Not every speaker cable manufacturer states that each leg of the cable be the same length. Alpha-Core states on its web site that their Goertz speaker cable does not have to be of equal length on each leg. My own personal experience has been that as long as the cables are relatively short (less than 15 feet), you will hear no audible difference between unequal lengths, PROVIDED the speaker cable has relatively low impedance.
High impedance in speaker cables causes frequency shifts, so it is possible that some "golden ears" could hear this frequency change with high impedance speaker cables. Of course, if a speaker cable has a high impedance, it's not particularly well suited to its task, and you'd be better off with another kind that follows good electrical design principles.
High impedance in speaker cables causes frequency shifts, so it is possible that some "golden ears" could hear this frequency change with high impedance speaker cables. Of course, if a speaker cable has a high impedance, it's not particularly well suited to its task, and you'd be better off with another kind that follows good electrical design principles.