Certainly not the best speakers you could ever have for your computer, the ACS33 nevertheless fills an important niche in the market.  If you're looking for subwoofered sound on the cheap, this is probably your best bet.  They're competent performers, without taking price into consideration.  Look at how much they cost, and you'll think there aren't better speakers made on the planet.  They have the potential to work, as do most speakers, on both Macintosh and Windows machines.