No experience with the SR brand. I have the HD800 and HD820, which came with two 3m cables--a 1/4" and 4 pin XLR. I wanted a 15' cable and bought a Black Dragon Premium dual 3 pin XLR. I like how the 800's sound with the 820's stock 4 pin cable, there's a bit more detail over the 1/4". There was a better jump in performance overall (especially detail) with the Black Dragon, but even more so when used with the 820's so that's where they stay. I mostly listen to analog where I prefer the 820, the 800 with digital. The Black Dragon is stiff and a pain to coil compared to the Sennheiser cables, but that may be due to the length. It's a well constructed cable.
Sennheiser HD 800 aftermarket cable
I have a pair of the HD 800 HP’s and have modded them with great improvement. I had been listening to them with WyWires platinum cable but I carelessly broke them and am now looking for something different. Does anyone have experience with Synergistic Research’s Atmosphere HP cables for the HD 800? If you like the combo please tell my why. If there’s another cable you think is a better pairing feel free to say so and please let me know why. $800 is a steep price to pay and I’d like to hear as much as possible about the SR cables before taking the leap. One good indication: I can’t find any for resale. And as 2nd interest, what about Moon Audio Black Dragon Premium cable?