RTA 12's

renowilliams

A friend of mine answered an ad for Polk monitor 12 speakers on Craigslist, went and got them. He now has them home and from the description he gave me their RTA 12's. How do you tell the difference between RTA 12, 12B and 12C?? Is it like the sdas where you need to determine which mid drivers are in it??

On3s&Z3r0s

I think sometimes there is a model number printed on the crossover circuit board under the top hat. Do you know if he's already looked there? Otherwise, I think it comes down to the cabinet style and driver complement. There are a few good threads with information about the various models. I'll see if I can find any of the links.

Here's a good one: http://www.polkaudio.com/forums/showthread.php?t=96857

drumminman

to determine which iteration your friend has.

I bought mine new from a brick and mortar store back in 1984, and the model designation was printed on the owner's manual that came with them - RTA 12C.

But. . . . .the printed circuit board on top of the speaker has RTA 12B printed on it.

However, the cup with the binding posts on back have has part of the serial number RTA 12C.

Apparently Polk used a variety of different speakers and other items from their parts bin when building these so you probably need to determine the model with at least two points of agreement.

Some early versions of the 12's used the Danish Peerless tweeter, later ones the #5514 USA made "Peerless" tweeter, some 12C's used the SL1000 (mine use these), and some the SL2000. But these were not used in linear fashion, i.e. oldest models = earliest tweeters. Polk kind of mixed and matched components based on what they had on hand at the time of production. :eek:

Some 12B's had the SL1000 and some 12C's the 5514 and some 12C's the SL2000

The crossover schematics for the RTA 12 can be a good place to start if you know how to read them. And pull the top hats and read the model number and the build date on the back of the tweeter. You could also pull the mids and read the model number and build date on those. The year of build would be one more piece of the puzzle. :biggrin:

I think geppy1 is the resident expert on the RTA 12's and the post above is a good place to start.

If you can post pics that would help too. Good luck!

Fred

geppy1

I need to see them and the serial numbers off the back. NOT the ones on the Xover board. I can guide you from there. Bear in mind there were Cs made in early 84 that are lower numbers then some Bs

renowilliams

what impedance are the RTA 12's??


Serial # off the back is 05863

geppy1

How tall is the cabinets?? Did you get stands with it?? Do the drivers have grey stuff around them?? Based on the numbers I suspect they are early RTA 12s with 6500s and danish peerless (verticle mounted) probably mid to late 1979. Take the nuts off the top Xover and unlug it, turn it over and there will be a date in white marker

renowilliams

it says 1980 what is the impedance

soundfreak1

They should be 4 olm.

geppy1

4 ohms like he said. The outside drivers are not rolled offf like the 12bs and 12cs and there only 1 xover

heiney9

nm...
H9

mavric

I am the guy with Polk RTA 12's Here is a link to the pictures, please refer to the captions for SN etc. Thanks for your time. https://picasaweb.google.com/pdeschp/PolkRTA12Speakers?authkey=Gv1sRgCPj-_OaV99nkCQ#

Also wondering if there is a left and right config for these early RTA 12's?

soundfreak1

That thread from geppy1 is dead on my 1983's /12b's

geppy1

No left or right on those early ones Keith

audiocr381ve

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