I made this small Bluetooth speaker as a throwback to the old tombstone radios of the 1940s. I have a full Instructables article on how to build it. It also has a long build video, a complete tool list, and many more photos. https://www.instructables.com/Retro-Battery-Powered-Bluetooth-Speaker/

All the electronics are off-the-shelf components. The unit as a whole is simple to assemble if you have access to the right tools.

Affiliate links for the electronics: Amplifier Board https://amzn.to/3Uuen0o Bluetooth module https://amzn.to/41o20oG Lithium Battery Charger Module https://amzn.to/43sQytM 10K Ohm Potentiometer https://amzn.to/402oxGA Red 3mm LED https://amzn.to/3zRbPzX 3.7 Volt Rechargeable Battery https://amzn.to/43ohevV Push Button Switch https://amzn.to/3KPL18v 1k Ohm Resistors https://amzn.to/3Kzh5Nw 3W 8 Ohm 50mm Speaker https://amzn.to/412IJcX

Over all, I am extremely happy with the final product. I spent a long time coming up with a design that is simple to put together, good-looking enough to have on display, and practical for every-day use. I have found in my use of the unit that it gets decently loud and has a battery life of 8–10 hours. Also, the sound quality isn't anything spectacular. For some songs, the sound can get a little distorted at max volume. But that is to be expected from the budget parts that we used in this build. I think it sounds really good for what it is. Just don't go into it expecting a Bose-quality speaker.