Thanks to all. Mike, once again your photo library had just what I was looking for. I picked up a pair of Blaster Hi-Lo units at AutoZone today, a choice between 125dB and 132dB a $2 differential price. Knowing that sound intensity increases with the square of the dB the seven point delta is almost 50% louder by the book, and I can attest that 132dB is LOUD!!! Not semi air horn loud, but definitely going to be heard.