I really dont know, but whenever I hit the horn on my 87 sammy, it just sounds like, really pathetic. I've honestly had weak motorcycle horns sound better. to my knowledge all the wiring is clean and good, as are all my contacts that I could find to check/clean.
I"m seriously debating an upgrade, but I cant decide what kind of horn I want for it, besides louder/less gay. Then again any old school caddillac fleetwood brougham horn set would significantly upgrade my sound. well, if I can figure out where/how to mount em.