Sat, there might be a theoretical maximum which would be many miles in magnitude, but of course that wouldn't have any relevance to home audio use. The effect of capacitance in connecting cables(typically around 20pF per foot)can result in small losses at very high audio frequencies above 10kHz if the cables are on the order of hundreds of feet long, but at subwoofer frequencies below 100Hz the distances required for any significant loss are beyond anything that would be contemplated.
A less remote possibility, although still not likely in typical home environments, is that external interference would be picked up in the course of a long run, causing an audible noise level.
