I'm not big into cables making a huge difference. I feel like, more than any element of audiophilia, the differences can easily be mental and not really there. However, I feel like this cable really brought out the best in my 650s. The thickness and durability is great and I love that I bought a lengthy cable. It might not be worth it to everyone, but it was for me. No regrets.
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Member Reviews: Cardas Sennheiser Replacement Cable For HD580, HD600 & HD650
Cardas cables have a good value for the price. I can't remember really how they sound anymore since I sold them a couple of years ago.
Pros: HD600 became more balanced and overall audiophile improvement. Awesome build quality.
Cons: Ultimitly power cables made more of a difference and I sold it
This cable improves the extension in both the treble and the bass and gives the whole spectrum a balance reminiscent of Beyerdynamic T1s. The Midrange becomes sweet and tones seem to take on a hue that serves to almost always improve the music. Grain seems to disappear, though transparency is only a little improved. The bass seemed to get deeper and also improved in tone. Overall a big improvement in audiophile qualities in the music.