Will the JBL 2012 or 2123 also work like the Alpha with a vented rear chamber to below 100Hz? Whats the current low limit of the Alpha 10 unit? Maybe you could even rear load the Alpha 10 to 70Hz... something like 1.25m length with 2000cm^2 mouth using only a single fold with the mouth exit at the front, underneath the midrange horn. though I'm not sure if loading both sides of the driver with different horn types is a good idea, I guess it could be OK though just like loading one side vented and the other a horn, it works although I'm just speculating.

Do current Pi Corner horns provide horn loading to 300Hz? Or are they direct radiator by then?