Re: Horn UPGRADE (honk honk)
Loudness really isn't the issue. Car horns are made to sound melodious, not brash or obnoxious. They are usually 2 tones that compliment each other. What you want is TRAIN HORNS! They are usually 3 tones that are 1 and 1/2 scale notes apart, making them discordant and hard on the ears. For instance, train steam whistles are like B-D#-F or C#-F-A. The problem is finding the right third horn to add to the ones you've got.
I put '56 Chrysler 6V long trumpet horns on my '67 Camaro. They were loud but still not good enough until I added one of my original Chevy horns, then it was a perfect match with a CSX freight diesel! BOY, did that get attention! I actually saw people jump in their seats. Then they craned their necks around trying to figure out where it came from. Then I'd give them another blast. Those 6 volt horns drew a lot of power on 12 volts so I had to use a relay and not hold down the button long enough to burn them out.
I've been trying to figure out what notes the jeep horns are but, alas, I'm no musician. GM horns used to be marked with their notes. If anyone figures this out, please post your findings.