[Wayne A. Pflughaupt]

I was waiting to see what your phase and distance changes got you before commenting, but yes, more of than not any “won’t equalize away” issues up that high can be attributed to the mains.

I now had a couple db dip at about 22hz and 60hz which I fixed with a +2 gain filter (I know, I know but i can't help it! )

Filters with that small of a gain change may or not be audible. In this case I wouldn’t worry about the boost so much as the bandwidth. E.G. avoid ultra-narrow filters.

HOWEVER I am quite confused... why would I get one curve and slope at one db level of the sub, and something different at high or lower levels?

Such is the nature of in-room measuring. You can’t get a perfect replication of displayed results from one month to the next, or day to day, or even in the same session. Kinda makes it difficult to craft perfect modal filters...

So anyway after I was done I took a few more measurements and found that with my overall system level db changing (i.e. very loud vs. loud vs. average level etc) I would get different response curves from REW.

Yup. Kinda makes it hard to... Nevermind.

So I'm left wondering - what is my real response curve? Is my system now properly eq'ed only for a particular listening level? Thanks!

I think you’ll find that even though on-screen results will look a little different from one session to the next, you won’t notice any audible change. Just get it where it sounds right to you, and start enjoying your superb-sounding subs.

Regards,
Wayne