Originally Posted by
jpw retired
I had the DD66000 and upgraded to the DD67000. What I noticed most were two things. The DD67 had been re-tuned or re-voiced for lower coloration and a more natural and accurate octave to octave tonal balance. This was most noticeable in the bass region where the DD66 could sometimes sound a bit thick and even boxy. The bass is also cleaner and better defined, hitting a little harder, and is less soft in it's attack than the DD66. Bass extension is about the same. The extreme high frequency response also was improved in smoothness. The DD66 had a peak at around 16khz that could be audible under specific circumstances. The DD67 is also slightly less forward and more relaxed in it's overall balance. Hope this helps.