There's no technical reason to keep them the same length (within reason). That cable is 1.03Ω/1000ft, so if you had one 10ft and the other 20 then the difference in resistance would be 0.0103Ω which is negligible and will make no difference to the sound quality. If one is longer than it needs to be then you may inadvertently create an inductor where it coils back on itself, this is also unlikely to impact audio unless there are a fair few turns.
If you are worried about the time difference between the cables, for the 20 and 10 ft example it would be around 10 nanoseconds or 1 cycle at 100MHz... which is again negligible in audio.
I suggest the best thing to do is to cut each cable the length it needs to be to reach from the amp to the speaker.
If you are worried about the time difference between the cables, for the 20 and 10 ft example it would be around 10 nanoseconds or 1 cycle at 100MHz... which is again negligible in audio.
I suggest the best thing to do is to cut each cable the length it needs to be to reach from the amp to the speaker.