The silicon pads on these Beyerdynamic earphones provide a snug, effectively noise-isolating fit. If you can tolerate such tightness (and not everyone can), your reward is excellent sound.
To hear the buds at their best, pack your MP3 player with high bit-rate music files. These allow the DTX50s to fluently display their taut (and surprisingly deep) bass, plus marvellous detail retrieval.
They may seem pricey, but if you're after a serious iPod upgrade, get burrowing with these buds.