What is the loudest vehicle horn?

Question

I know of train horns, but whats the most powerful?

Answer 1

train horns.

Answer 2

I own a shop, and have messed with horns all my life.  Once I saved all the horns from the wrecked cars & trucks we towed, and tied them together to see how many horns I could have blow at once.  "What a noise"!!!  I guess I must have had at least 50 horns go off at one time.  We towed wrecks for the State Patrol, and I was able to collect many different ones.  The truth of the matter is;  The vehicles that had two horns were the loudest, and was used from the mid 50's thru the late 70's.  The loudest of them all was the dual horns that were attaced on top of trucks, and used air.  The more air pressure applied to them, the louder they get.  I did find that the old six volt horns used prior to about 1955 were loudest.  Ironically, the six volt horns would really scream when hooked to a 12 volt supply.  Some horns require a relay to make them work in order to keep from making the wires heat up.  These type pulled the most amps, and seemed to be the loudest.  Contrary to the fact;  The horns that are speaker driven, and used also for anti-theft purposes, will reach well in excess of 130 dbs.  The mechanical type horns were the loudest when supplied with more voltage.  So... I would say the #1 horns would be the air driven horns, followed by the speaker driven horns, and then the mechanical horns that worked by a fluttering piece of metal activated by a pulse type magnetic coil.  I never actually used a db. meter to measure how powerful they were, but one can tell a lot by how well they can hear afterwards.  Interesting question.

Glad to add my 2 cents worth, Good Luck!!!