I have had Koss headphones in the past, Pro 4AA and QZ-99.  The Koss Portapro is portable AND has great bass response.  The work great with my Android phone and can be "rolled up" to be carried in my motorcycle jacket or computer bag without getting crunched.  They are very light and do not feel heavy or bear down on your ears even after listening to music with them on all day.  The sound is night and day better than any ear-bud could be and are almost as good as the Pro 4AA.  They are "open air" headphones so you cannot match the bass to the sealed types, but it comes close. For $32, you cannot go wrong. 

Question: How is the bass?
Answer: has great bass response