My bad then. I looked at these fairly closely. I thought even the JBL diaphragms would interchange. Either way, they actually sound pretty decent. I have them running right now in a three way as the midrange, xover points of 700 and 5600. I feel thye do really well in that application. They are on a fibergalss horn that is a little bigger than an 811b.

But, to get back to the 1235c - any suggestions as to drivers for the 511b horns. I think the tangerine plug drivers are going to be difficult to find and cost an arm and a leg too.