So i'm completely clueless about this kind of a stuff. But basically I want to get better sound from my Tv when playing games and etc. I was thinking about buying two smaller speakers one on each side of the sofa (maybe something like the Onkyo SKH-410) and a bigger one in front of the tv. But I don't know if these are the right kind of speakers, Do I need a reciver and what kind? And is subwoofer a must?