The stock horn on the R3 leaves much to be desired to say the least when it comes to the sound volume it produces.
So I got the DENALI SoundBomb Mini (
Amazon.com: SoundBomb Mini Electromagnetic Low Tone Horn: Automotive) and installed it in place of the stock horn. Couldn’t fit it on the stock bracket so I removed the bottom radiator/fan assembly screw and attached the horn there.
It’s a tight fit, but the good news is that the horn doesn’t touch anything on the bike.
Only two minor modifications on the DENALI horn needed to make it fit.

1) Bend the tabs to be straight out (just like the stock horn), such that the stock harness can be connected.
2) Take the DENALI provided ‘mounting strips’ and shorten them by about .5”/12.5mm, drill a hole for the screw.