Vandersteen 2C contour controls +-

change your outlets on the wall
PS Audio makes a nice affordable outlet or a hospital grade Hubbel is even less $
also get the amp and preamp on seperate circuits
try a ground cheater or two but absolurely ensure the power amp is grounded if you do
finally get all your wall wart switching supplies, digital hash producers on a third circuit

enjoy

also a careful read of the manual shows the coupler is a pretty low frequency animal...
so are you lacking low low bass or .?

now I get why Richard is terse...
the pads on the back do NOTHINg to bass
they adjust by 3db the tweeter and mid
the most excellent manual explains this....

i used Cardas for years....take a bit to break in, take more than a bit for the dielectric to form and also be very careful not to put preload or said another way a kink in the natural bend radius of the cable...

also i bet that ARC gear sounds kick A with 2’s !!!!!

those are pads for the mid and tweeter
the crossover points are fixed and worried over with hand matching and tuning to drivers in a anechoeic chamber
i would let the cables break in for a while
then download the free vandertones and get an inexpensive analog radio shack spl meter and see what is happening with bass in your room
the 2 has an acoustic coupler with the back wall so you want to hit sweet spot of coupled but not so close you pump up bass and destroy image depth
check your setup using the excellnt math based approach in the Vandersteen manual
jim