Shaun B

Advice wanted for AR-4

28 posts in this topic

I got lucky and met a guy who had a lot of vintage gear from. Dual1210, 2 Eico tube amps and a pair of AR-4's. I bought all of it. All of this had been in his attic for 20 years. I was excited the most for the speakers but once i got to test them, that excitement faded. The sound bad. I have never worked on speakers but i can do a fair amount on receivers so im sure i could repair them if I can get some advice and direction. I removed the grilles assuming I would need to refoam but its cloth and not foam. Tweeter on one doesnt seem to play on one. I would like to do a complete  restore but not sure where to start. I also would like to use the best parts for anything i might need to replace. There isnt a lot of info on these speakers so I was hoping someone here could help me. I hear Roy C is knowledgeable on this topic. Im anxious to hear what these speakers are capable of. Any advice is welcomed and appreciated. 

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Welcome to the forum, Shaun B, and congrats on finding the vintage gear. You are certainly correct about RoyC's wealth of knowledge, but you are also most definitely incorrect about the available info on these speakers - - in fact, there is an abundance of online information about all of the various models within AR's "4" series - - - the AR-4, AR-4x and AR-4xa. 

A first suggestion would be for you to post some pics of your speakers - - members will quickly confirm which model you have and provide helpful comments on condition, originality, and primary steps for diagnosis. That Dual-Eico-AR combo could be a really nice set-up, so good luck to you getting it all back in working order. 

 

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Shaun,

There are a number of very knowledgeable members in this forum, as well as much information about restoring AR speakers from the AR-4 era. Information regarding the repair of typical issues is applicable to all models. Your speakers, at the minimum, most likely require refurbished or new level controls. Bad controls are often the reason a tweeter is not producing sound, so you may want to verify the status of the bad tweeter by removing it from the cabinet and testing it.

Roy

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Welcome Shaun

ra.ra. and Roy are very knowledgable and gave good advice but I'll add my 2 cents.

First, download the AR-3a restoration guide (there's a link at the top of the AR section). The 4 was little brother to the 3a so a lot of what's in there is relevant.

ra.ra. is the 4 series enthusiast. Post a photo and he'll be able to identify it and tell you what needs to be done.

My 1st speakers were the 4x and my 1st restoration as well. I would bet your tweeter problem is a bad level pot. Of course it's a good idea to test the "bad" tweet but I think if you replace the pots with L-pads and replace the single capacitor (it's 20uF in the 4x and 4xa. Don't know about the 4) you'll have some real nice speakers.

-Kent

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Thanks for everyones response. Pics should be at the bottom. The are definatley the 4's. I have found some info about later editions to this series, just not a lot for the 4. Im in the south where it gets brutal in the summer and all of this has been in his attic for 20 years. All original boxes though and he even still had the 45 adapter for the Dual with Dual stamped in it.  Smh... amazing he didnt lose that. Anyway here are some pics. Let me know if you need to see something more. Thanks all. 

IMG_6287.PNG

IMG_6288.PNG

IMG_6289.PNG

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Ra-Ra, when I google Ar-4, I get hits on everything but an AR-4. I just spent 30 minutes reading a forum about pots vs L pads( which totally messed my head up) in a search I did for AR-4 and the speaker was never mentioned. Is there a site that you know of that just has replacement parts and info on the speaker that you search? I am not famaliar enough with these speakers to read the AR3 info and apply it to my speaker not knowing the difference in the two. I would like to keep it as original as possible but if I csnt, I want to use which ever parts are going to give me the best sound. Since Im only about 20 bucks into these speakers,  I dont mind spending a little scratch to get a great sound from these speakers. Thanks

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ra.ra. is the guy. Here's one of his threads. What you want is one 6uF film cap and one l-pad per speaker

another:

a comparison of the 4 series

 

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Lol well this is gonna be fun. I was just reading the thread on restoring the AR3 and i did the 3 finger test to see if the woofer returnd slolwy. It didnt move at all really because my thumb went right through and ripped it. I barely pushed and it tore and dust puffed everywhere. 20years in an attic is rough. And Im i correct in thinking that what has melted and become wavy(see pics) is metal? It seems like it. Soooo,  new woofers? Im guessing theres not much hope for these being brittle. Can i even get originals to go back? Im not sure if its gonna be worth it to put the effort into these if they are that far gone. I love the look of these little jokers and I want to hear them but is it feasible?  I have my Polks hooked up and a pair of Cabasse somewhere, but Ive always heard great things about these. Is it gonna be worth it? 

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A few years ago, I was clueless how to conduct a meaningful web search on specific topics until one of this forum's members from Europe straightened me out. If you copy and paste any of the lines below and drop into your favorite web browser, you will find plenty of information to read up on this speaker model. You are already getting very good advice here: first, check that the tweeters are functional, and then pay attention to the tweeter capacitor and variable control. Disassemble, examine, and assess the tweeter controls; then decide whether to restore the original potentiometer or replace with a new L-pad. You will find a single 6uF wax block cap in each cabinet which should be replaced. 

Also, IMO, particularly for speakers stored in a southern attic for twenty years, I would make every effort to ensure that the woofer surrounds have significant suppleness to eventually allow ample movement of the cone. Others probably have more sophisticated methods, but my first step is to brush apply a light application of solvent (I use lacquer thinner, but toluene is the original solvent) simply to try to dissolve and soften the original butyl coating on the fabric surrounds. Maybe this takes two applications, and the only objective is to maybe break up any "crustiness" that has developed over time, resulting in crunchy, stiff surrounds. Next, even though the woofer is not meant to be entirely airtight (see that vented dust cap?), I like to apply a light coat of Roy's butyl solution, which I feel enhances the cloth's flexibility.

site:classicspeakerpages.net "AR-4"

site:classicspeakerpages.net "AR4"

site:audiokarma.org "AR-4"

site:audiokarma.org "AR4"

Attached is a pic of a pair of AR-4's I restored last year. Make sure you have the correct tweeters as shown here.

fronts 1.jpg

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pics did not show up. When you reply, drag pics to the bottom next to the paper clip. Resize them first. About 100MB or so is ideal.

I don't know how far gone the woofers are but usually they can be patched. More on that after you post pics. ra.ra. should chime in too.

Worst case scenario, you could replace the woofers, tweeters and crossovers with parts from a pair of Avid 100s. They drop in and sound good. And the AR cabinets are much nicer. But let's concentrate on restoring the 4s.

Ah! ra.ra. just answered while I was typing.

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Uh-oh, sounds like a potential disaster may have occurred while I was typing my previous post. However, sometimes these things can be salvaged even after an "oops" moment has occurred, so try posting pics again of the damaged driver. Meanwhile, do not attempt the push test on the other woofer.

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Hi Shaun and welcome!

You have come to the right place for sure. Roy and others will give solid guidance on virtually all aspects of the process. ra.ra (Robert) is particularly well versed on the AR 4 model line and others will chime in as well. Your quest to restore these classics will be worth it in the end. The 4x particularly has a strong following and is highly respected in these circles as a very good 2 way bookshelf speaker. I am always on the lookout for a set of 4s but they just haven't revealed themselves to me yet.

Things to consider as this unfolds, take your time and use the guidance offered to fashion your approach. The cloth drivers in this model are highly regarded. Too bad about the rip but as stated by Robert potentially salvageable. The 3a guide is very helpful in showing many of the common traits of AR build and components and the more times you read it the more it will make sense.

On your specific set it is almost a certainty that the potentiometers are corroded/effected by age and environment. These are often able to be cleaned up and re-used, many AR hobbyists are of the mind to just replace with lpads. This is the beginning of making decisions on your approach. I personally strive to use oem parts, whether original or replacement, as opposed to a non oem alternative such as the lpad. These pots (Aetna Pollack) are the weak link in the vintage AR speakers and there is a strong case to be made for going the lpad route, I choose not to if possible. The same goes for drivers and other components. Then there is the needed capacitors to replace. The general rule of thumb is anything new is better than the dried out old one. No need to spend too much on these parts and you will get a ton of opinions on that.

Pictures are extremely helpful and there is no such thing as a dumb question.

Geoff

ra.ra those are beautiful by the way 

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Pic below shows similar woofer with cone puncture and 40 years of dust accumulation. Cone repair was simple and effective per suggestion from Bill LeGall - - - paper coffee filter patch applied with thin application of non-diluted Elmer's white glue on backside of cone.

Thanks, Geoff - - re: decent photos, even a blind squirrel finds a nut sometimes. 

damaged woofer.jpg

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AR 4's are a great find. Very rare around here. Have two sets of 4x's and one of 4xa's. All have cloth surrounds, but different woofers. One set of 4x's from 1968 have the smooth lighter colored cone. The other set are ribbed black cones. The 4xa woofers are smooth cones, but painted halfway black. How different are the AR 4 woofers? Does anyone know why some early AR and KLH woofers have the hash marks on the cones? Always wondered why. 

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Likewise, larrybody, I think my 4x's have identical woofer descriptions as yours, but I believe that all 4x woofs (except the oddball two-cap version of the 4x that employed the AR-4 woofer) originally had the same performance specs.

The hash marks seem to show up often on AR-4 woofers, as well as some 10" cloth surround woofers from the "2" series, and I believe it was a method to add a bit of mass to the cone, using the same butyl dope that was used to seal the surrounds. Perhaps someone else has a more accurate historical rationale?

On the AR-4, sometimes it was applied in a floral pattern, sometimes a tic-tac-toe grid, and sometimes a combo of both.  

woofer cone dope.jpg

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13 hours ago, ra.ra said:

The hash marks seem to show up often on AR-4 woofers, as well as some 10" cloth surround woofers from the "2" series, and I believe it was a method to add a bit of mass to the cone

I think that's right. KLH used the same method. I've never seen the "flower" pattern though. Peace and love, man!

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From a 2008 thread on this site:

The criss-cross on the woofer cone was done for improved damping (not stiffness). It was a soft compound that was poured on the cone with the effect of absorbing energy traveling across the cone at higher frequencies. This was similar to the damping rings used in some other woofers. AR (and KLH followed with some of their speakers) used this criss-cross method on several woofers, including the AR-2a woofer.

--Tom Tyson

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Did that pic show up?  Thanks to all who have taken the time to post. After the hole I stepped back and didnt think about these for a day or two. After work today I am going to start working on the speakers. I will post pics as I go and I found several YouTube videos on patching torn speakers.  Going to look for butyl today also. Again thanks and Rara those speakers are nice. I hope I can get mine close to that. 

Edited by Shaun B
Messed up

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59 minutes ago, Shaun B said:

After the hole I stepped back and didnt think about these for a day or two.

Good!

1 hour ago, Shaun B said:

I found several YouTube videos on patching torn speakers.

Remember you can't believe everything you see on the interweb. Robert mentioned Bill LeGall's advice: Use a torn coffee filter on the back. Apply with white glue. Bill is THE expert on speaker repair (you can google his name or Millersound. He's the best).

1 hour ago, Shaun B said:

oing to look for butyl today also.

What for? If it's to treat the surrounds, CSP/AK member RoyC has mixed up some butyl-based stuff that is just like the original. Send him a PM or buy some from ebay seller "Vintage_AR".  Again--there is all kinds of advice on the web about how to "re-dope" surrounds with everything from bathtub caulk to gasket cement. Any of those will permanently ruin the speaker. IF you need to re-dope, use only Roy's goo.

Finally, Robert (ra.ra.) is a real expert on the 4 series and has done some very nice restorations. Follow his advice.

-Kent

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Butyl?

Glad to hear you stepped back and regrouped. Be careful using youtube guidance and I would encourage you to ask here before doing anything.

Butyl?

the cloth surrounds do not typically need any treatment, especially some random butyl if that is your intention. There is a butyl concoction that Roy makes that is intended for cloth surrounds but again you likely don't need that on yours. This model was intended to breathe a bit, see your pic of the woofer and notice you can see through the dust cover which is a vent as it were. If the surrounds are stiff that is another thing entirely.

Geoff

Yes, Robert's set is certainly something to aspire to.

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Obviously Kent and I were typing at the same time! Curiously similar

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On 3/19/2017 at 9:29 PM, Shaun B said:

And Im i correct in thinking that what has melted and become wavy(see pics) is metal? It seems like it.

Now that you know how to post pics maybe you can show us this. I've never seen any melted metal on an AR speaker so I'm curious.

On 3/19/2017 at 9:37 PM, ra.ra said:

Also, IMO, particularly for speakers stored in a southern attic for twenty years, I would make every effort to ensure that the woofer surrounds have significant suppleness to eventually allow ample movement of the cone. Others probably have more sophisticated methods, but my first step is to brush apply a light application of solvent (I use lacquer thinner, but toluene is the original solvent) simply to try to dissolve and soften the original butyl coating on the fabric surrounds. Maybe this takes two applications, and the only objective is to maybe break up any "crustiness" that has developed over time, resulting in crunchy, stiff surrounds. Next, even though the woofer is not meant to be entirely airtight (see that vented dust cap?), I like to apply a light coat of Roy's butyl solution, which I feel enhances the cloth's flexibility.

I see where you got the "butyl" from. Again--follow Robert's advice. You want to clean and soften the surrounds. RoyC chimed in on the third post above. If you want "Roy's butyl solution" ra.ra. mentioned, send him (Roy) a PM.

-Kent

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Hey Shaun, I sort of cringed :( when I read your Sunday 9:29PM post regarding the damage to the woofer when conducting the three-finger push test. Your pics are posting here just fine - - can you show us the damage incurred?......and maybe we can then steer you towards the next steps to take. Hang in there, work slowly, and ask questions. The modest little AR-4 is a very fine small loudspeaker and has become highly sought after within certain circles. Even a small speaker restoration project has many steps involved, but it can be very satisfying to restore life back into these long-neglected audio boxes. Sometimes my own resto projects stretch out for many months as I conduct research, ask for assistance, evaluate options, search for parts, and try to find time and conditions to conduct the disassembly and reconstruction. Take your time, enjoy the process, and it will be worth it.

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ra.ra. (and others)

What do you think of this idea: Seems the paper cones have become brittle with the extreme heat. If the woofers are otherwise OK, maybe the paper can be reinforced.

A few years ago John, of M-Sound, suggested that for those who wanted a "wet look" speaker cone one could mix up some of his "WD" white glue with water to the consistency of skim milk and paint the cone. I believe Aileene's Tacky Glue is essentially the same thing and it seems to me this very dilute glue could seep into the paper fibers and revitalize the cone.

Thoughts?

-Kent

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