The speaker cable provided by Vandersteen seems rather light.That is because the input to the sub is the input to its amplifier, which has a specified input impedance of 100,000 ohms, and therefore draws negligible current and power. So heavy gauge speaker wire is totally unnecessary.
That said, I express no opinion as to whether an upgrade of the stock cable might result in a perceptible difference. If it does, however, the reason would not be the lower resistance that a heavier gauge would provide.
Regards,
-- Al