DXT handles 1.5kHz LR2 without a sweat, Mark K, the designer of the ER18DXT DIY design tested it and found it clean to 105dB/1m. Also the DXT would have wide top-octave dispersion (closer to constant directivity), while having wider vertical dispersion than the Viawave ribbon. I personally think the DXT is a much cheaper and proven driver. Plus Bliesma distortion increases below around 2kHz to slightly elevated levels for the size and price.
https://www.diyaudio.com/forums/mul...narrow-directivity-horbach-keele-filters.html
A Horbach-Keele design would be interesting and really give near-constant directivity vertically and horizontally.
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Hi
thank you for your valuable reply.
You have serious knowledge on hifi.
I’m targeting to reduce back waves and flor- ceilings early reflections But keep lateral energy if properly delayed at least 10- 20ms respect to direct sound to “fool“ my brain.
lateral reflections according to many research are positive from a psycoacoustic point of view if properly delayed respect to direct signal more than 10-20ms. they add liveness to sound reproduction without affecting articulation index and intelligibility.
Referemce floyd E. Toole and Herr Eng. S. Linkwitz.
the difference between listening into anechoic room and our home is the time between first arrival and second reflections (3rd 4th are fine since low in level)
listening with our ears at 36” height (T. J. N. and J. Atkinson, stereophile) from floor at 3 meters (sorry mixing Imperial and S. I. ) generates a floor bounce less than 1 ms after first arrival. That’s not good. Ceiling soon after. Bad too.
Lateral (if 10ms delayed) is fine, do not blur images and might help.
(That’s why lateral response have to be correlated to on axes!)
I’m remembering incredible exercise fron AR MGC1 speaker. See stereophile archive.
Let’s our brain capture the information cristal clear and eventuality be surrounded by positive lateral (never on axis) delayed 20ms coherent reflection. it makes the trick.
Summing up:
Kii three + BXT is sounding superb since BXT reduces ( it’s a vertical array) ceiling and floor bounce ((20-midrange) and (but not only for that) boost high SPL low-THD below 80Hz.
Mr. Putzeys clearly explain this to J. Darko on June 2018, youtube
I’m glad to be here. Looking forward to your feedback
My Best
Lorenzo