I have followed your advice regarding tone controls. Reducing the treble and increasing the bass makes a slight improvement. I have been positioning with small improvements. Interestingly, the loudness button does give me more body and is more pleasurable. But I don't think loudness should be engaged at all power levels to provide listening enjoyment. I have contacted a dealer who is both very knowledgeable about KEF and Luxman, and they stated that the 590 might not be the best combination with the KEFs. The KEFs are power pigs and require tremendous power to bloom. I will certainly give it some more break-in time, but my only option after that is more power. I know many state the prowess of the power output of the mighty 590AXII, but the amp still has limitations. All in all, I greatly appreciate your guidance on how to troubleshoot!!!
Happy holidays to all!