Unhappy with the first iteration, and with a bit more knowledge in electronics, i decided to go back and improve upon the original altoids speakers. This project was neater, cleaner, louder, and more reliable. The biggest change is in the circuitry, however- instead of a single transistor powering the speaker, i used a low voltage op-amp, which allowed for much louder sound output. It even has a gain knob on the inside!
This is the inside of the speakers tin- as you can see, everything is much neater than the first version (A comparison). The inside is dominated by the 8 ohm speaker, and the space left for the battery. The circuit board is obscured, but you can see part of the op-amp and the gain resistor!
I didn't save any circuit diagrams from this project, which might have been helpful, but i did save this wiring diagram. The central chip is an LM-386, a low voltage op-amp. The rest of the circuit is just volume/gain control var. resistors, two capacitors to center the op-amp output, and an RC circuit to match the speaker's impendance.
