The DOSS Soundbox XL seem to be plagued either by bad design issues or a high rate of poor manufacturing quality. I recently got one, and took off the cover to remove that speaker grill liner some reviewers said causes a rattle and saw the left tweeter cone was mashed in. I returned it to Amazon only to get a second one with an annoying bass vibration, one recent Amazon reviewer described as a "farting sound" with music with a strong bass line. It actually happens at 54 hz when you use a tone generator and comes from air blowing out the jack/slot holes in the back.