I've been facing this issue and I understand that it's a characteristic as far as wires go. Criss-crossing two wires will produce some kind of interference and my speakers are giving off a hum when my macbook charger is plugged in. Unfortunately, both my audio-out port and the battery port are on the same side. Is there a workaround to this humming problem? I do want my macbook to be charging while I listen to music without any humming. Yes, the humming goes away once I plug out the charging wire.