Thanks that was the next step.
I was wondering if anyone who had experience with Room EQ Wizard could comment on how accurate it is for a full range measurement.
Hi there,
It's not so much REW itself, but more the room interactions and the RS SPL meter that will make things crazy. IIRC, the RS SPL meter isn't so hot for accurate measurements above something like 5kHz.
If you are doing full-range measurement with both mains active, you may experience some comb filtering effects if the output from both speakers don't reach the mic at precisely the same time; try measuring one at a time and see if things are any better.
Also, room reflections will combine (or not) with the directly radiated signal for a similar effect. If you are working at all with room treatments, you should see an improvement in your "after" plots.
You may also be able to gain some clarity by applying "smoothing" to your plot. I would probably start with 1/6 octave smoothing, and perhaps to go to 1/3 octave from there. It will definitely remove some of the "peakiness" that you are seeing in your full-range measurements. You can find the smoothing options in the "Trace Adjustments" drop-down control on the left side of REW (assuming you're using V4.00 or greater).
Full-range measurements with REW, or any other tool for that matter, have some benefit in showing trends. However, I wouldn't consider it a valid method to be used to determine full-range EQ, as it's just to non-deterministic.
Good luck!