The linked pad says it's for hard surfaces, so it might not work in this application. You need a thin, hard surface. I use those opaque plastic floor protector things that you put under rolling office chairs. They have "teeth" on one side, and smooth surface on the other. Put the teeth down on your wall to wall carpet and lay the area rug on that surface. Cut the floor protector to fit with shears. Works great. If the area rug still buckles where heavy objects are placed, double up on the floor protector in that area, or use those floor protector "carpet cups" to expand the surface area of the leg to carpet interface. The "teeth" on the office chair floor protector things are mean! They will scratch any surface they come in contact with, including your skin. Have a helper to avoid accidents.
Sure enough. Didn't catch the "on carpet" initially. In that case a more rigid rug may be needed. Either that or lay down a hardwood floor and use the pad.
