If we have a choice (and we almost always do), we'd prefer short speaker cables to long interconnects. This because passing unimpeded music down a speaker cable into the complex load of a speaker is far more of a challenge than sending music between two low-level sources or controllers.
Sources and controllers are almost always easy loads. Low impedance out and higher impedance in. The signal size isn't too big and properly designed equipment and cables have an easier time making it from point A to point B without too much trouble.
That's hardly the case when delivering high powered, high voltage signals to speakers. Here, the challenge of passing music unimpeded is magnified by 30 times in the voltage realm and thousands of times in the current world. To make matters worse, speakers are finicky, demanding clients. Their impedance is all over the map. To get music to sound right we must deliver both voltage and current without distortion or modification.
As a rule of thumb, it's good to arrange your system around this idea of short speaker cables. When we're at shows it's not a problem because we want the audience to see our equipment while the music's playing, so all cables are short. But, near the speakers is not sonically the best place for sources and controllers, but hey! it's a show and we're here to get people into the equipment. At home, we'd like to keep our sources as far from the speakers as we can.
When it comes to speaker cables, short's the ticket.