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Refoamed Cerwin Vega D5

Z

ZanderTibell

New Member
Hey guys! Im a 14 year old guy from Sweden who loves vintage Hifi. In the past week I decided to try and refoam 3 pairs of speakers. My own (Luxor 8071), my brothers Cerwin Vega AT-40 and my oldest brothers Cerwin Vega D5. My Luxor 8071 sounds awesome now, same with the AT-40 but one of the D5 woofers scrapes. I did put paper in the voicecoil but it seems like I failed with one of them. I really don’t want to destroy his speakers. We tested them and one sounds good but the second one sounds bad. How could it get of center when I put “distances” in the voicecoil? Do I need to redo that woofer or can I dissolve the glue? Please help me, with kind regards Zander Tibell.
 
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Yes. You need to refoam that one woofer. I assume it was working fine before the new foam ?

You can try loosening the glue with a heat gun, or razor blade perhaps. It that doesn't work, then just tear it out and refoam. Run a test tone thru it as you glue it back together. That'll show where you have to nudge the foam to find the sweet spot so the voice coil doesn't rub.
 
I putted “shims” so I thought I didn’t need to put a test tone thru it. But how do I do it when I glue it? Won’t the tone do so the foam moves?
Do I use a heat gun to dessolve the glue? Can’t I damage the foam then? Is there other efficient ways to do it? Kind regards Zander Tibell.

EDIT, they haven’t been played on for about 20 years.
 
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There's certainly a chance that the heat will melt the foam. You gotta be careful. It also depends on what glue you used. I've had luck slicing the foam off with a sharp exacto blade. It's slow going, but worth a try. Worst case is you ruin the foam and have to put a new one on anyway.

I glue to the cone first. Then the next day i connect the driver to my amp playing a 30Hz test tone off Youtube, volume off. Then I apply glue to the basket side. I let it sit about 10 minutes so it gets good and tacky and just let it fall into place and press lightly around the edges. Turn up the volume and see if it's scraping...you don't need to go very loud. At that point the glue is still slippery and will allow for some adjustment, it's just trial and error to slide it around until you find that spot where the rubbing stops. Then press the glue down really hard and let it sit, continuing to press occasionally and checking with the test tone a few more times.

If there is no sweet spot, then somebody damaged the voice coil by playing them with damaged foam. But i've only encountered that once or twice.
Usually speakers sit for years unused, then get sold off as-is. Always remove the grills before you buy.

I wish you the best of luck. I'm confident you'll get it fixed.
 
If you didn't play it long and loud then you'll be fine. CV drivers are pretty forgiving.
 
We played a couple minutes and I played pretty loud but when I started to hear the scratchy noise I turned it of. I hope it’s not destroyed. By the way, I removed the foam now and putted some shims in the voicecoil. When I glue I wait and after 10 minutes I remove the shims and play a test tone. I cross my fingers!
 
ZanderTibell said:
I putted “shims” so I thought I didn’t need to put a test tone thru it. But how do I do it when I glue it? Won’t the tone do so the foam moves?
Do I use a heat gun to dessolve the glue? Can’t I damage the foam then? Is there other efficient ways to do it? Kind regards Zander Tibell.

EDIT, they haven’t been played on for about 20 years.
Click to expand...

The only refoam I've done that has failed was using shims.

It is possible you did the refoam fine but the spider has sagged. Sometimes this can be fixed by simply rotating the woofer 180 degrees.
 
Hey guys, I don’t know what to do anymore, I manage to move the foam and I didn’t not hear any scraping on a very high and very low volume thru the test tone. I tested it multiple times and i hold it up so it stood in the position like it does in the speaker cabinet and it worked fine but when I putted it in the speaker cabinet both elements started scraping. What is wrong, I don’t want to destroy the voicecoil, I just want to make my brother and myself happy… Please help me. With kind regards Zander Tibell
 
Hi Zander.
Sorry to hear the problem still exists, that should have fixed it.
I would swap drivers from one cab to the other, be sure the problem follows the suspect driver and it's not something else. Then look for excessive spider sag. Double check all glued connections...foam and dust cap.
 
I just thinks it’s so weird that I can play both elements at a very high volume thru my tonegenerator (even when I hold them up in the position like they sit in the speaker cabinets) but when I put them in the speaker cabinets they make this scraping sound.
 
The noise is coming from the woofer. Both speakers have this issue just that I can play louder on one of them before this weird noice starts. I think that I am supposed to be able to play louder on both of them before this noice starts. I turned both of them 180 degrees but it didn’t change anything. With kind regards Zander Tibell
 
Did you try the same setup with a different set of speakers ? Sure it's not amplifier distortion or something else ?
 
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Zander, can you post a short video ( on the Tube), of that noise, and let us look at the woofer?.
Maybe the woofer was already damaged before your 1st atempt?...
 
I've reformed several D5's where the customer complained of odd noises on loud bass notes. I ran signal sweeps through the woofer out of the cabinet. Finally tracked it down to loose panels in the cabinet. Forced glue into the offending joints and strapped them tightly. The odd buzzes and rattles finally ended.

Can't remember the speaker brand, but another woofer only buzzed when mounted in the cabinet. Turned out the wire from the crossover to the woofer terminals was pushing up into the woofers frame when I screwed the woofer into the cabinet. When the cone moved in and out it buzzed and rattled against the wire.

Just a couple thoughts .
 
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