Screens // Center Channel Best Practice

Here we'll collect the various sound advice from audio/video publications relevant to the center channel.  In a world of no guarantees, you can always count on these facts:

Home Theater

"Set up the speakers so that their drivers are aligned vertically.  This will provide the smoothest off-axis response.  Horizontal center speakers are an exception, but this arrangement can compromise the performance.  The horizontal driver configuration in most center speakers is driven by aesthetic and marketing considerations, not the best sonic performance."
Speakers: Where Do I Put Them?, Darryl Wilkinson, Feb 2010

"Horizontal dedicated centers are a throwback to the days when bulky TVs ruled the roost.  Their persistence in the market is rooted in the popular misconception that only a horizontal speaker can serve in the center position.  The people who design and market them know better.  Dedicated centers usually have a left-to-right woofer-tweeter-woofer driver array that's prone to horizontal lobing.  Lobing is the result of closely spaced drivers' propensity to sum and cancel each other, which causes uneven response from seat to seat around the room.  Better center speakers mitigate the problem with a vertically stacked midrange and tweeter or different crossover points for the individual woofers.  When a woofer-tweeter-woofer speaker operates vertically, what had been undesirable lobing can be seen as a possibly desirable limiting of vertical dispersion, which can reduce ceiling and floor reflections.  The best center speakers duplicate the sonic characteristics of your front left and right speakers.  An exact duplicate, placed with the same orientation, works especially well."
Loudspeakers Buyer's Guide, Don't Underinvest in Your Surround System, Mark Fleischmann, Feb 2010

Home Theater

Audioholics

"In every case where we measured a center channel speaker with redundant horizontal drivers we were able to improve the smoothness of its horizontal frequency response in that range by reorienting the speaker vertically."
"To get the most cohesive performance out of perhaps the most important channel in your home theater, strive for getting a center channel that is identical to your mains."  
Vertical vs Horizontal Center Speaker Designs, Chris Seymour, Audioholics, December 2009

"Indeed, a horizontal in-wall center speaker is a monument to ignorance."  "While it's true that dual horizontal midrange drivers covering the same frequency range will overlap and 'picket-fence' with each other at some angle off-axis, what is also true is that in the crossover region, where the midrange driver is crossing over to the tweeter, their output also overlaps and causes interference in the horizontal plane.  So it's not just the dual 5-inchers, it's also where the 5 inch crosses over and overlaps with the tweeter.  Even if it were a single 5 inch mid crossing over to a 1 inch tweeter, if they were mounted side-by-side, there would be a lot of crossover-region interference in the horizontal plane." 
Center Channel Speaker Design Additional Considerations, Steve Feinstein, Audioholics, April 2012

Audioholics

Widescreen Review

Widescreen Review editor Gary Reber:  "How should the center channel loudspeaker be implemented?"
BG Radia Loudspeaker principle designer Igor Levitsky:  "Horizontally positioned center channel with two midwoofers flanking a tweeter is a compromise and should be avoided if possible for serious home theatre systems.  If one has no choice but to use a horizontally positioned center channel, then use loudspeakers with vertically or coaxially positioned tweeter and midrange drivers.  The ideal setup, though, is to use a center channel loudspeaker that is identical to the left and right loudspeakers and positioned behind the screen."
Widescreen Review, June/July 2013

Widescreen Review

Blu-ray Forum

Here is for the most part a summarization of our previous Audioholics article, but the member "Big Daddy" has filled out some of the perspectives more, and of course who wouldn't be fascinated by another 25 pages of forum discussion?  Center Channel Speakers, Big Daddy, Blu-ray Forum, March 2009

Blu-ray Forum