All,

I need recommendations for a really loud, rude replacement horn for the Vision (that will fit, the train horns need a 2 gallon air tank).

A guy with his front windows tinted and sun glasses on pinched us into the cement wall on Saturday. He changed lanes and right into us and never looked to his left. The Vision's horn was barely noticeable at highway speeds. We were lucky that only the left highway peg sparked against the side wall and bent up before we were able to get out of the pinch.

So far, I found this one that claims to be 139dB @ 4 inches (normal audio speakers are measured @ 1 meter, thus their measurements seem suspect).

Stebel Nautilus Compact Motorcycle Air Horn

http://www.skene.org/K1200RS/horn/index_horn.htm

I appreciate any recommendations.

Thanks,

Tim

 P.S.

I have a RatShack SPL meter, so I will actually measure the deltas between the factory horn and the replacement horns. 

Ken,

I put one on order from Amazon.com. I will measure it before mounting it to verify that it is louder than what is already on the bike. If not, it is going back.

I saw some 150+dB train horns on the web. They should do the trick =), but they require a 2 gallon tank plus a compressor. I suppose I could rig up the tank inside of the tour pack =).

Tim

  Train Horns
 

I got a Stebel Nautilus for Christmas and haven't figured out how I'm going to mount it yet.  It looks like there's a ton of room where the stock horn is but when you move the front wheel around and account for suspension travel it's tighter than you think.  I may end up mounting it against the inboard wall of the left saddle bag, aimed down at the ground.  Tons of room in that space between the bag and the wheel. 

The Stebel comes with a 30A relay.  Anyone know what the stock horn relay is?

According to the shop manual wiring diagram, there is a 40 amp breaker between the battery and the horn relay and a 20 amp fuse between the ignition switch and the horn relay.

HTH,

Tim 

Boy, that was fast.  UPS just delivered the new horn.  I just measured it.  It measures 122dB on my RatShack SPL meter.  The stock horn measures 112dB on my on my RatShack SPL meter.

FWIW, 3dB is a doubling in power (2X).  It takes about 10X the power to produce a perceived doubling in loudness to the human ear, thus 10dB difference will sound about 2X as loud.  Some of the online horn sights give misleading information.  10X the power, does NOT sound 10X louder.

The manufacturer claimed 139dB for this unit, but my RatShack meter is only measuring 122dB.  139dB would have been great (@ 5X louder), but 2X louder is better than nothing.

Will post my results once it has been mounted.

Tim 

I mounted the new Nautilus horn and wasn't satisfied, so I mounted both the Nautilus and the stock horn, but I moved the bell out from behind the fairing. Measuring the horns at the center top of the font fender, the horns are in the mid-120 dBs now. At highway speeds it is much more noticeable.

The stock horn frequency is 400Hz.

The Nautilus low frequency is 530Hz.

The Nautilus high frequency is 680Hz.

I used a new 30amp relay to hook up the Nautilus and used the existing bike wiring or the stock speaker to not overload the existing wiring harness and switch.

It should do until I find something better.

Tim

I took it out on the highway and it is definitely more present.  The Nautilus adds a bit of a biting British tone to it which makes it stand out from the engine noise.

The freight train air horns should provide some authority, but they are too big for the bike. 

Tim