Let's think about Brainwawz R1. Double dynamic drivers. Wide soundstage and bass much better than M4. Cost something about 45-50$. I bought one for my son, he is "basshead" too.   Another one OEM with good bass -  Bose Quit Comfort 15 , but they are start from  230-270 $  

Astrotec AX 7>Sony MDR CD 270 > Koss Plug

Thank You, Mark2410! I think You ia right. I listened senn cx400....really Vshaped. Especially after Astrotec ax7:)))) I will try Brainwavz.

Hi, guys. Did somebody compaired M3 with sennheiser cx400, cx870 orIE 4? Which one is better? Help me, please!