I saw it too and wondered about the speakers. I don't know what they were but they didn't look cheap. They looked like the ones attached to a 100K I stereo I "auditioned" (i.e., acting like I might buy) at an emporium in Soho a couple years ago.
On the movie, the trailer looked pretty dumb, but amazingly, my wife wanted to see it, so I paid her back for Robin Hood and Prince of Persia. Also, amazingly, I started to chuckle and ended up really liking it. Low expectations helped, but I though that Jonah Hill was quite good and Russell Brand was...Russell Brand and that's likable enough. He did a perfect job of being himself or at least being consistent with himself in Sarah Marshall. Having seen lots of rock prima donnas in my life, his send up was terrific.