Last week I heard the KN7000 and 6500 side by side so I could really compare the two. I thinks that the improvement lies mainly in the other speaker setup. There is an extra speaker between the keys and display and the sound is much brighter and surround than with the KN6500. I haven't compared the two over the headphone yet, but I will certainly do. I had ea KN5000, but subscribed to a KN7000.