Repairing speaker cloth surrounds (AR-4xa)

[PkkHnttnn]

I am trying to repair a pair of AR-4xa speakers. Instead of foams this pair seems to have cloth surrounds. It does not look good, but I am not sure if and how I can repair it. Should I put some kind of rubber glue to prevent air going through the fabric or what?

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• PkkHnttnn
• Nov 21, 2020

AR-4xa suspension

 

[RxDx]

No glue. Vintage-ar on ebay sells a sealant that doesn't destroy the flexibility of the cloth.

 

[alteclipsch]

I'm not seeing anything wrong with that speaker in the image. Can you point out the flaw? The cloth surround appears dry but it is easily restored with the compound recommended by RxDx above. Any other treatment will destroy it.

 

[PkkHnttnn]

Thanks for the comments. I am a newbie in this so all advice is welcome.

 

[alteclipsch]

The AR 4X and XA are really nice speakers. With the correct maintenance to the woofer surrounds and crossovers, they're forever speakers. There are several threads to search here that will steer you in the right direction. Check them out before proceeding. And welcome to AK!

 

[GD70]

The 4x is an excellent small speaker. The sealer mentioned comes with a small brush to apply it. Apply one thin coat, then wait for a couple hours. These are not a completely sealed design, as the woofer dust cap allows some air to pass through it, but after the sealer has set for several hours, gently push the woofer cone inward, and let go. If is returns slowly, then no more sealer is needed on the surrounds. If the cone pops back immediately, then apply another very thin coat of the sealer. That should be all you’ll need.
Next, are the tweeters producing sound? When rotating the pot knob on the back, does the tweeter output increase and decrease smoothly, or fairly smoothly? Or does it completely drop out? The “pots” are notorious for corroding which blocks the signal to the tweeters. If this is happening, you’ll need to pull the drivers, fiberglass stuffing, and remove the pots for inspection, cleaning, or replacement if badly corroded. Lots of info on AK about this.
Thirdly, you’ll most likely want to replace the caps on the crossovers. Generally, age has caused them to drift out of spec. When I had mine, fortunately they sounded great and didn't feel I needed to do this, but most of the time vintage speakers benefit with a recap.
Just putting this all out there for you to be aware of, which is very common with vintage ARs.

Cheers, Glenn

 

[PkkHnttnn]

The 4x is an excellent small speaker. The sealer mentioned comes with a small brush to apply it. Apply one thin coat, then wait for a couple hours. These are not a completely sealed design, as the woofer dust cap allows some air to pass through it, but after the sealer has set for several hours, gently push the woofer cone inward, and let go. If is returns slowly, then no more sealer is needed on the surrounds. If the cone pops back immediately, then apply another very thin coat of the sealer. That should be all you’ll need.
Next, are the tweeters producing sound? When rotating the pot knob on the back, does the tweeter output increase and decrease smoothly, or fairly smoothly? Or does it completely drop out? The “pots” are notorious for corroding which blocks the signal to the tweeters. If this is happening, you’ll need to pull the drivers, fiberglass stuffing, and remove the pots for inspection, cleaning, or replacement if badly corroded. Lots of info on AK about this.
Thirdly, you’ll most likely want to replace the caps on the crossovers. Generally, age has caused them to drift out of spec. When I had mine, fortunately they sounded great and didn't feel I needed to do this, but most of the time vintage speakers benefit with a recap.
Just putting this all out there for you to be aware of, which is very common with vintage ARs.

Thanks, that is great piece of advice for a newcomer! It is a pleasure to learn new things. Both woofers and tweeters produce sound, luckily. I fell in love with this pair when I bought it in a garage sale and I try to do my utmost best that they are restored without any damage done.

Pots and caps have been in my mind. A question about this: the crossover is built on a piece of board on the cabinet wall. If it is necessary to take it out temporarily, how is it attached? Is it glued?

Regards
Pekka

 

[GD70]

Thanks, that is great piece of advice for a newcomer! It is a pleasure to learn new things. Both woofers and tweeters produce sound, luckily. I fell in love with this pair when I bought it in a garage sale and I try to do my utmost best that they are restored without any damage done.

Pots and caps have been in my mind. A question about this: the crossover is built on a piece of board on the cabinet wall. If it is necessary to take it out temporarily, how is it attached? Is it glued?

Regards
Pekka

You don’t need to remove the crossover. Take note of the original cap value for the replacement. Just cut the original wires from the old cap, solder in the replacement cap. The caps are non-polar, so it doesn’t matter which end of the cap is soldered to the original wires. New caps have a much higher Volt rating, which is fine. The cap value is what you need to match, 20uf.
Glenn

 

[nerdorama]

I might just mention that you can also buy the sealer direct from @RoyC here on AK. He will sell you a larger bottle for about the same price. The sealer is his development. Just send him a PM.
John