If I wanted to hook up a PC surround sound system to the TV, and simply have multiple speakers playing stereo sound, how would I go about doing that? I know I can probably just get a Y-splitter, but then wouldn't I be splitting the power output of that plug into 2 speakers, rather than giving each their own power?
Multiple speakers on a single speaker output from an ampflier is usually a bad idea. It halves the impedance which presents a much larger load on the amp. Most mass-market receiver are spec'd for 6 or 8 ohms max.
If you are doing it at "line level" then it shouldn't matter.Presumably you are using a pc speaker system with built in amplifier with line level input, and you are hooking it up to a tv with audio out also at line level.