genek

200043-0, aka 1200043-0, is the AR service replacement tweeter for the 58s, circa 1985-86 The second driver's P/N is an AR sequence, but later than either original AR or Teledyne. The third driver is most likely an off-brand replacement.

And that's nominal impedance. At some frequencies, impedance can be as low as 2 ohms.

The original 6 was introduced after the 4x and was essentially an improved 4x with a cabinet designed to fit on bookshelves that were not deep enough for the 4 series cabinet. It had a similarly complex crossover and had better specs and wider dispersion than the 4x because of its drivers, but when the 4xa followed it with the same drivers you really couldn't tell them apart just by listening. Later versions of the 6, especially the overseas models, had the simpler crossover. I've never heard any of those, so I have no idea if they sounded different.

I don't think any classic era 8" AR speaker ever crossed higher than 2000Hz. No idea what the upper limit of the woofer is.

The Q1R bottoms out around 2500Hz. The 4x crosses over at 1200Hz.

Ochestral music performed in large halls does not have much in the way of sibilance, sharp transients or pinpoint imaging from the audience seats. The halls are deliberately designed to scatter and diffuse the highs and blend the different instruments of the orchestra together to surround the listener in an immersive reverberant sound. Recordings in which you can pick out individual instruments and hear the strings squealing, i.e., "detail," are made with the mics placed close to the musicians. They would probably sound just right if played through flat response speakers on the stage of a music hall, but in your living room they tend to sound as if you are standing on the conductor's platform. A great place to be able to identify which member of the orchestra is playing out of step. Not such a good place to just enjoy the performance.

So what did you end up doing about the broken terminal block?

Not sure how I feel about making a 3a Limited vs AR-11. Might be more attractive if I didn't already have a pair of 3a's.

Thanks. Still have to make the moldings for the face frames, which is on indefinite hold until I can get out and shop for lumber. Once those are on, the cabs will get a light stain to even out variations in wood and then a final finish. Once they're assembled, the only clue to the restyling should be the badges. Have several options for those.

There might actually be a solid birch face from under all that gunk where the veneer has peeled off; it's just impossible to tell from the one photo. But if you're looking for a mate for an unfinished pine speaker, this is definitely not a viable candidate, because even if you could peel the veneer off, you would never be able to make it look like unfinished pine again.

So that definitely makes this pair someone's home project then.

Did they have labels on the back that said, "Unfinished Pine?" I would be very confused if I unpacked a new pair of walnut AR speakers and saw that.

I have a pair of AR-11 cabinets I bought a couple of years ago, and all the necessary drivers and 11b crossovers. So I could assemble a pair of AR-11b. Except, I've never cared much for the ADD styling. So I started playing with the idea of restyling them into 3a-style cabinets. I've filled in those dust-catching grooves around the faces with strips of walnut, and have measured out the necessary walnut trim to put face frames on them, but things got busy so they're just sitting in a closet.

Pine is a soft wood, so if these had not been finished prior to veneering, the glue used to attach the veneer would be deep into the fibers. It would potentially weaken the adhesion of any new surface finish and would make a penetrating finish an even worse prospect. It might actually be easier to refinish these if there was a coat of varnish under the veneer!

Rheostat is the generic term for a variable resistor. A potentiometer is a type of rheostat that has been configured to act as a voltage divider. Distinguishing by typical use is a bad idea, because anyone can use them for something atypical simply by the way they are wired into a circuit (by using only two or all three terminals).