I'm mounting my Helix horn in the stock location. It's been sprayed black and I'm waiting for it to dry.
I did a loudness test with both horns off the bike. Not a great test. I had my nephew stand about 25 feet away and I held the horn in my hand and touched wires to the terminals.
He said the factory horn sounded irritating to him and the Helix horn sounded better. Whatever that means?
He wasn't sure which was louder but he liked the sound of the Helix horn better. He really hated the less than manly sound of the factory horn so I'm not sure how objective he was.
So, no answer.
As soon as I mount it on the bike I'll be able to tell better. The holding in the hand while touching the wires created a poor connection anyways.