I think many have noted the Kef guide for the R7 holds true, I have the bungs in and that tames the bass, but you still need to be away from the back wall and a reason distance part.Audussey defaults the target curve to Reference which cuts high frequencies some (Flat target curve doesn´t) and there is also the BBC dip which you can disable with the app (midrange compensation to Off). If you got the app then you can limit the correction to around 300hz which is recommended (MultEQ Filter frequency range). Listen from this clip 23:07 about 7-10min forward the guy shows you where the things can be changed with the app, should be easy and the results are worth the price. It won´t do any correction higher up, you will hear the speakers and room. It will correct only the problem range room modes for speakers and subwoofer! Both movie and music should sound better when you have optimized the app.
If you don`t have the app set your receiver for 2ch stereo mode, go to Denon menu and under XT32 menu you can find the Reference, Flat and there is also ByPass for L/R which you can try. This keeps the correction for subwoofer, but does not apply any correction for main speakers. Also check do you have Audussey Dynamic EQ or Dynamic Volume enabled. See below link for explanation for each:
But keep in mind that any amp can´t help you if you have large speakers tucked too close to walls/corners and possibly your listening position is also against rear wall, so you get lot of bass boost which can easily muddy the mids and highs..
I have used the Kef 700 with a Denon 4500 and it worked ok, with XT32 I need the EQ app as the Mid seamed hollowed out. I suspect the OP issue related far to much bass rather the lack of top end and I personally from are pictures considering maybe the R3s