The outgoing tweeters were unmatched, one clearly second hand, missing key hardware, badly soldered, and over-torqued.
The process itself was “wee buns”.
I’ll do a proper write-up, probably when it starts raining again and I have to abandon outdoor work.
Willy
Yikes!
Sounds like ‘the horror, the horror!’ at the end of Heart of Darkness.
Look forward to the official analysis when it emerges - always useful to learn from such adventures.
Finally, this afternoon, got around to writing up the tweeter replacement. Started a new topic.
Willy.
Hi DBL,
Checked today - no phase plug kits left in stock or indeed any of the parts therein.
I’m still working on the instructions - early indications are not looking good I’m afraid.
Regards
Neil.
Hi Neil,
Thank you for trying. When I went to the Bristol Hifi show, Naim made a big thing about supporting all there past products. So I asked “so what about the DBL`s then” which bought stunned silence!
Hi Neil
I am really wondering what is this mystery about the dbl midrange drivers that there Is just dead silence from naim and absolutely no information or help with respect to its original manufacturer etc.
it would be really paramount for all us dbl owners who go a long way to refurbish their speakers to have a perspective in case the mid range fails and needs replacement or just being able to refurbish them completely and bring them back to their most full potential. 
I run an active 500dr/S1 system so I don’t want to hear something about turning the drivers 180 degrees or some selfmade plastic tube fiddling with the cones but a serious way to refurbish the mid drivers to their original specs.
My understanding from some years ago was that the midrange was the same drive that was used in the IBL - and indeed so was the tweeter.
It would be interesting, I think, to put SBL drives into a DBL. I would imagine that would work very well.
Yes I guess they are the same, but that doesn’t help much because even if you get your hands on Ibls they are at least 20 years old.
To use sbl drivers in dbls I dont think that’s technically possible but sorry i consider that a real nogo 
Well said Charlie.
Perhaps if all the DBL owners got together and signed an online petition or each sent an email direct to Naim Management, hopefully if they value there Customers as much as they say they do, they will be willing to help out and it will show that they do indeed value there Customers and can use it to promote the Naim Brand as a Company that cares.
You are probably sitting there reading this and thinking mine are fine, but so were mine until the problem started and no one has so far come up with a solution for an alternative or getting a refurb done.
Not sure about the practicality. Presumably the SBL mid/bass drivers are a little larger than the IBLs, and I can understand your reluctance to modify the cabinet.
DBL mids and IBL mid bass are NOT the same!
The DBL NBL mid is a pure mid range driver that has a different voice coil that is purposely designed to operate as a pure mid range driver. The IBL is designed to also cover bass, the voice coil is not the same and probably won’t perform as well as the DBL mid.
I believe naim used a KEF B110 basket to make the DBL mid driver so a KEF B110 fits perfectly, but it too was designed to reproduce bass also so not a pure mid driver. Falcon acoustics still make a B110, but it would have different characteristic to the naim mid especially the resonant frequency. Some speaker repairers can rebuild drivers if they have the voice coil specs but it has to be broken first!
I think the DBL mid can take quite a beating and doesn’t really deteriorate over time so if its all good, best to just leave it be and keep enjoying them. Otherwise, maybe naim could provide the original voice coil details (lenghth/gap?) so that it can be fixed by a reputable repairer.
Mario.
Correct. IBL drivers and DBL drivers are different. DBL and IBL tweeters are different too. There are three generations of IBL mid-bass drivers and (probably) two of the DBL mid.
For IBL, there was the Elac, then there was a Mordaunt Short and then the Naim. All three companies are defunct from a driver OEM perspective.
Putting a SBL mid-bass into a DBL is not something I would recommend.
Thank you Mario for sharing your most valuable insights. What I find quite annoying though is that there is no official clarification from naim on that issue what so ever. It’s all relying on hearsay and second hand knowledge as profound as this probably is.
Hi Charlie,
While I understand your frustrations regarding this, I find myself under-qualified to comment on the company’s stance.
If you wish to escalate the matter, please get in touch with Mark Bonner via Tech Support.
Regards
Neil.
I guess one of us should initiate the conversation with Mark Bonner to establish what options, if any, available.
Is it possible that a batch of Midrange units could be produced? I for one would happily pay in advance for a pair to pack away in cotton wool in the loft. I imagine others would also.
If not in-house then would it be possible for a third party (e.g. Falcon ) to manufacture a batch to Naim specification.
Alternatively would it be possible for Naim to provide sufficient detail to enable a third party to repair the units to the original standard.
Guess it’s all down to establishing the demand and the economics.
Anyone volunteering to contact Mark?
Willy.
I guess since I started this I’ll contact Mark via email then. I can post the mail here too.
Here is my mail to Mark Bonner sent today…
Please forward this message to Mark Bonner
Dear Mark,
I have initiated a thread on the forum with respect to refurbishing DBLs which caught a lot of attention from other DBL users:
It turns out that the mid range drivers are truly the achilles heel to bring DBLs back to their full spec. All other components ie bass drivers, tweeters, inner foamings, grills can be readily refurbished or replaced. I have done just that and the result is more than stunning.
Mind you, I run my DBLs in the context of an active 500DR/S1pre system and the options for other speakers in the league of DBLs that can be driven actively are sparse, if not down to zero. ( I had Kudos 808 on trial within my active system while my DBL bass dirvers were out for reconing at ATC. Good as they are, my DBLs are simply much more involving with sheer unbound effortlessness)
As helpful as comments from naim staff on the forum so far were, they fall short with a real solution for the midrange drivers in case they get damaged and needed replacement, or simply need a refurbishing job due to aging. It almost seems a mystery because there is barely any technical information available on these drivers.
So here is my heart felt request not just from me, but on behalf of several other faithful DBL users who are concerned about what if their DBL mid range drivers fail or have turned out compromized already:
Is it possible that a batch of Midrange units could be produced? I for one would happily pay in advance for a pair to pack away in cotton wool in the loft. I am sure others would also.
If not in-house then would it be possible for a third party (e.g. Falcon ) to manufacture a batch to Naim specification.
Alternatively would it be possible for Naim to provide sufficient detail to enable a third party to repair the units to the original standard.
Many thanks in advance for considering our request,
We remain confident that naim, well know to look after their faithful customers, will provide a satisfying solution in this matter
Kind regards,
Charlie
The mid/range drive unit in the DBL is similar to, but not exactly the same as the mid/bass driver in the IBL and in the Axess and Axent centre speakers (differences in coil and impedance), in spite of physically looking the same. AFAIK it is the same as the one used in the NBL.
AFAIK, Naim had to dismantle their entire loudspeaker department when they stopped making speakers some years back. This was to make extra space for producing the Statement amp and also just because the factory also needed to re-ordered so that production of the Unitis was possible. They made some spares stock, but knowing how involved is the process of making the drive units, I don’t think they have that capability any more.
AFAIK the midrange drive units are fairly straightforward in their build (they were built by hand, let’s not forget), and use certain standard “off-the-shelf” parts like the KEF B110 baskets. Of course, other parts were unique to Naim, but so long as these are not missing or damaged beyond repair, I would imagine that a competent restorer or repairer should be able to fix them.
I’ll be interested to see what Naim say or add here.
As an NBL owner from new that is my understanding too. In fact, the following text is taken from Paul Messenger’s review in Stereophile from 25 October 2000:
“Each NBL consists of two SBL bass sections crossing over to a DBL midrange/tweeter section, so there’s little new at the drive-unit end of the technology.”