MP3 through Autocom to ER6 earspeakers...and works great.
I'd steer clear of external speakers. I had such a system in a prior life. And, it was state of the art at the time. But with that approach you end up blasting the whole world so you can hear it. The sound quality is inferior because you have to blast through your lid and the gear/amp required to do the blasting probably isn't all that clean (more power = more distortion unless you spend real bucks). :blink: