this is simple and tiny and powerfull mini, mono, portable bluetooth speaker
speaker 4ohm 3w 40mm https://aliexpress.ru/item/1005005910605021.html?spm=a2g2w.orderdetail.0.0.49084aa6qjomnm&sku_id=12000034808136367
bluetooth module https://aliexpress.ru/item/1005005956162227.html?spm=a2g2w.orderdetail.0.0.57c24aa6iXcgW2&sku_id=12000035017296929
passive 26.7x45mm https://aliexpress.ru/item/1005005145674829.html?spm=a2g2w.orderdetail.0.0.4dd24aa6i8o2ue&sku_id=12000031846565612
battery any 700-800 mah li-ion
The author marked this model as their own original creation.