St. Louis County testing dead spots.

[bradhig]

http://www.fox2now.com/videobeta/c10d97 ... Dead-Spots

Already they are having problems with the new 2900s.

[bmeiser]

At least they're being thorough about this instead of just installing them and being done. I don't feel like Indianapolis was this thorough when they installed their new system of 2001's. We have quite a few coverage gaps.

[uncommonsense]

Already they are having problems with the new 2900s.

Agreed with bmeiser. Its not that the sirens are broken. Its that a computer just can't predict to 100% accuracy how houses, terrain, and the hussle-bussle of a metropolitan area is going to affect sound dispersion of the units.

Or how people are going to react when a siren that was next to their house is no longer there

This shows an amount of responsibility on the part of the County that I've come to expect and shows how much they really do care about doing this right the first time.

[federalsignal3001]

along with the possobility of unaccounted factors in computer simulations as uncommonsense mentioned, electronic sirens are typically higher pitched and a few decibles quieter then mechanical sirens, and as a result don't carry as far as mechanical sirens, whch might be a slight factor in this. Although not the problem in this case, I think it's worth noting electronic sirens don't have as distinct of a tone as mechanicals either.

[uncommonsense]

along with the possobility of unaccounted factors in computer simulations as uncommonsense mentioned, electronic sirens are typically higher pitched and a few decibles quieter then mechanical sirens, and as a result don't carry as far as mechanical sirens, whch might be a slight factor in this. Although not the problem in this case, I think it's worth noting electronic sirens don't have as distinct of a tone as mechanicals either.

Which is totally flawed logic in this case since this is over a hundred Whelens replacing over a hundred Whelens aside from a few cases of T-Bolts and 2T22s.

Modern Whelens operate at 560 hz in alert. Not too much more high pitched than the Eclipse, for example, which operates in alert at 525 hz (source: Eclipse manual). And the 1982 Whelens (the majority of the system) operated at over 700 hz. Again, flawed logic in that argument.

The 2910 is rated at 129 db at 100'. The db rating isn't the problem. Its not that they're quieter. Its comparative attenuation, which you eluded to as a "slight factor." It would be a significant factor if we were going from mechanicals to electronics. But that's simply not the case in STL County in an extreme number of cases.

[FedTB]

From what I understand, some of the sirens will be moved to better facilitate coverage.

The siren at the beginning of the video is actually a City of St. Louis siren. For those that don't know, it's located right along I-64, just east of Hampton Avenue, in Forest Park near the St. Louis Police Department Mounted Patrol barn.