I recently just picked up 2 of these and put them in a 1.5 cf sealed box, they sound nice at around 16-18 volume, but when i turn it up i hear like a knocking noise coming from my left sub, i dissconnected the left sub to see if the right sub would do it and didn't get the same noise, could this sub be damaged, i took the sub out and checked for air leaks but i didn't find any, could of this sub been damaged during shipping? i'm goin to pull the sub out and re-wire it to see if it helps, anyone have any suggestions? it is being pushed by a powerbass 3000d runnin at 2 ohm so it was seein about 700-800 watts a piece.
