Buy a more efficient headphone, and mind you sensitivity specs is just one thing. So you heally have to try them one by one. You wouldn't want carrying an amp would you?
If anyone wants a professional quality over the ear headphone for music, try the Sony MDR-V6. Probably the best you'll do under $100 (and out-shines many costing a lot more). They are sensitive, and have a response that is perfect for music. In other words, they sound perfect with a flat EQ.
