Yamaha Pro500 with Monoprice DAC/amp combo.   I used to be able to boost 30hz using AIMP3 player but all of a sudden I get crazy static with any kind of increase even at low volumes, even a slight +3db.  This happens at any bass frequency.  At first I thought I blew up the headphone drivers...

Hello.   I just got these in on Friday and the drivers seem to be loose inside the cups.  Give it a light shake and both speakers rattle inside the cups and the left side rattles more than the right side so that made me think that it isn't supposed to be like that.    I tried contacting...