I'm going to quote myself from another thread in another forum - not because I'm right or smart, but because I'm lazy and because I never got an answer to my question: In a 2 channel system you want everything equally balanced. In a 5 channel system, the front channels should match each other and the surround channels should match each other. There is not the need to match all the way around as the sound spectrum is far less demanding for all other channels than the L & R front. That is where timbre and image come into play. This may also be true of the front channel. Which leads back to a previous question I posed: If the center channel should be the same as the R & L front channels, why do, even high end speaker manufacturers, offer and tout specifically designed center channels? Not necessarily the same reason they would offer different rear channel speakers. Many buyers would simply not be able to afford to use the same speakers for mains and surrounds. That could be a reason that they offer a similar speaker at a different price point. Of course, some surrounds are dipole and this would be another reason (and another argument against "same speaker" home theater). As the center channel often costs more than a single front speaker of the same quality, the argument regarding cost could not be made. What seems most likely (to me) is that the center channel covers a different sound spectrum and is designed to best present that spectrum.