Currently I'm in INDIA with my FXDC.
I was doing a horn signal relocation.
Removed the OEM horn (Windtone Horn) & to my surprise I found out it was manufactured by a company named ROOTS & they are headquarted in a city called Coimbatore,India

Luckily the place where I live in India right now is Coimbatore. So I went to ROOTS factory store & got a aftermarket Horn (Windtone Horn). Now I dont know how much an original OEM horn costs in USA but this aftermarket windtone horn by Roots costs 525 indian rupees equivalent to 12 usd.
For 12$ you get both H-High Freq & L-Low Freq

Posting a link of both the OEM & aftermarket Horn test

http://www.youtube.com/watch?v=rgoDstqmfi0

 

Dont know if the video does justice to the sound, but heck yeah it sounds much louder than the OEM