Acoustic Research AR2AX

pjf610

pjf610

Active Member
Hi All, A friend of mine just gave me a pair of these speakers, he knows I am into restoring vintage equipment and said have at it. My question is whether or not to restore these, they sound pretty good,but I have not put them through it's paces. I am using my Marantz 2270 with a Pioneer PL-570 and an Akia GX-635D RtoR with Kef reference one's now. Just looking on what you experts think. And would need to know were to go to get the right parts.

Thanks Pat
 

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Yes, they are worth restoring. To know if they're keepers, likely the pots will need work,
woofers may need the correct sealant for the surrounds (vintage-ar on ebay), and new
aps. These rely on a tight cabinet seal for strong bass.
 
Thanks RXDX, Is that the only place to get parts for these on ebay, (I hate that place) I do not mine paying a little more. If there is someplace else to shop from.
 
They actually look pretty good. You can get carried away with this stuff. Be careful and do the research if you decide to restore.
 
pjf610 said:
Thanks RXDX, Is that the only place to get parts for these on ebay, (I hate that place) I do not mine paying a little more. If there is someplace else to shop from.
Click to expand...
Vintage AR on eBay is a solid seller and knows his stuff.
 
pjf610 said:
Thanks RXDX, Is that the only place to get parts for these on ebay, (I hate that place) I do not mine paying a little more. If there is someplace else to shop from.
Click to expand...
"... new caps ..."

parts-express.com is the usual source of caps- the Dayton brand is fairly
inexpensive and handles most people's needs. User RoyC here sometimes
has sealer for sale. Your pots will need to be opened up to determine their
condition. They're typically not usable as is.

And there are dozens of threads on restoration of these.
 
I am definitely going to change the cap's and pot's, now when you say sealer what do you mean???
 
The cloth woofer surround can dry out, causing loss of bass. It's supposed to be
a little sticky. Renew with RoyC's formula only (also sold by vintage-ar). Anything
else is destructive. When done right (sealant and cabinet seal), the woofer takes
a second or two to return to default position, after the cone is pressed down.
 
These are really easy to recap. You need a 4mfd and a 6mfd nonpolar caps.

The pots on these are guaranteed to suck at this point. If they were my set, I would bypass them, especially the tweeter. You will need all the output you can get to compete with the awesome bass response. I have a since AR2AX in my bedroom mono system. It is an awesome speaker
 
RoyC is a member here. Send him a private message to check availability
of sealer. Get his recommendation of replacement pots, too, if you need any.

You can bypass the pots, or L-pads can be used, but that alters the original
sound.

There are new pots available on ebay, though they are more expensive
than L-pads. I typically go to some lengths to repair the originals and have
been able to salvage all of them (four pair of 2 series systems). Soak them
in vinegar if there's any corrosion, then use some dielectric grease to
protect them (assuming they're not too corroded).
 
When you reseal, only use "just enough" to substantially seal the surround. Try one thin coat and see if that is enough. If not then apply another "thin" coat. If you over-apply then that will stiffen the surround and hurt the bass too. The AR speakers don't need the dust caps sealed (unlike classic KLH speakers). I can't speak to the push test on AR speakers for that reason, but you don't want cabinet leaks or leaks around the attachment flange of the woofers and tweeters.

In regards to the cloth surrounds they only need replacing if they are damaged and the driver can't be used without replacing them. As far as I know there are no cloth surround replacements so you'd have to go with a foam replacement which is much less desirable on these classic AR's. Finding a foam surround that would fit might be a challenge - I am not sure because I've never had to go down that path.

I use "mortise" plumbers putty to seal around my speakers. Others use thin foam sheets cut to shape. Your choice but the goal is to make sure air is not escaping the box as the air acts like a spring for the woofer.

For the pots (potentiometers), those are very problematic in AR speakers. They usually corrode and get scratchy or stop making contact altogether and thus make the tweeter stop working. Many threads out there on rebuilding the existing pots (yes, they are serviceable). I chose to replace them with modern L-pads which are connected slightly differently then the original potentiometers. If you go with L-pads you'll want to read up on how to connect them. Parts Express sells good L-pads (25W 8 ohm) if you wanted to go that route.

The classic speaker pages (CSP) site is also a good source of info on AR speakers. Both sites (AK and CSP) have lots of help for AR speakers. Good luck.
 
All the above info is great! My one suggestion is to test the woofers seal first, before buying and applying the sealer. Gently push the woofer cone inwards, and let go. If it returns slowly to its neutral position, no sealer is needed. If it bounces back immediately, then the sealer is needed. In almost every AR woofer I’ve tested this way, none needed to be resealed. For some reason, the seal has held up much better over the last 40 plus years, than KLHs do.

Regarding cleaning the pots. Use clear distilled vinegar and salt solution to soak them in. Wash and rinse with soap and water. Almost always, the disk surface needs polishing with a Dremel and fine grit flexible sanding disk. Reassemble and test on a meter, or temporarily reconnect to the speakers and see how well they work if you don’t have a meter.

You've got a very nice set of ARs. Keep us updated as you progress.

Glenn
 
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