RE-DOPING Is Not Always a Good Idea (???)

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Following Roy C's instructions to the letter, I resealed a pair of cloth surround woofers. They now sound flat with a dramatic decrease in bass. I wonder if anyone else ever encountered this situation: I can only theorize, the surrounds factory sealant had dried out many years ago and the speakers were played over those years. This caused irreparable sagging and stretching of the surrounds.

So, when I resealed them, all I ended up doing was adding mass to the surrounds and stiffening and preserving them in their stretched, saggy state.

They still work; so I donated them to Goodwill. It's OK, I learned a ton about speakers from this experience.

Thank you.

 

[Nat]

It's hard to know exactly what change you are hearing without knowing what speakers you redoped or anything further about the system, or your abilities - one person's following to the letter is not the same as another person's.
The amount of mass you added (I'm assuming that you used the AR dope sold on the internet) is not much at all - so little that people use it to redope ADS tweeters. And given that the compound remains sticky for a long time, if it hardened in a relatively short period, I suspect something in the surround is the culprit. f it caused sagging and stretching, I suspect that the surrounds weren't adhered to the basket or cone properly.
More likely, I guess, is that whatever speaker you doped sounded better to you with a very leaky enclosure (functionally a ported one), and in doping it, you changed its sound to something you liked less. Bummer. But not necessarily an indictment of the sealant.
I think you did a good deed in passing them on to someone who may like them as they now are.

 

[Grid]

It's hard to know exactly what change you are hearing without knowing what speakers you redoped or anything further about the system, or your abilities - one person's following to the letter is not the same as another person's.
The amount of mass you added (I'm assuming that you used the AR dope sold on the internet) is not much at all - so little that people use it to redope ADS tweeters. And given that the compound remains sticky for a long time, if it hardened in a relatively short period, I suspect something in the surround is the culprit. f it caused sagging and stretching, I suspect that the surrounds weren't adhered to the basket or cone properly.
More likely, I guess, is that whatever speaker you doped sounded better to you with a very leaky enclosure (functionally a ported one), and in doping it, you changed its sound to something you liked less. Bummer. But not necessarily an indictment of the sealant.
I think you did a good deed in passing them on to someone who may like them as they now are.

Thank you. Very good arguments, indeed.

The speakers were from a Utah A-100 acoustic suspension system. The dope is that sold by Roy C. The dope did not harden and was still sticky when I donated the speakers. Yes, maybe with age and dryness and continually playing them over many years, the surrounds were no longer adhered properly. I had not thought of that. And that attributed to the sag. So, by resealing them, without re-adhering them to the basket, I just made the sag permanent.

Also, I'm fairly sure the enclosure was leaky before and after resealing the surrounds.

I've attached photos of the dried out surrounds. I happen to have a second set of these woofers that have retained much of their factory sealant. I've included a photo comparing these with the dried outsThey have dramatically more bass

I should have been more clear. In no way was I indicting Roy C's dope or the practice of resealing surrounds. I just thought I'd post my experience so that others whose surrounds have dried out and stretched may as well not reseal what is essentially a damaged surround. That is, as I have learned from your reply, unless the surrounds can be re-adhered to the baskets. But then that raises the question I hope can be answered for my future reference: how does one know how to properly adhere the surrounds to the baskets so that they are not sagging? Are there specs on that? Measurements? By ear?

Again, thank you for your insights.

 

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P.S.: Yes, I really do believe they sound good enough to where the average Joe, who'll buy them cheap at Goodwill, will be happy. Also, you can't GIVE these away on eBay