I know behind the couch is not the best placement or is it? With two sonotubes, You don't have alot of options as far as placement. BUT with them there you really don't need bass shakers. You feel all the bass through the couch. One time I had several people over watching U571. I got me a small cup of water. When it got to the scene where the water starts shooting into the submarine, I threw the water on the guests for special effects. We all had a good laugh. We won't even talk about the duel of the dinasours scene in Jurassic Park 3. Everything in the house SHAKES.