Cables are very subjective in.my opinion. I'm no expert or pro either and I'm still in the learning process but in my own experience, this is what's happening. Now if you believe me or not it's up to you but I could agree it can't be the cable, it can also be the cable because maybe I got a defective one? I don't know but when I used the V Moda boom pro Mic, the" hissing was barely noticeable. This was while using a sound blaster z and a recon3d sub. Some people could say it's the source, some the cable etc. I don't own just a pair of these SHP9500, I have an AKG K7XX, Fidelio X1 and X2, M50 MA900, Momentum Over ears, Sennhesier PC350 SE. I used all of those with the sounds blaster z and recon3d and non of them gave me that "hiss". I don't recall calling it cable hiss but I did mention there was some hiss going on and that replacing the cable made things better. I'm not the only in this thread who mentions it. Some others also mentioned i Ned the hiss and that by replacing the cable, made it better. Maybe the headphones are a bit sensitive depending on source or maybe some defect in the headphone or in the cable or maybe you need your ears checked if you can't hear the small differences (not being rude, since some people have ear damage and can't hear certain frequencies or the low end of a sound)
The whole cable thing is debatable or even a placebo.
I just mentioned it because someone else mentioned it and I wasn't the only one, so I had to put in my opinion an experience as well.