For the 3V8 you are right single tones are louder (in terms of Decibels). I meant louder as in the multiple tones stand out more and I should have clarified that. The 3V8 is 107DB while the 2T22 is 113 according to this thread.https://airraidsirens.net/forums/viewtopic.php?t=12527
. Perhaps it's something with the motor?
Anyway about dual siren setups, I recently found that on one end of the Daniel Carter Beard bridge (or the big Mac bridge) is an ASC E class near Yeatmans cove, the stadium and Sawyer point park.On the the other end of the bridge is a Campbell county pole mounted modulator better viewed from the street running under the bridge. They're part of different systems being on different sides of the river. I haven't been out much since my journey to Massie township but I noticed it on the way to my grandparents to deliver masks. (I 3D printed a couple)
On the Ohio side by the E class is a thunderbolt on the roof a building. Doubt it's still active as it never rotates but you never know.