Basically, how long would you expect to be able to run a DIN to XLR interconnect for active speakers, before hum kicks in? I have two sets, the 5m run is ok. However, the 10m run causes the speakers to hum quite loudly, as if there was an earth loop problem. I have swapped the cables round and the hum is always on the longer run. The cable is an off the reel 'standard' cable made up at the dealer. Ironically, it was fine when it went from RCA to XLR, but now the DINs are on, hum kicks in. Any ideas? No doubt the magic Mark Grant cable is on the horizon.