Does a center channel have to match the front spke

Good question!
For proper film, center is for dialogue only-so that leads one to believe you could use a different speaker successfully. Music/effects are NOT sent to the center. However, there are some newer mixes that defy this and who knows what future mixers might do? So this sort of says "the only safe bet for the future" is all speakers the same. In my own case, I cannot do the same so I use (the same brand center) that is voiced the same as my L/R/SR/SL. Less low end in it (fine for dialogue) but sounds very much like the mains. I spent more than I thought I would for the center but all other lesser options sounded too different. I am glad I did, sounds really nice now.

For music, different story completely. Music mixers DO use the center for music, they can sort of do anything they want, so this means all speakers must be the same, rear channels, center, fronts.
Brad

I have been using a Kef 204c center channel with Revel Studio, Verity Audio parsifal and Avalon eidolon respectively, and I have always been very pleased with the result. However, ever susceptible to the "upgrade" itch I started looking around for a better match for the Eidolon's. Considering Avalon does not make its own high end center, (and if they did it would be prohibitively expensive), I ordered the Salk Soundscape center, which has the same accuton midrange driver. It will be arriving tuesday. During my search I came across a company call Selah, who will custom build a center with the driver you want to match. I believe he will charge you around $2500 and use the esoteric tweeter and matching midrange. Worth considering.

This is so often a snobs arguement. So many speaker use a box, a port, off the shelf drivers so how much at odds would sound be between similar makes and sizes? Could 90% pick a well matched non matching center with a blindfold? Could 50%? Could 20%?
Then you have those who have a "matched" center, yeah its from same company but the drivers arent even identical...huh?
The point is far, FAR more speakers that dont match makers or even drivers can and will work just fine, I have 3 surround systems with 1 correctly matched and 2 not matched but carefully selected, well 1 was lol,if anyone wants to come down and take my challenge I will film it and post on youtube.
Buy what you can or what you want, it will in almost ALL cases within reason work just fine.

A lot of debate about high-end audio is pure voodoo. Matching powercables anyone? That is part of the fun though.

I have two 5.1 systems in my house. My living room system has all speakers (except the sub) from the same company (Silverline Audio). My basement system was cobbled together from various speakers I had accumulated. The mains are old Paradigm towers and the center is from Boston Acoustics. The mains of both systems are of comparable size, and the centers are as well. The AVrs of the two systems have comparable power ratings and the rooms are of similar
dimensions.
fwiw, the basement system sounds better, especially with movies and t.v. I therefore don't think that it is all tha essential to have all speakers be from the same manufacturer, despite all the advice from HT gurus to the contrary.