Center Channel, Above or Below?

Matt Lee · 08-12-2003, 02:14 PM

This is probably a pretty trivial question, but I figured I'd ask it anyway since I can't quite seem to decide based on the information I have.

Basically, I'm putting together an HT setup with my roommate and until I buy a nice big HD RPTV, we're using his analog 25" Sharp (*shudder*). So the center channel will probably go on top of his TV but if it won't sit there securely I may have to get the Sanus TV-top shelf, or possibly just wedge something in behind the speaker (though that doesn't sound like the greatest idea acoustically).

Anyway, I'm thinking when I get the RPTV I might get a center stand, the kind that goes down in front of the TV. My question is basically is there any particular reason to choose above over below or vice versa?

Mainly I'd like to avoid buying 2 $30-40 stands (the shelf top vs the down-in-front). I kind of like the look and idea of the below placement with an RPTV but a lot of people seem to put theirs on top too. I read an article suggesting on top was preferable but w/o any specific reason, plus I figure if you had a front projector you'd have no choice but to put it below (unless you wall mounted the center speaker).

So I'm just looking for any reasoning I might have missed, or if its a matter of personal preference, what do you prefer and why?

John Garcia · 08-12-2003, 03:34 PM

There is such a thing as an acoustically transparent FP screen, which the center can sit BEHIND and centered!! THAT is the way to go

Make your own cheap stand a-la Sanus style, and worry about above or below later when you get the RP. I would probably say, for simplicity, above would be my choice.

Lew Crippen · 08-12-2003, 04:02 PM

In an ideal world, you would like all of the front speakers to be at listening level. And given a choice the most important driver to be at ear level is the tweeter. So if your R/L front speakers are floor standing models, the ideal position for your center speaker would be for the tweeter to be at the same level as the tweeters in your main speakers. Unfortunately this will probably be at about the same height as your display.

If you have bookshelf speakers (and they are actually on bookshelves), it may well be that the top of your RPTV will be at about the same height.

A technique that many people use is if they need to place their center speaker higher than ideal, they tilt their speaker down toward the prime viewing area. Or if too low, tilt it up.

This same thing can be done with the other front speakers if necessary.

Paul.Little · 08-12-2003, 08:27 PM

Quote:

There is such a thing as an acoustically transparent FP screen, which the center can sit BEHIND and centered!! THAT is the way to go

There really isn't such a thing as a 100% acoustically transparent screen. You should only put the center channel behind the screen if you are also going to put the L&R speakers behind the screen. And only ever if appearance is more important than sound quality in the room.

As for the speaker location question, my response would be try it both ways and decide which one you like best.

Matt Lee · 08-13-2003, 11:57 AM

I guess I should've mentioned...

My center will be a JBL S-Center, my mains are S38II bookshelf speakers, I plan to put them on either 24" or 30" Wood Tech metal stands (once I measure listening level, I move into this apartment next week, I have the speakers, haven't ordered stands yet). The speakers are about 11" high and I'm estimating the tweeter as 8" up the speaker so one of those stand heights should put the tweeter at ear level.

So one reason I was thinking about the stand for the center is I did figure it would put the center tweeter a little closer to the height of the mains, at worst, 1 foot below vs 2 feet above I'm guessing. Plus the center stands angle upward slightly.

I think I'm going to take the advice to DIY something for on top of the TV for now until I have the RPTV, and maybe even experiment with it if I can find something of the proper height to put the center on in front of the set as well, then I should be able to decide before I get the RPTV and order the center stand if necessary.

Thanks.

**HTF Ads**

RichardHOS · 08-13-2003, 01:56 PM

Matt,

You will almost always be better off with the speaker above rather than below the TV/Screen. Human ears have evolved to accurately localize sound at eye level and below, but have more difficulty localizing sound coming from overhead. If your center channel is below the height of the L/R speakers, your ears will pick that up and your brain will process the sound as being somewhere other than where the visual clues (screen) say it should be. This perceptual battle between ears and eyes may cause irritation and listening fatigue, or if your ears win the perceptual battle (which happens for many people) then you will perceive a change in height of the soundstage as sounds pan from side to side through the center channel.

With the center channel located above the screen, your ear/brain is much less capable of localizing its vertical position (though the horizontal cues still come through plenty clear). The tendancy for the brain to default to your eyes for localizaiton of the sound is much more likely, and the brain simply compensates for the sound and places it at eye level (where it is assumed the L/R speakers also lie). The result is a much more coherent vertical placement of the soundstage.

Pual,

Quote:

There really isn't such a thing as a 100% acoustically transparent screen. You should only put the center channel behind the screen if you are also going to put the L&R speakers behind the screen. And only ever if appearance is more important than sound quality in the room.

I disagree. The high frequency roll-off from AT screens is both measurable and predictable, and is easily enough adjusted for using equalization. When the size of the screen becomes large enough, then placing the center behind it becomes much less a matter of appearance and much more a matter of proper acoustics. You may or may not want to also place the L/R speakers behind the screen, but if you do it should be remembered to keep the path lengths to the listener equal (which in many cases means that you don't want to place them behind the screen with the center).

Additionally, an acoustically transparent screen offers much less of an offensively reflective surface smack in the middle of the front wall. It allows sound to pass through to proper sound absorption/disfussion treatments behind. In that manner, such a screen is entirely for acoustic purposes, not visual, regardless of where your center channel is placed.

Larry Talbot · 08-13-2003, 10:37 PM

I don't believe there are any hard and fast rules for whether the center speaker should go above or below your TV (other than it is best, as someone has already said, to get your tweeters as close in line as possible.)
Like you I searched for opinions on this subject, and there are many. In the end I did exactly what Paul has suggested you do: try it both ways and see which sounds best to you.
One of the reasons why there are no hard and fast rules here is because the acoustics of every room are different: what might sound better in one room will sound terrible in another. Among other variables: in some rooms you might get reflections off the floor if you have your center below your TV, in other rooms you might get reflections off the ceiling if you have it above your TV.
Having tried several different options, including the top of my TV, I have no doubt that, in my current configuration, my center sounds much, much better below the TV.
So try both. That is the only way to know for sure.

DavidES · 08-14-2003, 06:26 AM

If you decide to put on top of display, use a couple of RUBBER wedge door stoppers from local hardware store under speaker to angle and secure better. Extend the front of the speaker about 1/4 to 1/2" over front of display. You might be able to find some 1/8-1/4" thick rubber or dense closed-cell foam strips at store that have adhesive on one side . You could use those on front edge of tv cabinet along with stoppers to prevent sliding and to decouple speaker from tv cabinet. That's what mine came with and it works great especially with a heavy speaker.

Those with Paradigm ADP surround speakers wall-mounted will be familiar with the triangle-shaped foam stuff I'm talking about. That would be perfect for ya.

Hope it helps