BMW 1150RT horns. They require no special circuit or extreme volt/amps. They are loud...like a car horn.
Not familiar with the C-14 Horn mount.
I installed a set of louder horns on my first C-10. Was not the Fiamms, but was well worth the effort.
Ride safe, Ted
The set I put on my bike were off a 1967 "850 Fiat".
They; were loud enough to slow the bike when I blew the horn..
could make a person drop their shopping bag if you "snuck" up behind em' in a parking lot. <evil grin>
But, (somehow) I suspect they may be a litle hard to find now....
Ride safe, Ted
They're off a FIAT, and they still work?