Hi guys, so my Denon S500bt has had some... issues recently, and I'm looking into upgrading to a better quality reciever. I have a pair of kef reference towers anyways, and think that they are not quite reaching their potential with the current setup. My price range is $400-800, and while I know that it's hard to compare the sound quality on receivers, my top priority is getting a reciever that will compliment the kefs in a medium sized room. I don't know too much about the correlation between receivers and sound quality, so any info could be helpful. I'd also like something with atmos, at least 7.2 compatibility for the future, and 4k passthrough, which I assume shouldn't be a difficult ask at that price range. Power is a plus, but not a necessity. Have been looking at Denon 4300h and Integra dtr 80.3 as a point of reference. Again, main priority is sound quality, preferably something with a strong mid range. Thanks in advance.