Amps I don’t actually have a sub. The front speakers are 8 inch, and I have directed the amp to put all the bass on those. Judging by any Nolan-movie on disc with lossless audio that’s plenty enough for our tiny home theatre-room.
We also don’t have a sofa there, but a pair of lounge chairs (a friend said it makes us look like we’re living in a retirement home and hurt my feelings). If I do get a sub one day I imagine putting it between the chairs would be a good location.