I doubt changing the DBR for these would make a meaningful difference. The NAD should be able to handle the load.
I wonder if the way you have your speakers placed (in a cabinet) has anything to do with the sound quality. Are you sitting on-axis (toed in). Are your ears level with tweeter?
Sometimes measurements can tell you quickly if there is anything way off with your setup. It might be better to invest in measurement mic and check things out rather than blindly changing out speakers
Thanks for the reply
@warpdrive! I am hamstrung by the position, I've got a flat shelf in a built-in cabinet that is just wide enough for a TV, vertical amp and speakers. Speakers are at ear level but not even room to toe in speakers. My wife also wants it to be minimalistic, hence the D3045 with HDMI ARC from the TV.
I have borrowed a pair of Usher s520's and MA Silver 100's to trial in the same area. Both of them are much more intelligible with dialogue than the DBR-62 were; I find I am not changing volumes as much (up to hear voices, then down again with all the other sounds/music/explosions etc). Maybe the DBR interacting with my fixed room makes vocals worse? I've heard people subjectively refer to them as "boring" and "flat" and I would agree with that in this specific space (big caveat being this space - I understand they measure extremely well on the klippel). I don't have a mic to correlate frequency response to what I was hearing, although even if I did I don't really have the option of changing much anyway.
My other thought as above was power or lack thereof, plenty of talk on the web that the DBR's need 100+ watts to get going. Maybe they need more juice than the D3045 can give? I did like the DBR's in my big room, finding they were very neutral and without offense (again subjective). They did nothing wrong, did not give listening fatigue (important) but were lacking bass which was to be expected in the size of the room, although this was with much more power than the D3045. Interestingly in the same system I much prefer the Silver 100's.
Either way, I'll be putting the DBR's up for sale. I think a pair of these Silver 50's could be the ticket for my use case, and look better than the DBR's to boot (important to the wife).
Cheers, Andrew