I am very intrigued by the SEOS waveguide for the 140-15D dipole. How do you like the sound compared to no waveguide? I have a pair of these ribbons and planning my next build but I had no idea about these waveguides, very cool stuff. Is it mostly to control dispersion of the ribbon to match the mids? Or boost low-end efficiency?
i bought the waveguide mainly to match the forward dispersion with the ja8008 on a minimal baffle.
it needs some EQ to play as flat as the stock ribbon, but to my ears the hornloaded ribbon has more punch and liveliness.
my living-room is also acoustically untreated, so i suspect controlled dispersion helps the sound a lot.
if you plan to cross low, the added sensitivity below 5k also comes in handy
here you see the difference between stock (red) and waveguide (green) on axis
raal 0-90 dispersion without waveguide:
here you see how the raal+waveguide 0-70 dispersion matches the mid on an early prototype without proper EQ and XO
and a more current measurement after going full active.
(left and right speaker, mic placed in listening position, the lines are 5db apart)
i have since raised the volume of the tweeter and adjusted the woofer/mid xo, but i dont have any screenshots.