Interesting topic. My 2017 Super Duty horn sounded terrible - not as solid sounding as my 2016 Super Duty.
I think my 2018 Raptor horn sounds great. Its much louder than any other Ford horn I've ever had.
Ford had a considerably number of horns failing in 2017...its a two-note horn and typically one note would fail, making it sound weak. Perhaps for 2018 the supplier is different or the horn is revised.