For this project I wanted to take my music to the beach without worrying about the elements of nature and still have a big sound. But most importantly, it need it to be battery powered. A 50x4W car or marine radio draws about 2 amps per hour so a 14amp battery will last about 7 hours of continuous power. Already tested the box at the beach a few week ago and it was a success. You can use the radio of your choice and speakers to. The better the radio and the speakers, the better sound quality you will have. Any suggestions for improvement are accepted. Attached is a video made using a Zoom Q3 recorder so you have a good idea of the sound quality. Thanks for watching.