Since you are dealing solely with the lowest frequencies, I suspect having a cord with sufficient gauge conductors is the biggest requirement for a sub.
Do you run a high end power cord on your sub?
I have a Rel B2 sub in my system, and have never really bothered with a decent power cord for it. I have an "Iron Lung Jellyfish" power cord, which is better than a stock cord. It is a $30 cord but is actually suprisingly good when you are just "testing the waters" of what power cords can do. I am considering something better, but not sure if this is the best place to spend money? What are your experiences with upgraded power cords for subwoofers? I am thinking about an Audience Powerchord e, as I use Audience power cords on my other components.
Other components in my system:
Thor Audio TA-1000 mk II preamp
BAT VK-55SE amp
Hyperion HPS-938 speakers
PS Audio PWD mk 2
Audience AR6T power conditioner and power cords
Nordost Heimdall IC's
Anticables speaker cables
Other components in my system:
Thor Audio TA-1000 mk II preamp
BAT VK-55SE amp
Hyperion HPS-938 speakers
PS Audio PWD mk 2
Audience AR6T power conditioner and power cords
Nordost Heimdall IC's
Anticables speaker cables