Using satellite speaker as a center speaker a good idea in my case?

[PCFan]

A few days ago I bought a Sony SS360 Home Theater System. I don't use all the speaker that the package came with due to a lack of space in my bedroom. However I have room for front side speakers, center speaker, and the subwoofer. The problem is that the center speaker that came with the package has a smaller cone than the rest of the speakers and if I used that as a center speaker it actually sounds worse to me than not using it at all. If I use one of the surrounds for the center speaker since I'm not using rear speakers, which look exactly like the front side speakers then the center channel sounds better to me, more fuller with deeper base in the dialogue. Am I better off just using one of the surround speakers as a center speaker instead of the actual center speaker that came packaged with it since the surround speakers has the same specs as the front side speakers in this system?