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ccotenj
08-19-2007, 06:28 AM
any opinions on this?

it will be in front of and below a rear projection tv... either option passes waf, so that's not a problem...

i've always "believed" that the horizontal orientation of center channels was an aesthetics compromised, but "beliefs" aren't always "truths"... :)

opinions and comments greatly appreciated.

rogerm
08-19-2007, 10:19 AM
I have wondered the same thing. I just read an interesting article that addresses your question. We are in good shape with the Sierra-1 center channel design. Here is the link. http://www.audioholics.com/education/loudspeaker-basics/vertical-vs-horizontal-speaker-designs.

curtis
08-19-2007, 11:16 AM
I actually asked DaveF this same question.

Because of the crossover design and the Sierra's vertical and horizontal off-axis properties, he said there would be no appreciable difference between the two.

I was set to go with a vertical center, I told Dave this, and after what he told me, I went with the horizontal.

ccotenj
08-20-2007, 06:35 AM
thanks for the input. horizontal it is.

azanon
09-16-2007, 08:55 PM
Like the 170, i just don't see how this works as a great center channel. Seems like you'd have to choose either poor WAF/looks by placing the speaker off-center physically so that the tweeter of the speaker is centered with the TV, or center the speaker itself with the TV horizontally and, and a result, have the voice(s) off-axis.

I would think (without having actually tried it) I could notice oddities with the voice with the tweeter even a few inches off center.

IMO, a "center channel" is a speaker that, when centered with your TV, will have the tweeter perfectly in the middle: Like with the 340 or HTM-200.

Placed horizontally above the TV, the voice would be way too high above the TV. It might sound ok if you could place it vertically, immediately below the TV, but I've tried placing them below and it doesn't sound right to me. YMMV.

ebh
09-17-2007, 09:38 AM
Like the 170, i just don't see how this works as a great center channel. Seems like you'd have to choose either poor WAF/looks by placing the speaker off-center physically so that the tweeter of the speaker is centered with the TV, or center the speaker itself with the TV horizontally and, and a result, have the voice(s) off-axis.

I would think (without having actually tried it) I could notice oddities with the voice with the tweeter even a few inches off center.

IMO, a "center channel" is a speaker that, when centered with your TV, will have the tweeter perfectly in the middle: Like with the 340 or HTM-200.

Placed horizontally above the TV, the voice would be way too high above the TV. It might sound ok if you could place it vertically, immediately below the TV, but I've tried placing them below and it doesn't sound right to me. YMMV.

I don't know much about speakers in the grand scheme of things, but this thread (http://www.avsforum.com/avs-vb/showthread.php?t=903113&highlight=compromised) on AVS and rogerm's link show that a lot of people find the MTM design of centers to be the worst choice. I think the idea is that the MTM design does a good job of spreading the sound horizontally, but in a horizontal center channel you are getting good dispersion up and down, but not so much left and right, which is what the center channel is supposed to do to ensure that people sitting off axis are hearing the center as if it comes from the screen. Two drivers on opposite sides playing the same content apparently creates cancellations and other interference.

Of course I own a 340SE right now and like it, and davef has said that in most home theater environments the effects of the MTM design--especially with the way the 340s were engineered--are not such a problem. But I don't know if having a tweeter a bit off from the center is that big of a deal.

ccotenj
09-17-2007, 11:54 AM
well, to my ears (and to my ears only), i really can't tell if the tweeter is a few inches off center...

as far as above or below, i've always had my center below and angled up... maybe it doesn't bother me because i am used to it...

debo
09-17-2007, 02:10 PM
Like the 170, i just don't see how this works as a great center channel. Seems like you'd have to choose either poor WAF/looks by placing the speaker off-center physically so that the tweeter of the speaker is centered with the TV, or center the speaker itself with the TV horizontally and, and a result, have the voice(s) off-axis.

I would think (without having actually tried it) I could notice oddities with the voice with the tweeter even a few inches off center.

IMO, a "center channel" is a speaker that, when centered with your TV, will have the tweeter perfectly in the middle: Like with the 340 or HTM-200.

Placed horizontally above the TV, the voice would be way too high above the TV. It might sound ok if you could place it vertically, immediately below the TV, but I've tried placing them below and it doesn't sound right to me. YMMV.

I asked Dave where the center point of the Sierra is and this was his reply - "The center point for the OPPIX crossover is precisely halfway between the woofer and tweeter. So, for dead center listening, position the Sierra so that the main listening position is aligned with the center point between the woofer and tweeter."

Oh by the way I had the 340SE as a center and I like the Sierra better when sitting off Axis.

davef
09-18-2007, 12:55 AM
Seems like you'd have to choose either poor WAF/looks by placing the speaker off-center physically so that the tweeter of the speaker is centered with the TV, or center the speaker itself with the TV horizontally and, and a result, have the voice(s) off-axis. I would think (without having actually tried it) I could notice oddities with the voice with the tweeter even a few inches off center.

IMO, a "center channel" is a speaker that, when centered with your TV, will have the tweeter perfectly in the middle: Like with the 340 or HTM-200.

Hi Azanon,

I would be curious as to why you would assume the tweeter must be perfectly centered in the middle of the television? I can understand this from an aesthetic standpoint, but acoustically speaking, it is incorrect.

The vocal range of humans is typically from 80Hz to 4kHz, although some would argue that 4kHz is too high, others argue too low.. but this is an average. With this range in mind, 4 octaves are handled by the woofer and only 2 octaves handled by the tweeter. Meaning that the majority of the vocal range is handled by the woofer. Technically speaking, the acoustic "center" of the loudspeaker would be the halfway point in between the woofer and tweeter, and this is the point that should be considered as the middle, when positioning the speaker as a center (not the tweeter as the center point).

Honestly though, a few inches to the left or right, even if you are only 3 feet away from the speaker, will not induce any audible differences.

azanon
10-15-2007, 09:00 AM
Hi Azanon,

I would be curious as to why you would assume the tweeter must be perfectly centered in the middle of the television? I can understand this from an aesthetic standpoint, but acoustically speaking, it is incorrect.

The vocal range of humans is typically from 80Hz to 4kHz, although some would argue that 4kHz is too high, others argue too low.. but this is an average. With this range in mind, 4 octaves are handled by the woofer and only 2 octaves handled by the tweeter. Meaning that the majority of the vocal range is handled by the woofer. Technically speaking, the acoustic "center" of the loudspeaker would be the halfway point in between the woofer and tweeter, and this is the point that should be considered as the middle, when positioning the speaker as a center (not the tweeter as the center point).

Honestly though, a few inches to the left or right, even if you are only 3 feet away from the speaker, will not induce any audible differences.

I (mistakenly) thought most of human voice would be handled with the tweeter. You educated me and cleared up that concern. I use grills on so aesthetics behind the grill isn't a concern for me.

Thanks.

azanon
10-15-2007, 03:22 PM
........I think the idea is that the MTM design does a good job of spreading the sound horizontally, but in a horizontal center channel you are getting good dispersion up and down, but not so much left and right, which is what the center channel is supposed to do to ensure that people sitting off axis are hearing the center as if it comes from the screen. Two drivers on opposite sides playing the same content apparently creates cancellations and other interference.

Just FYI, this was confusing. Which is it, does it optimize the horizontal spreading of sound or not? You said the idea is that it does then, in the same sentence, said it doesn't do so well spreading sound left and right (AKA horizontally).

In any event, i want good vertical dispersion of sound from my center channel because the center typically has to be placed above or below the TV some distance, so I want it to seem like the sound goes with the actor(s) lips. As far as horizontal dispersion is concerned, i'm not concerned about that at all because I want the center channel sound to be "anchored" to the TV (in other words, NOT dispersing much horizontally).

dallas
10-15-2007, 04:15 PM
Hi Azanon,

I would be curious as to why you would assume the tweeter must be perfectly centered in the middle of the television? I can understand this from an aesthetic standpoint, but acoustically speaking, it is incorrect.

The vocal range of humans is typically from 80Hz to 4kHz, although some would argue that 4kHz is too high, others argue too low.. but this is an average. With this range in mind, 4 octaves are handled by the woofer and only 2 octaves handled by the tweeter. Meaning that the majority of the vocal range is handled by the woofer. Technically speaking, the acoustic "center" of the loudspeaker would be the halfway point in between the woofer and tweeter, and this is the point that should be considered as the middle, when positioning the speaker as a center (not the tweeter as the center point).

Honestly though, a few inches to the left or right, even if you are only 3 feet away from the speaker, will not induce any audible differences.

cartoons dave, cartoons. :)

azanon
10-15-2007, 07:36 PM
cartoons dave, cartoons. :)

T'is ok. I imagined a genuinely perplexed, but pleasant grin.

davef
10-16-2007, 12:51 AM
Just FYI, this was confusing. Which is it, does it optimize the horizontal spreading of sound or not? You said the idea is that it does then, in the same sentence, said it doesn't do so well spreading sound left and right (AKA horizontally).

In any event, i want good vertical dispersion of sound from my center channel because the center typically has to be placed above or below the TV some distance, so I want it to seem like the sound goes with the actor(s) lips. As far as horizontal dispersion is concerned, i'm not concerned about that at all because I want the center channel sound to be "anchored" to the TV (in other words, NOT dispersing much horizontally).
Hi Azanon,

The main principle behind a horizontal MTM center is symmetrical horizontal dispersion. The frequency response to the left of the speaker will match the frequency response to the right of the speaker. If the majority of your listening will be done within a +/- 15 to 20 degree horizontal window of the center speaker, MTM will work well.

Vertical dispersion between an MTM center or an MT center (like the Sierra-1) is not affected by the driver layout, it is controlled by the width of the baffle, the crossover point of the speaker and the characteristics of the drivers. Vertical dispersion with either of these two types of centers will be symmetrical and wide, neither have an advantage over another in terms of vertical dispersion, they are both very good.

azanon
10-16-2007, 06:03 AM
Interesting!

.......
I just miss my old "340" on my previous CRT TV. I'm excited that there's been improvements to the HTM-200 though. I have "on the list" to eventually tear out the existing cabinetry in my entertaiment center area and just re-doing it to accommodate whatever speaker configuration I want (which will be Sierra-1's, of course!).