genek

Your efforts would benefit considerably if you could measure the FR of your modded tweeter. It's harder to design a crossover if you don't know where your driver response rolloffs begin.

The upload cap is cumulative across all forums you post to. I expect that there are some who will follow your project's progress in Mods and Tweaks because they're interested in trying it themselves and others who will just wait to see what results you post in the AR forum and whether you'll start selling them because they're only interested in drop-in replacements they can buy.

Fyi, there's a cap on uploads. You'll fill up fast with crossposts. Better to use the share function to let people know there's a new post in another forum.

The question posed by the OP was whether there's a modern tweeter that sounds like the original, whether it's a drop-in replacement or not. If you look at past discussions, you'll find more than a few about how to create adapter plates and crossover mods to make various modern drivers sound like hard-to-find originals. And if your project ends with you posting a response curve for a modded PRT that matches that of the original tweeter, there will probably be a lot of people congratulating you because they think it's a very good thing.

The question is whether you are trying to improve the PRT by making it sound like the original AR tweeter or to make it sound "better" than the original. This is the key to determining whether to post here or in Mods and Tweaks.

Response also depends on context. The brand name forums of this site are devoted to the history, care and restoration of original speakers and sound. A discussion of how to adapt a non-original driver to replicate the sound of a now unobtainable original part will usually generate some interest and positive reactions. Starting out with a mission to "improve" originals with redesigns because you think original was somehow lacking may get interest and positive reactions in Mods and Tweaks, but is unlikely to here. Imagine you modded a 1920s art deco cocktail bar to add a beer keg tap and a margarita machine. There would probably be people who would think it was a cool project, but you would be unlikely to find them in a forum devoted to art deco antiques.

As far as I can recall, the people saying the PRT is a good replacement for AR-4s are usually the same people trying to sell them. The consensus here is that the only thing they really have going for them is that they fit in the cabinet. But the fact that nobody trying to sell these seems to have ever put a FR graph for them up may in itself be telling.

Do the backs look like this, with the recess, magentic latch washer and handle scoopout?

I would just look for someone who can cut new doors. My recollection is that the 10pi's doors were solid walnut, but the blackend edges of your doors look more like particle board. Are you sure they're the original doors?

Can you shoot some closeups of the touchups that didn't go well? Maybe we can provide some suggestions.

No, I can see how today's 6.5" woofers in a properly designed cabinet might outdo 50-year old 8" woofers. To compare to a larger 12" AR, you'd want something like this: https://usa.yamaha.com/products/audio_visual/speaker_systems/ns-5000/index.html

Most new speakers that I see and hear give me the impression that they were designed to part of a multispeaker HT array. If you have enough of them spread around the room and a couple of subwoofers, you could probably reproduce the same low end and room-filling soundfield that a pair AR-9s would produce, and defintely a lot more high end, since that's what most consumers prefer today. You'd probably need a bunch of equalizers to get that AR rolloff if you wanted it, though. A pair of two-ways with 6" woofers may very well outperform the 8" woofers in AR-6s, but AR-9s? No way is a pair of two-ways with 6" woofers going to do it by themselves.

Could just mean that the license was issued by "Teledyne Acoustic Research." As far as we know, AR never actually operated their own manufacturing facilities outside the US. They either licensed their IP to others or contracted others to manufacture for them.

The dual address suggests that at least some of these were manufactured overseas under license from AR. The existence of a UK AR brochure when there doesn't seem to be a US brochure reinforces that suggestion.

The SRTs were probably produced in a sort of semi-OEM arrangement, in which the buyer got a reduced price in return for taking on responsibility for things like distribution, marketing and service. Sears would've gotten a little sales boost from having the label say AR rather than some home label brand name, but no other AR support. AR would've drop shipped a a year's worth of stock to one delivery point, Sears would've shipped to stores using their distribution chain, the only marketing info would've been in Sears catalogs, and customers with warranty issues would've carted their speakers to their local Sears store rather than contacting AR for free return cartons. And I wonder whether those military exchanges got them from AR, or from Sears along with Craftsman tools and Kenmore appliances.

AR's legendary history stems from Edgar Villchur's invention of acoustic suspension. So in the eyes of AR enthusiasts, anything that lacks that feature is probably always going to be a poor cousin. As you get further and further from the Villchur years and the early Teledyne years in which the team originally put in place by him continued to design AR speakers, the less attractive the brand becomes. You'll find the same thing happening to KLH and Advent products produced after Henry Kloss departed those companies, as well as Allison speakers after Roy Allison. Especially if they happen to have ports.

It's probably the bass reflex. Other AR-branded speakers by subsequent owners of the brand that are not acoustic suspension get the same low regard.

Studio Recording Transducer, aka Sears Roebuck Throwaway. A budget product originally produced for Sears and later sold through military exchanges. Have never seen any AR-published marketing brochures for them. I suspect they were too embarrassed.

Zebrawood (astronium graveolens) is a real thing, but AFAIK the doors on the 10pi were made of walnut. Just like the rest of the cabinet in the photos you posted.

At $500 for all four, it might be worthwhile for a buyer to call a "pick, pack and ship" company.

Are the caps wax blocks or cans? If they're Sprague Compulytic cans, they're probably still ok as long as you don't see any splits or leaks.

If you had that spare 2ax woofer around because you also have 2ax's, might as well go ahead and use it if it sounds ok to you. But I'd keep my eye out for one of the later, correct woofers too. You might need that 2ax woofer someday for an actual 2ax repair.

Signal generator apps are readily availalble for both iphone and android. The advantage over music is that you are sending the actual tone you want to know whether the driver is outputting without the distraction of every other tone in a bit of music. Especially important once you get into the range above 10kHz.

"Unfinished."

The dark stain is similar to what the last generation of classic ARs with the Norwood address looked like.