Assume you mean a real speaker for center channel in 2.1 music?
in which case, its not there to begin with(ie purely 2 channels L+R + Sub).
Or you talking about multi-channel sound ?
In a 2.1 system thats properly setup( optimal speaker/listening position without unwanted reflections that can distort the soundstage), you get a fantastic front stage with a phantom(virtual) center in the middle, without the aid of any other gimmick. I hear this virtual center, all the time, in my 2ch music setup. Dont miss a dedicated center channel.