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HELP! Sometimes what looks easy at first seems next to impossible when you get into it....

soundminded

By soundminded
in Acoustic Research

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soundminded Rookie

soundminded

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Having solved the riddle of the KLH 6 capacitor so easily, I was ready to take on the riddle of the sphinx. Wrong. Now I've gone from PHD back to Kindergarten.

The same fine person who gave me that free pair of KLH6s also gave me a pair of AR2as and AR2axs. All 8 pots need cleaning/replacement...ok, no big deal. The AR2as have woofers with cloth surrounds that are in perfect shape. The AR2axs have foam rot. OK, clean the pots in the AR2ax, and swap out the woofers and I"ll have a nice pair of AR2axs while I'm waiting to get the woofers that came out of them refoamed. Sounds easy enough. Removing the 4 bolt AR2ax woofers was easy. OK the AR2as are 6 screws and removing them was easy too. I'll just drill the extra holes and use a large sheet metal screw the way KLH did. Now for the kicker. The AR2ax used foam gaskets for a seal. The AR2as, at least the pair I have used putty. I don't know if AR made the finest woofers in the world but there's no doubt they had the finest putty. It WON'T RELEASE the woofer. I don't know if this putty is 30 days old or 30 years old but whatever it is, it's the best putty I've ever seen. And so far, I've been completely unable to pry the woofers out. Any ideas? BTW, there is only about a 1/16" clearence between the woofer frame and the inside edge of the deeply routed cabinet. Can't seem to get anything in to pry it loose. I've started removing the putty around the edges but it's slow go.

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onplane Newbie

onplane

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soundminded:

I have no answer for, but can sympathize with your problem.

We own rental property that’s over 80 years old. Whenever I have to repair one of those original windows with the original window putty, it’s a challenge. I swear that putty has turned to ... rock.

The only way (and I’ve tried everything) is to apply heat. I use a torch, but that won’t help you.

How about a hair dryer?

Regards,

Jerry

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soundminded Rookie

soundminded

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Well I managed to pry one out. I scraped all the putty out that I could between the outside edge of the speaker and the routed well it sits in and then I found a piece of hardware (it was once actually once used for hanging venitian blinds) which had a small 90 degree lip on it which I managed to wedge in between the bottom of the driver and the putty and used as a prybar and finally the putty gave way. New problem, the outside diameter of the AR2a woofer is about 1/4 to 3/8 inches larger than the AR2ax and so does not fit in the same routed opening. So I can modify the cabinet or.....just wait to refoam the AR2ax drivers which is what I will do. I'm not sorry I took this woofer out, I have to remove the other one too. I've noticed quite a few differences.

AR2a is a heavy cast frame, AR2ax is a much thinner stamping.

AR2a has a felt ring glued near the center of the cone, AR2ax doesn't. And AR2a has the old round magnets, AR2ax has the square ones. Also AR2a does not have the screen mesh AR2ax used and AR2a used much heavier gage wire than AR2ax (not that it matters.) So, I will clean the pots for AR2a, put the speaker back together and use them while I wait for the AR2ax woofers to be refoamed. I've got quite a few other drivers which need refoaming too. Any recommendations near central NJ?

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johnieo Newbie

johnieo

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Any recommendations near central

>NJ?

Should you get to the city- Minh Luong is in Brooklyn; he too does excellent work.

re: prying woofer. Look in Home Depot for a paint can opener with an end like a screwdriver whose tip is bent 90 degrees to the side. Then pry against a flat metal piece like a putty knife as you did.

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soundminded Rookie

soundminded

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Thanks for the advice. I've spoken with Bill Miller of Millersound today and based on my discussions with him and recommendations here, I'm certain he will do an excellent job. He's only an hour's easy drive from me which is much better than going to Brooklyn. BTW, I managed to pry out both woofers by first removing most of the putty, what a job that was, and I didn't even damage them

Insofar as the crossover networks are concerned, I can't be sure if the woofer series inductor is the same for 2a and 2ax but the rest of the circuit seems exactly the same (except for 2a having 2 5" drivers in parallel instead of a single 3" midrange for 2ax of course and different tweeters. I'm thinking of substituting fixed resistors for the pots. Anyone have any data for the settings which give the flattest response for either or both of these models?

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dynaco_dan Newbie

dynaco_dan

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>Having solved the riddle of the KLH 6 capacitor so easily, I

>was ready to take on the riddle of the sphinx. Wrong. Now

>I've gone from PHD back to Kindergarten.

>

>The same fine person who gave me that free pair of KLH6s also

>gave me a pair of AR2as and AR2axs. All 8 pots need

>cleaning/replacement...ok, no big deal. The AR2as have

>woofers with cloth surrounds that are in perfect shape. The

>AR2axs have foam rot. OK, clean the pots in the AR2ax, and

>swap out the woofers and I"ll have a nice pair of AR2axs

>while I'm waiting to get the woofers that came out of them

>refoamed. Sounds easy enough. Removing the 4 bolt AR2ax

>woofers was easy. OK the AR2as are 6 screws and removing them

>was easy too. I'll just drill the extra holes and use a large

>sheet metal screw the way KLH did.

Hi there;

I will suggest you buy 1/4-20 T-Nuts from Home Depot or Lee Valley type store, and use these, as the tension on the woofers frame will be more uniform.

Also if you want to, try to replace the surrounds yourself.

I will be honest with you, if I can do it, you can too.

Patience is the pre-requisite, time and a comfortable place to do it.

My first 12" woofer took me about 1 1/2 hours and the second one about 10 minutes.

This would be for just the actual re-foaming, not removing and re-installing and testing the woofers.

If you are too busy, then you can have others do it for you, but I would suggest that you go for it.

You will also get a good feeling of accomplishment, and have a more intimate knowledge of how they were built, when you are finished.

It isn't all that mysterious, but, the correct surrounds are required, AR 12" not generic 11".

Being slightly Scottish, I will say that you can save yourself maybe $50.00+ by doing it yourself, depending whether you carry in the woofers or the entire enclosures, or ship them.

Good luck.

Now for the kicker. The

>AR2ax used foam gaskets for a seal. The AR2as, at least the

>pair I have used putty. I don't know if AR made the finest

>woofers in the world but there's no doubt they had the finest

>putty. It WON'T RELEASE the woofer. I don't know if this

>putty is 30 days old or 30 years old but whatever it is, it's

>the best putty I've ever seen. And so far, I've been

>completely unable to pry the woofers out. Any ideas? BTW,

>there is only about a 1/16" clearence between the woofer

>frame and the inside edge of the deeply routed cabinet. Can't

>seem to get anything in to pry it loose. I've started

>removing the putty around the edges but it's slow go.

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