Written By: Steve Feinstein, Director of Marketing and Product Development for Atlantic Technology
If we had a dime for every time we were asked this one, we’d be rich beyond our wildest dreams by now. Here’s the question we get asked so often:
“I’m putting in in-wall speakers…..so what should I use as a center-channel that’s horizontal?”
To which we answer, “Why do you want your in-wall center-channel speaker to be horizontal?”
To which we invariably get answers like, “Well, um…..aren’t they supposed to be horizontal? I mean, they look better horizontal above or below the TV, and besides, aren’t all center-channel speakers horizontal?
To which we answer 1) no, 2) only because you’re accustomed to seeing it that way, and 3) they shouldn’t be.
Here’s the full story. After you read this, you’ll never expect a center-channel speaker to be horizontal again. That doesn’t mean it can’t be horizontal; it just means that once you know the full story, you’ll never automatically expect them to be horizontal again.
In Home Theater Ancient History, the Home Theater Gods created Dolby® Pro Logic® Surround around 1987 or so. This format had a very special center channel track that contained the dialog, on-screen effects, etc. It needed a special speaker to play it. It was called the Center Channel Speaker, and it sat on top of the television. Well, since most speakers at that time were vertically-oriented (taller than wide), they would have looked pretty silly perched precariously like a smokestack on top of the TV. (See figure 1)
So Marketing decreed to Engineering, “Bring forth a speaker to me that’s horizontal, so it shall look safe and secure lying down on the TV.”
But Engineering protested, “A horizontal speaker doth have many acoustic problems and we don’t…..”
“SILENCE!!” spake Marketing. Thus, the horizontal center-channel speaker was born. (See figure 2)
In time, the great unwashed masses came to embrace the new horizontal center-channel speaker. So much so, that even when its original reason for being no longer applied (looking secure lying down on top of a TV), people still felt more “comfortable” seeing an in-wall horizontal center.
When you think about it logically, there’s no reason whatsoever that an in-wall center speaker needs to be horizontal. It’s not balancing on top of a television. It’s just that people are used to seeing them that way. And if they’re mounted behind an acoustically-transparent screen, the flimsy “looks” reason evaporates completely.
Actually, the ideal situation—acoustically—is to have three absolutely identical front LCR speakers. With three identical speakers, you get three identical tonal signatures and three identical radiation patterns (identical “sound coverage” patterns), which is good, because then the sound is seamless and perfectly continuous as it pans from left-to-center-to right. In other words, the “handoff” from one speaker to the next is undetectable by ear—which is exactly what you want.
Even better than three merely identical front speakers is three identical vertical front speakers.
You want your woofers and tweeters to be arrayed vertically (not horizontally), because a vertical sound source has clear, interference-free midrange-treble output to either side. Every good speaker engineer at every good speaker company knows this, which is why every “serious” speaker always has its drivers arrayed in a vertical line.
Side-to-side is the most important direction for sound in a home, because that’s how people sit in a room: to one side, in the middle, and on the other side. The problem with drivers mounted side-by-side is that in the frequency region where the output of the two drivers overlaps (the crossover region), their output interferes with each other in the horizontal plane. This interference is very audible, very objectionable, and it reduces the speaker’s horizontal dispersion. (See figure 3)
All very bad things.
If the drivers are mounted in a vertical orientation (tweeters and woofers in a vertical line), this interference (which is inevitable and unavoidable) occurs in the vertical plane, which is far less acoustically-objectionable than horizontal interference. With vertically-arrayed drivers, side-to-side output—which is the really important direction—is clear and unfettered. (See figure 3) Not only do you hear things clearly sitting in the middle of the sofa, but so does Uncle Morty sitting nine feet off to the side in his easy chair (assuming he’s still awake, that is).
If a speaker has to be horizontal, Atlantic takes very specific steps, like raising the tweeter and bringing the woofers close together, to make our horizontal center speakers much better than any conventional horizontal center speaker.
Our amazing THX Ultra2 IWTS-30 LCR has a rotating midrange-tweeter section so the mids/tweeter can be correctly vertical even if the rest of the speaker is horizontal. (See figure 4) And finally, if you simply must have a horizontal center in-wall, our THX Ultra2 IWTS-155 LCR is the best thing going, because its drivers aren’t in a straight horizontal line and it fits neatly between 16”-on-center stud construction. (See figure 5)