There are a few tweaks that I've used to improve the sound of the 645s; first the character and definition of the bass can be improved with the use of Tekna C-10 and C-12 vibration dampers, mounted to the back of the bass cabinets. I used one of each, for a distributed absorption of cabinet resonances. Their use made the bass much more articulate, and removed the "chestiness" from male voices, etc. They are magnetically mounted, and easily removed for an instant comparison. Two of these on each speaker was a very good and reasonably priced improvement. If you try these speakers, allow 2-3 weeks for the ribbons to break in, because they can sound bright at first, but it is well worth the wait, as they get smoother with playing. I would also try different kinds of wire for the short jumpers to the ribbons, because it made a big difference in my system. I preferred silver speaker cables (of any brand) over the stock Nordost Flatline supplied by Newform. With just a few tweaks, nothing in their price range can touch the sound of these ribbons; vocals and piano music are a special treat, and they image "wall to wall". The bass response will be deeper and smoother with a few feet of space behind the speaker to the back wall, so experiment for best balance.
Opinions on Newform Research speakers
I currently own M.L. ReQuests but am getting too much "room interaction" (room too small). I have read great comments on the R645, and because the ribbon IS NOT dipolar, was thinking these might interact less in my room? Anyone currently own the Newforms that were prior Logan or Maggie owners? Do they (Newforms) really sound as great as review (AudioReview.com) suggest? Do they match the magical midrange of the ReQuest? Thanks for any advice/comments!