Hm, it doesn't sound promising.
Any chance of replacing the whole sounder with a small piezo (80 dB) I guess the impedance will be pretty similar so the amp wont struggle with the capacitive load?
Then uplifting the output frequency to 25 kHz ( the best freq to silence dogs)?
I am pretty new to all that stuff.
So far have experimented with 555 at 10-25kHz, but the dB is too low. Even at 10kHz the output power is pretty low (measured by my Samsung app, OScope at distance 2-4 cm it's just a few dB). I am using a piezo transducer from an old sound system).
My...