I have Studio 20's for mains. Unfortunately, due to WAF issues, I can only mount them on bookshelves about 2 inches from the wall. Consequently, I am getting a little boominess. My question is this. If I plug the rear ports with something, I presume that will diminish the boominess. But will it also diminish base response? In other words, will the 20's not effectively go as low?