Hi every one ! I basically have a problem with my studio monitors Tannoy's. My monitors play sound and stop and play the sound every second. But its happening with every things (films online, music in iTunes in logic pro 9 etc etc ) that i play in my macbook pro retina 17 inch. BUT! when I unplug my external USB sound card that is connected with studio monitors, and play music and films on internal speakers every things is fine and the sound is playing right again. I thing it have some thing with Logic pro 9, basically i was creating new track in logic and some message appeared that sample rates error accrued. i dunno how to fix it. BUT ! when I plug in my studio monitors via my USB sound card to iMac every thing plays fine! its happening only with my macbook pro since i had this error in logic pro 9 but please tell me how to fix it lol!!