The Siren Board

Here is a couple of videos of Federal's new "Rumbler" siren. The Rumbler is basically a 80w police siren subwoofer. It takes the output of a normal siren, reduces the tone by 75%, and amplifies it. There was something posted about it on this board not to long ago. Anyway, here are the vids, the second vid has the Rumbler cutting in and out to help demonstrate the difference. Be aware that a video camera cannot capture the all of the harmonics produced by the Rumbler.


http://media.putfile.com/FedSig-Rumbler-Clip

http://media.putfile.com/Rumbler-vs-reg ... ren-sounds

Thanks Jason.
I posted about it somewhere.

Did you hear it in person?
What do you think?
Another expensive gimmick, or is it effective?

Thank you,

Depends. In the vids, I'd say it's not worth it. Although it sounds cool, it probably is not very effective. However, it probably is effective, because cameras cannot capture the full range. In effect, I'm saying "no idea".

StonedChipmunk wrote:Depends. In the vids, I'd say it's not worth it. Although it sounds cool, it probably is not very effective. However, it probably is effective, because cameras cannot capture the full range. In effect, I'm saying "no idea".

On the eLightbars.org board, several of the members have then installed on their POV's. Everyone of them gave it a good rating for their $400 price tag. Apparently, they penetrate into vehicles much better than a normal electronic siren.

These things reproduce the sound in somewhat of a square wave similar to mechanical sirens to allow people how hear it to feel it as well. So basically it takes the sine wave normally produced by electronic sirens and somehow amplifies it and the sound comes out in a square wave. The Tullahoma Fire Dept has one of these on a truck. The "Rumbler" is driving a whelen and they say its very effective.

The system uses one or two specially designed 80W very-long-throw speaker drivers to generate low-frequency sounds at a very high volume (about 120dbA@10ft). It gets its output from an existing siren tone generator. I've heard about rumble generators which are sometimes used in augmented reality systems and they are quite effective.

Electronic sirens produce SQUARE waves.
Square waves slam the diaphgram from one extreme to the other, creating the loudest dB output.

The Rumbler simply takes the output of an electronic siren and produces the same tone 2 octaves (75%) lower.
It uses two 6"? speakers, not horn type exponential speakers.