I'm making 4 speakers stands, each is 2 12"x9" pine boards separated by a length of 4" PVC. Tomorrow I'm going to Home Depot to pick up some closet flanges to attach the PVC to the wood, and I figured I might as well get the parts for the bottom. Half the stands will be over carpet, but the other 2 will be over a hardwood floor. I'm guessing I should get some kind of rubber carpet spike for the 2 over the carpet, but can someone recommend what to get for the hardwood stands? Perhaps some felt pads?