Bungled AR 2ax repair

[JeffPro]

Looking for some advice, 

Just picked up a pair of my fathers 1964 AR 2ax speakers from the speaker repair shop. After reading through this and other forums about the many successful repairs done to them, I decided to let a "pro" diagnose and repair them. I had brought them in because while both woofers produced sound, the mid and tweeter on both only crackled to life if I slowly turned the adjusters in the back to make contact, and only stayed there as long as I held it with a little pressure.  The repair shop has been in biz for a while and was told had experience with the older AR's so I totally left it in his hands. When I picked them up I was told the old crossovers were pulled and replaced with new ones and he told me the speakers were tested. I made the mistake of not asking for the old ones back, nor did he write down any specifics of the new crossover on the receipt. I have since left a message this morning asking him to please find the old crossovers as....

I brought them home, hooked up my also recently refurbished AR turntable, dug through my vinyl for the test subject, and when needle hit the groove, was surprised to get only one speaker functioning.

Checked all the connections a million times, switched cables around, and used the AM/FM tuner to confirm it was not the phono or receiver.

Pulled the grills - (shop velcro'd the grill back on to make that easy) to take a look. I could see, smell the putty used to reseal the woofers, but did notice the very edges of the woofer are not sealed up against the aluminum bracket in all areas. The working speaker had the similar gaps around the woofer cone edge but did produce sound. The weird thing I observed on the working speaker is that the woofer cone was fluttering quite hard while the record was playing, and the music was just some fairly folky Grateful Dead at low volume. Watching a few youtube vidoes of working AR's I did not see the woofer cones flutter hardly at all.

So now I feel sick. I should have consulted this forum BEFORE I had them worked on! Most of the posts I read about repairing these speakers usually mention just replacing components of the crossover or just cleaning, but I just did not feel up for taking the time to figure it all out and understand the electrical intricacies..

Is there any clues here to what is going on here? What questions can I ask the shop to make sure it is repaired correctly? If I cannot get this done properly, any other suggested shops in the Chicagoland area to bring them to?

Last dumb question, speaker wire terminals marked 1,2,3 - copper wire should hook up to 1 or 2?

Thanks for reading, Jeff

 

 

 

 

[ar_pro]

Hi, Jeff -

It would be helpful to take some photos of the woofers that show the condition that you've described.

Since the board that carries the crossover is stapled & glued to the inside rear of the cabinet, if the shop left this panel in place, it's less likely that the entire crossover has been removed. A photo of the rear panel would be useful. Hopefully, the shop merely cleaned the "adjusters" (level controls), and possibly replaced a capacitor or two.

I'd suggest having them provide an invoice that specifically states the work that was performed, and any part(s) that were replaced. Get it in writing, and you can proceed from there.

Refoaming AR woofers and dealing with level controls or crossover capacitor replacement is something that all of us have had to do, so don't worry; as long as the shop hasn't damaged or lost any important parts, you should be able to get your speakers up & running.

There should be a jumper wire beteen terminals T & 2. Your amplifier (+) lead will then connect to terminal 2, and the (-) lead to terminal 1. Do the same for your second speaker.

[JKent]

24 minutes ago, ar_pro said:

There should be a jumper wire beteen terminals T & 2.

I'll bet that's the problem.

And welcome Jeff. Do not despair. There's help here.

-Kent

[ra.ra]

With 2ax's dating from 1964, it would be assumed these are the 'early' version of this speaker model, but please post pics of both speakers without grilles to confirm that correct drivers have been returned to your father's speakers. It may be beyond your comfort level (regarding disassembly), but if you were to post pics of the "new crossovers", some additional and important feedback might also be forthcoming. Good luck, and welcome from me, too.  

[JeffPro]

Thanks for the calming responses! I hope to post some pics tonight (if not it will be a few days), probably images of only the back panel and speakers without the grill.  I'll wait to hear back from the speaker shop before I open anything up.

Hopefully the shop will stand behind his work and get it right. I will be optimistic... and after getting in writing what he used, hopefully finding the old crossovers,he'll fix what is wrong. I do have a feeling he'd rather gut and replace than take the time to fix the old one. Hopefully its just a connection/solder he made that did not hold? He is not open today, and I am out of town for a few days, so it will be a few days before I know more.

If I have the old crossovers back to work with, and you folks think I would be better off fixing them, than we'll cross that bridge later.

I checked the speaker cable hook up again, the jumper is in place just as the pic ar_pro posted and cables pos + to pos. The back panel was not modified, but he did tell me the High and Mid controls would not work. Tried the A & B connections on the receiver, tried making contact with the T supposing he wired it funny, every combo I could think of and no luck.

Good news ...I still enjoyed listening out of the one good speaker last night an entire album (Grateful Dead, Blues for Allah) as I set the good one on top of the other speaker, facing me from about 6' away. Probably the first time I really listened to that entire album so closely, trying to pay attention to the different instruments and voices to determine any weakness to the clarity or depth or inability to handle highs. I wish I had my little bookshelf Paradigm hooked up next to it for reference, but I was somewhat pleased with what I was hearing. It was also nice to hear that with the AR turntable only a foot away from the speaker that there was no feedback or rumbling as my "listening" room is small and will probably sit very close to each other on the same shelf. Watching the woofer, I did not see it flutter like before - maybe it did that when I tried pulling in radio stations and had crappy reception - I was sorta flustered at the time so now I'll have to experiment again. 

It was maybe the late 70's the last time I listened to this AR to AR set up! So glad dad thought to just hang on to them.

 Thanks, Jeff

[samberger0357]

1 hour ago, JeffPro said:

The back panel was not modified, but he did tell me the High and Mid controls would not work.

And was he supposed to fix them?

[JKent]

Hard to know what he meant by "new crossovers." It could be he disabled the level pots and either wired directly or put in resistors. What SHOULD have bee done to the crossovers is replace the 2 capacitors and either clean the pots or replace them with L-pads. I'm at a loss as to why one speaker does not work at all.

The photos below show what your crossover should look like. First is the original. The 2 round white ceramic things on the left are the pots (level controls), the square tan thing is the 2-part capacitor and the round coil of wire in the bottom right corner is the inductor. The second photo shows the same model crossover, with the 2-part capacitor replaced with two individual caps. The third photo also shows new caps, in a slightly different layout (the 2 yellow 3uF caps are paralleled to make a 6uF) and this one has new L-pads.

In order for your speakers to maintain the original sound that was carefully designed into them, they MUST include the 6uF and 4uF capacitors AND the original inductor. And although some restorers bypass the level pots this is a bad idea. New L-pads cost about $3.50 each and will work perfectly.

Hope this all works out. The 2ax is a nice speaker.

-Kent

[Stimpy]

On 1/22/2017 at 0:53 PM, JeffPro said:

Looking for some advice, 

Just picked up a pair of my fathers 1964 AR 2ax speakers from the speaker repair shop. After reading through this and other forums about the many successful repairs done to them, I decided to let a "pro" diagnose and repair them. I had brought them in because while both woofers produced sound, the mid and tweeter on both only crackled to life if I slowly turned the adjusters in the back to make contact, and only stayed there as long as I held it with a little pressure.  The repair shop has been in biz for a while and was told had experience with the older AR's so I totally left it in his hands. When I picked them up I was told the old crossovers were pulled and replaced with new ones and he told me the speakers were tested. I made the mistake of not asking for the old ones back, nor did he write down any specifics of the new crossover on the receipt. I have since left a message this morning asking him to please find the old crossovers as....

I brought them home, hooked up my also recently refurbished AR turntable, dug through my vinyl for the test subject, and when needle hit the groove, was surprised to get only one speaker functioning.

Checked all the connections a million times, switched cables around, and used the AM/FM tuner to confirm it was not the phono or receiver.

Pulled the grills - (shop velcro'd the grill back on to make that easy) to take a look. I could see, smell the putty used to reseal the woofers, but did notice the very edges of the woofer are not sealed up against the aluminum bracket in all areas. The working speaker had the similar gaps around the woofer cone edge but did produce sound. The weird thing I observed on the working speaker is that the woofer cone was fluttering quite hard while the record was playing, and the music was just some fairly folky Grateful Dead at low volume. Watching a few youtube vidoes of working AR's I did not see the woofer cones flutter hardly at all.

So now I feel sick. I should have consulted this forum BEFORE I had them worked on! Most of the posts I read about repairing these speakers usually mention just replacing components of the crossover or just cleaning, but I just did not feel up for taking the time to figure it all out and understand the electrical intricacies..

Is there any clues here to what is going on here? What questions can I ask the shop to make sure it is repaired correctly? If I cannot get this done properly, any other suggested shops in the Chicagoland area to bring them to?

Last dumb question, speaker wire terminals marked 1,2,3 - copper wire should hook up to 1 or 2?

Thanks for reading, Jeff

 

 

 

 

The woofer flutter probably isn't due to the speaker refurb.  It could be system related, as it sounds like LP induced rumble.  Make sure you aren't getting bass feedback, back into the turntable.  Move it away from the speakers, as far as possible.  Isolate it on a sturdy stand too.  And if your receiver/amp has a rumble filter, turn it on.  Hopefully, the turntable to properly set-up, and these tweaks will help?

One other thing, try another source.  Maybe a CD player.  Do you still see the woofer flutter?  If not, you definitely need to better isolate the TT.

Good luck, and welcome to CSP.

 

[JKent]

7 minutes ago, Stimpy said:

the very edges of the woofer are not sealed up against the aluminum bracket in all areas. The working speaker had the similar gaps around the woofer cone edge but did produce sound

A picture is worth  thousand words. Please post photos of these gaps.

[Stimpy]

Why me...?  

[JKent]

On 1/22/2017 at 0:53 PM, JeffPro said:

the very edges of the woofer are not sealed up against the aluminum bracket in all areas. The working speaker had the similar gaps around the woofer cone edge but did produce sound.

better? 

[Stimpy]

Thank You kind Sir...!  

[JeffPro]

Thanks Guys, sorry for not responding quicker as I was out of town this past week. Kent, thanks for the thorough explanation and images, that helped me understand the crossover set up much better. The shop told me he pulled something waxy out that was garbage, I assume that was the 2-part capacitor? I believe he bypassed the level controls,  so I will ask him to repair those instead as it does not seem like the correct parts would be hard to obtain and the consensus leans towards that repair. The specs on the capacitors is very helpful.

I am printing that out to bring down to the repair shop tomorrow and hope to get it all squared away.

The close up of the woofer edge where it meets the aluminum frame is where it is not glued down all the way around, I can pry it up with my finger in spots. Should that be glued back down so the edge cannot come up?

I'll let the repair shop remove the woofer as I don't want to be blamed for why the one is not working, although when I called him, he to suspects a solder did not hold. If he has time I will try to get him to open it up so I can take a pic of the inside. Hopefully he can get it fixed before he leaves for a trip this weekend.

Missing from the pic - I have the little "a" pin as well that was stuck in next to the AR badge, I took it off in case it got lost during transit or repair. The AR badges feel like they are nailed in as I was going to put the one badge in the same corner as the other, not sure which corner is correct - was this done on purpose at the factory? Probably just leave them be.

Thanks again for the input! - Jeff

 

[JKent]

Hi Jeff

“Something waxy” that was garbage was undoubtedly the old capacitor. He replaced it (I hope) with either two bipolar electrolytic or two film caps per speaker.

Repairing the controls is labor-intensive. Probably better to replace them with L-pads but the wiring for L-pads is different so I hope the repair guy knows how to do it. Here's a photo of a corroded pot http://www.classicspeakerpages.net/library/acoustic_research/original_models_1954-1974/original_models_pictures/ar-2ax_pot.html

Yes—glue down the edge. You can use Aleene’s Tacky Glue. Yours are early 2ax's. Very nice and the early woofer is especially nice, but they are old and may need work. Those woofers have alnico magnets, cast aluminum frames and cloth surrounds. All good. but things do come unglued and the cloth can become porous. If they seem to work well after gluing down the edge just enjoy them but if you have any problem with the woofers DO NOT let any local speaker expert touch them. Send them to CSP member RoyC.

The AR badge is screwed on. There is a screw glued to the back of the badge so it can be unscrewed if you want to. Your speaker on the left shows the AR INC badge in the correct location--lower right corner in the photo. The "a" pin goes in the upper right corner. They were originally intended to be put on a bookshelf in the horizontal position, so the badges were on the bottom left and right corners (I think. If this info is wrong Tom will have the correct information). Do you have both "a" pins? If not, send me a PM. Again--yours are early 2ax's. They look like 2a's. Take a look at this web page http://www.mbzponton.org/n2awa/ar2a.html  Later 2ax's had one rectangular logo plate that said "AR 2ax".

-Kent

[RoyC]

20 hours ago, JeffPro said:

The close up of the woofer edge where it meets the aluminum frame is where it is not glued down all the way around, I can pry it up with my finger in spots. Should that be glued back down so the edge cannot come up?

Thanks again for the input! - Jeff

Jeff,

The woofer issue is a common one, and can repaired. A word of caution...Make sure to check both mounting rings. If the ring is lifting under the surround, it is often lifting under the spider too. If you use new glue under the surround's mounting ring, it is much harder to later deal with the lower ring if it requires repair in the future. I often remove the entire cone assembly, shim, and re-glue both rings at the same time.

Roy

See photos:

 

[JeffPro]

I can only imagine this will make most of you folks cringe as it appears the original crossovers are completely bypassed with a set of Dayton XO3W -375/3000 crossovers. He pulled the wax box (2-part capacitor?) out to make room for the new board, but did not see an inductor coil set up like the one in the image Kent posted, he said the inductor was part of the speaker??  The level pots are bypassed as well.  I know you would like to see the inside, but if it is working, I may put that off for now and try to enjoy them for a bit before I mess with it.

The repair guy did not notice the bottom of the woofer cone detached but did glue the outer edge back down with a latex glue.

I picked up the speakers this morning and have not hooked them up yet, but I will tonight and report back. I was told the latex should be dry by this evening, but maybe I should wait longer?

I guess all I can ask of you guys at this point is if your familiar with the crossover he installed, while it may not reproduce the sound of the original set up, is it possible they can do any damage to the speaker?

Any other suggestions on how to treat these speakers going forward. Small room, seriously did not intend to play them loud, but....I am sure I will be tempted to see what they can do in certain sections. I would only play sections loud if the source was pretty clean. If not a good idea, the headphones will have to do.  

Whats done is done and I am just once again sorry I did not join the forum sooner.

Below is an image of the rear label.

Thanks again, Jeff

[JKent]

4 hours ago, JeffPro said:

I can only imagine this will make most of you folks cringe as it appears the original crossovers are completely bypassed with a set of Dayton XO3W -375/3000 crossovers.

YES. Cringe. The Dayton isn't a bad crossover, it's just not the right crossover. So you've spent over $100 on the parts alone: http://www.parts-express.com/dayton-audio-xo3w-375-3k-3-way-speaker-crossover-375-3000-hz--260-150  Roy and others can better address the effect this will have on your speakers.

4 hours ago, JeffPro said:

he said the inductor was part of the speaker?? 

No.

On 1/22/2017 at 0:53 PM, JeffPro said:

The repair shop has been in biz for a while and was told had experience with the older AR's so I totally left it in his hands.

Don't kick yourself--you didn't know. But I do not have anything good to say about the repair shop or their experience with older ARs. What SHOULD have been done was install 2 capacitors and 2 L-pads. Maybe $15 per speaker. AND the old pots could have been sold on ebay.

I don't know what to tell you. Maybe play them and see.

If the guy said he "pulled something waxy out" it sounds like he hasn't a clue (that was the old 2-part capacitor and yes, it was garbage). And the inductor coil does not just disappear. Either he pulled them (they are fairly valuable) to use in another "repair" or he didn't notice them or know what they are. I'm not certain what the specs are on the inductor but I came across a schematic for "early" 2ax's, drawn up by John O'Hanlon (editor of the AR-3a restoration guide). He shows a #5 inductor, L=1.187mH but he does not show the wire gauge or the resistance. I can check a spare AR inductor to see what AWG wire was used. One of these "may" work http://www.parts-express.com/cat/air-core-inductor-crossover-coils/297?N=21723+4294967118+4294962270+4294962269&Ne=10166&Nrs=collection()%2Frecord[endeca%3Amatches(.%2C"P_PortalID"%2C"1")+and+endeca%3Amatches(.%2C"P_Searchable"%2C"1")]&PortalID=1&showMoreIds=21806

Later 2ax's used the #7 inductor, as shown in my photos above. Those are more like 1.88mH.

This really sucks. Those are not something you found at the local Goodwill--they're your father's speakers.

I don't know if there are any CSP members in Chicago. And I would not let that chimp touch the speakers again but I'd tell him I want the big copper coils. If you feel comfortable opening them up yourself we could guide you in the rebuild or, in a pinch I could build new crossovers and mail them to you. 

-Kent

[ar_pro]

Yeah, this is just a shame.

Hopefully, all the shop did was cut some leads, and solder in the Dayton crossover; this would make restoration a much simpler task.

For starters, I would not try to play them - the crossovers are wrong, the status of the wiring isn't known, and the condition of the repaired woofers is still in question. Would it be possible for you to remove and disconnect one woofer, and then carefully (wear a mask & gloves) scoop out the stuffing from the lower portion of the cabinet so that the original crossover can be photographed? Good photos of the original and replacement crossovers would provide significant information.

Kent's advice is solid - it's difficult to imagine any good coming from a return to that repair shop.

[ra.ra]

Sad story indeed, but not a lost cause (yet). Good advice being offered here - - it would definitely be good to identify the actual crossover components installed - - but my biggest concern might be protecting the working original drivers, as ar_pro has already noted. With incorrect crossovers, it's possible that all drivers might be at risk, and who knows if that latex glue repair on the woofers is correct or comprehensive? 

Very generous offer of assistance from JKent, and as he's stated, if you can get the original coils returned (17 ga. copper wire, I think), proper new L-pads and caps would be a relatively small investment to get these fine speakers back in shape.

[JeffPro]

Okay...I'll open one up for a picture and we'll go from there. Just unscrew the alloy bracket and pull (gently) the sucker out.  Do the leeds to the speaker have clips or are they usually long enough to set it aside? Understand the insulation can be a mess, might have to wait until I have some free time on Sunday.

JKent is being very kind with the rebuild offer, I do hope the coil is there as it did not sound like the repair shop has any of the take out parts for me. He kept insisting it was just a waxy box from WWII.

This is a great forum guys, thanks.

[JKent]

2 hours ago, ra.ra said:

17 ga. copper wire, I think

I think you're right ra.ra. I just checked my parts box and found a couple of AR #5 inductors (I had forgotten I had them. In fact I'm still not sure why I have them). Measured the wire diameter with some digital calipers, it's ~1.17mm.  #17AWG is 1.15mm so....  If Jeff has to buy inductors something like these Madisound 16AWG may work https://www.madisoundspeakerstore.com/sidewinder-16-awg/sidewinder-1.25-mh-air-core-inductor-16-awg/

Or.... If I do build the xo's for him I can use the ones I have. But I'm sort of counting on Jeff's still being inside the cabinets where they belong. Hope springs eternal 

1 hour ago, JeffPro said:

He kept insisting it was just a waxy box from WWII

Well...... maybe. It's said Henry Kloss used to scour the surplus electronics stores that used to be on Canal Street in NYC. That's why some early AR speakers had fancy oil-filled mil-spec capacitors. Those Industrial Condenser Corp wax block capacitors may have been WWII era.

btw--capacitors used to be called condensers.

-Kent

PS: Take a look at the AR-3a restoration book. A lot of it is applicable to your AR-2ax's http://www.classicspeakerpages.net/library/acoustic_research/original_models_1954-1974/original_models_schematicss/restoring_the_ar-3a/

[ar_pro]

With the speaker lying face-up, remove all of the bolts, and then gently work a wide-blade screwdriver or paint can opener around the edge of the frame to free the woofer from its seal.

Gently & slowly lift the woofer - the leads should be long enough to allow you to rest the woofer on the edge of the cabinet, so that you can reach under, and remove the clips. Just place a towel or cloth on the cabinet to protect the finish. Oh, and be sure to save the stuffing in a plastic bag, for re-use.

Most important - take great caution that you don't damage the tweeter. The midrange driver has a screen over it, but that tweeter dome is naked to the world!

I'd suggest taking photos of the interior from different angles, as it makes it easier to follow the paths of leads, as well as tell the story of what's been done.

 

 

[JeffPro]

I couldn't wait, so I pulled one of the woofers, came out easy as he did not reputty it all the way around. The leads were long enough like AR_Pro said to set it on the face of the speaker with it lying on its back.

Wires to the speaker are soldered.

Tested the lower speaker cone and unfortunately he did not check them as they are not tight all the way around - his latex job on the top was good enough that I could not break it free. I see now how it will be a little tricky getting under there with the glue.

Pulled the insulation out, should have done it outdoors, I see flecks of the glass on the bench, must be all over. I wiped the area down with several damp paper towels. I believe there was a cloth that was to shield the woofer from the insulation, that was just shoved back in with the rest of the insulation.

Good news though, the large copper coil inductor is still there!

That new board is huge, in comparison to what was there.

The new crossover board is marked so even I can tell what (I think) is supposed to go where. However I could not make heads or tails of the wires coming from the rear terminals going in as it looks like he joined one of the original inductor leeds. The other inductor leed was cut. Also, one of the tweeter leeds was just hanging there, and only one tweeter leed was hooked up to the board so that sure did not look right.

I am so glad I did not hook them up to the receiver!!!

The camera cable is at work, I will down load the images tomorrow. I just had to share the good news (sarcasm).

I'll check the other speaker tomorrow night - in the garage this time.

[JKent]

Wow.

That guy should not be allowed anywhere near classic speakers.

7 hours ago, JeffPro said:

I believe there was a cloth that was to shield the woofer from the insulation, that was just shoved back in with the rest of the insulation.

Absolutely right. Funny the "expert" didn't know that but you figured it out! When time permits, look at the AR-3a restoration guide. It talks about removing the stuffing (page 9) and on page 21 mentions the kimpac--the flimsy paper that was just shoved in the box. And yes--remove the fg from the other speaker in the garage. You can save it in a plastic garbage bag, one per speaker.

Had a conversation with Roy, is is a REAL AR expert and one of the authors of the AR-3a booklet. He vounteered to help too and I would trust the tired old woofers to him. We can discuss further via email.

12 hours ago, JKent said:

I don't know what to tell you. Maybe play them and see.

In retrospect, this was a stupid comment. ar_pro and ra.ra. were right

7 hours ago, JeffPro said:

I am so glad I did not hook them up to the receiver!!!

Wise decision. But don't worry--we'll get them back to their original glory!

-Kent

[JeffPro]

Internal images of the first speaker, 2nd one in a few days.

I'll read through the restoration guide with a little better understanding now.   

-Jeff