SBL rebuild

Posted by: arb76 on 13 July 2017

My naxo is at Naim for repair/service so perfect opportunity to rebuild the sbls that i bought with it about 6 months ago...

I used a sharpened carving knife to slice through the sealant. It was a good seal yet, It all came off in one piece very easily.


LF driver box
You can see the 4 spike plates stapled on the underside.
(How the hell do you get those Staples out?)

The black grill - a diffuser?

Inside the boom box

Top plate

There is another gasket on the underside of the top plate, sealed to the boom box. It feels a bit squidgy, the top gasket feels firm which I'd expect (like the new gaskets I have). Has anyone ever replaced the lower gaskets? Are they even available? They look thicker than the upper gaskets.

What is this filler? - wool?

I will update upon completion.

Posted on: 13 July 2017 by Dave***t

I can only see the third picture, the others have a grey no entry sign. I assume I'm not alone?

Posted on: 13 July 2017 by arb76

I don't know why, i can see them fine.

How about these?...

1

2

4

 

Posted on: 13 July 2017 by Timo

Now, not a single photograph is visible...

Posted on: 13 July 2017 by joerand
arb76 posted:

I don't know why, i can see them fine.

arb76,

Most likely, you see them fine because you have internal links, assuming you're viewing on the same device you posted from. Try looking at your pics from a different device and see what you get. I don't see the pics from my PC notebook running  Windows 8.1, IE 11. Are you posting your links from a third-party host and using the URL?

Posted on: 13 July 2017 by arb76

I've no idea. I can't see them on my phone but ok on my PC which is where I uploaded them from via Google photos. Weird how one photo is visible though.

Are links to my shared Google photos album allowed?

Posted on: 13 July 2017 by arb76

While we're on the subject, there's a dbl Restoration post and all but the last photo isn't visible. However, unlike mine with the no entry sign, that says something about reaching the storage limit. Do others see the same? Anyone know how I can see those photos?

Posted on: 13 July 2017 by arb76

https://goo.gl/photos/oUDLQmLijYGnQ97k8

Posted on: 13 July 2017 by Willy

The problem could be that your photos in Google photos are to large and thus blocked by the forum software. Historically I've downloaded photos from Google, reduced them to 25% of original size, uploaded them to photobucket and linked from there. However having revisited my DBL thread it looks like photobucket have "moved the goalposts" and this is no longer working. Will have a look, post-coffee, and see if I can fix that.

Willy.

Ps can see the photos on your direct Google link. Not sure if this breaks the rules of no links in hi-fi corner?

Posted on: 13 July 2017 by Willy

Little bit of research and it seems that photobucket now want $399 per year to enable 3rd party hosting of images. Has, understandably, upset a lot of people. I guess I'll have to find another image hosting site.

Willy.

Posted on: 14 July 2017 by Richard Dane

The "wool" is goat hair.  don't mess with it - just make sure it hasn't compressed too far down inside the lower box.

The FAQ has a good thread on how to post pictures on the forum.

Posted on: 14 July 2017 by ianrobertm

Never, ever mess with Goats.....

Posted on: 14 July 2017 by arb76

I removed the spike plates, quite easy in the end; lift one side of the plate with a flat screwdriver and then prise off gently from under the plate.

From the photos you can see the spikes have pierced the plates and into the under section.

I think I have some spacers the exact size I can use for refitting and hopefully avoid this.

https://goo.gl/photos/oUDLQmLijYGnQ97k8

Posted on: 14 July 2017 by arb76

@Willy

Hopefully you'll be able to sort it, was looking forward to seeing the journey.

Did you say you've packed them up?

Posted on: 14 July 2017 by Willy
arb76 posted:

I removed the spike plates, quite easy in the end; lift one side of the plate with a flat screwdriver and then prise off gently from under the plate.

From the photos you can see the spikes have pierced the plates and into the under section.

I think I have some spacers the exact size I can use for refitting and hopefully avoid this.

https://goo.gl/photos/oUDLQmLijYGnQ97k8

The spike/plate interface is a key part of the way the SBL works. What you need to do is fill the holes under the plates with Ronseal High Performance wood filler. When it's dry sand flat and then install new plates. You can get the new plates from Naim as part of a gasket kit.  When reassembling the spikes should set on the plates but not penetrate. 

My DBLs are up and running, currently playing The Heart of Saturday Night by Tom Waits. Improving by the day as the reconed Bass units bed in. I'll try find time later to put the DBL photos into an album and post a link. 

Willy.

Posted on: 14 July 2017 by arb76

Thanks Willy

Great info.

I have said plates and gaskets ready to go. Just need to follow your advice now.

Still wondering about the lower gaskets though. I would assume they're original.

No rush as the naxo will be at naim for a few weeks but, missing music already, only been a week.

Enjoy.

Posted on: 07 September 2017 by arb76
arb76 posted:

I removed the spike plates, quite easy in the end; lift one side of the plate with a flat screwdriver and then prise off gently from under the plate.

From the photos you can see the spikes have pierced the plates and into the under section.

I think I have some spacers the exact size I can use for refitting and hopefully avoid this.

https://goo.gl/photos/oUDLQmLijYGnQ97k8

The spike/plate interface is a key part of the way the SBL works. What you need to do is fill the holes under the plates with Ronseal High Performance wood filler. When it's dry sand flat and then install new plates. You can get the new plates from Naim as part of a gasket kit.  When reassembling the spikes should set on the plates but not penetrate. 

My DBLs are up and running, currently playing The Heart of Saturday Night by Tom Waits. Improving by the day as the reconed Bass units bed in. I'll try find time later to put the DBL photos into an album and post a link. 

Willy.

 

Hey

It's been a while but, finally getting around to the sbls.

I downloaded a copy of the dbl/sbl manual and I'm just reading through it now. However, it says the spikes on the top of the boom box SHOULD piece the aluminium plates on the underside of the bass driver box, contrary to the advise above.

I wouldn't doubt the manual we're it not that Willy has done it and knows what he's doing.

Willy?

Anyone?

Thanks.

Posted on: 07 September 2017 by Richard Dane

I think the ideal is to have the spikes make enough of an indent in the Alu pads so that the box is located and planted yet not totally coupled.

Posted on: 07 September 2017 by arb76

Thanks Richard.

I meant pierce in case others misunderstood.

Yes, all else is done I'm about to silicon the 2 together.

I'm sure I read somewhere that a small amount of washing up liquid where the silicon will make contact on the gasket and the underside of the bass box. True?

Posted on: 07 September 2017 by arb76

For reassembly ease

Posted on: 07 September 2017 by Richard Dane

The thin smear of washing up liquid is an in-house trick that made it much easier to peel everything off when you have to keep re-doing the seals - as you did when moving demo speakers around all over the place. It's not strictly necessary, and maybe even something I would caution against as if it's down wrong then you may not have a good seal, but it does make things easier when you next take the speakers apart.

Posted on: 07 September 2017 by arb76

Both came apart very nicely with a sharp knife.

No idea if that was down to washing up liquid.

I will use the method as I may want to experiment a little.

Ta

Posted on: 07 September 2017 by stuart.ashen

Tom Tom have new gasket kits and grills if you are in need of spares. Costly but very good quality and worth paying for imho.

Let us know how they look and sound. Lovely 'speakers.

Stu

Posted on: 07 September 2017 by arb76

Thanks stu

I have said gaskets and like you say they're good quality. Plates too.

These speakers are a bit of a toy for me, along with the other CB boxes. 

I'm thinking about different filings etc.

The current system sounds good, this setup allows for good scope.

 

Posted on: 07 September 2017 by stuart.ashen

If you get them set up well they might become more than just a toy!

Posted on: 07 September 2017 by Willy

The wording in the DBL manual is "push down gently on middle cabinet to form spike indents in the aluminium pads fitted to its bottom surface" 

No suggestion in the (DBL) manual that the spikes should pierce the aluminium pads, which is in line with everything I've read elsewhere. 

Regards,

Willy.