Hello everyone. I have a fairly old but good subwoofer, it's the old Hertz ML3800: https://www.rgsound.it/prodotti/atch/pdf_ml3800.pdf
The woofer sounds great, and I would like to use it to make a sealed subwoofer for my car with Linkwitz transform.
However this speaker has what looks like a rubber coated fabric surround and it seems the rubber coating is cracking in multiple parts. Some parts are even coming off thus leaving the fabric surround exposed.
Beside looking terrible, I think this could have some effect on the sound on the long run as I suppose the rubber coating was there to make the surround stiffer and less lossy.
I would like to replace it but the original surround isn't available anywhere, even Axiomedia doesn't have it anymore.
Is there any way I can replicate this treatment to a cloth surround or should I just replace it with a generic rubber-only surround since it's gonna go in a sealed box?
The woofer sounds great, and I would like to use it to make a sealed subwoofer for my car with Linkwitz transform.
However this speaker has what looks like a rubber coated fabric surround and it seems the rubber coating is cracking in multiple parts. Some parts are even coming off thus leaving the fabric surround exposed.
Beside looking terrible, I think this could have some effect on the sound on the long run as I suppose the rubber coating was there to make the surround stiffer and less lossy.
I would like to replace it but the original surround isn't available anywhere, even Axiomedia doesn't have it anymore.
Is there any way I can replicate this treatment to a cloth surround or should I just replace it with a generic rubber-only surround since it's gonna go in a sealed box?
You could re-dope the cloth surround with this type of glue:
https://www.parts-express.com/Speaker-Repair-Glue-1-oz.-Bottle-340-076?quantity=1
Remove flaking parts, dope the cracks, then lightly brush on another coat inside and out.
https://www.parts-express.com/Speaker-Repair-Glue-1-oz.-Bottle-340-076?quantity=1
Remove flaking parts, dope the cracks, then lightly brush on another coat inside and out.
That glue isn’t going to have the same flexibility characteristics as the rubber.
I have used rtv silicone to do rebuilds of surrounds that have all but disappeared before, often using paper towel material impregnated with the goop, keeping it thin for smaller speakers, a bit thicker for larger drivers. Doing it in steps, applying smaller strips in a radial pattern to maintain alignment in the worst cases. Leave enough material for adequate throw.
Can you find a replacement surround, and use the glue shown above? That would be best.
I have used rtv silicone to do rebuilds of surrounds that have all but disappeared before, often using paper towel material impregnated with the goop, keeping it thin for smaller speakers, a bit thicker for larger drivers. Doing it in steps, applying smaller strips in a radial pattern to maintain alignment in the worst cases. Leave enough material for adequate throw.
Can you find a replacement surround, and use the glue shown above? That would be best.
Thank you for the responses.
It looks like the coating has hardened completely making the surround very stiff. If I push on one side of the surround I can feel a lot of resistance and it is very hard for the surround to "reset" to the original shape.
On the edge where the surround attaches to the gasket it has cracked along the entire circumference of the subwoofer. On the surround it's mostly fine, it's just super hard. I took some pictures of the damage. Excuse me for the very dirty speaker, it is stored in my garage.
I think adding PVA glue without removing the old hardened stuff may just make the surround even harder.
It looks like the coating has hardened completely making the surround very stiff. If I push on one side of the surround I can feel a lot of resistance and it is very hard for the surround to "reset" to the original shape.
On the edge where the surround attaches to the gasket it has cracked along the entire circumference of the subwoofer. On the surround it's mostly fine, it's just super hard. I took some pictures of the damage. Excuse me for the very dirty speaker, it is stored in my garage.
I think adding PVA glue without removing the old hardened stuff may just make the surround even harder.
FWIW, in another lifetime we used wintergreen to soften pro slot racing foam tires and mixed in some alcohol to 'taste' for rubber.
Small soft artist brush. Dip in acetone. Gently massage it into surround in a small circle.
When dissolved let it mostly dry and then make another circle next to and overlapping a tiny bit.
TV or newspaper close by are mandatory so as to not get bored. Same applies to ventilation. Yeah. - I would say that acetone simply doesnt provide a good high. Måre like dizzy headache.
Cheers!
When dissolved let it mostly dry and then make another circle next to and overlapping a tiny bit.
TV or newspaper close by are mandatory so as to not get bored. Same applies to ventilation. Yeah. - I would say that acetone simply doesnt provide a good high. Måre like dizzy headache.
Cheers!