Over the course of the last few years I’ve grabbed up the following drivers as they became available on the used market…
(2) Dipole 15-8
What I’d like to do is utilize them in an OB design along with a Radian 475PB compression driver (in a QSC wave guide) to cover upper mid range/HF. I have an open back cover for the compression driver so it can propagate a rear wave, effectively making it dipolar as well. My room is 20x16x8 and I’m fairly unrestricted wrt speaker placement as it’s more or less a dedicated listening space (which also has rather extensive acoustic treatments).
My initial idea was to use the Dipole 15 on the bottom of the baffle and perhaps house it in a U-frame. Above that would be the TD15M and above that the Radian in the QSC wave guide. I was thinking crossover points would be around 20-300 and 1.5k-2.5k as my inclination is to have the mid band driver cover as much of the mid range region as possible. My understanding is that off-axis response for the TD15 starts to fall off around 2k, but I’ve also been told it’s best to try to match the dispersion angle of the mid driver to the dispersion angle of the wave guide…which I believe is 90 degrees for the QSC….so I’m not sure what effect this would have on the crossover point except I assume it would push it well beyond 2k.
Not really sure exactly what to do with the IB15’s but I’ve been pondering the idea of slot-loaded open baffle or w-frame type subwoofers. If they could be integrated into the main panel, maybe one on top and one on bottom, to relieve the Dipole 15 drivers of the really low stuff perhaps that would be a course to consider. I have another active crossover (Rane AC23) I could dedicate to them.
I intend to go active with all this using an Ashly 3-way if that unit would be sufficient (since it a fixed 24db/octave slope) but the use of something like a MiniDSP is certainly not out of the question. I have several amplifiers to choose from, both tube and SS, to power all these drivers.
But then again I might be going about this all wrong and that’s why I’m asking for a little guidance here. Do any of you see a more fitting implementation of these drivers in an OB design or could you offer any tweaks to what I’m proposing?