fire engine sirens in Japan.

[q2bman]

They sure have the "low tone carries farther" theory down pat.

http://www.youtube.com/watch?v=ydOYzluwvg4

I wounder what they are saying as they scream down the road?

[Robert Gift]

Yes.
Interesting to hear very low frequency sweep of electronic siren.

Don't think our siren speakers would handle that low a frequency.

Love to know what was being said.
I'll ask.
PA system sounded very clear. Surprisingly little distortion.

Confucius say:
Man who jump through screen door, strain self

[Jim_Ferer]

"please to consider our request to make not obstruction to progress of sincere humble fire persons making attempt to try very hard to arrive at fire."

[q2bman]

" Move, stupid American!"

[AllSafe]

Don't think our siren speakers would handle that low a frequency.

Some of them will. Think of the bigger speakers some fire trucks or ambulances use. Some of them will reproduce frequencies that low.

[Jim_Ferer]

That's a darn good siren and I'd want one, just in that frequency spread.

[SirenMadness]

The frequency load is not too great, but the lower frequency does add to the overall distance. This is a far-better vehicle-siren than most that I know.

[Robert Gift]

Don't think our siren speakers would handle that low a frequency.

Some of them will. Think of the bigger speakers some fire trucks or ambulances use. Some of them will reproduce frequencies that low.

US siren drivers risk voice coil burnout below 400 Hz (or something).
So electronic sirens have a cut-off frequency above that.

We were several blocks from a hospital when our 100 watt speaker went silent. (Since we were nearing the hospital I was planning to go silent anyway.)

I later discovered that our old Unitrol 800 tone circuitboard was out of spec.
In Wail, the siren sweeps up and down to 500 Hz and back up.

In Manual, it goes up and descends to a lower tone to silence.

(My always sparsely sounding the siren in Manual probably led to the speaker failure because it was always decending to the lower frequency rather than going back up.)

Also, disassembling the Federal Signal driver revealed that the voice coil wire insulation had been gouged.

Fed Sig admitted that pieces of their magnet metal can flake off and get
into the tight voice coil gap and etch the varnish insulation.

Their old big magnet drivers should all be replaced by their new neodynium drivers.

[q2bman]

The old drivers sound so much better though! The Neos produce a high pitch. I gues they are not good a producing the low frequencies.

[SirenEnthusiast360]

"please to consider our request to make not obstruction to progress of sincere humble fire persons making attempt to try very hard to arrive at fire."

Let me guess, you used a translator.