Dbl refurbishing LF cabinet acoustic foam

Swarm knowledge needed
I know on the old forum was a thread about refurbishing dbls, in particular the LF cabinets. ATC still does reconing of the drivers which I am contemplating to have done sooner rather than later. Yet, it’s likely that the foaming inside may need replacement too. I got the specifications of the foam from Henry from naim customs support. thank you :blush:! Now, does anybody know from where I can get the foam with the specifics : 25THK reticulated polyurethane Foam 80 PPI ?
Maybe sbilotta can comment as he seems to have done that and reported in the old forum
Many thanks :blush:

Give Falcon Acoustics a call if no one on here can advise.

Hi Charlie,
I did this back in 2016 and it wasn’t very easy to find it.
These are the links passed on to me by Steve Hopkins: http://www.wilmslow-audio.co.uk/ or http://www.falconacoustics.co.uk/cabinet-parts-accessories.html and http://www.foamengineers.co.uk/foam-manufacturing-suppliers/reticulated-foam/, but I wasn’t able to find it at the time; you may want to try now.
At the time I lived in Rome so I tried Italian shops/sites (ebay) as well and finally found a store that would order a minimum quantity for me of nearly the same original spec foam (25 THK RETICULATED POLYURETHANE FOAM, 80 PPI), just slightly thicker (30mm) and slightly less denser (75 PPI), but that is just as good as the original.

I would also provide you the necessary amount of foam as I still have a decent amount left, but now I live in London while the foam is still in Rome…

I also have some orginal Naim diagrams of the DBL foam; not sure if they can be of any use to you but I can send them to you if you wish.

I hope the above is of help.

Hi Stefano
Thank you for your very detailed reply, in particular all the webpages you mentioned. I sure will check them out. As you can imagine I am somewhat cautious to open the bass cabinets before I am prepared to replace the foaming in case I really need to. So I d like to source the foaming ahead of my adventure. I got the drawings from naim already, so don’t need them, but thank you for your offer. If I am completely desperate and can’t find the correct foaming I may get back to you … maybe a good excuse to visit Rome again.

Did you settle in meanwhile in London in your new apartment ? Hope you brought your dbls along and they fit in nicely.
Many greetings :pray:

Do reach out if necessary and I’ll see what can be done.
Covid-19 has somewhat hindered my settling in as you can imagine; the house is 80% refurbished with only the essential furniture, but fully functional none the less.
Unfortunately all my system is still in Rome. I was planning to bring everything up this summer but now… only time will tell…

All the best!

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In late 2018, I purchased “NAIM SBL NAIM ALLAE interior foam damping pads” from PureSoundSales on eBay. The damping foam in the upper cabinet of my SL2s had turned to dust (as had the grilles, several years earlier) and needed replacing. It worked perfectly. I have no idea if this is what you need for your DBLs, but the product is still available on eBay.


Thank you Stefano !:pray:
Good luck then with your moving everything to UK. Not an easy task …:see_no_evil:
All the best :smiley:

@AHT I’m looking to replace the damping foam too in my SL2s. How did fix you the new damping pads? Is there a special glue you used?

No glue required. As far as I could tell, no glue was used in the original installation. If you buy the SBL pads on eBay, they are too big, but it’s easy to cut the foam with regular scissors. If you make them a bit larger than necessary, the pressure from the scrunched up foam keeps the pads in place. Highly recommended, they really rejuvenated my SL2s.


Thanks for the tip. I just bought a set from Puresound.

Looking forward to fitting them :+1:t3:

@AHT Update - I’ve now fitted the dampening foam to my SL2s. I wasn’t expecting to hear much difference but I’m pleasantly surprised. The top end sounds much smoother.

Thanks again for the tip :+1:t3:

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Hi Charlie,
I am looking to refurbish my DBL`s. But like you, I would like to know how the Foam is arranged inside before I strip them down. I got some plans from Naim but I am sure they are not all there. They sent me Sheets 429, 2 of 431 and 432. Can you tell me what they sent you. There is no indication of what goes where. It would be very helpful if you are able to advise.

I have those plans as well but quite frankly they didn’t help me when I had to arrange the foam within the cabinet.
The foam needs to be cut a bit wider than the space between the internal wood dividers so that they fit nice and snug, and that snugness keeps them firmly in position. Therefore, you will have several foam strips (don’t remember the exact number) within the cabinet, in between the wood dividers. Rather easy activity.
Hope that helps

Hi Stefano,
Thank you for your reply.
Did Naim only send you the same ones that they sent to me, it just seemed odd that there was no 430 sheet and just does not seem enough for all Cabinets.
Have you replaced the Foam in all Cabinets? My third Cabinet with the Horsehair type stuff in it, the Foam has just turned to dust.

Actually, I do have the n. 430 diagram. Send me an email at “first name initial”+surname (all attached) at Gmail and I’ll send it over.
I replaced the foam only in the LF cabinet, when I had ATC perform the bass drivers re-coning; that’s how I discovered that the foam needed replacing. I didn’t take out the acoustic “horsehair” (not sure what it’s called) in the main cabinet and hence didn’t notice any foam, or for it to be replaced.
Now that I will be in the near future, COVID-19 allowing, shipping my system to London, I will take the opportunity to verify the main cabinet and replace the foam. Thanks for the tip.

Hi dbl
First let me apologize for my delayed response.
My dBL speakers are from 2004. I always thought that the bass drivers would be ok still. Well, as I realized today the limb of the bass drivers are very week and on the brink of desintegration. So I was right to plan ahead to get the drivers sent to ATC for a refurbishing/reconing. The foaming inside the bass cabinets turned out to be crumbing as well in need for a replacement. I have not removed the foaming yet but probably will do so during the coming week and take a measurement as I am not convinced they match with what’s written on the factory sheets …:roll_eyes:

Hi Charlie
No need to apologize. I am just glad to find others with a similar problem.
Are you able to give me an up to date price for the reconing as mine are also really fragile.
Have you checked the foam under the Horse hair type stuff in the 3rd and larger cabinet. Mine has just fallen apart. I will be interested to know how you get on.

Here are some pics of the foaming snide the bass drivers.

The foaming is in really bad shape and barely tolerate to be taken out for a life size measurement. They crumble or break just by gently touching. I have to compare my measures with the sheets I got from naim …

I packed the drivers today and will get them to atc this week. I don’t remember the exact quote for reconing them but it’s „a bargain“.

I have checked the lower bass cabinets last year and found the wool fine but don’t know about the foam underneath … sigh :pensive: my need to break the seal again …:see_no_evil:
When you take off the bass drivers be careful when you loosen the screws. Leave at least two - one upper and one lower one in while you slice the silicone rim , so they don’t fall out. Best to do it with a second person to give a helping hand. You need to undo the soldering of the cables next.

As sayed before my dbls are from 2004 , so a relatively young pair and they are in high need for refurbishing …:stuck_out_tongue_winking_eye:

Also you can see here the rim of the drivers just fell apart while removing the drivers from the cabinet …

Hi Charlie
Thankyou for the info.
Is the foam on all of the sides and is it glued in or just a tight fit. I can see that the Drawings don`t seem to match what is there.
You can see from my pictures the holes in the Driver and the state of the foam in the main box.

Good morning
The foam is not glued just a tight fit. There seem to be two different types of foam the more greenish one bottom and top just brakes to dust while the one in the middle grey is in better shape.
The measurement of these match the specs from the sheet I got from naim sheet 430 and 431. it does not nention however two different specs just 25 thk reticulated Polyurethane foam 80ppi…

From which year are your DBLs?
Many greetings