hi everyone, I would need a approx. 5 or even better 7 meter cable for the hd-650.
where should I look for that?
Define "cheap"... I would think you'll want some degree of quality and durability, without totally blowing your wallet over cable voodoo and the likes.
A nice Mogami cord like this I think is $$ well spent. Should last you a really really long time.
I have been using the Grado extension cord fine for 7-8 years. its basically copper microphone cord, not unlike canare or Mogami. I recently rolled over it with my computer chair and killed the female end. I had to hack it up, re-flow the solder contacts and heat-shrink it all back up. Works fine, although it looks bad. At any rate, the Grado cord is also in the vicinity of $35. But I think the cable I linked above is better made.
Are you merely looking to extend the OEM HD650 cord?... or completely replace it with a long after market cord? the latter won't be cheap, I think option 1 is your best bet.