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Cassrat

Restoration stopped at woofer

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Good afternoon everyone!

I popped in on MikeW earlier to say hi.  We both have the same speakers, and it seemed like a good time, after reading through this website for a couple weeks.

So, quickly to catch up:  My girls are AX84793 & AX84707.  30+ in a garage, and only tweeters functioning.  I started looking on line when I realized they needed to be cracked open, and found this website.  As Kent suggested, I did load, read, and followed the manuals. So after removing grills, I THOUGHT I knew why my woofer wasn't playing, no glue.  Both rings had completely come unglued.  It fell out, hanging only by the braids.  So I de-soldered that, took it out, and set aside.

This is where I am at: The pots were cleaned in place, and not de-soldered.  They were very clean.  The copper pads barely had green showing on them.  The chrome crown was also clean.  Only the bottom edge of the center dial showed the mildest of white corrosion on the very edge.  They cleaned up beautifully.  I now have functioning tweeters and mids.  

The woofer....I cleaned the Masonite rings.  Because they were so powdery, I dyed them black to seal them, and give the glue something to hold on to.  I also roughed up the aluminum frame edge too, for the same reason.  The voice coil was tight in place (Wow!  A solid copper core, wrapped with copper wire...I thought they were all paper!), and showed slight separation.  I epoxied that crack, so it wouldn't fall completely apart after doing all this.  Wiped and cleaned it with acetone.  I then reinforced the seams of the woofer with a quick coat of glue..just in case.  I am now getting ready to resolder the braids back to the frame, that had been cleaned and prepped (screens removed).  However, when I set the cone in the magnet to do the battery polarity test...nothing.  No movement.  A tracer shows that something is getting to the woofer voice coil, but not moving it.  The magnet is clear too.  I saw some of the stuff that can come out, again, I'm clean as a whistle.  The wire strap between T & 2 is also in place.

Other than going to my friend's house to check the ohms on the woofer... What should I do next?  Am I screwed?  I don't want to start replacing caps (because they can be done later) and inductors for no reason.  This is not my forte.  I was attracted by the wood cabs (badly damaged) and the fact they both had the pins and badges.  Refinishing the wood, grills, and badges I can do in my sleep.  It's the rest I now need help with.  Even with the copious amounts of information on this website alone, and 2 weeks pouring through it, I am still embarrassing lost and have no problem admitting it. 

That's where I'm at.  Thanks for reading, and any advice you can give. 

Mark 

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2 hours ago, Cassrat said:

The woofer....I cleaned the Masonite rings.  Because they were so powdery, I dyed them black to seal them, and give the glue something to hold on to.  I also roughed up the aluminum frame edge too, for the same reason.  The voice coil was tight in place (Wow!  A solid copper core, wrapped with copper wire...I thought they were all paper!), and showed slight separation.  I epoxied that crack, so it wouldn't fall completely apart after doing all this.  Wiped and cleaned it with acetone.  I then reinforced the seams of the woofer with a quick coat of glue..just in case.  I am now getting ready to resolder the braids back to the frame, that had been cleaned and prepped (screens removed). 

Cassrat

I have been watching, thinking you would get a response before now but your post, IMO does ring some warning bells and could be causing some hesitation.

What you describe is clear and normal until the part about the woofer.  You seem to be describing actions that don't make sense unless your woofer is truly dead and you know how to repair it in which case you would not have posted to begin with. Stop where you are and supply photos of what you have done to the woofer and someone may be able to help sort it out.

Adams

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OK When you said unglued they really are completely unglued.   Your woofers are beyond the usual state of disassembly when these old speakers are opened.  They can be repaired I assure you and you may be able to do it yourself but I have never had to completely reassemble one of these.  I would say send them to Mr Legall for repair but others with deeper experience may see a simpler solution.    

That looks like a cast frame woofer. Did it or does it have a cloth surround intact?  You will need more complete photo coverage for better advice.

Adams

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Piece o' cake :-) I blew the glue on an AR-2 like this.

The spider needs to be attached first. Cut the dust cap mostly open (leave a bit so
you can just hinge it, and then reglue when done). Shim the voice coil to center it, glue
the spider. Actually you'll probably put glue on the spider and then shim the vc. Let
that dry, then reglue the surround. Solder the leads, you're done.

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dxho

Thank you for the response.  But my immediate problem is still the polarity.  Deciding which braided wire goes to the red "+" sticker on the frame .  Without being able to figure that out, the rest is moot until then.  But, should they work, I will take your advice on shimming.  Just not at that point yet. The battery test isn't working when I try it.  That's why I don't want to glue it yet.  I used clothes pins to hold the frame to the basket for the test, and saw or heard nothing.  

Adams

Yes, the "cloth"  surrounds (the material looks and feels to be an industrial silk, formed under high pressure), no rips, tears, or damage.  They were an uneven yellow smoke/nicotine color, that also was dyed for appearance.  I am not familiar with the gentleman's name you mentioned.  But, I'll get to that later.  I'll will post some pictures tomorrow in the day of the surrounds, and anything else requested.  Right now, calling it a day. Thanks again.

To all:  Please note, I appreciate any and all help.  My thanks ahead of time to everyone, just in case I should miss someone.  I don't want to anyone to feel snubbed or unappreciated.  I'm scatter brained, and simply may just forget altogether... Have a good night one and all!

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My feeling here is that your first step should be to see if your voice coil wiring is intact and conducting current. This is really best done with an ohm meter. If the voice coil form is tight/rubbing in the magnetic gap and you have seen some separation, that may indicate a damaged coil but a meter will tell you for certain. As far as polarity is concerned, if you were to solder the braided wires to the wrong terminals, all that would be necessary to correct things is to switch the wires connecting to the woofer.

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jessiAV

Good morning.  Yeah, the ohm meter reading was the next step I had planned.  As for polarity...I get what you are saying.  Basically, I can take the little red "+" and just move it to the other side of the frame, if I do it wrong.  Guess I over thought that one.  Doh!  I'll work on checking power through the cone coil.  I still have hope.  Thank you for the input!

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Check both the voice coil and the tinsels (braid wires) by an Ohm meter. Old tinsels  could be broken and measure open whereas the voice coil is OK.

Luigi

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Ok.  Morning (oops, afternoon) all.  Thank you Luigi, that's exactly what I just did. 

So to catch up.......I checked the braids.  I also touched the outside of the coil.  It wasn't until I touched the copper inside the coil, that the meter did anything.  My conclusion

Name:. Acoustic Research #84793

Date of birth: May 22nd, 1968

Date of death: March 12, 2018. (1:13p.m.) 

Cause of death: Voice Coil/OL

At this point the project is come to a grinding halt.  Any diy suggestions, or alternatives that are cost effective, are greatly appreciated at this point.

1520882371189-1986468458.jpg

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Sounds like the voice coil wire is broken somewhere on the former. Unless you're set up for
repair or rewinding, your options are to pay a pro to do that or seek a replacement used
woofer. Nothing available new will match. I don't know which would be more cost-effective.

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dxho

That's what I thought.  If I dissect the cone and manage to pull the voice coil, can it be rewound?  It has a solid copper core winding plate.  I would really hate to trash that.  If so, what is that cost, and who can do it?  Are there replacements?  Again,  this is assuming I can extract it.  I am beginning to fear BOTH speakers suffer from the same condition.  I would even be willing to wind by hand if I knew how.  At this point, what more damage could I possibly do?  What about saving the frame and putting in a all new innards?   Thoughts?  I have time and patience, just no money.  My house is 137 years old, was abandoned since the last century (I purchased in 2012), been on a city demolition list for the last 20 years, and needs... EVERYTHING.  Thus, the money situation.   Again, any info on coil repair or information is greatly appreciated.  I'm Detroit, maybe someone local here?  I should have listened....I should have thrown the damn things out.  I feel that that kid everyone talks about who rescues animals and brings them home.   With me...it's anything circa my era or older.  I should have listened...

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It's a pretty fiddly fix. Hard to know exactly what it needs w/o knowing where
it's broken. New voice coils are available ready to install for ~$35-40. Looks like
reconing is ~$85. But neither will match the original sound.

There's a used woofer at auction for $53. Others have sold for $25-85. You can
keep it cheap if you're willing to wait.

I like the sound of these things, but if you're done, the good parts will bring some
money.

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dxho

I appreciate the input.  I was hoping to get these going for regular players.  I have my father's mid 1950s Electro-Voice Esquires...but they need work.  Been pampering them for years now.  I may wait a little while before totally mothballing this project.  I will periodically check online for a woofer.  But, should I get ambitious, could you recommend a place where I could possibly get just the voice coil for that woofer?  Oh, and I think I saw the one for $53.  I know I saw one, but it said "has issues", not sure about that though.  Thanks again.  I'll check in later.  

 

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You are indeed correct on the $53 woofer. RoyC sometimes has units for sale at
reasonable prices.

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You may want to contact Millersound speaker repair. He's been in business a long time with a stellar reputation.

If these were mine, I'd just find a correct replacement and get to listening! Have you listened to the other speaker, and does it exhibit the same symptoms? I not trying to dissuade you from fixing them, but a full rebuild may cost more.

Glenn

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On 3/11/2018 at 9:54 PM, Aadams said:

I would say send them to Mr Legall for repair

 

On 3/12/2018 at 1:20 AM, Cassrat said:

I am not familiar with the gentleman's name you mentioned.

 

47 minutes ago, GD70 said:

You may want to contact Millersound speaker repair.

So... It's Bill LeGall of Millersound in PA. Great guy and an absolute speaker genius. Maybe give him a call....

http://www.millersound.net/contact-bill-legall-millersound.html

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JKent and GD70, two people say Millersound...so, Millersound it is.  I will contact them, and see what they say.  I have NOT REMOVED the other woofer...yet.  I will do both in the next day or so.  But I have looked for another woofer, and voice coil replacement/repair.  Thank you gentlemen.  I'll stand back, recoup....and do some more investigative work. I, on very (VERY) rare occasions, do have things that sometimes (eventually) do work out.  I'm hoping that is is one of those times.  I'll check in soon.

Mark

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Ok.  Hooked up little sister (AX #84707).  The tweeters play beautifully, mid range only scratches slightly when turning the knob.  Woofer...out.  The battery test clearly shows it's getting s signal (...yeeeeah....), just not paying sound.  This woofer DEFINITELY has a butyl coating, whereas the other had none.  I mean zip! 

Now, here is a truly dumb question...if one were to be over zealous cleaning the voice coil (because you thought there was a schmutz coating it, only to find out it may be a vanish or an enamel coating), and perhaps stripped that coating off...would that be enough to cause problems.  I.e.: say causing an ohm meter to read OL if tested? The wire is still attached firmly to the core, just shiny now.  I spent a good hour with a magnifying glass looking for a break, nothing (yes, it may be underneath, I realize that).  Did I screw up being too OCD, lol!?   Can I fix it?  What the heck is ferrofluid?   

I also removed the flat dust cap today without cutting, in case that the above mistake can be corrected, and I can shim the voice coil and reattach.

 

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Both voice coils need replacing.  Any recommendations?  What size should I get, and from who?   If I can get parts, that would be great!  Woofers first, then caps, and they should play.  I think the coils they are 1.125 length. Diameter is???  Both speakers are ready to go.

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31 minutes ago, Cassrat said:

Both voice coils need replacing.  Any recommendations?  What size should I get, and from who?   If I can get parts, that would be great!  Woofers first, then caps, and they should play.  I think the coils they are 1.125 length. Diameter is???  Both speakers are ready to go.

I still recommend that you send the woofers to Bill LeGall, at Millersound, for repair.  Sometimes it's best to leave certain repairs to the professionals.  :D

Millersound.

 

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Stimpy,

I appreciate the advice, but sending them out is cost prohibitive.  I may send an email to Millersound, but given how busy the website says he is,  I'm not going to expect an answer.  It says not to contact unless requesting service.  I'm not requesting service.  I need the correct parts, voice coils and caps.  That's it.  Cloth surrounds, dust cap, cone, Masonite rings and spider are all still excellent.  Parting them out is not an option, I'm limited by time, dealing with shipping, and the hassle.  What money I would get from it, would not be worth my trouble. Sad and frustrating, seeing as they make replacement parts for everything but the coil.

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On 3/12/2018 at 8:14 PM, dxho said:

It's a pretty fiddly fix. Hard to know exactly what it needs w/o knowing where
it's broken. New voice coils are available ready to install for ~$35-40. Looks like
reconing is ~$85. But neither will match the original sound.

There's a used woofer at auction for $53. Others have sold for $25-85. You can
keep it cheap if you're willing to wait.

I like the sound of these things, but if you're done, the good parts will bring some
money.

dxho,

Do you know where to get the replacement  woofer voice coils you mentioned?

 

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10 hours ago, Cassrat said:

Stimpy,

I appreciate the advice, but sending them out is cost prohibitive.  I may send an email to Millersound, but given how busy the website says he is,  I'm not going to expect an answer.  It says not to contact unless requesting service.  I'm not requesting service.  I need the correct parts, voice coils and caps.  That's it.  Cloth surrounds, dust cap, cone, Masonite rings and spider are all still excellent.  Parting them out is not an option, I'm limited by time, dealing with shipping, and the hassle.  What money I would get from it, would not be worth my trouble. Sad and frustrating, seeing as they make replacement parts for everything but the coil.

It's best to call Millersound.  If you do, at least explain the shape of the woofers, and ask for a repair quote.  Bill LeGall is very reasonable in his repair rates.  He'll probably cost less than you think.  Plus, as much as you value the woofers and the speakers, I'd hate to read later on that the restoration failed, for whatever reason.  At least with Bill, that won't happen.  Even do one woofer at a time, as funds permit.  No need to rush.  Just do it right.

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