Bonneville America Forums Forums Technical Forums Accessories Horn Ratings

In another galaxy long, long ago, someone wrote:

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The Bad Boy only reports 118 db

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There have been quite a few discussions in these forums about the Stebel and Bad Boy horns, but I don't think the subject of rating methods has been mentioned (sorry if I've missed it). In short, when SPL (sound pressure level) is used to specify output of a transducer in dB, the rating must also include measurement distance from the source. Most transducers, such as vehicle horns and stereo speakers, are rated at a distance of one meter, with somewhat fewer conforming to a two meter specification. In Stebel's case, the 139 dB claim is accomplished at four inches. Such a spec is largely meaningless unless you plan to throw the horn at the next motorist who cuts you off.

Dealers like to hawk the Stebel at 139 dB for obvious reasons, but a more useful number is available from the manufacturer's site. The company claims 115 dB at two meters, and that translates to approximately 118 dB at one meter. (Half the distance = double the SPL = +3 dB.) That's a much more reasonable number, and more in line with what I would expect from a device like this. Not surprisingly, it also coincides with the Bad Boy claim.

So - which horn is louder, Bad Boy or Stebel Nautilus? I don't know, because I haven't been able to determine the distance at which the Bad Boy rating was achieved. I suspect the two models are virtually identical, but until Wolo publishes the data, there's no way to know for sure. It's worth noting that there are also different weighting systems for making SPL measurements, and that can substantially affect the numbers. The bottom line is that all the relevant information is required in order to make a knowledgeable decision. Lacking that, you might as well just order the model that mounts the easiest or looks the best.

One last bit of errata: I've come across a few ads in which manufacturers or dealers claim that doubling the SPL (adding 3 dB) produces a horn that's twice as loud. In fact, an increase or decrease of 3dB corresponds to a change that is barely perceptible to the human ear. Loudness and SPL are not at all the same thing and are not interchangeable when discussing the effectiveness of a horn.

My search on these particular horn ratings came about because I was squeezed out of my lane on the local loop earlier this week. Traffic was roughly 65MPH, and if I hadn't hit the brakes quickly, it would have been a serious accident. The cager seemed not to even notice that I was leaning on the horn. I ordered a Stebel within 30 minutes of arriving home.

Hope this info is helpful to other riders. More info on dB (decibels) can be found here:

http://www.phys.unsw.edu.au/jw/dB.html



Jack

I feel a pop quiz coming...

The two horns in question sure look like the same units. Thanks for the info on ratings. It reminds me of the ratings used by gray market car audio folks. "2,000 watts per channel !!!" from a box that weighs 10 ounces...

Interesting post, Jack; very informative.

I think I've pressed my horn button once, when I picked the bike up. The way I see it, if you've time to sound your horn, you've time to take alternative action that takes you away from any danger. That said, a decent horn is on my list,,,it's near the bottom, tho. I'm thinking of a proper air horn; the amount of use it would get, the gas would last me forever.

I am spoiled by the horn on my truck. I bought an 85 Ford 150 and then added a JC Whitney Air Horn. Mounted on the roof with the compressor in the engine compartment along with the required air tank.

The thing scares the crap out of people! It sounds like the Queen Mary coming through the narrows. If only I could mount one on my bike I would. However I probably would have to get a sidecar and mount the 24" horns on the front top deck and the compressor and air tank inside along one of the sidwalls. It may be doable!

BTW it was rated at 145 DB by the manufacturer. I believe them!

I have the bad boy and really like it. Its compact, easy to mount and sounds great.

Very informative and interesting.

Frequency is going to play into the perceived "loudness" as well - lower freq will travel further so at a given distance a lower freq horn of the same Db will seem louder than a higher pitch.

The stebel has such a high pitch and I thought I heard there was another horn out there with a lower note but can't remember which. For the money and considering what was said about db ratings the electric horn that Brent sells is right up there at 119db if I remember correctly. Plus it was $14.99 last time I looked.

mike

Hopefully this is valuable too:

http://www.webbikeworld.com/motorcycle-horns/motorcycle-horn-comparison.htm

+1 for the horn Brent sells. It was cheap and it sure as ****** gets people's attention!

I have the Stebel on both of our bikes and it is LOUD, can't stop playing with it! LOL I love it. I also heard Jacks Bad Boy and there really isn't much of a difference if any. I found a place that sells the Stebel with the relay and all for about the same price as the Bad Boy sp I bought it. I wanted it before Johnstown bike week too and time was a factor. I had actually bought 2 Bad Boy horns after hearing Jacks. Harbor Freight said it was going Fed Ex and it meant I would have it in time. When I went to track it it wasn't a Fed Ex number but a USPS number, I was P!SSED since they told me Fed Ex. Turned out they didn't lie they just didn't tell me the whole truth. They use a service where Fed Ex picks it up but they just drop it at the USPS and it ships by them the rest of the way. So I ordered it elsewhere and they did give me a full refund when I returned them.

Both made in the same factory in China.

Just installed a Stebel Nautilus this afternoon, and like the sound of it. The only thing that worries me is it will stop the breeze from hitting the radiator.

Where has everybody else fitted theres

I just asked the wife to rate my horn, she only gave me a 7 out of 10

I have one in my now empty airbox. unless you run pod filters thats not an option i guess
G

I've had the stebel for a while now, was out on a poker run at a stop for lunch, partial got split up and a few beeped their horns and then I laid on mine. One guy on a harley about two bikes down about dropped his bike when he was trying to look around to see where the train was. He said certainly that is now a stock horn. And yes the rest of the group that was going past noticed that we had stopped for lunch.