Helo wel as we al know piezo horns and fire alarms can co up to 111 db at 1 metre right? But there are piezo sirens or indoor sirens wich inwolve piezo technology reaching 120 db!!! i heard
https://www.satel.pl/en/product/256/SPW ... -signaling this one at a supermarket at my town and it was amazing. very powerful and loud