John Mulcahy

No.

Yes, those dips are occurring at frequencies where the L and R speakers are out of phase with each other due to room effects. You can...

No, use the RTA.

Looking at your screenshots the Marian interface is using the Int32LSB24 format, which is 24-bit data in the lower bits of a 32-bit...

As above, install the V5.30 beta.

You don't need the Pro upgrade, that's for capturing from multiple mics simultaneously. Install the V5.30 beta release though.

It looks flat because the SPL axis span is now about 400 dB instead of 6 dB, keep an eye on the figures on the graph axis. You can...

Be mindful of the graph range for the soundcard cal measurement, the whole span is only +/-3 dB so those variations are actually tiny.

That looks good. You're way ahead of me, bypassing the Dante was next on my list :) In the Analysis preferences, frequency response...

What is shown on the REW level meters when you are not generating any output and not trying to measure?

By driver I mean the choice made in the REW soundcard preferences, which can be Java or ASIO.

You can send a full range Pink periodic noise signal to either of the channels and look at the response on the RTA using the settings...

REW can only access the channels the interface offers. If you have an ATMOS replay system (rather than a studio ATMOS authoring system)...

If the levels clip when making a measurement that is typically due to monitoring being active. If the input levels clip when REW isn't...

That is the actual reading. The SPL figure in the levels panel is the total input across all frequencies, the level of any individual...