Federal Signal 2001-130 Vs. 508-128

[Yershkmatov]

This is a question I have for those of you who may have a good bit of knowledge on Federal Signal sirens. Why are these two sirens in production alongside each other, and what roles do they each fill? Both are long distance rotating sirens, with similar DB output, with a similar design, the only real differences between these two models seem to be the sound frequencies that they output, and different housings to better suit each siren's chopper.

Why would a particular city or county choose a system of 508s over a system of 2001s, or vice versa?

[Non-Zero]

definitely would choose the shrill scream of a 2001 in a city, carries better

[Bijay]

definitely would choose the shrill scream of a 2001 in a city, carries better

For real? I thought it was lower frequencies carry a lot better than higher.

[Yershkmatov]

definitely would choose the shrill scream of a 2001 in a city, carries better

For real? I thought it was lower frequencies carry a lot better than higher.

That's actually part of what I was wondering. It would make sense that different pitches carry better in different environments. Perhaps higher pitches carry better in cities and lower pitches carry better over flat lands? If that were the case, I suppose it could explain the production of the 508 and 2001 side by side.

[carolinasignalco]

In the city, a 2001 is better. low freqs cary better hence why I can hear gunshots from our neighbors 5 mi away, but not the bwomping country music, that is just as loud. same thing with the lancaster motor speedway. you can hear the cars from 2 mi away, but can only hear the anouncer in the parking lot. the 508 is better foe mountanous, wooded, or unimprover terain. note that there arent that many sth10s in the country, where thier low tone brother far excedes them in effective range.

[Yershkmatov]

In the city, a 2001 is better. low freqs cary better hence why I can hear gunshots from our neighbors 5 mi away, but not the bwomping country music, that is just as loud. same thing with the lancaster motor speedway. you can hear the cars from 2 mi away, but can only hear the anouncer in the parking lot. the 508 is better foe mountanous, wooded, or unimprover terain. note that there arent that many sth10s in the country, where thier low tone brother far excedes them in effective range.

Good to know, that's kind of what I was thinking. The thing that surprises me is that the 508s in MN all seem to be in the suburbs, while most newer rotating sirens in the country are 2001s, though that might just be because the 2001 series has been in production almost 20 years longer than the 508 iirc. Either way, thanks for the info.

[carolinasignalco]

In the city, a 2001 is better. low freqs cary better hence why I can hear gunshots from our neighbors 5 mi away, but not the bwomping country music, that is just as loud. same thing with the lancaster motor speedway. you can hear the cars from 2 mi away, but can only hear the anouncer in the parking lot. the 508 is better foe mountanous, wooded, or unimprover terain. note that there arent that many sth10s in the country, where thier low tone brother far excedes them in effective range.

Good to know, that's kind of what I was thinking. The thing that surprises me is that the 508s in MN all seem to be in the suburbs, while most newer rotating sirens in the country are 2001s, though that might just be because the 2001 series has been in production almost 20 years longer than the 508 iirc. Either way, thanks for the info.

that is mostly the reason. the 2001 is proven, and the 508, isnt quite as proven. one county wanting a system, says, hey, xyz county has 2001s, and they never fail. maybe we can get a package deal from fs, since half our state uses em. this is my theory on why every nuclear plant in sc, besides one has all 2001s, and many towns use em to. 508s are over $1000 more also

[DJ2226]

The 508 was created mainly because of regulations that nuclear power plants have requiring sirens that run in the 500 Hz range or close to it. Before FS created the Equinox, which the 508 is based on, the only sirens they had in their lineup that would hit this frequency range were the Eclipse series and the Modulator (UVs can be set to run at whatever frequency you want, but most plants typically stay away from electronic sirens generally). Meanwhile, all of ASC's Tempest lineup fit this requirement, and a lot of plants that were formerly using FS products ended up switching to ASC because of it. When the Beaver Valley plant decided to upgrade its system FS whipped up the Equinox using the Eclipse's rotor and an 8 port version of the 130's stator and submitted a bid with it to comply with the requirements. Obviously, their plan to push out something quick that complied worked as FS won this bid and the following bid for the Perry plant. Once they had a base design for a siren that would fit the requirement established they used CAD software to take the existing Eclipse chopper assembly and build a more effective siren to utilize the SPL from the chopper better; keep in mind that the Equinox is only rated for 125 dB while the T-128 is... well the SPL is in the name. That led to the creation of the 508 which could both fit the pitch requirement and now compete head-to-head with the T-128. The model would eventually go on to win bids for the TVA nuclear plants, so FS's plan to hang onto some of their customers and avoid them all going to ASC by putting some sirens together almost at the last minute and throwing it out there ended up working out. They got more than they bargained for too since the sirens picked up popularity as a lot of vendors were willing to push them in their bids, enough so they felt that the Equinox would be a good addition to have in the lineup and they officially brought it into the 2001 series. Had these plants not had to comply with these standards FS would have continued to push forward with the 130 in that segment of the market. Since there isn't any particular demand for sirens to run at a specific frequency outside of nuclear facilities, the Equinox would have never been created because there wouldn't be a justification to put the R&D funding behind it for development, and as a result, we wouldn't have the 508.

As many people have already mentioned the lower pitch of the 508, and Equinox for that matter, allows them to carry better into the distance. This is due to atmospheric absorption where the air acts like a sponge and soaks up the sound as it travels. The longer wavelength gives lower pitch sounds more penetrating power much like how an FM signal will travel WAY farther into the distance from a transmitter site versus the signal from a cell tower, especially LTE and 5G. If you want the higher pitches to travel farther you'd have to amplify them and increase their SPL. Likewise, you don't need a siren to be super loud to compete with a higher SPL one if the higher SPL siren has a higher frequency. The WPS-2910 and 16V1T-B are good examples of sirens that get dominated by a 130 up close but will drown one out in the distance, which is kind of a slap in the face for Federal when you take into consideration both of the sirens are omnidirectional versus the 130's beam of sound. The Equinox on the other hand would probably compete with them pretty closely while the 508 would probably outperform them both up close and likely edge them out in the distance. FS's own literature only cites the Equinox and 130 as having a 400-foot difference in range. Considering that the Equinox will run you like $2000 less than a 130 it's really a better deal in the long run IMO since I view range as more important than sheer SPL.

The only downside to the lower pitch is once you drop below 500 Hz you start to increase ground impedance, which is when the sound coming from the siren gets reflected off of the ground and scattered. That can cause a slight decrease in range, but between the older Whelen sirens and basically every other 8-port siren that runs in the 450 Hz range it tends not to be much of a problem. Tones close to 500 Hz are also a double-edged sword since they sit right in between the octaves of general background noise (250 Hz) and Mother Nature's sounds (2 kHz). 500 Hz on the dot will blend in with the environment, so in alert it might make it hard to distinguish. Elektro-Arola, the Finnish company that produces the Teho-Ulvo sirens commonly found in the country, actually dropped the peak pitch of their sirens from 500 Hz to 445 Hz to avoid this and was able to get a better range out of them. That's definitely not a problem with the 130, and while I'm not a fan of that model I will concede that they probably work better in cities particularly because their tone stands out way better. Chicago's SRNs are very effective and catch people's attention very quickly.

[Ziginox]

The 508 was created mainly because of regulations that nuclear power plants have requiring sirens that run in the 500 Hz range or close to it. Before FS created the Equinox, which the 508 is based on, the only sirens they had in their lineup that would hit this frequency range were the Eclipse series and the Modulator (UVs can be set to run at whatever frequency you want, but most plants typically stay away from electronic sirens generally).

This is your exact answer. Customers wanted something in a lower pitch, and were willing to make the compormise with the slightly lower sound pressure output. For customers that want the pure output level, the 2001-130 still exists.