

Not to be a bummer, but the loudness of the horn will be limited by the max amperage of the relays. If the horn relay maxes out at 15 amps for 12 volts, you get about 180 watts of energy to the horn. Most horns are just a coil that vibrates at a set frequency to move the rubber or vinyl diaphragm inside the horn. That’s the noise.
Short version, you can put really any horn in there, but the total amount of watts will be the limiting factor. A more efficient horn (aka a new one) will make more sound for equal input wattage.
The other option is to make an array of junkyard horns and set them up with more relays to lift the limit. You’d need to have multiple fused connections unless you just want to be a hillbilly and run them right off the battery with a giant ass relay.
You might start a fire but it will be loud as shit for a few minutes before it burns down.







There was a city agency that did this in Columbus Ohio. SMART Columbus.
They used tax money to subsidize ebikes for low income folks.
Turns up low income people don’t need an expensive bike that they have nowhere to store securely and they can’t use to transport their families.
Those that got them, turned around and sold them as quickly as possible.
This was a very DUMB way for the city to take a lot of taxpayer money, hand it to a brain-dead organization, pay the employees to organize everything, waste a lot of time to give low-income folks less money than if they would have just handed it out.
SMART Columbus: turning a lot of money, into a little money.