Speaker Repair 101?

[Sprague]

clueless here, how would I fix that wee perforation at the bottom right there? man, it's delicate! gargles away in the quiet bits. (hehe, I know, "just turn it up!") awesome speaker though, (Sonab OA 14)

 

[hbrocks]

refoam kit....

 

[RamblinE]

It's not hard to do. I did it once. I got glue all over the place then I had to hold the new surround on with stacks of pennies that I found in the pockets of my jeans and jackets. If I can do it......

 

[87RangerXLT]

If it is paper you can always try this method...

http://www.youtube.com/watch?v=jW7xuJ2gHOY

 

[HTHMAN]

Refoam it. The top left of your surround looks like it is cracked. Won't be long until the whole thing fails. It is easy. Search this forum and you will find a lot of advice and some tutorials.

 

[woodj]

It looks like the foam is cracking up

Hard to tell, but as HTHMAN says, there appear to be some cracks. A refoam on these would probably be for the best. If the foam all around was good, a skillful application (holes only, sometimes a couple of applications) of rubber cement could work.

 

[Sprague]

thanks fellas, I think it's all paper though, I don't see any foam! (yes, that's how clueless I am)

Anyway, I gave this one a burl,

If it is paper you can always try this method...

http://www.youtube.com/watch?v=jW7xuJ2gHOY

thanks Ranger, diluted-glue gently dabbed (man, it is delicate paper, surely the whole thing could crumble at any second) just waiting for it to dry

 

[Sprague]

Well, the dried glue looked good. Couldnt see any glaring holes. But I must have buggered it up cos' the bass is decreased and the gargling is worse. Now I might be needing a time machine to go back to Carlsson labs circa 1974. Thanks.

from Carlsson site:

Too thick coating makes the cone heavy and the sound reproduction is heavily reduced.

Bugger. Seemed like I hardly coated any on but I'm guessing this is what I did.

Tried going back to my ol' Sony SSV715 AV speakers but man, they sound like muffled wool in comparison.

Wonder if the neighbours wouldn't mind joining me in a seance to connect with Stig Carlsson. He'll know what to do.

 

[Copa1934]

Old surrounds will almost turn powder like, so it could be confused for paper. And based on how "delicate" you say it is, it almost has to be foam surround. Looks like a fairly common angle front attach surround. Couldn't find a replacement by name, but possibly by dimensions. If you can PM me and provide measurements I can let you know if there is a generic surround available.

 

[Sprague]

Thanks chief. Some fairly terrifying stuff for the layman c/o the Carlsson site:

DISASSEMBLY
Start by removing the speaker from the enclosure. DO NOT touch the screws outside the speaker-rim, these are fixing the acoustic-damping device behind the mid-bass woofers. This acoustic damping device has been impedance adjusted at the Sonab factory to give each speaker correct bass-reproduction and the correct transient response. Just unscrew the four screws going through the rubber suspension into the speaker perimeter.

 

[juniorJBL]

It appears to be an inverted foam glued to the front of the cone.

If you feel a ridge where the color changes out towards the edge of the cone that is another "layer" of foam where it attaches with glue to the cone.
This is the part that is "replaceable".

Cntact GordonW for parts.:thmbsp:

 

[RayW]

It sounds like your "acoustic damping device" might be an aperiodic vent, kind of like the Dynaco A25. If that's the case then it's possible that over the years it has gotten gummed up with dust, dirt and general detritus. If so, that would put greater pressure on the surrounds (causing gargling) and giving less bass.

If you fixed one part of the surround but left another hole open then I would expect the gargling to increase as the air speed and force would increase in the unfixed hole.

 

[Copa1934]

Thanks chief. Some fairly terrifying stuff for the layman c/o the Carlsson site:

By the way, go to youtube and check out the speaker surround repair links. Either it will help or it will scare you off. Either way, you'll want to know what's involved and how other people have done it.

 

[Sprague]

yeah thanks chief, had a look at them, thats where I got the diluted glue idea but as Ray says, if i7d missed a tiny hole, more air would be whooshing through? Kind of terrified to unscrew the whole thing, down the runway we go, through the tyres, over the field, and into the drink.

 

[RayW]

It might be worth it to just treat the whole surround. It would cover any holes that exist, shore up the existing surround, and not leave you any worse off than you are now.

 

[Sprague]

It might be worth it to just treat the whole surround. It would cover any holes that exist, shore up the existing surround, and not leave you any worse off than you are now.

yeh mate, this is what I've done, just waiting for it to dry. Big thanks to Copa for his helpful & patient PM's but man, I just cannot see myself delving underneath there. I can pretty much see how that will go...

http://www.youtube.com/watch?v=OBBFzerJ1Ss

 

[Sprague]

Hopefully problem solved. Or at least staved off.