Testing the drivers on 2.3

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  • FTGV
    FTGV Posts: 3,649
    edited October 2010
    schwarcw wrote: »
    Please explain that "R-L L-R signal which is out of phase" how is that done if the speaker itself is not generating the signal by being out of phase. I don't understand how it can be both ways???:confused:
    When you connect the SDA cable to each speaker it connects the dimensional drivers to the amplifier in a way that extracts the difference or out phase R-L signal.The dimensional drivers are wired in phase but because they recieve the out of phase R-L signal, crosstalk cancelation can occur.If you remove the SDA cable the dimensional drivers should still be operational,as they are also fed the <100hz bass from the stereo signal.In this way they augment the stereo array drivers,if they were wired out of phase bass cancelation would occur.


    Is that clear as mud?
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  • erniejade
    erniejade Posts: 6,321
    edited October 2010
    Correct on the celing. It sucks. That is why I am thinking of partially finishing off the basement and cut it in half. Or close to half so it can have an odd number on one wall.
    Klipsch The Nines, Audioquest Thunderbird Interconnect, Innuos Zen MK3 W4S recovery, Revolution Audio Labs USB & Ethernet, Border Patrol SE-I, Audioquest Niagara 5000 & Thunder, Cullen Crossover II PC's.
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  • Schurkey
    Schurkey Posts: 2,102
    edited October 2010
    erniejade wrote: »
    Correct on the celing. It sucks. That is why I am thinking of partially finishing off the basement and cut it in half. Or close to half so it can have an odd number on one wall.
    "Half" won't do you much good.

    Ideally, none of the room dimensions will be multiples/factors of each other. There was a thread about this a week or three ago; and the general consensus was "golden ratio".

    You'll want to investigate room boundary treatments. Could make a HUGE difference in the sound.

    There's pretty much nothing you can do about a null; but you can knock down the peaks with room treatments (somewhat frequency-dependent--high frequencies seem to be easier to deal with than lows.)

    Don't forget that speaker placement and listener placement can make a big difference, too. Don't sit in a "peak" or a "null"!
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  • schwarcw
    schwarcw Posts: 7,338
    edited October 2010
    FTGV wrote: »
    When you connect the SDA cable to each speaker it connects the dimensional drivers to the amplifier in a way that extracts the difference or out phase R-L signal.The dimensional drivers are wired in phase but because they recieve the out of phase R-L signal, crosstalk cancelation can occur.If you remove the SDA cable the dimensional drivers should still be operational,as they are also fed the <100hz bass from the stereo signal.In this way they augment the stereo array drivers,if they were wired out of phase bass cancelation would occur.


    Is that clear as mud?

    LOL! Yes it still is clear as mud. What I don't understand is the "in a way that extracts the difference or out phase R-L signal". I glanced at the SDA "White Paper" and it also is not specific. However, I do recal the Matt Polk story about how the SDA theory came to him as he watched ripples in water. For the for the cross talk cancellation to occur I am at a loss to understand why it happens other than simple wave cancellation as shown in the graph:

    Wavecancellation.gif
    Carl

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  • FTGV
    FTGV Posts: 3,649
    edited October 2010
    schwarcw wrote: »
    What I don't understand is the "in a way
    It is done by connecting the negative terminals of the dimensional drivers together instead of to amplifer ground.At the same time the dimensional drivers are connected and operate in parallel with the stereo drivers below 100hz or so.
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  • erniejade
    erniejade Posts: 6,321
    edited October 2010
    Wow. Where is this thread at?? I will do a search. So no matter what I make the room into, it won't help? When I say in half or an odd demintion on one wall like 10 x 13 or 13 x 18. Would be with carpet and wall treatments to help make it a bit more dead down
    there.

    Your right about sitting in the peak parts though talk about getting thumped out!!!!
    Klipsch The Nines, Audioquest Thunderbird Interconnect, Innuos Zen MK3 W4S recovery, Revolution Audio Labs USB & Ethernet, Border Patrol SE-I, Audioquest Niagara 5000 & Thunder, Cullen Crossover II PC's.
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  • DarqueKnight
    DarqueKnight Posts: 6,765
    edited October 2010
    schwarcw wrote: »
    Please explain that "R-L L-R signal which is out of phase" how is that done if the speaker itself is not generating the signal by being out of phase. I don't understand how it can be both ways???:confused:

    Phase shifts can be generated mechanically by wiring speakers out of phase or generated electronically by the crossover circuit. The phase inversion techniques employed in SDA's is similar to those employed by amplifiers which electronically invert phase.

    The June 1984 Audio magazine article by Matthew Polk provides a more mathematically rigorous explanation of SDA than the "SDA Surround Technology White Paper".

    From page 38 of the Audio magazine article:

    "In order to cancel the crosstalk, a phase-inverted version of the sound could be acoustically delayed to arrive at the proper ear at the precise time to cancel the crosstalk signal."

    From page 40 of the Audio magazine article:

    "The left and right speaker cabinets were interconnected with a cable to provide the components of the stereo difference signal to the dimensional drivers, and a complex crossover matrix was designed to provide the correct frequency response for each array as well as the critically important phase relationships between them."

    The complete mathematical discussion of SDA's phase inversion mechanism is discussed in pages 35-40 of the Audio magazine article.

    Carl, if I recall correctly, you have SDA 1 C's? The wiring diagrams, and crossover schematic, for the 1 C are posted in the SDA schematics section of the forum.
    Proud and loyal citizen of the Digital Domain and Solid State Country!
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  • schwarcw
    schwarcw Posts: 7,338
    edited October 2010
    DarqueKnight wrote: »
    Carl, if I recall correctly, you have SDA 1 C's? The wiring diagrams, and crossover schematic, for the 1 C are posted in the SDA schematics section of the forum.

    Hi Raife!

    My SDA's are the 2.3's. The SDA drivers are clearly moving out of phase or opposite the movement of all the other drivers. What's curious is that my SDA effect is enormous!! So, could it be this out of phase wiring is "enhancing" the effect. I am going to try and reverse the phase of the SDA drivers to see what happens. Does it matter if I do it at the crossover board or the speaker terminals?

    Regards,
    Carl

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  • DarqueKnight
    DarqueKnight Posts: 6,765
    edited October 2010
    I've never done the "battery test", so I don't know if what you are experiencing is normal. I wouldn't be surprised if applying a DC voltage (0 Hz) would cause weird behavior.:smile:

    Before you start disconnecting drivers, you could verify that everything is wired properly per the wiring diagrams and schematic posted in the SDA schematics thread.

    I am not aware of a case when drivers were mis-wired, yet the SDA effect was enormous.
    Proud and loyal citizen of the Digital Domain and Solid State Country!
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  • schwarcw
    schwarcw Posts: 7,338
    edited October 2010
    DarqueKnight wrote: »
    I've never done the "battery test", so I don't know if what you are experiencing is normal. I wouldn't be surprised if applying a DC voltage (0 Hz) would cause weird behavior.:smile:

    Before you start disconnecting drivers, you could verify that everything is wired properly per the wiring diagrams and schematic posted in the SDA schematics thread.

    I am not aware of a case when drivers were mis-wired, yet the SDA effect was enormous.

    Thanks for the guidance. It is curious. If these were wired improperly, it would suggest my SDA effect would be comprimised. This thread was originally started by the OP as he noticed a lack of bass, which is not a problem for me either. I will check the wiring diagram. It's interesting that you noted the potential of weird behavior because of the DC input. Any more thoughts on that?

    I won't be able to jump into it before next weekend at the earliest. I will report back on this.

    For other SDA owners, try this simple test and report back your findings.

    Regards,
    Carl

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  • FTGV
    FTGV Posts: 3,649
    edited October 2010
    For determining phase go by the wiring diagrams not by what you see with the battery.The schem for the 2.3 show all drivers to be connected with normal polarity.Save the battery test for finding a non working woofer.
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  • zarrdoss
    zarrdoss Posts: 2,562
    edited October 2010
    yeah listen to this guy , he really seems to know what he is talking about^^^^
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  • Schurkey
    Schurkey Posts: 2,102
    edited October 2010
    FTGV wrote: »
    For determining phase go by the wiring diagrams not by what you see with the battery.The schem for the 2.3 show all drivers to be connected with normal polarity.Save the battery test for finding a non working woofer.
    I don't understand.

    If all MW drivers are connected in "normal" polarity, why wouldn't they all move the same direction in response to a DC impulse?

    Seems to me that the battery test is valid for polarity testing and for finding non-working drivers.
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  • zarrdoss
    zarrdoss Posts: 2,562
    edited November 2010
    thats one of the things I don't like about this forum, too many people think the way they would do something is the Gospel.
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  • analog97
    analog97 Posts: 328
    edited November 2010
    What's curious is that my SDA effect is enormous!!/QUOTE]

    Carl,

    I bear witness to your HUGE soundstage, especially the lateral projection. I have never heard a pair of SDA's do what yours do!! DON'T TOUCH ANYTHING!! Bury your curiosity in the backyard. You should charge me an admission fee on my next visit. Can't wait to hear Morph The Cat. :smile:
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  • FTGV
    FTGV Posts: 3,649
    edited November 2010
    Schurkey wrote: »
    I don't understand.

    If all MW drivers are connected in "normal" polarity, why wouldn't they all move the same direction in response to a DC impulse?
    Intuitively thats what one would expect,but since his are'nt yet they seem to be sound correct then defer to the schematic not what you see with the battery.
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  • schwarcw
    schwarcw Posts: 7,338
    edited November 2010
    analog97 wrote: »
    What's curious is that my SDA effect is enormous!!/QUOTE]

    Carl,

    I bear witness to your HUGE soundstage, especially the lateral projection. I have never heard a pair of SDA's do what yours do!! DON'T TOUCH ANYTHING!! Bury your curiosity in the backyard. You should charge me an admission fee on my next visit. Can't wait to hear Morph The Cat. :smile:

    Hi Larry!

    That's what I'm curious about. If my SDA drivers are out of phase this may be an enhancement.

    I was thinking of coming over and testing your's with a battery LOL!


    I need you to come over for a listen. I'll call you tomorrow evening.
    Carl

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