I had a different experience and Stringreen. I swapped in some Elrod Statement cables in place of the Vandersteen supplied ones on my Quatro's, and I definitely got better defined and more impactful bass coming from the powered subs. But what shocked me was how it all helped the upper bass/lower midrange region, too. I just could hear more into the mix in that critical range, and with more "musical finesse", as it were. And this was with the use of some Voodoo Cable AC extenders to get through those damned heat sink fins (they don't allow beefy connectors).
I think it might just depend upon the cords? It is clearly worth exploring, IME.