In a nutshell, we have a 41 foot sailboat. Going to mount signal horns on the mizzen mast. The regulations are hard to find - but I found them. (Electronic Code of Federal Regulations:
I looked for the regulations because the specifications by manufacturers do not always tell you such things as "Complies with regulations for vessels up to X meters"
You can take a look at the chart in the link above.
The first two headings: Length of vessel in meters
and Fundamental frequency range (Hz)
are perfectly understandable as is the last: Audibility range in nautical miles
But the other two headings are a bit obtuse:
For measured frequencies (Hz)
and 1/3-octave band level at 1 meter in dB referred to 2×10−5N/m2
Any audio engineers out there can explain this?
The reason I ask is I am trying to decide if dual horns are enough more effective to spend the extra money on. Is that column which says "For measured frequencies" which has two sets of frequencies listed for each length category have anything to do with the dual horns?
Have I bored you enough? Hello, are you still awake?