Ok...i understand that...
Before going down the route for changing avr or speaker, may I suggest you to try the audyssey app from playstore/appstore. It is a paid app but it can help you with tweaking the curves. This app is common for both denon and marantz avr, so even if you get a marantz avr later, it will still work (Only take note of compatible avr from the list, but for sure denon x1600 and marantz 1608/1609 is supported). For me, calibration via app gives better result and advantage is that you can tweak the curve on the go and doing trials becomes so much easier. Worth the price, if you ask me. Despite its low rating on playstore, it has worked well for me (around 90% time).
Audyssey MultEQ Editor app for Denon Marantz AV Receiver products
play.google.com
If you decide to get it and need further help on the app, you can PM me.
Cheers
Siju