I did a quick comparison between the following horns to be installed on my Scout Bobber:
Denali Soundbomb Mini
PIAA 85114 Slim Line Sports Horn (400hz)
My final thoughts are Stock sucks.
Denali is maybe a bit louder than PIAA but sounds rough.
PIAA sounds more refined and smoother and just as loud as Denali.
Both install was almost plug and play, had to bend a small metal area with pliers. Took about 10 mins.
Hope this will be helpful for future reference - enjoy!