Sennheiser HD800S (https://en-us.sennheiser.com/high-resolution-headphones-3d-audio-hd-800-s) NEOTECH OCC SILVER internal wiring The upgraded wires improves bass articulation, imaging, separation, and detail retrieval over the stock HD800S. As you know, the original HD800 has less 2nd harmonic distortion than the HD800S. This gives it better bass articulation (punch and decay). Without the distortion that influences this warmth nature, it gives you the impression that it has less body and weight to it. The HD800 signature has been known to be somewhat thin for a long time coming. The added warmth and treble peak reduction introduced in the HD800S gives it more embodiment due to it's more balanced tonality (frequency) The HD800S isn't as articulate in bass, but it's bass is slightly louder (or at least it gives the impression that it's louder). The conducted wire upgrade made the bass articulate and punchy again like the HD800, but warmth remained (good thing). I feel like the upgrade to the HD800S made it either on the same level or pulls slightly ahead of the HD800. I've done similar mods to the HD800 expecting an improvement, in which it did, but it made the sound overly edgy. Condition: Like New Come with a custom silver headphone cable to compliment the headphones. No original box or accessories (only custom cable). Comes with full warranty.