Newbie: When to refurbish AR 4x speakers

amplifiers, receivers and loudspeakers
billsea
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Re: Newbie: When to refurbish AR 4x speakers

Post by billsea » 20 Jan 2019 16:09

A question for phivates. Are the woofers designed for foam or putty cabinet seal? Is this aspect specific to the speaker or the type of cabinet?

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Re: Newbie: When to refurbish AR 4x speakers

Post by phivates » 20 Jan 2019 16:23

AR used a non-hardening putty with a name I don't recall; I have relied on foam weather stripping when remounting drivers when the funny putty didn't survive the removal. A minor consideration I would say, but AR thought through everything in those days. The putty probably contributes some damping to the junction between driver and enclosure.

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Re: Newbie: When to refurbish AR 4x speakers

Post by derspankster » 20 Jan 2019 16:38

You can use duct seal available at home centers and hardware stores. It's basically the same thing. I've used it quite a few times. Not expensive and easy to apply. For instance - https://www.amazon.com/Rectorseal-81880 ... B008A3UG94

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Re: Newbie: When to refurbish AR 4x speakers

Post by phivates » 20 Jan 2019 17:40

Do not use silicone, btw. Ductseal is a good idea, if it doesn't glue the driver in place. I have some; will give it a try.

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Re: Newbie: When to refurbish AR 4x speakers

Post by derspankster » 20 Jan 2019 17:52

Duct seal will not glue the driver in place. Duct seal is as close to what was originally used in my 3a and 4x as I have seen. I'm sure you can find some repackaged stuff on web sites for 20x the price.

billsea
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Re: Newbie: When to refurbish AR 4x speakers

Post by billsea » 20 Jan 2019 18:39

May try duct seal. I would buy some stuff from Vintage AR ebay store but he is away and soon to be on vacation.

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Re: Newbie: When to refurbish AR 4x speakers

Post by jdjohn » 20 Jan 2019 19:41

I've used Aramacell tape to make gaskets. It's cheap and works great. Just cut a long strip to the needed width, and it self-sticks in place on the rim of the cabinet. I recently used it on woofers for a pair of AR-2ax.

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Re: Newbie: When to refurbish AR 4x speakers

Post by Spinner45 » 20 Jan 2019 20:44

What AR, Advent, and others have used for speaker basket seals is Mortite.
It's a caulk/weatherstripping putty-like ribbon.
Available at Home Depot and other hardware stores.
mortite.JPG
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phivates
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Re: Newbie: When to refurbish AR 4x speakers

Post by phivates » 20 Jan 2019 22:44

Why am I not surprised you would know this?

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Re: Newbie: When to refurbish AR 4x speakers

Post by jdjohn » 20 Jan 2019 22:53

Whichever type of gasket material you use, make sure to take care of the hurricane nuts on the inside of the cabinet when re-installing the woofers. Don't push the screws all the way through the holes, or you will also push the hurricane nuts out. Start the screws gently so they grab the threads of the hurricane nuts, and then continue tightening. To that end, don't cover the screw holes up with the putty if you go that route...you don't want the putty going into the threads of the hurricane nuts.

billsea
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Re: Newbie: When to refurbish AR 4x speakers

Post by billsea » 20 Jan 2019 23:19

phivates wrote:
20 Jan 2019 22:44
Why am I not surprised you would know this?
He does always seem to be spot on. As for the hurricane nuts, I have found them and by dumb luck they are all still in place. These tips are much appreciated! I'll attach a pic of the circuit. It has a Sprague cap which I've read hold up pretty well. The wisdom seems to suggest I replace it anyway.
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Re: Newbie: When to refurbish AR 4x speakers

Post by phivates » 20 Jan 2019 23:43

One point of view is that if the cap measures close to its stated value then carry on with it. The other main view is that something 50 years old is still working luck is involved and luck runs out. So if you replace them, do you go fresh electrolytic (cost effective) or poly plus some resistance? And which poly? Do you try a series connection? Get ready for a long haul

billsea
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Re: Newbie: When to refurbish AR 4x speakers

Post by billsea » 21 Jan 2019 01:59

I saw Roy C. recommend Carli 20 mfd caps with a voltage of 150. Its a poly I think. I think I can clean my pots/rheostats n wire em back in. I've yet to look into the parallel/series thing.

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Re: Newbie: When to refurbish AR 4x speakers

Post by Spinner45 » 21 Jan 2019 03:04

phivates wrote:
20 Jan 2019 22:44
Why am I not surprised you would know this?
LOL! :lol:

When for about 45 years you've sold (professionally), repaired (professionally), and personally owned a plethora of equipment during that time, and through that, rubbed elbows on occasion with numerous manufacturer's engineers and staff, you kind of amass a little bit of knowledge.
Plus, receiving service bulletins from manufacturers along with tips on servicing.

As for the Mortite - glad to be of help.

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Re: Newbie: When to refurbish AR 4x speakers

Post by derspankster » 21 Jan 2019 03:34

Or you can use duct seal. Many people do. Best of luck on your work, newbie!