Where I live I'm not near any of the sirens in my county however, I live about a mile from a Whelen WPS-4004 from the next county. They are working, however, to get a countywide siren system where I live.
I've been doing alot of work in a neighborhood a few miles away from me in Dublin, OH. I've heard their system of Whelen 2750s and 2805s several times but never heard them up close until yesterday. I was able to catch a recording of one of the 2750s but I can't find the cord to transfer it to the computer. I'll post it once I get it uploaded which will most likely be later tonight.
Here's a map of the Dublin system. The red circle os the one I recorded and the blue circle is the one I took pictures of.
![Image](http://img2.putfile.com/thumb/6/17817274154.jpg)
Here's a map of how far I was from the siren. The yellow box is where the house I recorded from was
![Image](http://img2.putfile.com/thumb/6/17817274163.jpg)
This is the siren I recorded which is located on Bright Rd. between Campden Lakes Blvd. and Connie Dr.
![Image](http://img2.putfile.com/thumb/6/17817144093.jpg)
Here's another one of Dublin's 2750s located in Scioto Park along Riverside Dr.
![Image](http://img2.putfile.com/thumb/6/17817144017.jpg)
The siren head.
![Image](http://img2.putfile.com/thumb/6/17817144042.jpg)
Underneath the head.
![Image](http://img2.putfile.com/thumb/6/17817144152.jpg)
And here's the control/battery box. See that green cylinder with the cone on top? My best guess would be that it's some kind of insect trap because underneath the cone is a light bulb and beneath that is some kind of conve shaped screening. All of their sirens that I've seen has these and if I guessed correctly on what it is I assume it's to help prevent insect nests being built in the controls and speaker arrays.
![Image](http://img2.putfile.com/thumb/6/17817144145.jpg)
The visual difference between a 2750 and a 2805 is that the supports between each "plate" on a 2750 are silver and on a 2805 are black. Also, 2750s have no visible screening between speaker driver housings and the 2805s do. Sound wise a 2750 sounds pretty much the same as a 2016 or a 3016, high pitched, aprupt windup and slow windown. 2805s have a much deeper tone.