The center channel speaker is arguably the most important speaker in your system, but not because it reproduces sound any differently, but because in movies the center channel receives 90% of the dialogue. If you plan on using an in-wall speaker for the center channel then we recommend using a single speaker identical to the front left and right speakers for the center channel location. This is the only way to guarantee a 100% perfect “timbre match”, meaning that all three of the front speakers will sound exactly the same.
You might have assumed that a center channel in-wall speaker should look different because most cabinet-style center channels, which are arranged more horizontally then vertically, look different from their comparable "bookshelf" speakers. The reason for this is best understood with a short history of the derivation of the center channel speaker:
When speaker manufacturers first started selling surround sound packages the sets were sold with five identical bookshelf speakers and a subwoofer. This inevitably caused complaints about the aesthetics of standing a bookshelf speaker on top of a television. The initial “fix” was to place the logo on the long side of one of the speakers so that the speaker could be positioned horizontally thus providing a lower, more pleasing-to-the-eye, profile.
The problem is that listeners positioned more to the side of the tweeter (which produces the highest frequencies) would hear a "brighter" sound from the center channel speaker than those seated on the woofer (mid and lower frequencies) side. The solution has been to make a more symetrical speaker that contains a woofer on either side of the tweeter. The final result is a lower profile speaker that sounds essentially the same regardless of where you are seated.
With in-wall speakers you will typically experience a major problem trying to fit a horizontal speaker with two woofers and a tweeter into a standard space between studs (approx 14.5"). And while we could design one that would fit, the odds are not good that the speaker would line up centered with your TV. For most people, an in-wall speaker that is positioned vertically does not have any negative aesthetic appeal. In fact, the best overall "look" is often also the best acoustic solution; that is, arrange three identical in-wall speakers (for front left, center, and front right) all in a row at the same height.