Whelen 4004 and 4003: What is the difference?

[gman 1]

I was looking on Whelen's website, and found that they make a WPS 4004, and a WPS 4003. I looked closer, and it said on the website the 4003 has 3 active drivers, yet there were four drivers. Can some please what is the difference between the two?

[uncommonsense]

You are correct. 3 v. 4 active drivers. But the two units use the same speaker head but the 4003 has an empty channel.

[gman 1]

But why waste all of that fiberglass, what I don't understand is... why not get rid of the empty channel?
Is there any way to tell the difference without taking it apart and counting the drivers?

[DJ2226]

But why waste all of that fiberglass, what I don't understand is... why not get rid of the empty channel?
Is there any way to tell the difference without taking it apart and counting the drivers?

Well they make them out of plastic. It is more expensive to make different sized arrays, so they stick to making one. It's easier this way. It's the same deal with the Vortex R1, just one driver. You'd have to look inside the array to see which how many drivers are installed or get access to the panel to see how many amps it's holding.

[gman 1]

The one near my house looks like fiberglass, I'll have to look closer next time I pass it.

[DJ2226]

The one near my house looks like fiberglass, I'll have to look closer next time I pass it.

I mean the current ones. The older ones are made out of fiberglass.

[holler]

It's actually an injection molded composite with different materials mixed in, not straight plastic. It's pretty tough, a lot tougher than the old fiberglass ones. Plus the slick surface helps keep down the buildup of the "funk" that seems to grow on old fiberglass sirens.

As for using one mold for everything, it's much cheaper that way. Plus if the customer wants to upgrade to a larger unit all that has to be done is add an extra amp, pop out the plug in the back of the horn and install a new driver. Then program the software so that the siren will actually know that the driver config has been changed. Bryan has done a bunch of R-4 conversions on the Vortexes in Ft. Worth.

[gman 1]

oh... that explains A LOT OF STUFF!!!!!!!!!!

[Bryan]

Somewhere I've got a picture of the inside of a Vortex R-3 and you can see how they cap off the top horn. I'll post it once I find here in a bit

[gman 1]

That would be great.