No you do not have to buy the sound bar but my husband got talked into buying it. I never remember to turn the sound bar on & to me the sound quality is great. But my husband always uses it when he watches the tv. Sound bar does make it a lot louder and it has taken several weeks for our 3 dogs to quit barking at the different sounds that reverberate when the sound bar is on. It makes the sound seem to come from different ares of the room. So because of that I would say it definitely makes a difference in the sound quality.