I'm surprised you didn't notice the hiss from the terrible ANC in the Beats. The bass heavy part is probably due to it not really producing good sub bass; it only does one note bass bloat. And $350? Last check, they were only $300. I suggest you track down your seller unless those prices are the norm for your area.
Headphone Reviews and Discussion - Head-Fi.org
What set up did you use? Was the source lossy or lossless?