I have 22 foot runs of Groneberg Quattro Reference speaker cables that go under the floor in my main rig. I have never experienced any problems with the sound in the 10 years they have been in the system. I spoke to the cable manufacturer and was told anything less than 50 feet is a moot point. I never felt they were hindering my system in any way.
I would look elsewhere to upgrade as you will NOT hear any difference with a shorter speaker cable.