sda-srs (originals) troubleshooting help needed

paingod
paingod Posts: 31
edited July 2011 in Vintage Speakers
I was getting ready to lay out the $400 for the rdo-194 tweeter upgrade, when I discovered an issue with my sda-srs (originals).

im getting weaker output on my right speaker and its lacking the bass responce of the Left speaker. only really noticible when I more the balance all the way left and right

I dont have the manual but here are the few things ive tried.

1. checked all connections (good)
2 switched amp to a mono signal (no effect)
3 disconnected the sda cable. (no effect)
4 ran left & right signal to the left (no effect)
5 ran left and right signal to the right (no effect)

nothing Ive tried has made any difference to the sound im hearing!
ive check the reading at the posts, both are at 4.5 Ohm.

I suspect some of the bass drivers arent working & possible a tweeter is going bad, but I cant really tell as all the drivers move in the sealed cabinet (weither their firing or not!) and the tweeters are so close I cant identify a possible bad one by ear.

so before I pull every speaker out and check them individually???
does anyone have any tips to save me some time trying to identify the problem? (im assuming it has to be a bad driver or 2? I believe some of these are wired in parallel?) or a problem in the crossover (which wouldnt make it a bad time for the upgrade caps!) I dont know what else to try?
Post edited by paingod on
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  • heiney9
    heiney9 Posts: 25,165
    edited July 2011
    There is a troubleshooting guide here, I'd start with this. Others will chime in with ideas I'm sure.

    http://www.polkaudio.com/forums/showpost.php?p=1297248&postcount=9
    "Appreciation of audio is a completely subjective human experience. Measurements can provide a measure of insight, but are no substitute for human judgment. Why are we looking to reduce a subjective experience to objective criteria anyway? The subtleties of music and audio reproduction are for those who appreciate it. Differentiation by numbers is for those who do not".--Nelson Pass Pass Labs XA25 | EE Avant Pre | EE Mini Max Supreme DAC | MIT Shotgun S1 | Pangea AC14SE MKII | Legend L600 | BlueSound Node 3 - Tubes add soul!
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  • OldmanSRS
    OldmanSRS Posts: 419
    edited July 2011
    A quick, non-invasive test to check the mw's is to momentarily connect a 1.5V battery to each main input and observe the cones. All should move in or out at the same time and in the same direction. The sw's should move opposite the mw's. Compare L/R speakers against each other.
    '65 427 Shelby Cobra
    '72 Triumph TR-6
    __________________
    '88 Polk SDA SRS 1.2, with upgraded XO caps and Erse SDA inductors
    '86 Polk SDA CRS+
    '84 Polk Monitor 10A (Peerless tweeters)
    '05 HSU VTF-3 Sub (Original OEM)
    '20 HSU VTF-3 Sub (three more, 100% cloned)
    '93 Carver TFM-35
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    '88 Adcom GFA-555 (a second one upgraded/restored)
    '05 Onkyo DV-555 media
    '89 Fosgate 360 Digital Space Matrix
    '89 Fosgate 360 Digital Space Matrix, internal surround amp bridged to drive only a center channel
    '91 Kenwood Basic M1D Amp
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    One PGA2310 based custom built remote volume control
    Four Polk T-15's
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  • paingod
    paingod Posts: 31
    edited July 2011
    OldmanSRS wrote: »
    A quick, non-invasive test to check the mw's is to momentarily connect a 1.5V battery to each main input and observe the cones. All should move in or out at the same time and in the same direction. The sw's should move opposite the mw's. Compare L/R speakers against each other.

    Sw? Mw??

    "main input"? Do you mean binding posts?
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  • paingod
    paingod Posts: 31
    edited July 2011
    OldmanSRS wrote: »
    A quick, non-invasive test to check the mw's is to momentarily connect a 1.5V battery to each main input and observe the cones. All should move in or out at the same time and in the same direction. The sw's should move opposite the mw's. Compare L/R speakers against each other.

    You just gave me a great idea!

    I grabbed an iPhone tone generator app.
    And just ran a 30hz tone through an extra input on my amp!!

    It appears none of the sda drivers on the right are firing.
    (and the tweeter on top is "faintly" acting like it wants to play that tone??)
    Also both speakers do not balance out without the cable. (left is still weaker)
    So I really haven't gotten much farther but at least I'll know which drivers to pull 1st???

    It doesent really get me anywhere
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  • fiero11
    fiero11 Posts: 23
    edited July 2011
    I know this is fundemental, but my original instruction book for my SDA's said to confirm the speaker polarity and phase for the problem you have. Have they been disconnected or anything? Good luck with your troubleshooting.
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  • heiney9
    heiney9 Posts: 25,165
    edited July 2011
    SDA drivers don't play 30Hz tones, so even if there wasn't an issue you wouldn't know. Did you read the trouble shooting guide I linked to. They suggest measurements with VOM. That's one of the best ways to trouble shoot, visualizing it doesn't get it done. There is no tweeter in history that will play a 30Hz test tone, so either you made a typo or you don't know what you are doing.

    H9
    "Appreciation of audio is a completely subjective human experience. Measurements can provide a measure of insight, but are no substitute for human judgment. Why are we looking to reduce a subjective experience to objective criteria anyway? The subtleties of music and audio reproduction are for those who appreciate it. Differentiation by numbers is for those who do not".--Nelson Pass Pass Labs XA25 | EE Avant Pre | EE Mini Max Supreme DAC | MIT Shotgun S1 | Pangea AC14SE MKII | Legend L600 | BlueSound Node 3 - Tubes add soul!
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  • Joe08867
    Joe08867 Posts: 3,919
    edited July 2011
    Do we have another guy that refuses to listen?

    Heiney9 linked the troubleshooting guide in his first post.
    Have you tried any of that?

    A 30hz tone is way to low for the speakers. If you want to send a tone make it a full sweep not a single extremely low tone like 30hz.
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  • heiney9
    heiney9 Posts: 25,165
    edited July 2011
    I did what I could Joe, I doubt he'll call Polk CS either since they are evil and can't be trusted since they supposedly gave him the wrong replacement driver info. :smile::rolleyes:
    "Appreciation of audio is a completely subjective human experience. Measurements can provide a measure of insight, but are no substitute for human judgment. Why are we looking to reduce a subjective experience to objective criteria anyway? The subtleties of music and audio reproduction are for those who appreciate it. Differentiation by numbers is for those who do not".--Nelson Pass Pass Labs XA25 | EE Avant Pre | EE Mini Max Supreme DAC | MIT Shotgun S1 | Pangea AC14SE MKII | Legend L600 | BlueSound Node 3 - Tubes add soul!
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  • Joe08867
    Joe08867 Posts: 3,919
    edited July 2011
    Where are they coming from lately. Is it the water? global warming? what?
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  • heiney9
    heiney9 Posts: 25,165
    edited July 2011
    I figured it out, see this thread

    http://www.polkaudio.com/forums/showthread.php?p=1611732#post1611732

    He's been using McIntosh mono blocks with his SDA's............I'm willing to bet the farm he damaged the SDA's since you can't use mono's (which by definition are NOT common ground) with SDA's unless you use the AI-1 cable. SRS's can't use that cable. SDA's can't be run with non-common ground amps without damaging one or the other or both.

    H9
    "Appreciation of audio is a completely subjective human experience. Measurements can provide a measure of insight, but are no substitute for human judgment. Why are we looking to reduce a subjective experience to objective criteria anyway? The subtleties of music and audio reproduction are for those who appreciate it. Differentiation by numbers is for those who do not".--Nelson Pass Pass Labs XA25 | EE Avant Pre | EE Mini Max Supreme DAC | MIT Shotgun S1 | Pangea AC14SE MKII | Legend L600 | BlueSound Node 3 - Tubes add soul!
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  • paingod
    paingod Posts: 31
    edited July 2011
    Wow these 3 threads are getting mixed together!
    I won't repost the same response
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  • paingod
    paingod Posts: 31
    edited July 2011
    After taking out (and checking) all the tweets and drivers were ok!
    Then I pulled the crossover, and everything there checked out fine too?

    (I was thinking bad sda cable??)

    But my buddy suggested switching amps.. (same problem)

    Then I switched pre-amps.....BINGO!
    right channel Back to 100%!

    All that work for what will most likely turn out to
    Be a dirty pre-amp!!

    But NOW I've kinda got the bug now for the crossover recap
    (and new tweets!). what the hell it's only money!
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  • paingod
    paingod Posts: 31
    edited July 2011
    heiney9 wrote: »
    I figured it out, see this thread

    http://www.polkaudio.com/forums/showthread.php?p=1611732#post1611732

    He's been using McIntosh mono blocks with his SDA's............I'm willing to bet the farm he damaged the SDA's since you can't use mono's (which by definition are NOT common ground) with SDA's unless you use the AI-1 cable. SRS's can't use that cable. SDA's can't be run with non-common ground amps without damaging one or the other or both.

    H9

    Heiney, I guess I won the bet! when can I see my new farm?
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