mctr Posted April 28, 2021 Report Share Posted April 28, 2021 I will start this off by saying although I've dug through many threads about restoring, recapping, refoaming, repotting these speakers I am pretty much a total newbie to actually doing the things. The other day I came across some pretty decent looking AR-5s on the local marketplace. Took em home, took off the grills, and the foam is gone. Alright, I can handle that. Pulled the woofers. One measures 6 ohm, which is fine I think, and the other, open. Not great! So I dig out the rockwool and look at the crossovers: One appears to be fine, the other looks like where the resistor wire (?) is on the little board has basically burnt to a crisp including a bit of the surrounding insulation. I didn't remember to make not of which speaker came out of which cabinet but am I right to guess that the blown woofer probably came out of the cabinet with the fried resistor? My questions are: 1. What might have happened here and what kind of damage may this have caused to the blown woofer, if in fact it came out of the same cabinet? Or are these things unrelated? 2. What might it cost to get this blown woofer fixed? I'm looking around and guessing I won't be able to find the right drop in part any time soon. I'm not far from Millersound, I'm guessing that is the best place to go for a repair. Thoughts? Next move is going to be clean up the pots (or bypass) to see if the mids and tweets are functional. Then caps after that. Thanks for any help Quote Link to comment Share on other sites More sharing options...
Aadams Posted April 28, 2021 Report Share Posted April 28, 2021 2 hours ago, mctr said: My questions are: 1. What might have happened here and what kind of damage may this have caused to the blown woofer, if in fact it came out of the same cabinet? Or are these things unrelated? 2. What might it cost to get this blown woofer fixed? I'm looking around and guessing I won't be able to find the right drop in part any time soon. I'm not far from Millersound, I'm guessing that is the best place to go for a repair. Properly restored AR5s are among the cream of the crop of all speakers, including new ones of today. Photos of drivers would be helpful so we all know that we are talking about the same things. For instance your pictures show glass fiber but you mention rock wool. Are your drivers original or service replacements? The resistor and woofer burned out from too much current, perhaps someone messing with signal wire with the amp turned on would be my guess. Adams Quote Link to comment Share on other sites More sharing options...
mctr Posted April 28, 2021 Author Report Share Posted April 28, 2021 Oh yes my apologies. I will add pictures as soon as I can. The driver is stamped Oct 1972 with a square magnet with rounded edges if that helps for now. Quote Link to comment Share on other sites More sharing options...
RoyC Posted April 28, 2021 Report Share Posted April 28, 2021 The speakers were probably driven at high volume for an extended period of time. The burned resistor wire is in series with the midrange. Roy Quote Link to comment Share on other sites More sharing options...
mctr Posted April 28, 2021 Author Report Share Posted April 28, 2021 45 minutes ago, RoyC said: The speakers were probably driven at high volume for an extended period of time. The burned resistor wire is in series with the midrange. Roy Makes sense. What would you expect to find with the midrange? Fried? And would you think the woofer would be repairable by a pro (millersound)? Quote Link to comment Share on other sites More sharing options...
mctr Posted April 28, 2021 Author Report Share Posted April 28, 2021 6 hours ago, Aadams said: Properly restored AR5s are among the cream of the crop of all speakers, including new ones of today. Photos of drivers would be helpful so we all know that we are talking about the same things. For instance your pictures show glass fiber but you mention rock wool. Are your drivers original or service replacements? The resistor and woofer burned out from too much current, perhaps someone messing with signal wire with the amp turned on would be my guess. Adams Here is a driver and the speaker sans grill as found. Quote Link to comment Share on other sites More sharing options...
Aadams Posted April 28, 2021 Report Share Posted April 28, 2021 8 minutes ago, mctr said: Here is a driver and the speaker sans grill as found. What you are showing is original. Do the corresponding drivers in each cabinet appear identical? Quote Link to comment Share on other sites More sharing options...
mctr Posted April 28, 2021 Author Report Share Posted April 28, 2021 Just now, Aadams said: What you are showing is original. Do the corresponding drivers in each cabinet appear identical? Yes they are both identical. When I took the grill off it seemed like it had never been removed. The disintegrated foams were all up in there. Quote Link to comment Share on other sites More sharing options...
RoyC Posted April 28, 2021 Report Share Posted April 28, 2021 4 hours ago, mctr said: Makes sense. What would you expect to find with the midrange? Fried? And would you think the woofer would be repairable by a pro (millersound)? Millersound could repair it, but the rebuild kit results in a somewhat different response compared to the original. If these were driven hard enough to fry the resistor wire (a rare occurrence) all the drivers should be checked independent of the level controls and crossover. The capacitors should be measured or simply replaced. If you are not experienced, and are located near Millersound, just have Bill check everything out. Roy Quote Link to comment Share on other sites More sharing options...
mctr Posted April 29, 2021 Author Report Share Posted April 29, 2021 15 hours ago, RoyC said: Millersound could repair it, but the rebuild kit results in a somewhat different response compared to the original. If these were driven hard enough to fry the resistor wire (a rare occurrence) all the drivers should be checked independent of the level controls and crossover. The capacitors should be measured or simply replaced. If you are not experienced, and are located near Millersound, just have Bill check everything out. Roy Given the options I think I'd prefer using the original driver as opposed to trying to find one that matches or two new ones that (likely) aren't original. I guess the #1 order of business would be to check to see if the mids and tweeters are still operational and figure everything else out after that. Caps and such are trivial. I'm about an hour from Millersound but I am also trying to do this without spending a ton of money, unclear what they would charge. Quote Link to comment Share on other sites More sharing options...
JKent Posted April 29, 2021 Report Share Posted April 29, 2021 You can call Bill. I’ve used his services a couple of times and thought he was very reasonable Quote Link to comment Share on other sites More sharing options...
Phxjohn Posted May 6, 2021 Report Share Posted May 6, 2021 I have a pair of original 6's. A previous owner abused them or had a mishap. The pots were not corroded, they were burned. The spiders on the woofers were also torn loose. That might be something to check for with the OP's woofers. Quote Link to comment Share on other sites More sharing options...
mctr Posted May 6, 2021 Author Report Share Posted May 6, 2021 24 minutes ago, Phxjohn said: I have a pair of original 6's. A previous owner abused them or had a mishap. The pots were not corroded, they were burned. The spiders on the woofers were also torn loose. That might be something to check for with the OP's woofers. Woofers physically look fine (obviously one is reading open). Unfortunately this might be a long project as I have a newborn. Yet to even pull the pots out. Quote Link to comment Share on other sites More sharing options...
Phxjohn Posted May 6, 2021 Report Share Posted May 6, 2021 I am glad that the woofers look fine because to rebuild the woofers is expensive. Kent T on here has the correct pots at great prices. I am going to get four for my AR 3a's as they were rebuilt with L-pads before I purchased them. Quote Link to comment Share on other sites More sharing options...
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