Hello, Refer to my set up below please. I am in the process of moving all of my AV gear into a different room. I dont have a sub, as I think that I get a lot of bass from the M72's as they drop as low as 56hz, but please advise me if adding a sub will 'really' improve my sound or make it become unbalanced. I am in a position where I am unsure what to do as i do not want to fork out the cash and then find that there is not a lot of difference. All told, am I missing the .1 in 5.1??? Zero experience with a sub so advice greatly taken. Thanks, Captain Benefit.