Dbl refurbishing LF cabinet acoustic foam

With respect to the tweeters there are two separate connections

  1. drivers screwed onto the slit plates -ie those inner four screws with internal edges -Allen bolts - which are attached tight so most likely those 2nm

  2. attachment of the plate onto the wooden cabinet with rubber grommets fixed just tight enough that the plate can not move freely and for instance sink towards the lower lip and touch the wooden cut out, yet loose enough that the rubber grommets are not squashed, so probably those 0,8 nm

The information I received did associate the 0.8Nm value with the tweeter to spring plate interface though there seems to be more of a concensus around 2.0 Nm for that. Hopefully we can have a definitive value from Naim directly.


Hi Guys,

I’ll see what I can find out regarding the torque settings.
I recall that the NBL was shipped with an aluminium plate with a cork gasket mounted over the mid range driver using two of the (diagonally offset) mounting bolt holes, in order to prevent the wooden leaf springs breaking under inertia from the driver weight. So these two bolts were longer - I wonder if this was also the case for the DBL?


Sounds like I have opened up a can of worms asking about the Torque settings!

Charlie I did try and get the foam for the pillars in without removing the Plates, but soon realized it was not going to happen. In the end I used a longer Screw placed a block of wood up against the Cabinet and used a Claw Hammer and they both just popped out. I see that they are sealed with Hylomar. I used the 340 Foam and pushed it up to the Plate and it is just level with the bottom of the Pillar and have put the two ends together at the back.

Willy, the plate on the Tweeters. Should they be perfectly flat? Mine are slightly bent.

I downloaded the manual from “manuals lib”. Have it as a pdf. Here’s a screen grab of what they have to say on the tweeter plates…

If you can’t find the manual online then get my email address off Richard, ping me and I’ll forward a copy.



Ok, I have spoken to the chap who used to build DBLs - the bass & mids are torqued to 3.6Nm & the tweeter to plate 0.8Nm, plate to cabinet enough to not squash the grommets. He thinks the confusion may come from the direct tweeter to cabinet (e.g. SBL) being 2Nm?
He also confirmed that the longer screws in the mid range drivers are indeed due to the transit plate (as above).






Thank you Willy. I have found the online manual so now can sort that little problem out.

The information from Neil on the Bolt length and Torque settings also solves that mystery.

Getting those beasts back inside their box :wink:


Been following this with great interest. An excellent and innovative use of a Fraim shelf.


Glad you liked my innovative (ab)use of a fraim shelf. I needed to come up with a stabilized position for the heavy drivers while doing the soldering. Somehow I thought that the cut out of the fraim would give a perfect recess to prevent the driver from slipping away. I used some of the foaming for further stability. Also the wooden block was rounded to accommodate the heavy magnet of the drivers .

The fraim is ok and back to its normal place meanwhile …:wink:

Hi Neil
Would you please also confirm the torque settings for the various bolts on SL2s?
Especially the smaller bolts that hold the tweeter plates to the baffle.

… maybe also could You find a source for A replacement of the mid range dbl drivers …:see_no_evil:

and a replacement for the DBL tweeter plates :grimacing:

Hi JD,

I’ll see what I can dig up.
As for the other requests - I think they may be a taller order. But I’ll ask some questions anyway!



Charlie, have you had any issues with the mid range? One of mine does distort every now and then and I have to gently push the cone in and out a few times. If I push on one side it can make things worse, so have to push on the opposite side. It seems as though the cone is not moving freely enough and have found using rubber rejuvinator does cure it for a while, but this is not ideal. I have inquired with several speaker people, but no one seems to want to know. Hopefully Neil maybe able to come up with something.

While you’re at it, perhaps you could build me a pair of DBLs. I mean, you must still have the blueprints…now hard can it be?!


:rofl: :rofl: :rofl:

Actually no thanks g‘d! My midrange drivers seem fine. But they seem the most obscure for me. I have not been able to find out who the original manufacturer was, and possibly from where replacement drivers would be available from. As I said mine are fine no issues what so ever but still I would like to have a spare pair just in case. Also now herding what reconed bass drivers deliver I wouldn’t be surprised if the midrange has undergone some degradation as well over all those years so a refurbishing or replacement would be nice to have. :wink:

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