jviss

So, the sand is about 50lb. per 0.5 cu. ft., and the stand's bags take 0.15 cu.ft., so that's 15lb. per bag, plus the 17lb. speaker, so I'm under the 40lb. max.... (I hope my math is correct!)

One speaker: 17 lb., 3 oz. (7.79612 kg.) Why? My Kanto SX26W speaker stands are rated for 40 lb., max, speaker plus dampening sand. That is all. Kanto SX26W speaker stands on Amazon (no relation to seller, etc.)

Two pics. Note in the first, "as found" pic, there was a strip of butyl rubber, same material as used to seal the woofer to the cab, over the metal clip that holds the pot together: After update: I know, it's no big deal, but it was exciting for me! Ha, ha. It took me like 5 tries to properly staple those tie wraps for the cap. The biggest deal was cleaning the pot: removing the verdigris, polishing the contacts, etc. Very satisfying when completed. Oh, by the way this is speaker serial number FXI76356. I'm not sure if that third character is the letter "I," or the number "1." The date code on the woofer is March 13, 1966.

I just did my first 4x. I found the same layout as @ra.ra documented. Replaced the cap with a Dayton 20µF 250V polypropylene film cap. I refurbished the pot, which was severely corroded. I soaked the parts in vinegar for a bit, then had to resort to the Dremel with a tiny nylon brush to clean that center conductor. Lubed with Deoxit-5 as I couldn't find my dielectric grease. Works, measures 16Ω total. I cleaned the solder off the woofer terminals with solder wick and then fitted push-on spade terminals to the wires to ease assembly. The tweeter works now, but it seems a bit weak to me. Could be the source material I'm playing. I'll post pics in a bit.

Cool. I'm curious as to the defects you find and how you address them.

That makes sense. Has anyone ever done a mechanical restoration of an AR driver?

Thank you! And Merry Christmas to you and to all the forum members. I'm listening now, two pair of AR 4x speakers going at once, driven by my recently resurrected Pioneer SX-424 receiver. I think that long neglected speakers "loosen up" with exercise.

Oh, wow, is that so? You mean, used originals that have been pulled form cabinets? I have at least two functional ones, maybe four, depending on whether the tweeters or crossovers are at fault in two cabs.

Thank you!

I wonder how folks test drivers on the bench, tweeters, woofers, etc., safely and surely? I'd like to test my tweeters when I open the cabs. I don't want to blow them! I have a signal generator, etc. Wondering if anyone here has knowledge and experience in this area. Thanks, jv

Oh, interesting, @Aadams, thank you! Note that, as I'm sure you're aware, aida cloth can be linen, too. I know some they mix with synthetics, etc., but the one I have is all linen. I just dyed a sample with tea (Lipton ) and it's not indistinguishable in color from the original cloth. I'll try to make some close-up pics of what I have. I have to dig out the DSLR with the macro lens, etc.; I can't find anything since I moved! I also have a binocular microscope, as I mentioned previously, but I don't recall what I did with the camera adapter (which dropped into one eyepiece socket).

Interesting. The grill frames on my 4x speakers are stick-built of 1/2x5/16" wood, probably basswood. You'd need some larger 5/16" stock for the gusset where the nameplate attaches. This wood is commonly available in hobby stores. Would be potentially more work, but a lot less waste than making them from panels.

That's O.K., it doesn't really matter. I'm not going for a museum-quality restoration of these, I just want something that looks good and sounds good. Based on the original cloth I have (and I know it's original as my father bought these new, and I am aware of the chain of custody and what wasn't done since), the aida cloth I bought is much, muc closer in weight and weave than the 28 ct. linen recommended. And, it's easier to work with. It's lighter in color, like a bleached linen. If I wanted I guess I could dye it with tea. I might try that with a swatch and see how it looks. I wish I had access to my engineering school's anechoic chamber, I could measure the effects of the various grill cloths! Wouldn't that be cool? Yes, ditto on the staples! The originals were definitely more like SF13's or JT-21's than T-50's. Probably just regular old desk staples!

Interesting, thank you.

I'm sorry, but I have seen posts here referring to it as Aida cloth, and, indeed, seen references online for it described as such. While they apparently don't offer the 18ct. product any longer, Wechert does offer the 20ct., and I believe they call it aida. But, no matter, whatever works. I'm not necessarily going for an exact match in looks, but I don't want to upset the sound quality. It seems to me a more open weave, i.e., 16 or 18 as opposed to 28, will be more acoustically transparent.