I used this cable to make an extension for my Senn HD600's based on some recommendation somewhere long ago. Canare L-4E6S + some connectors from Partsconnexion or PartsExpress.
Worked out very nicely. Ideally I would like one complete length of cable rather than making another 10' extension, but this worked out very well indeed and headphones are an occasional thing, so no rush to do otherwise right now.