genek

The problem with shorting plugs for RF interference is that the signal wire is still exposed to the interference. What I was referring to was a cap, basically a metal shield that fits over the plug rather than going into it. https://www.audioquest.com/accessories/audio-enhancements/noise-stopper-caps/rca-noise-stopper-caps However, there's not a lot you can do about one radio station overpowering another in your tuner. If you're lucky enough for the offending station to not be in the same direction from your home as the stations you want, you could try a more highly directional antenna. Another alternative is to see if the stations you want to listen to stream their sound online. If so, you could bypass your tuner altogether and feed the sound to your Aux inputs. I haven't used any of my tuners other than the radio in my car for years now.

The original masonite grill panels were not painted black, but had a black melamine film thermally fused to the smooth surface. If you paint yours black, do not use a latex or any other water-based paint (or better yet, use an alcohol-based stain) and overcoat the black with a couple of coats of clear polyurethane (also non water-based) or eventually the black will bleed through the cloth. It may take years for it to happen, but it will eventually.

Do you get this if there's nothing at all plugged into the amp inputs? You could try shielded RCA caps in the the unused input jacks.

About 10 years ago we downsized for retirement. I sold off several pairs of speakers and consolidated the remaining ones into one multichannel HT system. With AR-3a as the front speakers, AR-2ax as the rears and AR-1ms as center channels I am now listening to all my remaining AR speakers at the same time.

8 ohms nominal.

A pair of empty 10 pi cabinets with crossovers, no drivers and decent veneer all around recently sold on eBay for $102.50. You have no woofers, untested mids and tweeters, incomplete crossovers and peeled veneer. I'm assuming you don't have original foam grills in good condition, either. Your speakers in their current condition are worth less than those empty eBay cabs.

Consecutive AR serial numbers are very, very rare unless the speakers originally came boxed as a set.

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.