Subwoofer Stock Power Cord ... Go Figure

Today, I did some experimenting with power cords for my JL Audio e110 Subwoofer. Tried some cords from Cardas, Harmonic Tech, and an older PS Audio Mini-Lab. Surprise, surprise, surprise ... the stock power cord sounded the most open and had the best bass slam. The other cords constricted the sound and made the instruments appear very small. It's the only component in my system that hasn't benefitted from an aftermarket power cord. Go figure.
I had a similar experience with my REL subs…I use a PS Audio "garden hose" thickness AC cable on one sub, and the other uses the supplied thinner cord with a magnetic anti hum thing as part of it. I've swapped these, and they don't seem to have any effect on the sound of the subs.