The new-to-me R1200R has a wimpy horn. I have a pair of Fiamms on the RS that work very well. I see two different series of Fiamms now available:
72002 (high)/72012 (low)
They look like the same physical size. The latter series is called "Freeway Blaster," and the specs given at Amazon show a bit more sound.
Anyone have any specific information about or experience with these products?
I haven't actually bought a Fiam horn for years, but I've never seen a bad Fiam product. I've seen some cheap knockoffs from across the sea (the other sea) that look like Fiams but don't work like Fiams, but I've not seen a bad Fiam product.
O'reilly Auto parts will get you either one & they are loud enough. You will need to splice the wire ends and some heat shrink connections will improve the job.
eBAy Fiamm Horns
The name Fiamm draws a lot of bids on eBay but here is a secret. Do not tell anyone. Volvo and Saab car horns are Fiamm but if the seller just lists them as Volvo or Saab, bidders looking for the Fiamm name miss these postings.