Piezo stacks are ideal here (though hackers have also used cheap buzzers!). ... Effectively the capacitor acts as a weak piezo electric speaker. Using a 100V drive voltage ...

The Lassen micro-speaker measures just 3.2 x 5 x 1.15 millimeters, which is roughly the size of a grain of rice. Still, it boasts 115dB SPL in the 6kHz to 20kHz frequency range, "delivering sound ...

An amp emulation pedal can transform your acoustic amp into an electric combo, giving you the best of both worlds ...