I'm thinking of replacing our horns also. I've found several different horns on ebay and amazon. Some claiming up to 139 db, which is pretty darn loud. Some are air horns that come with small electric compressors for air, some are just electric, that would probably easily hook up to the existing horn wiring. I'll probably just go with a set of electrics myself.
Harley Ultra Classic (Geezer Glide) Rider, Retired US Army Paratrooper, fisherman, shooter. Proud to have served, proud of those that still do, or have done so with pride.
2005 National Dolphin 34'