SDA SRS How do they work ?

redbullet
redbullet Posts: 66
edited November 2007 in Vintage Speakers
Ok, Like to know how the SDA SRS work. I can kind of grasp the older versions with the muti-conductor cable, But how do the single wire versions?.
If memory serves me correctly, The originals would feed the left channel out of phase to the right channel and visa versa. But is this true of the late single cable versions.:confused:
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  • dorokusai
    dorokusai Posts: 25,577
    edited November 2007
    SDA's all work the same.

    Multi-Conductor cable?
    CTC BBQ Amplifier, Sonic Frontiers Line3 Pre-Amplifier and Wadia 581 SACD player. Speakers? Always changing but for now, Mission Argonauts I picked up for $50 bucks, mint.
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  • redbullet
    redbullet Posts: 66
    edited November 2007
    dorokusai wrote: »
    SDA's all work the same.

    Multi-Conductor cable?


    If I remember the early ones had three pins later used both wires Then the last pin only.
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  • dorokusai
    dorokusai Posts: 25,577
    edited November 2007
    There are some odd connections on the early models but it's not important. Traditionally only one of those "conductors" or terminals is neccesary. The blade/blade connector has two terminals but only one is used, the other is for support of the cable, at the loudspeaker. The pin/blade is the same way, the pin being the active connection....the blade being the supporting terminal.

    I can't comment on the construction of the DIN socket model, as I simply don't remember. One of the other Polkies can answer that.
    CTC BBQ Amplifier, Sonic Frontiers Line3 Pre-Amplifier and Wadia 581 SACD player. Speakers? Always changing but for now, Mission Argonauts I picked up for $50 bucks, mint.
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  • schwarcw
    schwarcw Posts: 7,335
    edited November 2007
    Here's a link to a SDA "White Paper" Matthew Polk wrote. Look Here
    Carl

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  • lightman1
    lightman1 Posts: 10,788
    edited November 2007
    Thanks Carl. Good read there for anyone who wants to know the idea for SDA came about.
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  • redbullet
    redbullet Posts: 66
    edited November 2007
    schwarcw wrote: »
    Here's a link to a SDA "White Paper" Matthew Polk wrote. Look Here

    Good reading still just trying to figure out how they do left right information across one wire.
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  • Joe08867
    Joe08867 Posts: 3,919
    edited November 2007
    The Din Socket worked the same also. Only one wire carries the signal. My guess is they used the Din instead of making there own plug to save early developement costs or something like that. This way if it didn't take off they would have lost more money.

    I have the Din style connector on my original series SDA2's.
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  • dorokusai
    dorokusai Posts: 25,577
    edited November 2007
    Thanks Joe.
    CTC BBQ Amplifier, Sonic Frontiers Line3 Pre-Amplifier and Wadia 581 SACD player. Speakers? Always changing but for now, Mission Argonauts I picked up for $50 bucks, mint.
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  • schwarcw
    schwarcw Posts: 7,335
    edited November 2007
    lightman1 wrote: »
    Thanks Carl. Good read there for anyone who wants to know the idea for SDA came about.

    You're welcome!
    Carl

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  • lightman1
    lightman1 Posts: 10,788
    edited November 2007
    redbullet wrote: »
    Good reading still just trying to figure out how they do left right information across one wire.

    Common ground to both speakers from the amp (?)
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  • DarqueKnight
    DarqueKnight Posts: 6,765
    edited November 2007
    redbullet wrote: »
    Good reading still just trying to figure out how they do left right information across one wire.

    The same way a road can have traffic traveling in two directions simultaneously. I posted an explanation for this a while back. You should be able to find it with the search function.
    Proud and loyal citizen of the Digital Domain and Solid State Country!
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  • redbullet
    redbullet Posts: 66
    edited November 2007
    DarqueKnight wrote: »
    The same way a road can have traffic traveling in two directions simultaneously. I posted an explanation for this a while back. You should be able to find it with the search function.

    Can't seem to find that post, I would like to read it.
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  • DarqueKnight
    DarqueKnight Posts: 6,765
    edited November 2007
    See post #9 of this thread:

    How Does SDA Work?

    Post #6 of the thread has a link to a white paper that explains SDA in more detail. Refer to pages 2-6 of the white paper.
    Proud and loyal citizen of the Digital Domain and Solid State Country!
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  • redbullet
    redbullet Posts: 66
    edited November 2007
    DarqueKnight wrote: »
    See post #9 of this thread:

    How Does SDA Work?

    Post #6 of the thread has a link to a white paper that explains SDA in more detail. Refer to pages 2-6 of the white paper.

    Thanks, BTW guess the Compendium is no long available?
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  • DarqueKnight
    DarqueKnight Posts: 6,765
    edited November 2007
    The Compendium has passed on into audio lore.
    Proud and loyal citizen of the Digital Domain and Solid State Country!
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  • SDA SRS 1.2
    SDA SRS 1.2 Posts: 255
    edited November 2007
    DarqueKnight wrote: »
    The Compendium has passed on into audio lore.

    My first edition sits on top of my left speaker and the second sits on the right for handy reference - I swear they make the 1.2's sound better! :)
    Main System: Polk SDA SRS 1.2 Speakers, Sunfire Signature 600~two Amp, Carver C-16 Preamp, Carver TX-11b Tuner, Marantz 6350Q TT, Philips CDR-775 Recorder, Teac V-707RX Cassette Deck, Signal Cable Double Run Speaker Cable

    Upstairs Den: Marantz 2325 Receiver, Marantz 5220 Cassette Deck, Marantz HD-880 Speakers, Marantz 6370Q TT

    Exercise (Kabuki speaker) Room: Kenwood KR-9600 Receiver, Pioneer CS-99a Speakers, Sansui SP-X9000 Speakers (not pretty, but LOUD! :) )
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  • Marty913
    Marty913 Posts: 760
    edited November 2007
    dorokusai wrote: »
    There are some odd connections on the early models but it's not important. Traditionally only one of those "conductors" or terminals is neccesary. The blade/blade connector has two terminals but only one is used, the other is for support of the cable, at the loudspeaker. The pin/blade is the same way, the pin being the active connection....the blade being the supporting terminal.

    I can't comment on the construction of the DIN socket model, as I simply don't remember. One of the other Polkies can answer that.

    So now I'm confused. My SDA2's (blade/blade) have two wires (blue, white) from the SDA connector to the Dimensional crossover board, and then onward to the dimensional tweeter and dimensional mid. The white is ground so the blue is carrying the difference signal. Right? Could I then assume that the "ground" is needed to complete the difference circuit path and that the second blade is not just for support (in which case it would not need any wire connected to it) but is required to ensure common ground between the two SDA crossovers. :confused:
    Sony 60'' SXRD 1080p
    Amp = Carver AV-705THX 5-Channel
    Processor = NAD T747
    Panasonic BD35 Blu-Ray
    Main = SDA-1C Studio with RD0s, spikes, XO rebuild, rings, I/C upgrade
    Center=Polk CS10, Surround = Athena Dipoles, Sub= Boston 12HO
    Music/Video Streaming = Netgear NEO550
    TT = Audio Technica
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  • DarqueKnight
    DarqueKnight Posts: 6,765
    edited November 2007
    Marty913 wrote: »
    So now I'm confused. :confused:

    In most blade/blade SDA's, both the wide and narrow blade (called pin #1 and pin #2 on the schematics)carry a signal.

    In the pin/blade SDA's, only the pin carries a signal and the blade only provides mechanical support. However, the blade connect in pin/blade models is used for testing and diagnostic purposes. The pin/blade cable does contain two wires, but they are both connected to the pin. There is no electrical connectivity between the blades of the pin/blade cable.

    When Polk was transitioning from the blade/blade to the pin/blace cable, some models that were designed to use the pin/blade cable, such as the SDA 1C and the SDA 2B, were retrofitted with blade/blade SDA cable sockets and cables. This was done in order to use up parts stock.

    In the retrofitted SDA 1C and SDA 1B models, the electrical connection was the same as with the pin/blade cable, in that only one blade (the small blade, pin #2) was active.

    If you go to the vintage speakers section of the forum and refer to the SDA schematics for the SDA 2A, SDA 2B (blade/blade) and SDA 2B (pin/blade) you will note the following:

    1. On the SDA 2A schematic, the wiring connections for the the SDA cable are different at each speaker and thus each blade carries a signal.

    2. On the SDA 2B blade/blade schematic, only the small blade (corresponding to the pin in pin/blade cables) has connectivity.

    3. On the SDA 2B pin/blade schematic, only the pin has connectivity.
    Proud and loyal citizen of the Digital Domain and Solid State Country!
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  • DarqueKnight
    DarqueKnight Posts: 6,765
    edited November 2007
    Marty913 wrote: »
    Could I then assume that the "ground" is needed to complete the difference circuit path and that the second blade is not just for support (in which case it would not need any wire connected to it) but is required to ensure common ground between the two SDA crossovers.

    That is correct.

    In the pin/blade cable, the ground connection is provided through the common ground path in the amplifier.
    Proud and loyal citizen of the Digital Domain and Solid State Country!
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  • Marty913
    Marty913 Posts: 760
    edited November 2007
    DarqueKnight wrote: »
    That is correct.

    In the pin/blade cable, the ground connection is provided through the common ground path in the amplifier.

    Thanks DarqueKnight, as always you have been very helpful. I know this isn't "world-affecting" stuff and I'm usually lost when it comes to electrical engineering but I was scrounging around inside my 2's over the weekend (obviously no life at all :o). I saw the two connectors and remembered the posts about only one wire needed for SDA. I figured since it was ground they must have used the amp-ground in later models. Might be why A-I doesn't work with true blade-blade. :p

    Regardless, it's worth documenting here that "some" SDA's require ground between the two dimensional crossovers. I doubt any damage would occur but I'm pretty sure there wouldn't be any SDA affect. :eek:

    Thanks again.
    Sony 60'' SXRD 1080p
    Amp = Carver AV-705THX 5-Channel
    Processor = NAD T747
    Panasonic BD35 Blu-Ray
    Main = SDA-1C Studio with RD0s, spikes, XO rebuild, rings, I/C upgrade
    Center=Polk CS10, Surround = Athena Dipoles, Sub= Boston 12HO
    Music/Video Streaming = Netgear NEO550
    TT = Audio Technica
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  • John in MA
    John in MA Posts: 1,010
    edited November 2007
    SDA SRS 1.2 wrote: »
    My first edition sits on top of my left speaker and the second sits on the right for handy reference - I swear they make the 1.2's sound better! :)

    You must have the version with the magic beach rocks sewn into the cover. :)
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  • Marty913
    Marty913 Posts: 760
    edited November 2007
    John in MA wrote: »
    You must have the version with the magic beach rocks sewn into the cover. :)

    And all of his CD's have green magic marker stripes on them.
    Sony 60'' SXRD 1080p
    Amp = Carver AV-705THX 5-Channel
    Processor = NAD T747
    Panasonic BD35 Blu-Ray
    Main = SDA-1C Studio with RD0s, spikes, XO rebuild, rings, I/C upgrade
    Center=Polk CS10, Surround = Athena Dipoles, Sub= Boston 12HO
    Music/Video Streaming = Netgear NEO550
    TT = Audio Technica
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  • VSAT88
    VSAT88 Posts: 1,257
    Marty913 wrote: »
    John in MA wrote: »
    You must have the version with the magic beach rocks sewn into the cover. :)

    And all of his CD's have green magic marker stripes on them.

    Old Old Old thread here but they must also be painted black ^ Sorry, could not help myself.
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