For the ambulance, you used the wrong siren. Most departments, including mine, uses a model called CARSON or SVP SS700 or Federal Signal, Dual Unitrol Omega 90 (Popular one) SVP: http://www.youtube.com/watch?v=t0Iq7Kkjf0U...feature=related Carson:
-Full siren.http://www.youtube.com/watch?v=MC1tdn4F90Y- Demo I really want you to use Carson, becasue it's an excellent choice. Unitrol:
Yes, the Unitrol has Dual Sirens, one plays Wail while the 2nd siren is your choice (Yelp, Wail, et cetera) http://www.youtube.com/watch?v=1j1J6Wiis3Y