New power cord needed for speaker with powered subwoofer?

I use two PS Audio P10 regenerators for my system, and this past year I upgraded my system's sound purely with changes in aftermarket power cords.  Yep, even with a really good regenerator between the wall and the equipment I found the improvement significant enough to plunk down my dollars, and this was with a significant home trial period allowed.  Just the change in power cords seem to bring my system's sound significantly closer to the sound of live music, with better dynamics and truer tonal quality.  Just my experience, in my system, to my tastes, YMMV, etc.

I'm an engineer, and I used to believe on principle that power cords could not make a difference (assuming adequate current capability).  But actual listening trials converted me from a skeptic on "theory" into a believer in practice.  I'm just saying "Give it a try".  With return privileges is best, then what do you have to lose?

Yep.  Like Nonoise above, every single component I have tried has been improved with the use of a suitable aftermarket power cord.  Not subtly, either.

My experience with Vandersteen Quatro's was that some Elrod Statements feeding their built in subwoofers brought worthwhile improvements in bass reach and tonality, and also brought better nuance and tonality well up into the midrange.  That surprised me.  The Quatro's come with a very heavy gauge OEM power cord, unlike many, but the aftermarket cords were definitely worth it for me.