I’ve been a happy owner of a pair of Naim NBLs for 14 years now (passive setup). Lately, I’ve been doing some fine-tuning and maintenance, and I would like to check and reset the correct torque specifications for all the drivers and structural components.
As we all know, Naim is incredibly strict about these values to maintain the correct mechanical grounding, speed, and energy transmission.
Could the experts or anyone with the official factory checklist confirm the exact torque settings (Nm) and technical specs for the following?
Tweeter (ScanSpeak D2010 to plate): 0.8 Nm (from my understanding)
Midrange driver: 3.6 Nm
Tweeter plate to cabinet screws: ? Nm (Should these be just nipped by hand to avoid squashing the rubber grommets?)
The internal bass driver iron “truss/bar” (traliccio): What is the official torque for the long bolts/bar that clamp the horizontally opposed woofers together inside the enclosure?
Additionally, since these speakers are getting older, I need to check the internal damping. Does anyone know the exact factory specifications for the acoustic foam (spugne) used inside the chambers? (Thickness, PPI/density, or reticulated polyurethane type?) My original foam is starting to degrade/turn to dust, and I want to replace it with something as close to the original Naim spec as possible.
Any advice, official factory document clips, or tips from anyone who has recently fully refurbished or serviced their NBLs would be massively appreciated!
Fabulous speakers - I still have my old ones and recently swapped them into my system in place of my new(er) Kudos Titan 808’s.
Whilst I feel the 808’s are better, the NBL’s still have a certain magic, although I played mine actively with Olive 250’s. They are certainly not “disgraced” by the Titans, different and lacking in some areas but still amazing.
I checked my original user manuals, but sadly they do not contain the information you’re seeking.
It might be worth highlighting your post to gain the attention of Steve at Naim, or maybe someone else knows?
Just a guess but I’d expect there to be a nut on the inside of the cabinet so it would be driver off and foam out, what chance the foam is still viable after all this time? I’m leaving mine well alone and just retorquing the hi and mid drivers, leaving the bass drivers alone unless they start buzzing (something that did happen with the Thiels that preceded the NBLs in my system).
Yeti unfortunately the mid is fixed in a closed housing and even by removing it the terminals are not reachable. The only way to reach the rear terminals is to remove the panel with the instructions printed on it. Which I did but there are no screws or nuts there are only the 4 speaker wires.