I have heard that it is not a timing issue, but an issue of impedance affecting the quality of the sound. The sound will not be the same due to different impedance in the two speakers. The timing is not really a factor because the signal travels through the cable at a significant factor of the speed of light, whereas it travels through the air (i.e. from the speaker to your ear)at the speed of sound. Thus, moving the speaker a few inches, or tilting your head, makes more of a timing difference than thousands of feet of cable. However, because impedance builds over length, the cables should be at least nearly equal for the two speakers to sound the same.