RTA 12B refurbish

FestYboy
FestYboy Posts: 3,861
edited May 2017 in Vintage Speakers
Recently purchased a pair of 12Bs with the nude mounted tweeter, but they need some love. Particularly the tweeter mounting plate, and one of the coils. They were demoed before purchasing, and there didn't seem to be any detrimental affects to the sound, but esthetically, things are askew. Would someone be so kind as to point me in the right direction to obtain the correct coil and standoffs? Also, what's the most popular way to post pics on this forum? I'm used to using photobucket, but if there is a more direct method, I'm all ears.

Thanks!
Arty
Post edited by [Deleted User] on
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  • txcoastal1
    txcoastal1 Posts: 13,283
    i81hah2amla8.jpg
    2-channel: Modwright KWI-200 Integrated, Dynaudio C1-II Signatures
    Desktop rig: LSi7, Polk 110sub, Dayens Ampino amp, W4S DAC/pre, Sonos, JRiver
    Gear on standby: Melody 101 tube pre, Unison Research Simply Italy Integrated
    Gone to new homes: (Matt Polk's)Threshold Stasis SA12e monoblocks, Pass XA30.5 amp, Usher MD2 speakers, Dynaudio C4 platinum speakers, Modwright LS100 (voltz), Simaudio 780D DAC

    erat interfectorem cesar et **** dictatorem dicere a
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  • FestYboy
    FestYboy Posts: 3,861
    edited May 2017
    Awesome sauce.
    Well here they are:
    zhi9c35vqbab.jpg I'll take more critical pix tomorrow of the areas that need attention.

    srbtfy0obo1y.jpg
    9s99mpxdptmw.jpg
    That's the rest of the Polk collection so far, headed to NJ to pick up a pair of RTA 11tl tomorrow.
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  • FestYboy
    FestYboy Posts: 3,861
    Well here they are, my new to me 11Ts (not TL, but low serial number).
    7960y5soo166.jpg
    They need resealed (bleed off box pressure in just over one second), and the upper driver on the left needs the surround replaced due to an odd cut at the 6 o'clock position. But I think I did ok at $160/pr. Thoughts?

    Ok so back to the point at hand... The 12Bs.
    f558owiqadtz.jpg
    pmyd43tgx82k.jpg
    7mggk1m9djoh.jpg

    Yeah so as you can plainly see, I'm illiterate, lol.
    Anywho. As see in the pics, the upper tweeter is clocked to the right, and has a damaged inductor and missing standoffs, the lower is shifted hard to the right.

    Getting the tweets realigned is no big thing, but the inductor and standoffs... Not sure which direction to go with that. Also, does anyone have any detail pics of the tweeter mounting hardware? Some is missing and/or doesn't appear stock. I picked these up for $250 and am not afraid to mod them, so if there are any glaring "must haves" beside dynamat, JB weld and hurricane nuts, please don't hold back.

    Thanks, Arty
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  • Faustin
    Faustin Posts: 1,149
    Probably want to consider rebuilding the crossovers, as the capacitors are well past their prime. Also replace the SL 2000 tweeters with the RDO 194 tweeters that are available from Polk. Much better sounding tweeter. I have an extra pair of RTA 12b tweeter/crossover assemblies if you are interested. Send me a private message if you are.
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  • codycatalist
    codycatalist Posts: 2,662
    Im of no help but MAN do I love those top hats on those speakers!
    Just a dude doing dude-ly things

    "Temptation is the manifestation of desire which equals necessity." - Mikey081057
    " I have always had a champange taste with a beer budget" - Rick88
    "Just because the thread is getting views don't mean much .. I like a good train wreck doesn't mean i want to be in one..." - pitdogg2
    "Those that don't know, don't know that they don't know." - heiney9
    "Audiophiles are the male equivalent of cat ladies." - Audiokarma Member
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  • DaveHo
    DaveHo Posts: 3,515
    The crossover looks like a 12B, but I think the SL2000 only came on the 12C. @geppy1 can probably confirm. At any rate, a complete rebuild of the crossover is in order. Oh, and there is a second crossover inside the cabinet.

    $160 would be top dollar for a pair of RTA11Ts in these parts.
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  • soundfreak1
    soundfreak1 Posts: 3,414
    The board is marked 12"B".
    Main Rig:
    Krell KAV 250a biamped to mid/highs
    Parasound HCA1500A biamped to lows
    Nakamichi EC100 Active xover
    MIT exp 1 ic's
    Perreaux SA33 class A preamp
    AQ kingcobra ic's
    OPPO 83 CDP
    Lehmann audio black cube SE phono pre, Audioquest phono wire (ITA1/1)
    Denon DP-1200 TT. AToc9ML MC cart.
    Monster HTS 3600 power conditioner
    ADS L1590/2 Biamped
    MIT exps2 speaker cable
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  • pitdogg2
    pitdogg2 Posts: 25,441
    soundfreak1 wrote: »
    The board is marked 12"B".

    good eye mister eagle :p
    I also looked at that but you beat me to it.
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  • FestYboy
    FestYboy Posts: 3,861
    Yeah, for some reason at past midnight, I was stuck on 12a in my head. If a mod would be so kind as to correct the error, that'd be awesome.

    As for the caps, I definitely want to swap them out with something more respectable, as for the coils though, I need some guidance. I know they can be replaced, but AFAIK, they don't go bad or age like caps do.

    Faustin, I may take you up on your offer if only to have a spare set so that I can build one and have an original to A/B for fun/testing
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  • Nightfall
    Nightfall Posts: 10,086
    codycatalist wrote: »
    Im of no help but MAN do I love those top hats on those speakers!

    Really? They're the second best Polk's I've ever owned but I thought the top hats were uuuuugly
    afterburnt wrote: »
    They didn't speak a word of English, they were from South Carolina.

    Village Idiot of Club Polk
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  • FestYboy
    FestYboy Posts: 3,861
    DaveHo wrote: »
    $160 would be top dollar for a pair of RTA11Ts in these parts.

    Which parts are those? I'm in SE Pa.

    And speaking of the 11s, what's involved in making them TL spec?
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  • geppy1
    geppy1 Posts: 3,075
    What are the serial numbers on the board and the back cup??
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  • geppy1
    geppy1 Posts: 3,075
    edited May 2017
    Yes those are 12B caps and 12B or early C tweeter holders they just screwed the SL 2000s over the opening Numbers will help me
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  • xschop
    xschop Posts: 5,000
    Is there any way to hide the ugly crossover on that model?
    Don't take experimental gene therapies from known eugenicists.
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  • soundfreak1
    soundfreak1 Posts: 3,414
    7szocesk96x2.jpg
    rwfuemc3hy6c.jpg
    This is what they look like with clarity esa caps.
    Main Rig:
    Krell KAV 250a biamped to mid/highs
    Parasound HCA1500A biamped to lows
    Nakamichi EC100 Active xover
    MIT exp 1 ic's
    Perreaux SA33 class A preamp
    AQ kingcobra ic's
    OPPO 83 CDP
    Lehmann audio black cube SE phono pre, Audioquest phono wire (ITA1/1)
    Denon DP-1200 TT. AToc9ML MC cart.
    Monster HTS 3600 power conditioner
    ADS L1590/2 Biamped
    MIT exps2 speaker cable
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  • Nightfall
    Nightfall Posts: 10,086
    xschop wrote: »
    Is there any way to hide the ugly crossover on that model?

    Yeah, there's top hats that cover the entire top as well as reduce high frequency diffraction with a little ramp.
    afterburnt wrote: »
    They didn't speak a word of English, they were from South Carolina.

    Village Idiot of Club Polk
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  • xschop
    xschop Posts: 5,000
    Those would be trick with an RDO tweeter housing reminiscent of a B&W
    Don't take experimental gene therapies from known eugenicists.
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  • FestYboy
    FestYboy Posts: 3,861
    geppy1 wrote: »
    What are the serial numbers on the board and the back cup??

    As soon as I get home from this job, I'll post them up. Got any pics of what they should look like unmolested?
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  • FestYboy
    FestYboy Posts: 3,861
    Was just looking at the schematics for the 12b.
    The tweeter is reverse polarity??? That doesn't seem right.
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  • pitdogg2
    pitdogg2 Posts: 25,441
    FestYboy wrote: »
    Was just looking at the schematics for the 12b.
    The tweeter is reverse polarity??? That doesn't seem right.

    Its right, iirc the signal gets reversed in the crossover and reversing at the tweeter corrects that.
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  • codycatalist
    codycatalist Posts: 2,662
    Nightfall wrote: »
    codycatalist wrote: »
    Im of no help but MAN do I love those top hats on those speakers!

    Really? They're the second best Polk's I've ever owned but I thought the top hats were uuuuugly

    I love the look of the stand alone tweeter/cross over showing and the cloth top hats. I don't know what specifically about it but I just can't get enough (cue Depeche Mode?).
    Just a dude doing dude-ly things

    "Temptation is the manifestation of desire which equals necessity." - Mikey081057
    " I have always had a champange taste with a beer budget" - Rick88
    "Just because the thread is getting views don't mean much .. I like a good train wreck doesn't mean i want to be in one..." - pitdogg2
    "Those that don't know, don't know that they don't know." - heiney9
    "Audiophiles are the male equivalent of cat ladies." - Audiokarma Member
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  • FestYboy
    FestYboy Posts: 3,861
    geppy1 wrote: »
    What are the serial numbers on the board and the back cup??

    As requested:
    db22zq69wjak.jpg
    oc7m2roa8w3x.jpg
    j403zp4xfzgs.jpg
    yflmiivcdvpq.jpg

    Also, can you tell me more about these 11Ts?
    huzfut91fqld.jpg
    41d9s9u6038y.jpg
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  • pitdogg2
    pitdogg2 Posts: 25,441
    What do you need to know about the RTA11t ? great speakers.
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  • FestYboy
    FestYboy Posts: 3,861
    Well, given their low serial number, there was a question as to their vintage (PO claims 1990), just want to verify. I'm assuming they have the SL 2000 tweeter?

    In that same thought, I'm looking at a pair of 11TLs for $100 as well.
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  • FestYboy
    FestYboy Posts: 3,861
    Man I'm reading my posts... I need to organize my thoughts and threads better, lol. Too many different models in the same thread.
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  • pitdogg2
    pitdogg2 Posts: 25,441
    Yep you're all over the place man get a straight train of thought will ya...
    :p:p
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  • FestYboy
    FestYboy Posts: 3,861
    I took up Faustin's offer for spare crossovers, so now I can refurbish mine with factory parts. Gonna replace the caps of course and order some 194s. I getting excited :smiley:
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