SVP sirens

[q2bman]

and another thing!

I think the reason you hear a Q so much better is number 1 they are louder number two they produce a saw tooth wave and not a sine wave. The saw tooth is better at "going arround and through" materials that may stand in the way of a sinewave!

[Robert Gift]

You're right, the eQ mimics the Q's complex harmonics (partials).

But most efficient for producing sound is a square wave, which is what all
electronic sirens produce.

Square wave accelerates driver diaphragm from one extreme to the other, creating the most power.

I remember the big outputransformers in the sirens I worked on.

Interesting that adding another speaker lowered your siren's frequency range.

What caused that?

Maybe pulling more amperage to drive the additional speaker drained more current and lowered voltage, which affected tone generation.
I would connect another wire from battery to amplifier to see if it restores
original frequency range.

You don't wanthe frequency to get too low or it may burn out the
voice coils.
Sorry that I cannot remember the cut-off frequency.

I wish I could see all manufacturers siren curves.

Do you remember the very slow, "forlorn" San Francisco sirens in the Dirty Harry movies.
Who made those?