The MX500 exists in cool metallic blue and white (the ones we tested) to match your iPod.  They feature the classic Sennheiser design which is sober and discreet with nice finishing touches.  Unlike the MX450 and 550 there is no "Basswind" technology; however, a small volume control is built into the cable.

The portable music player headphones par excellence

In terms of quality, the MX500 has the solid foundation of the other Sennheiser headphones we previously tested.  There is a particularly pure sound and especially an excellent dynamic range.  Highs and mediums are well produced while basses are a little drier than with the MX450 but are still of good quality.  Overall, these headphones also have a somewhat dry sound but it doesn’t seem to be a fatal flaw for this product.  Finally, in terms of comfort we didn’t encounter any ear fatigue after prolonged use.