AR 58B repair HELP!

[Guest shutterbug1_99]

Hi,

My name is Jerry Sirois. I have a pair of AR 58B's that I purchased new in the 80's. I have two daughters (grown and moved out now) I think one of their less than intelligent boyfriends stuck their finger into the dome shaped piece on the center of the woofer and midrange. Using a piece of cardboard tubing and some suction was able to pull them back out, their not perfect but pretty good. The midrange speaker seemed to be detached approx. 25% of the way around the outer edge where it connects to the frame. I powered up the speakers and that part seems to have reattached itself (does the glue never dry?) I also noticed a small tear in the outer ring of the midrange, my first thought was super glue but this would stiffen it and that's a very flexible part. On the other speaker I don't see the woofer moving at all and can't hear any sound from it. Even in this condition these speakers can send a chill up my spine. I would like to bring them back up to peak performance, but before I go any further I decided to seek some opinions. Pictures of woofer and midrange attached.

Any help would be very much appreciated

Jerry Sirois

[r_laski]

Jerry,

>> The midrange speaker seemed to be detached approx. 25% of the way around the outer edge where it connects to the frame...

I also noticed a small tear in the outer ring of the midrange, my first thought was super glue but this would stiffen it and that's a very flexible part.<<

The “outer ring of the midrange” you are referring to is the foam surround of the midrange. The tear and detachment indicate the surround has “dry rotted” and needs to be replaced – what is often called re-foaming. You should have both midranges re-foamed at the same time.

You may encounter a problem with finding a speaker repair shop that can re-foam these for you. It is difficult to find new surrounds for these small size midranges.

>> On the other speaker I don't see the woofer moving at all and can't hear any sound from it. <<

We need to know if the woofer is “locked up.” If you gently push on the woofer cone just outside of the dust cap (dome shaped Piece in the center of the woofer), does the woofer cone move in and out? (You push in on the cone slightly and the suspension will return the woofer cone to its neutral position.)

If the woofer is locked up – it doesn’t move – you have two options:

1) Have the woofer re-coned where the cone, voice coil, spider, and surround are replaced.

2) Purchase a replacement AR woofer.

If the woofer moves freely, you need to check to see if the wires inside the cabinet are still connected to the woofer and check (or have someone check) the electrical continuity of the woofer.

By the way, given the condition of the midrange surrounds, the woofer surrounds are probably in similar condition and you should consider having them re-foamed as well. If the "non-working" woofer has to be re-coned, it will be re-foamed. You should have the working woofer re-foamed at the same time.

Rich

[mluong303]

Hi Jerry,

You may want to contact AB Tech about replacement drivers for your AR-58B speakers. Re-foam job on the midranges may cost close to the new drivers themselves!

http://www.abtechservices.com/pages/2/page...h=1134188465692

Tel: 800-225-9847

Ask them if the spec is compatible?

Minh Luong

http://www.classicspeakerpages.net/dc/user_files/1282.jpg

[Guest shutterbug1_99]

Hi Rich & Minh Luong

Rich: I did as you said, the woofer was not locked up so I checked the wires (I read somewhere about putty between the speaker and cabinet these don't have putty it's just a gasket) I found a lack of continuity between one of the terminals and the wire that goes to the cone. I heated it up with a soldering iron and pushed it in about 1/32" and applied more solder. This was the problem, It thumps again I also read somewhere to check the surround, use a pencil eraser and lightly drag it around, the surround should flex and pop right back into position. This sounded quite risky but I tried it anyway, I'm certainly not an expert but I think the surrounds on my woofers are ok, they seem very flexible and pop right back into position and the eraser does not leave a mark at all. I believe the damage to the surround on my midrange speakers was caused by finger abuse. I found some 4" surrrounds on ebay, I ordered 2 for $3.00 including shipping. They list the ID of the surround at 2 3/4". My cones are a little less than that and it is my understanding that the surround should overlap a little. I'll see when they get here. At that price I'm not losing much.

Minh: If I am unable to repair or have repaired at a reasonable price, I will contact abtechservices. I have looked at their website and $45. ea seems reasonable.

I have learned the dome in the center of the speaker is called a dust cover. I guess dents in this do not affect the sound?

Thank You both for your input, you have helped me out very much

Jerry Sirois

[r_laski]

Jerry,

>> Thank You both for your input, you have helped me out very much. <<

Your Welcome! Glad we could help out.

>>I found a lack of continuity between one of the terminals and the wire that goes to the cone. I heated it up with a soldering iron and pushed it in about 1/32" and applied more solder. This was the problem, it thumps again. <<

From your description it appears you had a cold solder joint (dirty or corroded) between the terminal connector and the braided wire. Great job finding and fixing it! You saved $$ by not having to re-cone or replace that woofer.

>> I also read somewhere to check the surround, use a pencil eraser and lightly drag it around, the surround should flex and pop right back into position. This sounded quite risky but I tried it anyway, I'm certainly not an expert but I think the surrounds on my woofers are ok, they seem very flexible and pop right back into position and the eraser does not leave a mark at all. <<

You are probably right about your woofer surrounds. Had the eraser poked holes or caused tears in the surround, it would be time to replace them.

>> I have learned the dome in the center of the speaker is called a dust cover. I guess dents in this do not affect the sound?<<

Generally speaking, a dented dust cover on woofers and cone midranges have little impact on their sound. However, you do not want to have any dents in the dome of a domed tweeter or domed midrange speaker.

>> I found some 4" surrounds on ebay, I ordered 2 for $3.00 including shipping. They list the ID of the surround at 2 3/4". My cones are a little less than that and it is my understanding that the surround should overlap a little. <<

Let us know if those surrounds work for you. If not, there are a couple of web site / speaker repair shops that should have the 4” surround kits you need, or they can re-foam for you.

Rich

[Guest JIm Tavegia]

Jerry, I am new to this forum but spend considerable time at the Stereophile web site and forum. I also own a pair of 58s.

I have refoamed the woofers with supplies from New Foam. The link below sells replacement woofers. They might be able to help you locate the small surrounds for the midrange if you ever need them.

If you replace the foam surrounds there are mylar strip spacers that fit between the magnet assembly and the voice coil to keep it centered so it will not loose position and "scrub" when the glue dries. It is not that hard of a job, it just takes time.

The center "dust cap" just keeps stuff out of the voice coil and you get new ones with the kit. Make sure you pull out the mylar spacers before you glue on the new dust cap.

http://www.simplyspeakers.com/index.htm

http://www.newfoam.com/

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I am now using Triangle Cometes in my main listening room, but I still have not heard anything but Quads that would make me give up or sell my 58s. There is something magical about a 2 cubic foot box that my original AR 3s did well. I really regret ever selling them. I use my 58s in my vintage system that I use for computer audio now.

Regards,

Jim Tavegia

Atlanta