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Reducing current

An 8 ohm speaker will have 5 ohmsish of DC resistance.

If you have two 8 ohm 10" Eminence Deltas in parrallel and one 4-ohm 15" Eminence delta, you'll get roughly the same SPL from the same electrical input. So surface area looks like the bottleneck; that's twice the coil and twice the magnetic ... loss.

The 10" is suspiciously like -3dB "quieter" than one 15".

Of course the Thiele-Small for those two speakers are different. "101 db @ 1 Watt-Meter" usually involves a 1 KHz tone. And we're assuming an optimum enclosure, all that.

Horn-loaded enclosures are known to be much more efficient than acoustic suspension/ported designs. Horns are a means of "acoustic impedance matching".

So bandwidth-amplitude product? Agreed.

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Les Cargill
Reply to
Les Cargill
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When I was a kid learning about electricity, I discovered a really horriblle noisemaker, take an electric motor with a pinion (cog) on the shaft and arrange for the cog to rub on an arm attached to a diaphragm (I used the base of a tin can)

Makes a noise like a hacksaw going through sheet metal.

All my first burglar alarm experiments used this sounder.

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umop apisdn
Reply to
Jasen Betts

When I put in our first alarm system, in our home, I found that sirens produced over 20dB louder than bells, BUT sirens were NOT permitted to be mounted outside your home by city ordinance! So the solution suggested to me by the city official was to mount the siren inside the home with it pointing through an 'open' window, or a wire screen pointing to the outside and that complies with the 'letter' of the law, not the 'spirit' of the law, so is ok. However, I found it far better to put several sirens INSIDE the house. NO burglar can stand 140-150dB of 'captured' siren noise for very long. Like standing on the tarmac behind a jet. No, it discombobulates the brain and any intruder simply wants OUT!

Reply to
RobertMacy

Ours has a horn-style speaker located in the A/C ductwork with a shrieking "siren" sound... deafening. ...Jim Thompson

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| James E.Thompson                                 |    mens     | 
| Analog Innovations                               |     et      | 
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I love to cook with wine.     Sometimes I even put it in the food.
Reply to
Jim Thompson

I only test ours when I want to 'clear' our sinuses. ;)

Reply to
RobertMacy

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