Aparently u didn't have a longer piece of wire?? I mean as long as it soldered correctly it should have any issues, but just the though of the middle of a "solid" wire being solder and the ends being strands would make me a lil uneasy.
Its only being used as a ground for the little power acoustik amp.. i wraped them around a peice of copper then soldered all around the wire then put heat shrink then tape.
Part of a copper ring terminal that i cut.. because at first they wouldnt stay together so i put that through both wires and wrapped them around it kinda..