The center channel in a full-blown home theater does far more than many people realize. The center channel comprises more than 60 percent of everything heard during a Dolby Digital or DTS movie. In addition to anchoring dialogue on-screen, the center channel handles music and effects mixed to the middle. Comparing center channel speakers to themselves and to similar-looking soundbar speakers is therefore one of the more important tasks you'll undertake when shopping for surround sound speakers.
1Off-Axis Response: Off-axis response -- that is, how intelligible dialogue is for listeners not directly in front of the center channel -- is an important quality in a center channel speaker. Part of the task of the center is to keep dialogue attached to the characters speaking it onscreen. Dialogue should sound good even at a 30-degree angle or more. Compare center channel speakers sitting directly in front of it, then shift your position gradually more and more to the side. If dialogue becomes muddy or hard to comprehend, the speaker probably has poor off-axis response and should be eliminated from consideration.
2Vertical vs. Horizontal Designs: Lobing is a problem facing nearly any center-channel speaker designed to sit horizontally on top of a shelf, stand or television. This effect makes dialogue increasingly hard to understand at varying distance intervals from the speaker. Additionally, cancellation occurs from the sound waves of the two woofers flanking the tweeter colliding at some point in front of the speaker, reducing or eliminating some audible frequencies. Some center-channel speakers marketed as "LCR" or left, center and right speakers may be used vertically, eliminating much of this concern. Still others offset the tweeter from the woofers in the speaker, placing it atop the cabinet or slightly off-center and helping the sound if the center must be laid horizontally. Horizontally oriented center channels can be well designed, but if you're comparing multiple units featuring this layout, be sure to audition them for clarity, intelligibility and overall sonic detail
3Timbre Matching: Although some media and self-professed expert outlets will tell you it's acceptable to use an orphan bookshelf speaker or random center channel from a different brand than your main front speakers, this is not wise for a number of reasons. Major speaker manufacturers take great pains to ensure that as sound pans from left to right, the sonic signature or timbre doesn't change significantly or at all. Adding a center channel from a different manufacturer adds a potentially completely different sound to the front sound stage, creating uneven balance. Better surround systems make you less aware of the individual speakers, and timbre matching helps greatly in this regard. If movie watching is your primary focus when choosing a new speaker package, it may be wise to audition center-channel offerings first from manufacturers under consideration, working your way out to the mains and surrounds.
4Sound Bars: Sound bars look in many ways like center-channel speakers, and in some environments suitably replace them. The caveat to this is that no sound bar will match other speakers from other brands, and all sound bars incorporate center channel, left, right and surround-simulating drivers designed to bounce sound off of side walls. If the environment is small or narrow and doesn't reasonably accommodate a full surround array, a sound bar is intended to replace the entire package, not just the center channel. Adding a subwoofer to a sound bar rounds out a compact yet full-sounding system. Sound bar speakers mount directly underneath flat panel sets, or on a TV stand directly below the set