I've tried to read thru this thread and I'm not sure if I've seen what I'm looking for. If you siren is solely a 100-watt siren: it only has a 100-watt amplifier; then w/o having it totally rebuilt, it remains 100-watts....period. A 100 watt amp will drive two 100 watt speakers nicely and get a bit more sound output. Some of your later PA200s and PA300s and some of the Carson-built SA400s that were built for SVP have switchable wattage from a selector switch inside the amplifier case. Problem solved there.
Now here are a couple of things I've seen: Federal PA15A Director is rated at just more than 75-watts output, if I remember correctly. No way to make it 100-watts or 200-watts; but I saw an ambulance in Amarillo one time that had a Director siren connected to three PA100 speakers. That thing was loud! I'm sure there was no actual wattage change in the Director's amp., but using three 100-watt speakers made a difference.
We had a 1972 Type II Chevy van ambulance that came was a 100-watt North American siren. It drove a pair of CP100 speakers, ane was sufficiently loud. But a couple of our guys got the proverbial "wild hair" and removed the North American siren and replaced it with a switchable PA200. In addition they added another pair of CP100 speakers to the mix, setting the PA200 to the full 200-watt output. That siren was awesome. Most of you know, I'm "old school" when it comes to siren. I'd rather have a Q or a B&M than anything. But that setup was loud! One of the few electronic sirens that actually hurt my ears. And I could drive with my window open and a Q or B&M overhead with no problem. With that PA200 setup, up went the window!
