# Cloth Surrounds on older speakers



## TJ Mobile Audio (May 6, 2009)

I'm restoring some Marantz Imperial 7s (not the best speakers, but definitely not the worst) and my major hang-up is the doped cloth surrounds on the 12" woofers. They are still intact, and I can't hear anything wrong with the bass, they just look "dead". I've been reading on some HT forums, but since I'm here I'll start here.

Does anyone have experience restoring cloth surrounds? They just look grimy and dry, with lint and stuff stuck to the original surround doping. I can't seem to rub the old gunk off, and I don't want to tear the surrounds trying to get it off. The cabs are ported, and there's no acoustic reason to change anything (as far as I can tell), but I'd like them to not just sound but also _look_ new when I'm done, so I can show them off!

I've thought of replacing them with foam, but there's something to be said for both the durability and charm of cloth surrounds IMO.


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## chad (Jun 30, 2005)

You won't get the old doping off, if it has settled mount the driver upside down and carry on.


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## TJ Mobile Audio (May 6, 2009)

Thanks for chiming in, Chad. The dope hasn't settled, so much as dried in place. But I did rotate the woofers 180° on a whim when I first got these speakers about 5 years ago. I haven't noticed any change. PS, is there any way to recoat them, or is that inherently evil?


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## chad (Jun 30, 2005)

Well I have never seen is dry up.. let me google those drivers..... the doping I'm thinking of is like the stuff on Lansing/JBL stuff.


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## TJ Mobile Audio (May 6, 2009)

I think it only seems dry because of all the dust it's collected over the last 30+ years, which may have also pulled some of the dope away from the cloth. In a few places the surround creases a bit when the speaker moves, which suggests to me that the fabric is no longer supple enough. Perhaps this is normal with cloth surrounds, but if the creasing is a problem I don't want to let the them crack or tear from normal use.


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## chad (Jun 30, 2005)

that's supposed to be dry, it's not s sticky type doping right? The pleats you see when you push hard are normal, the speaker will likely never excurt that far. They can likely be cleaned with a lightly dampened cloth or a tack cloth from a paint store.


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## TJ Mobile Audio (May 6, 2009)

It's a bit tacky on the less dusty side. What used to be the bottom collected more dust over the years (presumably due to gravity). The creasing starts when the speaker moves just less than 1/4". I have occasionally seen it crease like that on it's own while the speaker was playing, but you are correct that I rarely have it that loud. I think the woofers are a bit prone to unloading with the way the cabinets are tuned, but this hasn't been a concern because I mostly use them for movies and classical music, not hip hop etc.

I will try dabbing them with a slightly damp cloth and see if that works. You don't recommend putting anything on them though? I suppose if they ever did wear out I could easily go to foam.


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## TJ Mobile Audio (May 6, 2009)

I just spent about 5 minutes cleaning a 1 cm section of the surround, and it got pretty clean. It sure would be nice if I could get them to shine like new, but that is really just vanity. Do you know of any light product I could use after cleaning them? Or is it just standard practice to leave doped cloth surrounds alone?


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## chad (Jun 30, 2005)

I'd leave them alone although I'm kinda known to use Scotchgard on pro drivers.


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## TJ Mobile Audio (May 6, 2009)

Thanks for the pointers, Chad. I'll bump dealing with the surrounds to the bottom of the list, the mids and crossovers still need attention. I'll give it some extra listening time and maybe meditate for a while before I worry any more about the surrounds. I'll probably just end up cleaning them and leave it at that.

Hmm, Scotchgard...


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## chad (Jun 30, 2005)

TJ Mobile Audio said:


> Hmm, Scotchgard...


rain proofs 'em


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## TJ Mobile Audio (May 6, 2009)

chad said:


> rain proofs 'em


Now you've got the wheels turning. Next on my project list: building outdoor speakers with paper-cone woofers!

:laugh:

You think I'm not serious...


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## chad (Jun 30, 2005)

most pro speakers are glass reinforced paper.. or reinforced with something


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## benhinkle711 (Jun 30, 2009)

Sounds like you came up with a solution but in the future you may want to try AudioKarma's Speaker forum. The guys there are very friendly and extremely knowledgable about vintage speakers. And there is a very good chance someone there has experience with the speakers you're working on.


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## TJ Mobile Audio (May 6, 2009)

Thanks, I actually signed up there and did some reading, but haven't had time to dig into it. Chad is familiar enough with "non-car" audio that I'll probably take his advice and just leave it alone.


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