210s with separate subs.. What would it take?

[Phil-G]

So if I built a pair of 210s the best I can come up with for drivers would be some 515ghps. as I understand it they don't go down much more than 50hz. That's doesn't seem very low. any suggestions for something that would go low and keep up?
i'm thinking of movies semi outdoors. 150' x 150'

[Elitopus1]

Maybe a quad of JBL 18" woofers per side.

Or some nice tapped horn subwoofers.

[GM]

Hmm, I chopped out the horns, compression loaded them and perched them on dual 515B subs ultimately tuned to 14-16 Hz, but these were for corner loading, though if I'd had room to leave them intact, compression loading them and using the rest of the cab volume [Vb] for a multi driver subsystem XO'd around 80 Hz? Need to ask Mac what XO he used [if I only knew how to contact him these days] for his custom 210s + Sensurround subs.

Anyway, for a prosound app, probably better to just add some serious THs so they can keep up with the 210's peak SPL capability.

GM

[LOUDER]

I've used sensurround bins on both 828 and 210's. They can still be found and you can upgrade with better 18's.