Sun Jul 30, 2006 5:04 pm
Whelen, with their rotating sirens, use the speaker heads inside a case at the back of those sirens, having each speaker head direct its sound through its own projector. The small profile of the projectors accounts for better control and efficiency once the sound goes through the mouth of the horn.
The omnidirectional models simply have the speaker heads spreading their energy sideways to the black pods. Don't the omnidirectional sirens from Whelen only have one speaker head per pod?
Whelen officially fitted their omnidirectional sirens with low-tone heads, but their large waves of vibrations caused them to blow soon, which is the case with the WPS 2800 series. But they solved that with the WPS 2900 series.
I don't know about battery life, but I do know that it can work for a longer time than one from a mechanical siren.
~ Peter Radanovic