I recabled my Q701's to 4 pin Mini XLR, hardest part, REMOVING THE STOCK JACK! Holy S***, I ended up having to cut the jack out with a dremel, and apoxy the piece back around the new jack. Looks bad from the front, not too bad from the back. Cable has piercing treble on some songs though, so I am going to reterminate the stock AKG cable to test that out, I think its the cable, the mogami that is, thats causing the sound, I double checked my solder joints.pics (Click to show)
You should tin the exposed copper of the wires where you soldered them to connectors. I would use rough sandpaper on the inside of that plastic tube where the male xlr is so the cup closes better. That is the likely source of the treble issue, unless you get the piercing treble in both channels. A mogami cable otherwise wouldn't contribute to such a sound as it is not a bright-sounding cable at all.