Yes, of COURSE I could tell you how to drive one speaker from two audio
sources using a transformer. Would it provide the same reliability that a
dual-cone speaker gave you? I don't know because I can't run the tests that
the Cessna engineer ran to certify the sucker. I'm not about to tell you
how to do something that would compromise that design.

Sorry, no, I was speaking from the standpoint of "Couldn't the Cessna
engineers have designed it to use a conventional speaker, using some
sort of transformer...etc". I take your answer to mean basically "yes,
but perhaps they felt this was more reliable, etc". I doubt the Cessna
engineers considered the effect that many a pilot (not me, of course)
would continue to fly their plane without warning horns while he was
trying to find and order an oddball speaker whereas he would have just
picked one up from Radio Shack and put it in, had it been a standard
off the shelf unit.

BTW, Mr. Neal replied right away, that he did not have the parts for it


Thanks,
John