How important is it to use the same name brand speakers in a HT setup ??

[D.G.]

I recently began to assemble a small 5.1 HT system in my bedroom.Im using a Onkyo TX-SR503 receiver ,Energy C100 bookshelf speakers for fronts with the intention of purchasing all Energy speakers in the future with the exception of the subwoofer ( using a Polk PSW 110 sub )but while looking around in Best Buy I found a center channel by a company call Definitive Technology( I dont know much about them being a newbie) , its a ProCenter 1000 and it was $79.99 (open box item).It sounds absolutely great but it seems to play just a little louder than my Energy's which simple adjusting solved but my main concern is about the whole timbre matching thing. Is it really that important ? I just want decent HT in my bedroom that sounds good without paying an arm and a leg.Thanx. Guys im also so sorry about the duplicate thread but I DONT KNOW HOW TO REMOVE IT !