Speaker refoaming

QuadraphonicQuad

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I recently purchased a complete vintage stereo system. It included a Marantz 2325 and a pair of Cerwin Vega D9 speakers, turntable, cassette recorder, graphic equalizer, and sound processor. The woofer foam of the speakers was dried out. I am in the process of repairing them. I have a refoaming kit on order, which should arrive next week. It includes foam, glue, dust caps, and voice coil shims. Any tips or advice would be appreciated.
1 Speaker removed from cabinet
2 Spacer removed
3 Foam removed from frame
4 Dust cap removed
5 Foam removed from cone
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ar surround

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A couple of tips:

- Be sure remove ALL of the old foam and glue. 91% isopropanol should do the job, but be patient.

- Be sure to use the shims. Don’t eliminate them in the process.

- You will install the surround first. Make sure the glue has totally cured (even waiting overnight) before removing the shims and installing the new dust cap.
 

par4ken

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A couple of tips:

- Be sure remove ALL of the old foam and glue. 91% isopropanol should do the job, but be patient.

- Be sure to use the shims. Don’t eliminate them in the process.

- You will install the surround first. Make sure the glue has totally cured (even waiting overnight) before removing the shims and installing the new dust cap.
I've never used shims, none of the kits that purchased ever came with any but they are a good idea, If the voice coil rubs then you've wasted your time. I've always prefered woofers with rubber surrounds, I've never seen them rot like the foam surrounds do.
 

ar surround

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I've never used shims, none of the kits that purchased ever came with any but they are a good idea, If the voice coil rubs then you've wasted your time. I've always prefered woofers with rubber surrounds, I've never seen them rot like the foam surrounds do.

I had never used shims and never had a problem until I did a set of Boston Acoustic speakers. One came out fine, but the voice coil rubbed on the second one. I had to buy a complete new refoam kit and remove the freshly glued surround. The shims are definitely worth the extra coin.
 

Bill B

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Really cool thread. Good information and succinct.
I have never tried that before but I have learned a lot. Beats the hell out of throwing them out.
Thanks to all who participated (y)

One question. Do most speaker manufacturers sell the kits?
 

par4ken

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Really cool thread. Good information and succinct.
I have never tried that before but I have learned a lot. Beats the hell out of throwing them out.
Thanks to all who participated (y)

One question. Do most speaker manufacturers sell the kits?
I don't know for sure if any do. There are many aftermarket kits available though. Do an internet search. I know that there are many available on eBay as well.
 

godathunder

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if youre not using shims the best way of centering the coil in the magnet gap is to play a low frequency tone at very low power (cone barely moving) through the speaker while the adhesive sets.
 

Doug G.

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I have also never used shims to refoam, either. Reconing yes, it's mandatory, but with refoaming, the cone is already centered where it is attached to the spider.

All that needs to be done is to keep the VC parallel to the pole piece and that is accomplished by pushing down on the cone around it's perimeter as the glue sets/dries. If there is no rubbing at any point, it's good. I have never had a failure in the many drivers I have refoamed.

And, although a picture of shims installed was posted, it's not really clear where they are. They go between the VC former INNER circumference and the pole piece.

Doug
 

ar surround

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Great picture and actually, the original picture depicting where the shims go is pretty good, too. My eyesight is just bad.

Doug
Mine ain’t exactly 20-20 either

Good ole OptiVISOR to the rescue:
 

Sonik Wiz

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I did a test drive today, and it seems the operation was a success. I just need to glue the new caps on. Here’s a picture of the system I bought.Thanks to everyone for the information and encouragement.View attachment 73273

Congratulations on a successful project! I've been following this this thread with quite a bit of interest. I sent out my Infinity Kappa 8 (fronts) and Kappa 7 (rears) to be refoamed professionally once. Based on what I've learned here I might give it a try myself next time.

A question for those that know more than me: how does one purchase or choose with assurance they are getting replacement surrounds identical to OEM specs?

I liked your pic & seeing the Pioneer RG-1 Range Expander. I had two of those at one time, for front and rear. I think they are preferable to the following model RG-2.

How/why did you arrive at that EQ curve? Most folks I know with multi-band EQ (including myself when I used to need one) used a "V" shape to get a bit more boom & tizz out of the speaker.
 
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