I have had an American electrical/mechanical doorbell for years. It has two solenoids and the plungers strike a resonant bar of metal. It wasn't loud enough to be heard throughout my home. So i went to buy a better one and saw the same thing as I had. It was expensive.
I also saw a cheaper Chinese electrical/mechanical doorbell that has plastic resonant chambers beside the resonant metal bars and it works much better and is much louder.
Of course it is powered by a transformer. The transformer is cheap and is good quality.
I also saw a cheaper Chinese electrical/mechanical doorbell that has plastic resonant chambers beside the resonant metal bars and it works much better and is much louder.
Of course it is powered by a transformer. The transformer is cheap and is good quality.