Original RTA 12 Specs

oldhifi

Greetings All,
I scored a pair of original RTA-12's months ago and really enjoy them. I have found specs on the 12b's, but cannot find much on the 12's. I searched through this site and saw an original flyer stating that they are 96db for one watt, but not the impedance rating. I was running them with 100wpc NAD receiver and recently switched to tubes. The tube amp I am running is about 20wpc and I am running it 4ohm. The tubes are really impressing me and made them come alive for the lower volume listening that I do.
These are keepers for me and I was hoping to get some more information on them. Really any information would be much appreciated. I included some pictures for fun. Thanks!

pitdogg2

geppy1
January 2017
The original RTA 12s and RTA12B and Cs are completely different speakers. The B and C version have larger cabinets. The B uses 6600 drivers with peerless or SL 1000s The C uses 6501s with SL 1000 (early) and SL 2000s. The B and C are mirror image speakers with the outer drivers rolled off at 600 verses 2000 for the inner drivers The original RTA 12 does not do this. It used 6500s and peerless It is like a Monitor 10 with a 12 inch passive and open air mounted peerless tweeter. The B and C also went to great lengths with the top hat and ramp to control diffraction effects.

Found this^^^^ in the way back machine.


If you have a multi meter it is easy to get an idea of the impedance. Unhook cables at the speaker binding post and set meter to ohms and place one probe in each binding post. If it's above 6 ohms its 8 ohm if its 5 or below its 4ohm.
It's not an absolute science but it gets you very close.

oldhifi

Thanks pitdog2! I don't but I have a multimeter but I will go purchase one today and give this a shot.

Gardenstater

I tried to find out for you, but so far come up emptyhanded. Apparently the original RTA-12 was introduced in 1979 and I purchased my 7B's in 1979 and was given this sales brochure, which shows the Monitor 10 at the time being 6 Ohms nominal impedance which leads me to guess that your RTA-12 is also. Does your RTA-12 have the MW6500s in it, along with the Peerless tweeter?

Gardenstater

Found this in Oct 1979 High Fidelity, but drats no nominal impedance given. Freq. response was 27 Hz to 20.5kHz +/- 2 dB, which is pretty incredible. It appears you have the original stands shown in the advertisement, with the rounded corners.

Jazzhead

I'm an original RTA-12 owner as well (bought them in 1980). The literature I have says:

Impedance: 6 ohms
Frequency Response: 19-25000 Hz , 27-20,500 +- 2
Maximum Output level with Musical Program Material: 120db
Recommended Associated Amplification: 10-500 watts per channel

They are nice speakers in their stock form, and there are many mods/upgrades you can do (if you have the inclination) that will greatly improve their performance.

oldhifi

Gardenstater wrote: »

Found this in Oct 1979 High Fidelity, but drats no nominal impedance given. Freq. response was 27 Hz to 20.5kHz +/- 2 dB, which is pretty incredible. It appears you have the original stands shown in the advertisement, with the rounded corners.

Thank you so much! They do have the MW6500's and Peerless. I actually found these in a thrift store and I walked around the corner after an employee set them out. I called my wife to bring a cart and had to fight off a coupe of folks. I lost one badge in the process but the wife of the man who dropped them off was in-front of us in the check out line. She said they bought them new in early 80's and they have been his babies since. He apparently got new speakers and she tried to call him so we could chat. However, she left the house because of how loud he was listening to music so he missed the call. Thanks for the information and looking for me! They are really fantastic speakers.

oldhifi

Jazzhead wrote: »

I'm an original RTA-12 owner as well (bought them in 1980). The literature I have says:

Impedance: 6 ohms
Frequency Response: 19-25000 Hz , 27-20,500 +- 2
Maximum Output level with Musical Program Material: 120db
Recommended Associated Amplification: 10-500 watts per channel

They are nice speakers in their stock form, and there are many mods/upgrades you can do (if you have the inclination) that will greatly improve their performance.

Yes!! Thank you so much! I am a big jazz fan and love all my records through these. I really appreciate you posting the information. I will have to check into the mods and upgrades down the road.

Gardenstater

Congratulations! I dare say I would've been one of the ones you would've had to fight off lol! Talk about being in the right place at the right time.

Check out the bass with Fanfare for the Common Man on Minnesota Orchestra - Copland: Fanfare for the Common Man, Appalachian Spring & Symphony No. 3

Good tweeter jazz check - Take Five by The Dave Brubeck Quartet from Take Five (Hi Rez)

Good all around jazz check - Speak Low by Tsuyoshi Yamamoto Trio