I used my eyes. You wrote nothing about cobbling a system together.
Do yourself a favor though, and start saving to replace them. Part of the magic of 5.1 is when it becomes "seamless" ...which can only happen when the speakers are timbre matched (or voiced) to sound the same.
ie. sonically the same. That way the pitch doesn't change as the sound moves from speaker to speaker.
I had some big $800/per Polks on the side with a "good" Atlantic Technology $300 center speaker. When I replaced the Atlantic Tech with the "proper" Polk center, the improvement was astounding. Same tweeter, don't you know.
For anyone looking to build on a budget, I suggest getting a good Yamaha (or my favorite) Denon receiver for around $400. Get 3 MATCHING front speakers (LCR...meaning Left / Center / Right) and the BEST subwoofer you can afford ($300 or better). Use your old stereo speakers for your surrounds (or rears) until you can match the front.
One all-in-one set I really like is the Mirage AVS small speaker system (4 identical speakers with matching center) which is usually matched with a Mirage sub and Denon/Yamaha receiver and sold as a package for $999.
Surprisingly good!
Stay away from Bose....not only outrageously overpriced, but poor sounding as well. The above system beats the $3000 Bose like a poor redheaded lefthanded step-child.
Good satellite system. DefTech has a new acclaimed satellite/sub system, also. And no, I don't work for Definite Technology...I'm a bi-polar fan, but hear they have medication for that.
No kidding! I remember back in the "old days" when I first heard the Lifestyle 12 5.1 system and how incredible it sounded to me! Then, a few months ago, I went to a new Bose store and heard some of their latest stuff. It all sounded like crap. My Aiwa mini-system was easily just as good. My, how the mighty have fallen...