Tannoy Chatsworth 12" MG rebuild advice.

[awkwardbydesign]

I've started making the curved sides. I couldn't get 4mm birch ply locally, so I am making them like barrels, with staves. 3mm hardboard inner face, then the staves (cut at 3.75 degrees) and then a 3mm hardboard outer skin. One glued, another drying.

This is the shape. 33mm thick front, 24mm top and base. 24mm back, 24mm sides. 18mm cross braces, bitumenised felt damping, black foam grilles, veneered panels, dark brown leather front, vertical oak side strips. Most of which I have, so I will be using it.

 

[awkwardbydesign]

All 4 sides made, and one pair screwed to the top and bottom plates, to maintain the curve.

 

[awkwardbydesign]

 

[awkwardbydesign]

And as I can't safely lift them now...

 

[awkwardbydesign]

Now making the blocks for the slot vents. 48 needed, 20 done. 10mm x 144mm in 18mm and 9mm ply, to allow for tuning. 4 slots per cab, calculated as 81mm deep, plus 28mm fronts for 109mm total, plus extras, up to a max of 127mm.

 

[awkwardbydesign]

Both fronts slotted, and one set of blocks screwed on. Total slot depth 109mm, inc front panel. Removable to adjust, plus or minus.

 

[awkwardbydesign]

And this is how it fits together.

 

[awkwardbydesign]

First side with the hardboard skin clamped on. Now to remove it, glue it and re-clamp it.

BTW, should this thread now be in DIY? I have moved on from asking for advice, into a full-on build.

 

[awkwardbydesign]

Outer skins done, ready for veneer. Oak side strips cut and fixed with dowels, so I can remove them.

 

[awkwardbydesign]

Base and back veneered on first cabinet.

 

[awkwardbydesign]

First curved side panel veneered. A bit tricky to handle, stopping the veneer touching the cabinet in the wrong place, but it worked OK. Just have to do it another three times.

 

[sq225917]

They're bloody lovely

 

[awkwardbydesign]

They're bloody heavy. 40kg is too much to lift now, and just turning them is a struggle. Especially as they are getting easy to damage.

 

[fraserking]

That’s a very impressive build , can’t wait to see them finished.

 

[fraserking]

Is it cherry veneer?

 

[awkwardbydesign]

No, beech. Because it is available locally, and wide enough to not need a join. And cheap, as it is old stock. Not my favourite wood, but needs must.
Second curved side just glued on. Annoyingly it appears to be shrinking slightly and a couple of small splits have appeared. A bit of filler will sort that though.

 

[awkwardbydesign]

One of the splits has lengthened to 15"! Don't know why, never seen it before in 40 years. Did I somehow stretch it while applying it? Very odd.

 

[awkwardbydesign]

Well, I've overcome the veneer problem, and it's all on. The leather fronts are applied on one and nearly done on the other. The velcro strips for the grille foam should cover the screws and joins. Then I'll stand them up on wheeled trolleys and finish spraying them. The wood trim is being rubbed down with 0000 grade wire wool, which gives a nice sheen.
I tuned the vent lengths with a signal generator, so once they are lacquered I will have to get them indoors. That will be fun, with the steps!

 

[Woodface]

Great work

 

[eguth]

My Chatsworths had a resistive port when I first got them. I thought they were significantly better when I sealed the port up and I haven’t ever had the urge to go back.

There may have been a decrease in frequency extension when I went to sealed, but the increase in detail and definition right across the spectrum was very clear.

YMMV as I have yet to hear a ported speaker i could live with and obviously not everyone hears the same way.

Very good post. I agree with most of it. You make imPORTant points. Port is something I love- when it is vintage, comes from Portugal, and has been properly stored for at least 10 years.

Impressive work, awkby des!