Horizontal Center Channel Speakers and Why They Should Be Avoided

[Texitura]

My "new" fronts are vintage KEF Reference bookshelves with a Uni-Q co-axial driver which has the tweeter in the middle of the woofer. There's no orientation: horizontal, vertical, upside down, it's all the same. For my center upgrade, I'll try to find a used Reference 100c, same principle.

[prerich]

Originally Posted by ozzman

For some reason i knew this,but never dived in and look for facts like you did Dad.Awesome job.

I want to just say with the center i have the first thing i thought of was movie theaters have the speaker(s) behind the screen Because thats the effect i feel iam getting with my center.

I know that this can sounds ridulas but really thats how it sounds too me.

Now in the case of my center what are you opinions on it(vertical is not an option).Remember my fronts are timber matched to my center ,so right away it sounded Better then my PSB ,then i noticed the fullness of the center(giving me the effect that it was coming from the screen and above)Is this all in my head ,Iam i wishing this to be my truth,Have i gone a little nuts LOL

Give it to me straight Doc

http://www.miragespeakers.com/na-en/...pecifications/

You're fine Ozz - the Mirage speakers are omni-polar a different animal altogether - you should be straight!

[prerich]

Originally Posted by Driver_King

What would you say to a Polk SDA CRS speaker for a center for my SDA II's? Or should I try to find another SDA II?

Another different animal - remember one driver in the SDA is actual phase cancellation. When not connected with the cable - I'm told that the driver is nil, and the SDA CRS is a three-way design with a 10 inch woofer in the rear, a phase cancellation mid-range (and tweeter depending on the model) and a normal mid-range and tweeter. A vertical Monitor 7 or Monitor 10 would make a good standing center channel - but you would be ok with a CRS on a stand. I had this in mind at one time but CRS' are a rare find. A third SDA II (if you have the room) would be nice but I would more than likely go with a Monitor 7 or 10 (if you want a floor standing speaker).

[prerich]

Originally Posted by Texitura

My "new" fronts are vintage KEF Reference bookshelves with a Uni-Q co-axial driver which has the tweeter in the middle of the woofer. There's no orientation: horizontal, vertical, upside down, it's all the same. For my center upgrade, I'll try to find a used Reference 100c, same principle.

The Uni-Q speakers are the acception to the rule as well as some Tannoys and Bag End - they also have coaxial mounted tweeters - as does the DCM CX-17.

[jomari]

Originally Posted by prerich

The Uni-Q speakers are the acception to the rule as well as some Tannoys and Bag End - they also have coaxial mounted tweeters - as does the DCM CX-17.

this is duly noted on other center speakers as well. as i mentioned earlier, most companies have addressed lobing and other concerns via newer technologies. some 'claim' to have, but some definitely have proven graphs and test done not only by their company but by others as well.

[crazyBLUE]

Having changed my front speakers to all match , Making the center vertical instead of horizontal . There was A noticeable change !
Dialog seemed more centered to display than stretched over middle 3rd of display .
Thing's moving from one side to the other seemed to flow threw the sound stage more evenly .
Upon moving from center seating to one side the only change seemed to be, that side front was stronger because the other front was farther away , The center did not seem to change sitting off center !

Just my opiniun !

[naturephoto1]

How about my Nola LCR Reference speaker ($2200 list), should this be OK?

For the new towers that are being made up, we are considering making a horizontal center channel speaker based on the old KEF design with 2 woofers on the left and 2 on the right (we expect the speaker to be 9" tall and 42" long). There will be a midrange speaker between these with the tweeter situated above the midrange. I am not sure if this will be a problem, but it will match the drivers of the big towers. In a vertical orientation, this would probably be too tall to have in front of a screen or the 50" Plasma TV.

Rich

[Blown 4.3]

i didn't read the whole thread. i do understand the horizontal issue. i have this question.

what would happen if one were to use horizontal centers. 1 above the set, and one below ?

i have not tried this, so i don't know. but i do have extra speakers, so maybe i will.

[Big Daddy]

Originally Posted by naturephoto1

How about my Nola LCR Reference speaker ($2200 list), should this be OK?

For the new towers that are being made up, we are considering making a horizontal center channel speaker based on the old KEF design with 2 woofers on the left and 2 on the right (we expect the speaker to be 9" tall and 42" long). There will be a midrange speaker between these with the tweeter situated above the midrange. I am not sure if this will be a problem, but it will match the drivers of the big towers. In a vertical orientation, this would probably be too tall to have in front of a screen or the 50" Plasma TV.

Rich

It looks like they have already accounted for the problem and placed the tweeter on a different axis. However, I will bet you that if you position it vertically, it may still give you an improvement in two areas:

• Center stage and imaging
• Off-axis response

In most cases, a vertically placed good quality bookshelf speaker performs better than an horizontal center speaker. See Post #2.

[Big Daddy]

Originally Posted by Blown 4.3

i didn't read the whole thread. i do understand the horizontal issue. i have this question.

what would happen if one were to use horizontal centers. 1 above the set, and one below ?

i have not tried this, so i don't know. but i do have extra speakers, so maybe i will.

Two center speakers receive the same signal and will have the phase cancellation problem. You really have to do a lot of experimantion to position them properly or mess with their wiring to change their phase.

The difference between two center speakers and the front left and right speakers is that the main speakers receive different signals (stereo).

[naturephoto1]

Originally Posted by Big Daddy

It looks like they have already accounted for the problem and placed the tweeter on a different axis. However, I will bet you that if you position it vertically, it may still give you an impriovement in two areas:

• Center stage and imaging
• Off-axis response

In most cases, a vertically placed good quality bookshelf speaker performs better than an horizontal center speaker. See Post #2.

I may give that a try. The Nola LCR Reference speakers are intended to be a mirror imaged L & R open baffle midrange and tweeter dipole design and they are also used as a center channel speaker.

If I find that it is an improvement, maybe we will rethink the design of the speaker to match the new tower speakers that will be made.

We are also toying with some interesting designs for the L & R surrounds (which will be placed on spikes and installed on carpeted pedestals) and will probably end up using my rebuilt and upgraded twice Dahlquist DQ-10 speakers as a mirrored pair for the L & R rear channels in my future 7.1 system (I will place them on spikes and install them on carpeted pedestals to raise them to the proper height).

Rich

[crazyBLUE]

prerich ! Know that I have my front 3 all the same . I can not tell in you're gallery if you're front 3 are in A straight line or do you have the center offset back or forward from that line ! What would be best !

[prerich]

Originally Posted by crazyBLUE

prerich ! Know that I have my front 3 all the same . I can not tell in you're gallery if you're front 3 are in A straight line or do you have the center offset back or forward from that line ! What would be best !

I have my center off-set back and my L/R toe'd in just a little not much. Experiment and see which is best in you listening area - straight across may work well for you.

[tlmaclennan]

From what I can tell they are in a straight line much like you would have with a horizontal center speaker. Have you tried your new setup yet crazyBLUE? I'm waiting to see if you like the change enough to keep it!

EDIT: prerich beat me too it.

[prerich]

Originally Posted by tlmaclennan

From what I can tell they are in a straight line much like you would have with a horizontal center speaker. Have you tried your new setup yet crazyBLUE? I'm waiting to see if you like the change enough to keep it!

EDIT: prerich beat me too it.

It's alright . You can't tell very well in the Klipsch photos but they are in a small arch with the center channel a few inches back of the mains. When I run YPAO on my Yamaha - it even measures it (distance)- very acurrately I might add

[crazyBLUE]

Originally Posted by prerich

I have my center off-set back and my L/R toe'd in just a little not much. Experiment and see which is best in you listening area - straight across may work well for you.

Thanks prerich ! At the moment my center is back about 8" . I will move it around this afternoon , THANKS ..

Originally Posted by tlmaclennan

From what I can tell they are in a straight line much like you would have with a horizontal center speaker. Have you tried your new setup yet crazyBLUE? I'm waiting to see if you like the change enough to keep it!

EDIT: prerich beat me too it.

I have watched A couple of Blu's w/all 3 front's the same & there is A difference not having the center horizontal !!! I really can't wait to get A 3rd BOSTON Tower to have my Bostons back up front !!

[Driver_King]

Originally Posted by prerich

Another different animal - remember one driver in the SDA is actual phase cancellation. When not connected with the cable - I'm told that the driver is nil, and the SDA CRS is a three-way design with a 10 inch woofer in the rear, a phase cancellation mid-range (and tweeter depending on the model) and a normal mid-range and tweeter. A vertical Monitor 7 or Monitor 10 would make a good standing center channel - but you would be ok with a CRS on a stand. I had this in mind at one time but CRS' are a rare find. A third SDA II (if you have the room) would be nice but I would more than likely go with a Monitor 7 or 10 (if you want a floor standing speaker).

I guess another SDA in the middle would be the route to go then. I do not want any issues with voices going from the middle speaker to the other two. Then I would need to find another place to put my A2-300 (it is currently in the middle of the SDA's on the front wall). If I can find another SDA II with the matching Silver Coil Dome tweeters (the SL1000's to be exact), I would buy it if the price was right.

[kpkelley]

Big Daddy, if one were to use three bookshelf speakers for their center channel, what would be the best way for them to be oriented? Square, toe-in, toe-out?

[Big Daddy]

Originally Posted by kpkelley

Big Daddy, if one were to use three bookshelf speakers for their center channel, what would be the best way for them to be oriented? Square, toe-in, toe-out?

That is a very difficult question to answer. It depends a lot on your speakers, size of the room, room acoustics, and the location of your listneing area.

As a general rule, using more than one speaker for center channel will give you difficulty and phase cancellation problem. The right and left front speakers receive stereo signals that are not the same. However, multiple center speakers receive the same signal and the drivers can cancel each other.

If I were to guess, the best way to arrange 3 center speakers is to make sure that they are not on the same horizontal path and perhaps they are at a very slight angle to each other. You may try puting one up in the middle (slightly toed downward) and the other two in the bottom of the screen. You really need to experiment to find the best option.

If there is a choice between improving horizontal off-axis performance as opposed to vertical off-axis performance, the answser is to make sure horizontal performance is improved more. Most of us do not watch a movie satnding up.

[Blown 4.3]

Originally Posted by Big Daddy

Two center speakers receive the same signal and will have the phase cancellation problem. You really have to do a lot of experimantion to position them properly or mess with their wiring to change their phase.

The difference between two center speakers and the front left and right speakers is that the main speakers receive different signals (stereo).

care to give a brief explination of the phase cancelation thing ?
(though i think i know what you are talking about)