I still had a Tda7492p board laying around. That’s a stereo Bluetooth 4.0 board with 2x50W (8-25V).

I made Franken - Bluetooth speakers. Works better than I thought. One 3rd party ryobi battery is enough for a festival week. The second Bosh lawnmower battery adaptor works fine too.

The only thing is that both devices need to be in the same WiFi net. But it also works on the road when the laptop uses the phones Hotspot.

Electric Callboy: Sorry! We’ll rename. Austria: …