In my experience depending on the cables, length may affect the sound. If your cables are affected by length, then the sound will not be balanced and/or may not sound the same. Another reason to get the same length.
Pros/Cons of Same Length Speaker Cables?
Like many others, my amplifier, cd player, rack, etc. is off to the side rather than between the two speakers. This means the cable length is different for each. I've heard some (dealers!) say the cable lengths should be identical for both speakers. Aside from the cost issue for good cables, isn't it bad to have too much cable coiled up behind the rack? Why have identical lengths if it means one of the speaker cables has more than 6 extra feet coiled up? I know that resistance can be an issue, but is this really an issue with one cable at 16' and the other at 9'? Thanks in advance for your advice