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Cornell University 2900 series Whelen voice and Whoop

Posted: Sat May 31, 2008 9:12 am
by ver tum
This is in Ithaca, NY.
http://youtube.com/watch?v=RPLTQnvSkcY

The Whoop signal sounds different than I'm used to hearing.

Posted: Sat May 31, 2008 9:40 am
by md5
Listen to that echo however, quite the re-verb from the area around if I am not mistaken! I'm use to hearing it from a rotating Whelen, not an Omni-Directional however. So it's probably why you had those original thoughts. :)

Posted: Sat May 31, 2008 10:29 am
by ver tum
The Whoop tone is lower pitched than I'm used to hearing on a Whelen. This is perhaps an older 2900 series siren.

Posted: Sat May 31, 2008 4:08 pm
by SirenMadness
The whoop doesn't go up that far in pitch most likely to reduce wear on the speaker-coils, as going from a really low frequency to a very high one can cause wear sooner, due to changes in temperature.

Posted: Sat May 31, 2008 6:36 pm
by JasonC
SirenMadness wrote:The whoop doesn't go up that far in pitch most likely to reduce wear on the speaker-coils, as going from a really low frequency to a very high one can cause wear sooner, due to changes in temperature.
How would going to a high pitch cause an increase in temperature??? Speaker drivers are designed for higher pitches, low pitches are what causes excessive overheating.

Posted: Sat May 31, 2008 6:43 pm
by ver tum
Jason is right. It takes more energy to produce a lower tone than it does to produce a higher tone. Therefore, the speaker drivers heat up more when producing lower tones

Posted: Sat May 31, 2008 9:35 pm
by SirenMadness
JasonC wrote:
SirenMadness wrote:The whoop doesn't go up that far in pitch most likely to reduce wear on the speaker-coils, as going from a really low frequency to a very high one can cause wear sooner, due to changes in temperature.
How would going to a high pitch cause an increase in temperature??? Speaker drivers are designed for higher pitches, low pitches are what causes excessive overheating.
What I meant to say was a change in temperature, not higher heat. The higher pitch produces a lesser heat, and the temperature change between the low pitch and the high pitch might be what causes slightly faster wear. So going from warm to slightly cooler might cause faster wear, not the temperature itself, so to keep the temperature more uniform, the pitch would have to be more uniform. Other than that, though, it might just be a newer tone choice.