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  1. #1
    Forum Regular brad1138's Avatar
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    Dual Center Channel...

    I just replaced my Athena C1 center with 2 Athena S1's. The C1 is basically a S1 with a passive radiator. I have 1 S1 upright below the TV and the other upside down above it. My wife has my camera and is out of town or I would post pictures of the way I mounted the top S1. I am running both S1's in parallel off my Marantz MA-500 mono amp. Other than the obvious benifit of the vocals coming from the TV rather than below it, they come across more powerful and more full, giving the effect of a much larger spk, I am really pleased with the results. The S1's were just sitting around not being used anyway. The S1's tweeter is aimed slightly up (5-10 degrees?) which works well for this setup in that the tweet aims toward the listener from both "center" spks.

    Anyway, I am glad I decided to do this and would recommend it to anyone else.

    Brad
    Home Theater:

    Emotiva UMC-200, Citation 5.1 running Mirage M-3SIs, Harman Kardon signature 2.1 running Mirage M-CSI (center) & 4x BIC V-52 (surrounds), 2 x Velodyne ULD 15 Series II Sub & Amp, PS3, PS4, XBOX 1, 2x Adcom ACE-515, Vizio E-701B-3

    2.0 setup:

    Schiit Freya Tube PreAmp, Citation 5.1, Mirage M3SIs, Onkyo DV-CP702 (CD transport), Schiit Modi Multibit DAC.





  2. #2
    M.P.S.E /AES/SMPTE member Sir Terrence the Terrible's Avatar
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    Quote Originally Posted by brad1138
    I just replaced my Athena C1 center with 2 Athena S1's. The C1 is basically a S1 with a passive radiator. I have 1 S1 upright below the TV and the other upside down above it. My wife has my camera and is out of town or I would post pictures of the way I mounted the top S1. I am running both S1's in parallel off my Marantz MA-500 mono amp. Other than the obvious benifit of the vocals coming from the TV rather than below it, they come across more powerful and more full, giving the effect of a much larger spk, I am really pleased with the results. The S1's were just sitting around not being used anyway. The S1's tweeter is aimed slightly up (5-10 degrees?) which works well for this setup in that the tweet aims toward the listener from both "center" spks.

    Anyway, I am glad I decided to do this and would recommend it to anyone else.

    Brad
    Brad,
    You may have convinced yourself it sounds good, but this really is a bad practice and I don't care how well it is done. Either you are hearing the effect of frequency combining, or you are hearing the tweeters cancelling, but there is no way this kind of setup is even close to flat. If you drop two rocks side by side in a pond, and watch the waves come together, that is what your set up is doing. When those waves meet, depending on the wavelength and frequency, they will either be is phase and boost the output at those frequencies, or they will be out of phase and cancel some frequencies. Either way this venture veers away from a flat frequency response, and depending on where you sit in the room, you will hear different tonalities and timbres coming from this setup.

    Not recommended at all.
    Sir Terrence

    Titan Reference 3D 1080p projector
    200" SI Black Diamond II screen
    Oppo BDP-103D
    Datastat RS20I audio/video processor 12.4 audio setup
    9 Onkyo M-5099 power amp
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    9 Onkyo M-508 power amp
    6 custom CAL amps for subs
    3 custom 3 way horn DSP hybrid monitors
    18 custom 3 way horn DSP hybrid surround/ceiling speakers
    2 custom 15" sealed FFEC servo subs
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    THX Style Baffle wall

  3. #3
    Suspended PeruvianSkies's Avatar
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    Quote Originally Posted by brad1138
    I just replaced my Athena C1 center with 2 Athena S1's. The C1 is basically a S1 with a passive radiator. I have 1 S1 upright below the TV and the other upside down above it. My wife has my camera and is out of town or I would post pictures of the way I mounted the top S1. I am running both S1's in parallel off my Marantz MA-500 mono amp. Other than the obvious benifit of the vocals coming from the TV rather than below it, they come across more powerful and more full, giving the effect of a much larger spk, I am really pleased with the results. The S1's were just sitting around not being used anyway. The S1's tweeter is aimed slightly up (5-10 degrees?) which works well for this setup in that the tweet aims toward the listener from both "center" spks.

    Anyway, I am glad I decided to do this and would recommend it to anyone else.

    Brad

    This is the type of rubbish that confuses those who are new to this hobby and have little time to really investigate the proper ways to utilize their home theater.

    Obviously using two speakers will have a fuller sound than just one, it should produce twice the sound, but that's not really the point here. The center channel should in in balance with the left and right, which takes calibration time to adjust.

    More importantly, it could cause overload on the receiver depending on how this is hooked up since most receivers or amps only have outputs for 1 center channel.

    Newbies beware.

  4. #4
    Forum Regular brad1138's Avatar
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    Quote Originally Posted by PeruvianSkies
    This is the type of rubbish that confuses those who are new to this hobby and have little time to really investigate the proper ways to utilize their home theater.

    Obviously using two speakers will have a fuller sound than just one, it should produce twice the sound, but that's not really the point here. The center channel should in in balance with the left and right, which takes calibration time to adjust.

    More importantly, it could cause overload on the receiver depending on how this is hooked up since most receivers or amps only have outputs for 1 center channel.

    Newbies beware.
    First of all, I adjust volume levels with an SPL meter and set them in 1/2 dB increments with my Lexicon Pre amp. My Marantz MA-500 is 4 ohm stable and runs them fine. When listening the sound, primarily vocals, come from the center of the screen.

    The same argument trying to be made against it could be made against using two speakers for mono playback (say an old Beatles CD) or even Stereo playback for anyone not sitting dead center. I have Googled a bit on it and found arguments for and against it. But don't tell me that my post is complete rubbish because you don't agree with it. I have a very nice system and a fairly critical ear, this works great for me.

    As I walk around my (or anyones) room while listening to stereo music, I don't get a horrible (or any) oscillation as the L & R tweeters move in and out of phase w/each other. I don't think your argument holds much water.

    Brad
    Home Theater:

    Emotiva UMC-200, Citation 5.1 running Mirage M-3SIs, Harman Kardon signature 2.1 running Mirage M-CSI (center) & 4x BIC V-52 (surrounds), 2 x Velodyne ULD 15 Series II Sub & Amp, PS3, PS4, XBOX 1, 2x Adcom ACE-515, Vizio E-701B-3

    2.0 setup:

    Schiit Freya Tube PreAmp, Citation 5.1, Mirage M3SIs, Onkyo DV-CP702 (CD transport), Schiit Modi Multibit DAC.





  5. #5
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    I have heard arguments for two centers before as well but never really researched it. it would seem two centers would more focus the sound from center screen, a stronger image than just one below or above. Having two centers could also help balance out only having a bad placement option, like too far above or below the screen. I thought that was well thought out pointing the top center firing the tweeter downward.

    Like frequencies do increase but that would be minimized by recalibrating. Not sure what effect another center would have on overall frequency response, the only way to know for sure is to measure before and after for comparison. Wonder if any one has done that and put it into print?

    Some receivers actually have outputs for two center channels, not the norm, but I have seen them. You can come off a center pre out with a "Y" adaptor into a stereo amp and easily hook up two centers. Just one of a few safe options.

  6. #6
    Suspended PeruvianSkies's Avatar
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    Quote Originally Posted by brad1138
    First of all, I adjust volume levels with an SPL meter and set them in 1/2 dB increments with my Lexicon Pre amp. My Marantz MA-500 is 4 ohm stable and runs them fine. When listening the sound, primarily vocals, come from the center of the screen.

    The same argument trying to be made against it could be made against using two speakers for mono playback (say an old Beatles CD) or even Stereo playback for anyone not sitting dead center. I have Googled a bit on it and found arguments for and against it. But don't tell me that my post is complete rubbish because you don't agree with it. I have a very nice system and a fairly critical ear, this works great for me.

    As I walk around my (or anyones) room while listening to stereo music, I don't get a horrible (or any) oscillation as the L & R tweeters move in and out of phase w/each other. I don't think your argument holds much water.

    Brad
    You are comparing too many different things. First, most people don't walk around aimlessly while listening to music, if you are setting up a room to fill the room with sound from a variety of spots, there are other methods that can be used to decrease any type of phasing.

    Most people (at least here) watch movies or listen to music in a dedicated spot, and the soundfield should not be that far off-center if you have things properly setup with a 5.1 or even 6.1/7.1 setup. A proper 2.0 stereo system with excellent speakers will give the illusion that sound is coming from all over to begin with, most notibly it will not sound like sound is coming from left or right, but the center field will be filled based on the recordings intentions and will be three-dimensional in width, height, and depth.

    The only time that I could see using more than 1 center speaker would be in a theater system like a movie house with a huge screen and a room that is large enough to house 20 or more people.

  7. #7
    Forum Regular luvtolisten's Avatar
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    Hi Brad, nice system you have there.Sounds like you're happy with it and that's all that matters. Since you are the one, who did the actual experiment, and just didn't go by theory, it holds more credibility with me. If you had a not so good system, an all in one Walmart special, I would question it, but that's definitely not the case here. We all hear and perceive things differently. And where &how we listen to them differently too.Otherwise, we'd all be sitting around with the same exact system. I applaud you for experimenting and sharing your results.
    The only thing I would caution you on, is the impedance factor, (I'm assuming you have your centers in parallel, therefore cutting your impedance in half) be sure your amp can handle it and not cause any damage to it, should you decide to crank it. Enjoy!!
    Last edited by luvtolisten; 07-26-2010 at 03:39 AM.

  8. #8
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    I found this link, the writer talks about the parallel effect I unknowing described in my former post. He does say dual centers would be for larger screens or projection screens.
    http://www.axiomaudio.com/tips_cente...nel_sound.html

    Most drawbacks I've read about seem tey could be taken away by calibrating, ie. level, delay.

    I do have to add top/bottom dual centers I think can work in certainsituations but a beside the TV placement would defintely be a no no.

  9. #9
    M.P.S.E /AES/SMPTE member Sir Terrence the Terrible's Avatar
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    Quote Originally Posted by Mr Peabody
    I found this link, the writer talks about the parallel effect I unknowing described in my former post. He does say dual centers would be for larger screens or projection screens.
    http://www.axiomaudio.com/tips_cente...nel_sound.html

    Most drawbacks I've read about seem tey could be taken away by calibrating, ie. level, delay.

    I do have to add top/bottom dual centers I think can work in certainsituations but a beside the TV placement would defintely be a no no.
    First, you cannot correct the negative acoustical effects of using dual center speakers with calibration. It is an acoustical issue caused by two acoustical waves interacting with each other to produce complimentary and negative reflections.

    Top and bottom, side by side setups both produce the same effects on different planes, but the end effect is exactly the same - nonuniformity in the propagation of the frontal wave.
    Sir Terrence

    Titan Reference 3D 1080p projector
    200" SI Black Diamond II screen
    Oppo BDP-103D
    Datastat RS20I audio/video processor 12.4 audio setup
    9 Onkyo M-5099 power amp
    9 Onkyo M-510 power amp
    9 Onkyo M-508 power amp
    6 custom CAL amps for subs
    3 custom 3 way horn DSP hybrid monitors
    18 custom 3 way horn DSP hybrid surround/ceiling speakers
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  10. #10
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    Sir T, I hear what you are saying but isn't dual centers basically the same effect asrear speakers? Especially in the day of Pro Logic.

  11. #11
    M.P.S.E /AES/SMPTE member Sir Terrence the Terrible's Avatar
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    Quote Originally Posted by brad1138
    First of all, I adjust volume levels with an SPL meter and set them in 1/2 dB increments with my Lexicon Pre amp. My Marantz MA-500 is 4 ohm stable and runs them fine. When listening the sound, primarily vocals, come from the center of the screen.
    As it should.

    The same argument trying to be made against it could be made against using two speakers for mono playback (say an old Beatles CD) or even Stereo playback for anyone not sitting dead center. I have Googled a bit on it and found arguments for and against it. But don't tell me that my post is complete rubbish because you don't agree with it. I have a very nice system and a fairly critical ear, this works great for me.
    The difference between what you are doing, and what is done on a Beatles recording is the Beatles recording uses eq, and you are not. Secondly, if you measured the response of those two mono sources hitting your ears at identical arrival times, you would see both cancellation and reinforcemant of certain frequencies over others. Down the center, you would notice a profound notch at 2-4khz. Move your head to the left or right, and the notch disappears.

    I can always convince myself that something sounds good, but can I convince others that it does?

    As I walk around my (or anyones) room while listening to stereo music, I don't get a horrible (or any) oscillation as the L & R tweeters move in and out of phase w/each other. I don't think your argument holds much water.

    Brad
    You are listening to the wrong thing. Listen to the bass, and you will get a much different result.

    If you are looking for better listening room coverage, you choose a loudspeaker with a wider dispersion pattern, not another speaker. If you are looking for more power, you choose a speaker with larger drivers or one with more drivers covering the individual frequencies. You don't get another speaker.
    Sir Terrence

    Titan Reference 3D 1080p projector
    200" SI Black Diamond II screen
    Oppo BDP-103D
    Datastat RS20I audio/video processor 12.4 audio setup
    9 Onkyo M-5099 power amp
    9 Onkyo M-510 power amp
    9 Onkyo M-508 power amp
    6 custom CAL amps for subs
    3 custom 3 way horn DSP hybrid monitors
    18 custom 3 way horn DSP hybrid surround/ceiling speakers
    2 custom 15" sealed FFEC servo subs
    4 custom 15" H-PAS FFEC servo subs
    THX Style Baffle wall

  12. #12
    M.P.S.E /AES/SMPTE member Sir Terrence the Terrible's Avatar
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    Quote Originally Posted by Mr Peabody
    Sir T, I hear what you are saying but isn't dual centers basically the same effect asrear speakers? Especially in the day of Pro Logic.
    The requirement for the rear channels in the prologic days was diffusion. In the front of the room it is directivity. All you get with two front center speakers is an uneven frequency response, and a equally poor coverage.
    Last edited by Sir Terrence the Terrible; 07-26-2010 at 04:20 PM.
    Sir Terrence

    Titan Reference 3D 1080p projector
    200" SI Black Diamond II screen
    Oppo BDP-103D
    Datastat RS20I audio/video processor 12.4 audio setup
    9 Onkyo M-5099 power amp
    9 Onkyo M-510 power amp
    9 Onkyo M-508 power amp
    6 custom CAL amps for subs
    3 custom 3 way horn DSP hybrid monitors
    18 custom 3 way horn DSP hybrid surround/ceiling speakers
    2 custom 15" sealed FFEC servo subs
    4 custom 15" H-PAS FFEC servo subs
    THX Style Baffle wall

  13. #13
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    I tried two W-T-W center channels one on top of the other and I did not like the sound. The two speakers wire wired in parallel.

    The second thing to take into account is the internal wiring scheme of center channel speakers. I am talking about the W-T-W design. I have noticed that some come with the two woofers rated each at 12 to 16 ohms wired in parallel giving you and impedance of 6-8 ohms. The other type appears to be two 3 to 4 ohm speakers wired in SERIES giving you 6 to 8ohms impedance. I would think that the latter might cause the two woofers cones to "fight" each other causing them to not properly work in phase with the rest of a 5.1 channel system. The former two wired parallel speakers are in-phase with each other and to me appears to blend with the rest of a 5.1 system. The wiring scheme of the latter system is similar to wiring for a passive surround system. Is that what one wants for their center channel sound? How does one know that they are getting from any manufacturer if they getting the former or the latter whether you look at it or even take an ohm meter to measure the DC resistance. I can tell you this that my parallel unit is not going anywhere unless I am dead. Now for those who have a 6.1 system, the series unit might be the speaker to use for the ES/EX sound. I just have a theory that it might work well but I have never been able to try it. Somebody out there might want to try it provided they know that their unit is one of those series units.

  14. #14
    Forum Regular brad1138's Avatar
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    I have been very busy and don't have time for a full reply, but I will say that the the center chan amp I am using is THX cert and handles 4 ohm load w/o any trouble. Rated at 125 @ 8 ohms & 200 @ 4 ohms.
    Home Theater:

    Emotiva UMC-200, Citation 5.1 running Mirage M-3SIs, Harman Kardon signature 2.1 running Mirage M-CSI (center) & 4x BIC V-52 (surrounds), 2 x Velodyne ULD 15 Series II Sub & Amp, PS3, PS4, XBOX 1, 2x Adcom ACE-515, Vizio E-701B-3

    2.0 setup:

    Schiit Freya Tube PreAmp, Citation 5.1, Mirage M3SIs, Onkyo DV-CP702 (CD transport), Schiit Modi Multibit DAC.





  15. #15
    Forum Regular brad1138's Avatar
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    Quote Originally Posted by PeruvianSkies
    You are comparing too many different things. First, most people don't walk around aimlessly while listening to music.
    You really missed the point. I never said I wander around aimlessly listening to music (a.h.) If you can move across your room while listening to 2 stereo speakers and the sound doesn't change much, then the same thing should be the case if your ears are not exactly between the 2 center speaker, it just so happens that in my set up my ears are within a couple inches of dead center between the 2. the difference in distance between the 2 is negligible.

    Quote Originally Posted by PeruvianSkies
    A proper 2.0 stereo system with excellent speakers will give the illusion that sound is coming from all over to begin with, most notibly it will not sound like sound is coming from left or right, but the center field will be filled based on the recordings intentions and will be three-dimensional in width, height, and depth.
    I am fully aware of that, my Mirage M3-SIs are a great imaging speaker that completely vanish, if you close you eyes you couldn't even point them out. They are a StereoPhile Class B speaker.

    Quote Originally Posted by Sir Terrence the Terrible
    You are listening to the wrong thing. Listen to the bass, and you will get a much different result.
    You are correct that bass varies as you move around the room, but I am not worried about bass from my center chans I have 2 subs that handle that. I have a 7.2 system.

    I am not sure how you believe that there would be any hole if you are dead center between mono sources, the frequencies should match perfectly and there would be no cancellation.

    I get the issues that 2 centers can create, I believe you guys are blowing them WAY out of proportion. The same issues that 2 centers can cause can be caused by the left and right speakers to anyone not sitting in the exact center. So I guess to make sure everything is just perfect, everyone should have there own individual home theater.

    You are so quick to judge, and be rude about it. I am sure glad I shared my experience. Regardless of what you have to say, my ears will tell me what sounds good, not you.

    Brad

    P.S. luvtolisten and Mr Peabody, thank you for you comments. Also here are pictures of my system/room, A few changes have been made since the pix, but they are listed in the Sig.
    Home Theater:

    Emotiva UMC-200, Citation 5.1 running Mirage M-3SIs, Harman Kardon signature 2.1 running Mirage M-CSI (center) & 4x BIC V-52 (surrounds), 2 x Velodyne ULD 15 Series II Sub & Amp, PS3, PS4, XBOX 1, 2x Adcom ACE-515, Vizio E-701B-3

    2.0 setup:

    Schiit Freya Tube PreAmp, Citation 5.1, Mirage M3SIs, Onkyo DV-CP702 (CD transport), Schiit Modi Multibit DAC.





  16. #16
    Forum Regular pixelthis's Avatar
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    Cool

    Hate to agree with Talky on anything(you sure the world aint flat?) but hes' right in this case.
    Get a really big honkin center , never use two unless its a large room and they are a good distance from each other, and then its a no alternative thing.
    LG 42", integra 6.9, B&W 602s2, CC6 center, dm305rears, b&w
    sub asw2500
    Panny DVDA player
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  17. #17
    Forum Regular pixelthis's Avatar
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    Unhappy

    Quote Originally Posted by luvtolisten
    Hi Brad, nice system you have there.Sounds like you're happy with it and that's all that matters. Since you are the one, who did the actual experiment, and just didn't go by theory, it holds more credibility with me. If you had a not so good system, an all in one Walmart special, I would question it, but that's definitely not the case here. We all hear and perceive things differently. And where &how we listen to them differently too.Otherwise, we'd all be sitting around with the same exact system. I applaud you for experimenting and sharing your results.
    The only thing I would caution you on, is the impedance factor, (I'm assuming you have your centers in parallel, therefore cutting your impedance in half) be sure your amp can handle it and not cause any damage to it, should you decide to crank it. Enjoy!!
    Some aborigine tribes sacrifice virgins to a volcano, is that okay as long as they enjoy it?
    A LOT of fender heads luv luv luv luuuv BOSE, doesnt change Bose's position as the
    center of evil in the known world.
    Point is, this freakin hobby is about accurate reproduction, or as close as you can get, and this person is missing out.
    Big time.
    Attached Images Attached Images  
    LG 42", integra 6.9, B&W 602s2, CC6 center, dm305rears, b&w
    sub asw2500
    Panny DVDA player
    sharp Aquos BLU player
    pronto remote, technics antique direct drive TT
    Samsung SACD/DVDA player
    emotiva upa-2 two channel amp

  18. #18
    M.P.S.E /AES/SMPTE member Sir Terrence the Terrible's Avatar
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    Quote Originally Posted by brad1138
    You really missed the point. I never said I wander around aimlessly listening to music (a.h.) If you can move across your room while listening to 2 stereo speakers and the sound doesn't change much, then the same thing should be the case if your ears are not exactly between the 2 center speaker, it just so happens that in my set up my ears are within a couple inches of dead center between the 2. the difference in distance between the 2 is negligible.
    Here is where your logic fails you. Two stereo speaker will be reproducing two different signals with two different phase characteristic. Two speaker reproducing mono information is subject to almost totally cancellation between 2-4khz because of the HRT effect of both speakers output hitting the ear simultaneously. Now you can EQ this notch out, but then as you move off axis of center the sound will be much too bright. So you have narrowed your sweet spot substantially. Two woofers and two tweeter spaced apart will have driver interference issues that impact the frequency response of the signals themselves.


    You are correct that bass varies as you move around the room, but I am not worried about bass from my center chans I have 2 subs that handle that. I have a 7.2 system.
    Then you should be worried about frequencies from the crossover point of the subs and upward. There is no such thing as a 7.2 system, you only have one LFE channel. Just because two subs are reproducing it does not make another channel. The proper distinction would be a 7.1 system with two subs.

    I am not sure how you believe that there would be any hole if you are dead center between mono sources, the frequencies should match perfectly and there would be no cancellation.
    Its not a belief, its a fact. Have you ever heard of driver interference or lobing. This happens when two spaced drivers reproducing the same frequencies interfere with each other at certain frequencies. There is also comb filtering occurring as well.

    http://www.integracoustics.com/MUG/M...icles/sources/

    Go to the bottom of the page, and look at the moving example on the left

    I get the issues that 2 centers can create, I believe you guys are blowing them WAY out of proportion.
    I think because of your lack of knowledge of how the ear works you are underestimating the effects.

    The same issues that 2 centers can cause can be caused by the left and right speakers to anyone not sitting in the exact center. So I guess to make sure everything is just perfect, everyone should have there own individual home theater.
    The difference between left/right speakers and dual mono speakers lies in the fact the former is playing completely different information with different phase characteristic, and the latter plays the same mono signal with two speakers.

    You are right, people should have their own hometheater systems, so they can make their own stupid mistakes, ignore good advice, and have a compromised system as a result.

    You are so quick to judge, and be rude about it. I am sure glad I shared my experience. Regardless of what you have to say, my ears will tell me what sounds good, not you.

    Brad

    .
    Brad, nobody is quick to judge anything. Do you really think you were the first person to think up this hair brained idea? No, you are not. I have seen these setup dozen of times, measured them, and showed the owners of these set ups the results. I disconnect one speaker, remeasured, and showed them the improvements. I am not a novice at these kinds of dumb set ups. If one is good, two must be better is a foolish concept when it comes reproducing mono signals.

    If you think I am rude, I think your are stubbornly ignorant of a great many things when it comes to audio science. Now that we have voiced our opinions of one another, we can removed the personal issues out of the way, and deal with this bad idea.

    Anyone can convince themselves that something is good if only to justify the reasoning for doing something.

    Go to this page

    http://www.falstad.com/ripple/

    When the applet comes up, click on one source and look at the wave pattern. Now click on two sources, and see that wave pattern. The first has a nice clean wave, and the second with two sources shows considerable interference in the wave patterns. This is what is happen with you two center setup.

    All one has to do is look at your setup, and you can see a bunch of problems with where the center are placed, along with the effects I have mentioned.
    Sir Terrence

    Titan Reference 3D 1080p projector
    200" SI Black Diamond II screen
    Oppo BDP-103D
    Datastat RS20I audio/video processor 12.4 audio setup
    9 Onkyo M-5099 power amp
    9 Onkyo M-510 power amp
    9 Onkyo M-508 power amp
    6 custom CAL amps for subs
    3 custom 3 way horn DSP hybrid monitors
    18 custom 3 way horn DSP hybrid surround/ceiling speakers
    2 custom 15" sealed FFEC servo subs
    4 custom 15" H-PAS FFEC servo subs
    THX Style Baffle wall

  19. #19
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    Pix has escaped again! I haven't seen this many new posts since the last time he forgot his medication Maybe he was locked up for a while.

  20. #20
    Forum Regular pixelthis's Avatar
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    Cool

    Quote Originally Posted by Mr Peabody
    Pix has escaped again! I haven't seen this many new posts since the last time he forgot his medication Maybe he was locked up for a while.
    I decided that the world couldnt live without my brilliance.
    Besides , somebodies gotta counter talky and his nonsense.
    AND get the word out about Emotiva(audiophillia on the cheap).
    And warn against buying plasma.
    AND INVESTING IN 3d(MORE like 3 dead)
    SO MANY LIES, SO LITTLE TIME....
    Attached Images Attached Images  
    LG 42", integra 6.9, B&W 602s2, CC6 center, dm305rears, b&w
    sub asw2500
    Panny DVDA player
    sharp Aquos BLU player
    pronto remote, technics antique direct drive TT
    Samsung SACD/DVDA player
    emotiva upa-2 two channel amp

  21. #21
    Forum Regular pixelthis's Avatar
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    tuscaloosa
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    Talking

    And Polluted(er, peruvian) skies is back.
    NO WONDER Dracula is his favorite movie, no matter how many times you stake him,
    he still keeps on coming back, like the Energizer bunny, even having nothing to say
    doesn't slow him down
    Attached Images Attached Images  
    LG 42", integra 6.9, B&W 602s2, CC6 center, dm305rears, b&w
    sub asw2500
    Panny DVDA player
    sharp Aquos BLU player
    pronto remote, technics antique direct drive TT
    Samsung SACD/DVDA player
    emotiva upa-2 two channel amp

  22. #22
    Forum Regular luvtolisten's Avatar
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    Feb 2009
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    Rochester, NY
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    Quote Originally Posted by pixelthis
    Some aborigine tribes sacrifice virgins to a volcano, is that okay as long as they enjoy it?
    A LOT of fender heads luv luv luv luuuv BOSE, doesnt change Bose's position as the
    center of evil in the known world.
    Point is, this freakin hobby is about accurate reproduction, or as close as you can get, and this person is missing out.
    Big time.
    Says YOU!!!
    I would love to sacrifice a couple of virgins, are ya game?
    http://www.youtube.com/watch?v=XRGd0...eature=related

  23. #23
    Suspended
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    Just make sure they are virgins, any one see Jennifer's Body.....

  24. #24
    Forum Regular brad1138's Avatar
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    Quote Originally Posted by Terrible
    There is no such thing as a 7.2 system
    O...K... It's just semantics in the end, fine, 7.1 with 2 subs.

    I found this post on a different forum, it really sums up, or puts into better words, the points I was trying to make:

    Dick Pierce has been dispelling many audio myths on google groups rec.audio etc for the last couple decades. Makes for enjoyable reading.

    When asked the same question about dual centers and comb filtering, here was his response.:


    quote:
    "The ONLY way possible to avoid comb filtering effects is to have a
    single loudspeaker placed in an anechoic chamber.

    As soon as you introduce multiple sources, whether real or virtual,
    you WILL have comb filtering. (A "virtual" source is a reflection
    of a real source. For example, place a loudspeaker 2 feet above the
    floor: at frequencies where the floor is reflective, which is most
    frequencies, there is an apparent or "virtual" source 2 feet BELOW
    the floor, giving a doublet source with a separation of 4 feet).

    That means that ALL stereo systems, ALL home theater system in ALL
    rooms suffer from pretty massive amounts of comb filtering due to
    path length differences to multiple coherent sources. It is completely
    unavoidable in practice.

    That being said, it can be argued that the more real sources you have,
    especially sources that are placed different distances apart from room
    boundaries and each other, the more evenly distributed the nulls of
    the comb filtering will be and thus the smoother the overall response
    due to comb filtering will be.

    I think it can be argued, that, at its WORST, and additional center
    channel speaker will NOT make things worse, and may potentially make
    things better.

    The arguments of the people you cite might be strictly true in a
    first-order analysis but fail or at least loose much of their strength
    when the entire boundary and multiple source considerations are taken.
    One can further suggest that two competely coherent sources, placed
    vertically, restrict radiation in the vertical plane, but not in the
    horizontal plane, and thus can arguably REDUCE comb filtering effects
    due to interference effects with the virtual sources under the floor
    and above the ceiling.

    Another point: the demon "comb filtering" itself is something of a red
    herring in reality. Comb filtering can only occur if the size of the
    radiating sources are very small compared to the wavelength while at
    the same time the separation between them is large compared to the
    wavelength. For something like the dual center-channel approach,
    the ONLY frequencies where this is relevant is high frequencies, and,
    within the listening window, the path length differences are simply
    not big enough to cause the problem AND where they are big enough,
    you're sufficiently far enough off axis that you don't care.

    I believe the comb-filter argument against using dual center-channel speakers is specious and unsupportable."



    I Googled "Dick Pierce" and found he is a long time professional in the audio industry, not just "some guy on a forum".

    With obvious arguments on both sides, I believe this is opinion and not fact. My opinion is that done correctly, as I believe I have, it can work well.

    We will just have to agree to disagree. You can feel whatever you want about me as I enjoy my HT.

    Brad

    P.S. My "rude" comment was referring mostly to "PeruvianSkies"
    Last edited by brad1138; 07-31-2010 at 09:58 PM.
    Home Theater:

    Emotiva UMC-200, Citation 5.1 running Mirage M-3SIs, Harman Kardon signature 2.1 running Mirage M-CSI (center) & 4x BIC V-52 (surrounds), 2 x Velodyne ULD 15 Series II Sub & Amp, PS3, PS4, XBOX 1, 2x Adcom ACE-515, Vizio E-701B-3

    2.0 setup:

    Schiit Freya Tube PreAmp, Citation 5.1, Mirage M3SIs, Onkyo DV-CP702 (CD transport), Schiit Modi Multibit DAC.





  25. #25
    ISCET CET, FCC CTT, USITT Dual-500's Avatar
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    A few decent replies and a lot of misplaced theory.

    Never in the naysayers arguments did I see a hint of nearfield size and it's overall effect on reverberation control of the environment. EDIT: The post above is the real deal.

    Having "Doubled up" so to speak on the centers has increased the near field radiation at the source.. Yea all the cancellations and other crap happens, but the room does a job on net performance anyway. We aren't listening in half space test lab, it's your viewing area. The overall performance of the environment is what really matters.

    So, let's lighten a little on theoretical perfection. Comb filtering and it's effects are something to consider in design for sure. But not an absolute. If it were, the argument would render the very concept of STEREO OBSOLETE as well as center/right/left/rear/side.

    Having increased the near field radiation will do a few beneficial things. The primary being the system will handle room reverberation better. i.e. standing waves. And, in a theatre system that's real important - the more standing waves in a given envrionment, the more it matters.

    This is probably why you like the way it sounds.

    With theatre the dynamic range on a peak to average is probably much wider than music would be. Lots of quieter vocal passages, so near field size at the source plays into the equation even more than with a pure music reproduction system. During the times when it's pure dialog from the center at mid to low levels, the ability of the system to control room reverberation is at it's lowest. Increasing this at the source, as you have done is the best soution.

    Let me give you an example. Suppose we were to setup a PA in a typical high school gymnasium. Let's say wireless mics for awards presentation and the game announcer, mics for officials making the game calls and reinforcement for a live band playing the post game dance, Not enough PA, there will be nothing but mic feedback and echo from room reverberation. Speech will be unintelligable and the band will sound like crap. Now, put in a LARGER PA system, with gain capability to push the reverberant field to beyond the listeners (i.e. control the environment) and you will be able to understand the announcer and the band will sound good.

    Same basic concepts apply to your listening room on a little different scale.

    Psychoacoustically speaking, the larger the near field at the source, the larger the percieved size or stage will be. And in theatre applications that's real nice.

    In my setup, I'm giving honest consideration to doing away with the center all together and using phantom mode where the center channel signal information is routed to the L&R mains. Uh oh, then I'll have inherent comb filtering and lobing issues. Oh well! Life it full of compromises.

    Cheers!

    Let the shark attacks commence.
    Last edited by Dual-500; 07-31-2010 at 01:44 PM.

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