The Siren Board

Does anybody have any info on the T-132 since they are not showing anything about it on their site? I know they are only sending that siren's info out through the mail right now.

Here's a spec sheet I got in the mail.

Front: http://www.putfile.com/pic.php?img=3525086

Back: http://www.putfile.com/pic.php?img=3525087

Looks like the final closing of the chapter of Penetrators.

great thanks bud!

This is from the Wikipedia article:

The decibel (dB) is a measure of the ratio between two quantities, and is used in a wide variety of measurements in acoustics, physics and electronics. While originally only used for power and intensity ratios, it has come to be used more generally in engineering. The decibel is widely used in measurements of the loudness of sound. It is a "dimensionless unit" like percent. Decibels are useful because they allow even very large or small ratios to be represented with a conveniently small number (similar to scientific notation). This is achieved by using a logarithm.

When used as a measurement of power or intensity, a decibel is defined as



And yes, the decibel was named in honor of Alexander Graham Bell by the folks at Bell Labs (greatest site of inventing ever). There had been some though of naming the unit after Alexander Graham Kowalski, who was famous for being the first telephone Pole.

Jim_Ferer wrote:And yes, the decibel was named in honor of Alexander Graham Bell by the folks at Bell Labs (greatest site of inventing ever). There had been some though of naming the unit after Alexander Graham Kowalski, who was famous for being the first telephone Pole.

Yes, I believe he invented phone sex, but it never caught on because those old magneto phones couldn't support his weight.

Not to dig up an old post or anything (spotted this while searching for siren redesign ideas ), but I reckon why they just keep bumping up the frequency on the siren is to make it more attention seeking.

When I listen to any 2001, even the older ones; the signal really gets under my skin, and personally; I'm more likely roused by a 2001 scream than a T-128 dull roar.

I assume they merely spin the rotor faster to pump more air to create higher pressure to increase dB output.

Unfortunately, that also increases frequency.

If I can ever acquire a real siren, I'll block various combinations of stator ports to see what that does to the frequency and sound output.

You cannot pump air with a simple rotor-siren; the air gets sucked in by the rotor. A rotor spinning inside a stator does have a certain maximum speed at which it can push out the most air, though spinning a rotor somewhat faster would not hurt. Also, some new sirens just use bigger rotors, to decrease the need for a faster speed of the rotors.

Also, covering some of the ports on the stator would not change the frequency of the sound outputted; look at the fact that any T-bolt only has one stator opening with no low pitch. That is because it is almost solely the amount of ports on the rotor, that matters: what determines the outputted frequency is the speed at which rotor-ports pass through a stator-port, which is what determines the fluctuation of air of every chop, as the more chops you have in a time, the less time the air escaping from a previous chop has to not be pushed by the chop after it, producing that pressure which allows the chopped air to only move so much as the rotor speeds up, to make a smaller fluctuation, resulting in a higher pitch.

The vanes in a rotor would take in more air the faster it spun, up to a point; the benefit would be counteracted by the lesser amount of time that the rotor and stator openings lined up. One effect would counteract the other. it would take some fancy calculus to figure out when the 'crossover point' was.