I just read this on Stefan AudioArt's site
This is very interesting since everywhere I looked, people said the HD 650 cable is better. I just received my HD 650 cable today (I've been using a HD 600/580/565/545/535/525/265 cable with my HD 650) and I did a quick 5 minute comparison; left side with HD 650 cable and right with HD 600 cable both connected to same source with a splitter. I noticed the 600's cable have noticeably more highs and are less muddy than the 650's with a stereo/reverse stereo test, however I didn't have time to do an in-dept testing since I'm in a loud environment at the moment. Anyone know or have any experience of the two stock cables?