@saeed79 Its not only the horn design that affects sound quality. My early 1980's Klipschorns came with the K401 horn, a cast iron exponential horn. That thing rang like a bell when you knocked on it, damping these horns was the common 'fix'. So I tried various materials, amounts and placement of those materials, nothing worked to my satisfaction, nothing close to natural timbre. Point is the material horn made of also important, I'll posit any metal or plastic horn ain't gonna do it. And yes, the original design with that horn and placement of drivers made for an in your face listening experience, so much so that I couldn't live with them in stock configuration. It took all new drivers, placement of those drivers (at least physical time alignment) , Volti tracktrix horn, reworking of crossover to get these speakers to generate a proper sound field with natural timbre. Haven't heard the latest Klipschorns but what I observe they seem to be on the right path. As for outboard dsp unit, obviously you can get the speaker to measure better with dsp, but there has to be an inherent cost in that the dsp unit will color/voice the speaker to some extent. I only like SET tube amps with my Klipschorns, and the rest of system is specifically chosen for my preferred presentation, any dsp unit will upset that equation. And this will remain true for present iteration of these speakers, some may continue to prefer to alter presentation via rest of system, others may not care or notice the voicing/coloration/presentation of this dsp unit.