I'm looking for new headphones. My previous ones were the Sony MDR-V6, but something happened recently, and when I plug it in all the way, I'm not hearing the full sound. I have to only plug it in to the last groove. I first strongly considered the Sennheiser HD 380, then the Sennheiser HD 598. I liked the 598, but I don't think I can get an open ear back, most of my listening right now is during my commute, and I don't want sound to leak out and bother others. I know that's not the best environment to listen to music, but nothing I can do. I'm having trouble finding a closed ear equivalent. What is a pair that: 1) Has replaceable parts, especially the cable. 2) Closed ear design so it doesn't disturb others. 3) Low impedance, so it doesn't need an amp and can be powered by portable audio players, which is my most common way to listen to music with headphones. I still want it to come with a 1/4" adapter, so I can plug it into something which requires a bigger jack, like an amp or receiver. I'll also sometimes listen to music on my desktop CD player and sound card. I have a feeling the 598 sounds at least moderately better than the 380, so I don't want to consider the 380 anymore. Thanks.