Refoaming woofer drivers

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I came by a pair of old Allison AL-120 speakers a while ago that had deteriorated woofer surround foams. I removed the 4 woofers and cleaned up the cones & baskets. The new replacement surrounds arrived today from SimplySpeakers. I have glued the 4 foam surrounds to the cones this afternoon and they are curing/drying. Soon I will be aligning and gluing the foam to the baskets. Anyone else here rebuild speakers? I've never done this before. May be a new career move (at 75 yrs old)
 
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Great Lakes
Heh, I have plenty of speakers, but none of them old enough to need new foams. I think my oldest are PSB Alpha B bookshelves that I bought in 2006, and a 12" SVS cylinder sub bought around the same time. Any pics of your speakers and the refoaming process?
 
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Central Arkansastan
I have done that before. Saved an older set of JBL 8 inchers. Once you glue down the cone to the basket, immediately run music through them while they dry, and that will help align the voice coils so they don't bind on the magnet
 

AVB

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1,461
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Georgia
I have done one pair. The foam kit I ordered came with a cd to play at low power to keep the coil centered. I think it was like a 40hz test tone to keep it from moving too fast. It also came with clear plastic shims to center the voice coil, but you have to remove the center cap to use them.
 
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2,027
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WY
Just follow the instructions and space the voice coil evenly. Make sure you are at the null point when you glue the circumference. The new foam is stiff enough to pull or push the coils so be careful. I haven't tried the playing music on uncured glue trick.
 

AVB

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1,461
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Georgia
You don't need the music to be loud enough to hear, just enough to make the coil center it's self. Using a battery may be even better because it would hold the cone stationary. I am not sure how many volts you would need a 2 AA holder from lowes or home depot should work and not over heat the voice coil.
 
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Ohio
I just refoamed my old Rockford Fosgate Punch HE2s which are almost as old as I am. I'm 18 now and I ran them as my first system when I got my car at 16. I bought them at a garage sale still NIB with my lawn mowing money for $10 back in (IIRC) 4th grade, my dad and I built a box together and put them in his truck and he ran them until he took them out because he needed extra cargo space and never put them back in. I ran them until the foam totally just crumbled to nothing during the summer of 2018. Between my love for old-school gear and the background story these subs have I couldn't let go of them. About a month ago I found a pair of new-old-stock foam surrounds on eBay and with a lot of clothes pins, some cancer-glue, and an xacto knife I refoamed both subs and currently have them running on my home theater receiver.
 
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Originally Posted by Quattro Pete
Heh, I have plenty of speakers, but none of them old enough to need new foams. I think my oldest are PSB Alpha B bookshelves that I bought in 2006, and a 12" SVS cylinder sub bought around the same time. Any pics of your speakers and the refoaming process?
Pete: I figured out how to post pics thumbsup
 
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681
Location
New Hampshire USA
Found a pair of heavy speakers in the ditch a couple years ago and connected them to an old Kenwood car radio and they sounded fine. After reading the previous posts am fired up to replace the mostly missing cones. Believe they fell off somebody's moving truck.
 
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MD
Have you looked at the crossovers? Upgrading the capacitors can really improve the sound sometimes.
 
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1,334
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texas
Yes if they are really old and they used electrolytic caps you might consider replacing them as they dry out over time. No need to go crazy with quality here but any NP electro cap from an audio place (Parts Express, Madisound) would work. The metal film (mylar or Poly) caps last forever so no need to replace them.
 
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Originally Posted by ET16
Have you looked at the crossovers? Upgrading the capacitors can really improve the sound sometimes.
You may be on to something ..... I got the 4 woofers done,installed in the cabinets and ready for their first road-test. It was then that I found one of the tweeters intermittent and suffering from exactly what this gentleman found with his speaker https://www.youtube.com/watch?v=okaZeSYzctA My refoamed woofers appear to be well centered and quiet in their excursion yet muddy in their sound reproduction in some passages - both tweeters are working now. The speakers aren't performing up to par and the cross-overs would be the next circuit to examine ....... [Linked Image]
 
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The speakers needed a "burn-in" period of running with the new foam surrounds. I checked all components and re-assembled the speakers and test ran them for awhile under load (Led Zeppelin) The longer they ran the better they sounded...... I got them wired up in the TV room and they sound great. My $10.00 Onkyo 7.1 TX-SR606 driving my $50.00 (repair parts) Allison AL-120 speakers make a great sound bar/stereo setup. [Linked Image]
 
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