He wants to leave them on the TV stand. There used to be a bookshelf behind the TV, I don't know if it's still there or not, I forgot to ask. When I asked him about them I discovered that he turns the bass up on the receiver. Then I remembered the ports, that they are just firing into thin air.
So, theoretically then I guess putting a plate behind the speaker, probably made out of 3/4 inch plywood, would not work then. It would have to be not much bigger than the speaker itself or it would take up too much space.