New RTA 12's - But which ones?

Bigerik
Bigerik Posts: 149
edited October 2011 in Vintage Speakers
Hi Folks.
I just picked up for near enough nothing a pair of early RTA 12's. They have the vertical Peerless tweeter, I know they are early, but that is about where my knowledge of these things runs out.

Can anyone ID these better? Any info is appreciated.

Sorry for the crap cell phone pics!
Post edited by Bigerik on
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  • drumminman
    drumminman Posts: 3,396
    edited October 2011
    I'm guessing RTA 12 without a letter designation (the very first ones). Others who have done more research will chime in I'm sure.
    "Science is suppose to explain observations not dismiss them as impossible" - Norm on AA; 2.3TL's w/sonicaps/mills/jantzen inductors, Gimpod's boards, Lg Solen SDA inductors, RD-0198's, MW's dynamatted, Armaflex speaker gaskets, H-nuts, brass spikes, Cardas CCGR BP's, upgraded IC Cable, Black Hole Damping Sheet strips, interior of cabinets sealed with Loctite Power Grab, AI-1 interface with 1000VA A-L transformer
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  • Joe08867
    Joe08867 Posts: 3,919
    edited October 2011
    RTA 12 no other letter. Those are the first in the series. Look good too. I always loved that Peerless tweeter.
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  • Bigerik
    Bigerik Posts: 149
    edited October 2011
    Thanks. They are not in bad shape. And they threw in all the dust for free. :)

    The grilles look like **** tho...
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  • Bigerik
    Bigerik Posts: 149
    edited October 2011
    I am guessing the crossovers could use a re-cap. Anyone have any thoughts on that? Anything to do while I am working on it?
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  • Michael8it
    Michael8it Posts: 192
    edited October 2011
    You have the "original" RTA 12 - the easiest way to vewrify this is to pull the woofer and see if there is a crossover network attached to the terminal posts inside the cabinet. If not, they are RTA 12's - if it is there, These are 12B's. But looking at your speaker cones, and how your tweeter is mounted, these are 12's (they are identical to mine).

    the tweeters look like Peerless, possible Denmark made, which are very sought after. If you want a schematic for these I rewrote one (the schematic on this site was handwritten and incomplete).

    One thought - I picked up a pair of 12B crossovers, and it made an HUGE difference, even with the 'wrong' drivers in the cabinet. Even without recapping them.
    Carver C-1, M-500 MKII, Yamaha HTR-5835, Polk RTA 12BM's (M-for mod'd).
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  • Bigerik
    Bigerik Posts: 149
    edited October 2011
    Hi Michael.
    I would love the schematic. How can we arrange this?

    How would I know if they are the Danish driver?

    What changes did you notice when you made the swap to the B crossover?

    Thanks for the info.
    Erik
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  • drumminman
    drumminman Posts: 3,396
    edited October 2011
    Definitely should put recapping and new resistors on your tweak list. Those caps are 30+ years old so they're probably out of spec, and new caps and resistors are of such higher quality.

    You'll be amazed at the difference this makes.

    I'd also say that if you can get the 12B Xover from Michael this would probably be a good upgrade. Later designations of RTA 12's had the woofers playing different parts of the audio frequency band. This along with the time alignment/open air tweeter allowed them image like nobody's business :cool:
    "Science is suppose to explain observations not dismiss them as impossible" - Norm on AA; 2.3TL's w/sonicaps/mills/jantzen inductors, Gimpod's boards, Lg Solen SDA inductors, RD-0198's, MW's dynamatted, Armaflex speaker gaskets, H-nuts, brass spikes, Cardas CCGR BP's, upgraded IC Cable, Black Hole Damping Sheet strips, interior of cabinets sealed with Loctite Power Grab, AI-1 interface with 1000VA A-L transformer
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  • Bigerik
    Bigerik Posts: 149
    edited October 2011
    Sorry, I wasn't clear. DEFINITELY going to do caps. And resistors. I bet they are no where near their original values. And better quality too, if not the ultimate in audiophool quality.

    Gotta do some more reading on the RTA 12's. Seems like an interesting speaker, in all of it's versions.
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  • drumminman
    drumminman Posts: 3,396
    edited October 2011
    Bigerik wrote: »
    Sorry, I wasn't clear. DEFINITELY going to do caps. And resistors. I bet they are no where near their original values. And better quality too, if not the ultimate in audiophool quality.

    Gotta do some more reading on the RTA 12's. Seems like an interesting speaker, in all of it's versions.

    Check this out. It's what inspired me to go forward with the mods I did to my 12C's: http://www.polkaudio.com/forums/showthread.php?116480-RTA-12C-s-upgraded-for-forum-member-w-pics
    "Science is suppose to explain observations not dismiss them as impossible" - Norm on AA; 2.3TL's w/sonicaps/mills/jantzen inductors, Gimpod's boards, Lg Solen SDA inductors, RD-0198's, MW's dynamatted, Armaflex speaker gaskets, H-nuts, brass spikes, Cardas CCGR BP's, upgraded IC Cable, Black Hole Damping Sheet strips, interior of cabinets sealed with Loctite Power Grab, AI-1 interface with 1000VA A-L transformer
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  • Bigerik
    Bigerik Posts: 149
    edited October 2011
    Great thread and incredible work. Thanks for the heads up!
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  • drumminman
    drumminman Posts: 3,396
    edited October 2011
    Just realized that your RTA 12's probably don't have the second Xover, so using the 12B Xover boards may not work. The 12B and later iterations had a second Xover attached to the binding post cup, in addition to the one on top of the cabinet. I don't think you can just switch out the top Xover without degrading the sound.

    Geppy1 is one of the RTA 12 experts here - ask him.
    "Science is suppose to explain observations not dismiss them as impossible" - Norm on AA; 2.3TL's w/sonicaps/mills/jantzen inductors, Gimpod's boards, Lg Solen SDA inductors, RD-0198's, MW's dynamatted, Armaflex speaker gaskets, H-nuts, brass spikes, Cardas CCGR BP's, upgraded IC Cable, Black Hole Damping Sheet strips, interior of cabinets sealed with Loctite Power Grab, AI-1 interface with 1000VA A-L transformer
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  • BottomFeeder
    BottomFeeder Posts: 1,684
    edited October 2011
    Geppy is the RTA 12 bomb, so do look him up.

    I think the easiest way to tell if you have the first version of the RTA 12 line is to know that both the "B" & "C" models have a few inches of extra wood on the bottom in order to "de-couple" them from the floor.
    "Wish I didn't know now what I didn't know then." Bob Seger
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  • Joe08867
    Joe08867 Posts: 3,919
    edited October 2011
    drumminman wrote: »
    Just realized that your RTA 12's probably don't have the second Xover, so using the 12B Xover boards may not work. The 12B and later iterations had a second Xover attached to the binding post cup, in addition to the one on top of the cabinet. I don't think you can just switch out the top Xover without degrading the sound.

    Geppy1 is one of the RTA 12 experts here - ask him.

    They can work if he places the one board inside the cab and the other board on top like the B models. Definitely more work involved with that idea.
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  • Bigerik
    Bigerik Posts: 149
    edited October 2011
    Doesn't sound like too much work...
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  • Bigerik
    Bigerik Posts: 149
    edited October 2011
    Anyone know where I could find some 12B crossovers? :)
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