Jordan, I have done the same thing since I could not afford to buy a proper set of home theatre speakers.
I had 3 pairs of speakers and no sub, so I put my pair of old Technics speakers (/w tweeter control, which I found under the stairs when I moved into my house) under my TV and wired them with a set of wires each coming from the receiver(in parallel). This worked fine for me until I bought the Epic 80 system (w/o the sub, getting an SVS).
I did it that way because I felt the speakers would not produce enough treble/midrange using only one for the type of speaker.
You just have to be careful how you wire it due to your receiver's minimum speaker ohms.
