If computer, what Sound Card are you running? Subwoofers not too bad, could do with a lower bottom end frequency level for the great movie bass, but it will do. What is the Nominal Power on the speakers (example, max on my surrounds is 100W but nominal is 60)
If you are watching Blu-rays it will be a good investment just to get a center speaker to make it 5.1 the center handles dialogue which makes it a slightly higher priority than surrounds imho. But not too bad for the price you've paid so far.