I'm planning to buy a central speaker but I have a question. How can I match up the central speaker with the surround speakers, if you got the speakers like in 1993? I know matching up the central and surround speakers are important, so I don't want to buy one in which the sound would suck. They are 100 watt Infinity speakers (they still sound great), but I don't know where to start on how to match it up with a central speaker. Also I don't the money to buy new surround speakers. Thanks for any help.

As I understood, the center channel speaker doesn't have to match the rest at all.

I'd grab another infinity center channel because they sound great. I mate of mine uses Polks for his center channel and they are highly recommened too!

No, no, no...you have been misinformed!
Ideally (although it is highly impractical for most) three identical speakers across the front soundstage (L,C,R) will give you the best possible sound for smooth panning and achieving a seamless soundfield.
Those who prefer small, monitor-sized speakers as their mains should have no problem buying another matching speaker to go along with the two mains (although depending on the deaker, you may have to buy a pair). If this is not possible, at least buy a center that is made to be timbre-matched with the mains. Most manufacturers are selling their HT speakers in series, so that theoretically any speaker purchased from that series will be timbre matched to the others. This is not always true, but it's a heck of alot better then mismatched speakers from different makers.

Welcome outcastja! It is very important to have your front 3 speakers matched. The rears aren't as much as a concern, but for front sound stage panning, it is a must! One easy way to match up the speaker the best is to match the tweeter, because the most noticible sound differentiation will be in the voices and the 'highs' as they pan form left to right, or vice versa. If you have two 100W Infinity fronts from 93, I would check out the new Infinity centers. You woud look for something with a tweeter that matches your in size and material as close as possible. Also, you could contact Infinity, and they could probably tell you the best 'now-in-production' speaker to match yours.