the REW calculation, but not with any other input device. Since you're accounting for any shortcomings of FR in the receiver via the cal file, you will no longer be able to account for such shortcomings by using the filters of the BFD itself.
In the end, I think this is a pretty limited case, though, and you're probably fine to go that route. Your receiver FR is probably essentially flat from 10 Hz to 20kHz.
You're right -- my result of everything being pretty close may be different than yours: different receivers, different soundcards, etc. However, it sounds like you are fully set up to determine those same results.
-- Otto |