Thanks, Mark. My concern is C to C distance, not the upper FR of the 15″ and dispersion which I know is particularly well behaved and could match well with the QSC. If I could custom build my own, I would route into the QSC wg as the late Zilch had done to get closer still. The CNC pics you post look really great. I can only wait and see.
The real question is if an ~11.5″ C-C distance is significantly better than a ~13.125 C-C distance. The difference is barely more than an 1/8th octave of change, while the piston area yields 4dB greater headroom, along with greater sensitivity. When it comes to implementing a passive version, the added sensitivity is significant for many, and makes for much greater performance from amplifiers that don’t have noisy fans, and even from high value receivers.
The vertical integration of a 2 way horn + woofer always makes for some practical compromises. Having modeled the potential polar response with the same tools I have previously correlated with my current and past designs, I see more benefit than compromise with the 15″ woofer.
If there is sufficient interest, I see no problem with at minimum offering a cabinet for a TD12 + horn where the cabinet can likely shrink 1-2″ in the width and 4″ in the height. That said, I have no intent of offering a dozen different cabinets of the similar concept, as I’d much prefer to get a few well polished.