We always say that you should choose quality over quantity. Having one amazing speaker is going to get you better sound than having multiple speakers that are just okay. For the vast majority of people, we think two speakers is the perfect number. (Just make sure the speakers can sync up). Music is normally recorded for a stereo setting, so having a left and right channel will do wonders for fidelity. And if you have a smaller space with good acoustics, one really good speaker should do the trick.