[SentraSE-R]

You folks know me, the inveterate tester.

One of the neat features of my Android-based Nexus 7 tablet is its ability to measure dB of sound, via its built-in microphone and apps like Smart Tools and Android Toolkit.

A couple of decades ago when I was riding motorcycles, I strapped a compressed gas cylinder boat horn to my handlebars, and found it a great safety feature. A blast on that horn, and cars immediately reversed their lane changing intentions. One problem was cylinder cooling when the horn was used, greatly lowering the horn's efficiency.

I replaced the boat horn with an electric compressor twin air horn mounted low on my motorcycle frame. This horn didn't seem as loud. It was high-pitched, and I had doubts about the amount of air put out by its compressor.

Fast forward to today. Now I have a way to measure my horns. The standard is dB loudness three feet or one meter from the horn. Initial impressions are not good. I haven't found an assistant, so I held my Nexus 7 out the open window of each family car at the front corner of the door frame facing the engine compartment, and blew the horn.

Wife's 2012 Hyundai Elantra, stock dual electric diaphragm horns - 86 dB.

My 2006 Scion xB, triple Fiamm electric compressor air horns - a high-pitched and disappointingly weak 86 dB. My cheapo horns suck. I'll do proper testing with a yardstick this weekend. Maybe the horns will sound much louder at the proper distance in front of the cars.

I think I'll spend an afternoon at the shopping center with a yardstick, earplugs, and my Nexus 7.

Hypothesis. The loudest horn will be one with a large (5 gallon?) air tank under high (125 psi?) pressure, with large trumpets.

Hypothesis: Some electric diaphragm horns will do well (110 dB?). Will they be in trucks? Luxury cars?

I'll appreciate your suggestions on which horns to test, theories on the best horns, suggestions on testing methods/procedures.