I asked my engineer uncle what he thinks about balanced headphone cables, and he looked at me a bit weird. He didn't know such things existed, and couldn't see why they would be any better than regular headphone cables.
Balanced preamp is completely different story though.
What kind of material is the capsule? Acetone is pretty good for removing glue residues.. But if the surface is painted it might remove the paint also^ so be careful
Just enjoying some Submotion Orchestra (sort of jazz influenced dubstep) on my DT48. This band is very well recorded and it shows. The DT48 sound fantastic.
I remember there was some youtube video that explained pretty well how to clean velours, but I couldn't find it now.
Btw, if they smell bad, putting them in the freezer for a day can help kill the bacteria and the smell
+1 this one, this is exactly what you're looking for if you want a brighter headphone than HD600 series.. Acoustic guitars and such sound very crisp through them, compared to HD600. HD600 almost sounds muddy in comparison. But then the treble gets fatiguing..