Kleinn Train Horns

Air horns versus train horns

Kleinn sells two families. Air horns, like the Model 130 chrome triple set, are compact trumpets that run happily on a small sealed compressor and a 1 gallon tank at 130 psi, and they are the step up from a stock electric horn: much louder, with a deep multi-tone note, but still mountable behind a grille. Train horns, like the Model 220 and the Demon 730, are the real thing in miniature: large trumpets up to 18 inches long that need 150 psi and several gallons of air to reach their rated output, which Kleinn lists at over 150 decibels at 150 psi for the Model 141 and 154 decibels for the Model 220. They are mounted under a bed or on a frame rail and take up serious space. Decide how loud you really need to be and how much room you have before anything else.

Complete kits or build your own

• Complete horn and air packages such as the HK3 and HK9 include the horns, compressor, tank, pressure switch, safety valve, air line, fittings, wiring and the horn button. This is the simplest path and the parts are matched.
• Horn only listings, for example the Model 130 or 141 trumpets, assume you already have onboard air for lockers or tires. Check the horn's minimum tank size; the JK220 kit specifies at least a 1 gallon tank.
• Onboard air systems such as the JKOBA for the 2007 to 2018 Wrangler Unlimited give you a waterproof compressor, tank and tire inflator with brackets made for the Jeep, and a horn can be added later.
• Direct drive dual horns bolt a small compressor straight to the trumpets with no tank, for a 132 decibel horn that fits where a train horn will not.

Sizing the air supply

Volume matters more than pressure for a horn. A big train horn blown for two seconds can empty a 1 gallon tank, after which the note sags until the compressor catches up. Kleinn pairs the Demon horns with 3 and 5 gallon tanks for that reason. Compressor duty cycle sets how quickly the tank refills and whether the compressor can run continuously; the 150 psi units in the full kits are rated for 100 percent duty. If the same air system will also fill tires or run lockers, size the tank for the horn and the compressor for the tires, and add a pressure switch so the tank holds at working pressure when parked.

Installation

Mount trumpets facing forward or down with the bells angled so they do not collect water, and leave the drain at the bottom of the tank reachable. Many kits bolt to vehicle specific brackets; the JK kits use the factory horn circuit so the stock button works, which keeps the install bolt-on. For a separate button, the Detonator and Mini Detonator flush mount in the dash with spade terminals, and the wiring kit supplies a 5 pin relay, fuse holder, wire, crimps and Teflon tape with a color coded diagram. Run compressor power through the relay and fuse to the battery, ground to clean metal, and use thread sealant on every NPT fitting. Leak test with soapy water at full pressure before the first blast.

Using a train horn responsibly

At 150 decibels a train horn causes hearing damage at close range and can startle drivers into mistakes. Keep it for genuine emergencies and off-road signaling, never aim it at pedestrians or cyclists, and know that many states and cities restrict horn volume or ban train horns on public roads. Fit a selector so the factory horn stays available for normal use, and treat the big horn as the last resort it was designed to be.