Tannoy Balmoral mk2 cabinet build

[fraserking]

After months on planning I have finally made some progress with my DU316 drivers.
I bought the drivers off ebay a couple of years ago with no cones and had some fitted by Nick at Lockwood. They sounded so much better than my hard edged 12"HPDs in the bass that it prompted me to recone my HPDs with standard foamed cones (pictured in cherry cabs below) which Nick supplied me and I fitted ( much hand holding from Frank) this had the added benefit that I got lovely new looking blue tinted cones on those too.
Here are my current cabinets with 315s :

and the DU316/K3128 drivers I got from ebay:

prompting me to get these:

I had always planned to build some Legacy/HPD style cabs for the spare K/DU drivers at some stage and when a local friend expressed an interest in buying some cabs for K drivers if i made some up I decided to make a start.I learned a lot building some System 8 clones a couple of years back and have used a brace system based on that pro range for the last couple of Tannoy builds - my SRM10b clones (another thread coming) look like standard cabs from the outside but have the System style bracing and are the deadest cabs you`ll ever tap your knuckles on!
My local timber supplier had a sheet of Teak veneered MDF left over from an overorder and let me have it cheap and thats what kick started this build.
Here`s a top panel showing the routed slots for the front and rear panels:

I edged them up with iron on Teak edging before cutting the 45 mitres,
theyre sitting on the matrix bracing:

Just the cheapest 18mm ply my supplier had:

Front baffle is 19mm MDF with 12mm birch glued/clamped behind
Rear is 18 glued to 9mm birch - just cos thats what i had spare off cuts from my latest kitchen build.

I ordered some lovely looking ports from Hifi collective- 100mm flared at front , but they looked so enormous when i offered them up I had to look again.

They looked somehow wrong being bigger than the DC dustcap. Alas i couldnt find anything like the ports I used on my other 100L cabs in the previous pic anywhere on the web so decided to have a go making my own in a size that looked better suited to baffle/driver.
Very chuffed with the fit of these, they just need spraying up to finish .I may yet try making some in Iroko or Teak as an alternative now that I`ve taken the trouble to make a jig for the job!

and with the front edge rounded over:

and flush fitted to the baffle:

dry run:

to fix brace to cabinet walls , same sort of stuff Tannoy used in System 15 etc,strong but flexible :

First cab glued:

and then Osmo oiled - first with Raw then with standard Polyx hard wax oil matt- all the beauty of Danish but with added protection of the hard wax. The Teak veneer is like Rizzla paper!

Very pleased with colour and finish of the Teak. Better than I had hoped.Just the badges to sort to finish with Legacy/HPD style rounded corner grilles. The engravers have had 3 goes at matching the original logo size on the badges - this is the closest so far but he reckons he can get it spot on.He`s only working from a photo i sent him!

So just terminal and crossover panels to cut on the rear panel and the ports to spray and the teak plinths to fit to the bases. I`m gonna make a panel big enough for the terminal and the crossover - removable so that alternative crossovers/connections can be fitted without leaving a hole.
I`m not quite at the shoot out stage with the HPDs yet but i did line 1 cab with foam and did a temp screw on of the back panel and fired 1 cab up - very nice with clean, even bass down to 33 HZ just as i get with the other 105L cabs I have fitted with the HPDs. This is the biggest size of cab I can fit in my living room but frankly I dont think I need any more bass than this gives.Its proper live music bass.
I will update with more pics over the coming weeks. Still got the crossovers to deal with...
If my friend keeps these cabs I`ll be making another pair for sure as i love the 70`s look of these.

 

[cooky1257]

Excellent build Fraser.
They look fabulous, the floating brace is a thing of beauty. There are a few published builds going on at the mo and yours look top class.
The precision and craft skills on display are the equal of or better than the ‘immediate’ tannoy enclosure competition options (and a fair bit better than mine!)
Anyone contemplating a bespoke build should give you a call.

 

[fraserking]

Kind words Frank ta but all the tech stuff comes from you! My Tannoy journey started in your living room 32 odd years ago so ta for that too

 

[cooky1257]

Plinth, skids or solid base?

 

[fraserking]

I’ve got a about a 4” strip of Teak MDf left so I’ll just do a 25mm high strip mitred underneath. They’re about 100cm tall now so I don’t need any extra height , it’s just to protect the cab corners. There’s enough for a spare plinth in case of damage with moving!
Solid Teak would cost ££££

 

[ToTo Man]

Beautiful teak veneer, it has a lovely walnut hue to it.

 

[fraserking]

I was inspired by that chap who had his cabs made from planks cut from solid logs of Teak in another Tannoy thread - literally thousands of pounds in the UK if you could find it. I think the 1 sheet of veneered mdf I used for this should have been £250 - I usually pay about £80 odd for Walnut by comparison . I’ll get some better pics of the tops - they look particularly beautiful.

 

[Cesare]

That's a lovely looking build, puts my woodworking skills to shame. I'm unsure about how you've managed to make those ports - can you explain a little about how you've cut these, and the corresponding recess in the baffle for them to fit?

 

[fraserking]

I routed 4 circles in 18mm mdf - 2 to the rear then 2 to the front. I tested the sizes first to get a snug fit for the cheap ducting pipe ( £1.35 at Toolstation) and a snug fit for the mdf ring in the baffle which was another 2 router passes. The last pass was with the guided rounding over bit on the inner front edge.

 

[Tarzan]

@fraserking The speakers are looking superb, well done.

 

[fraserking]

Many thanks for the likes and compliments I’ve not seen any Legacy Tannoys in the flesh but that was the look I was going for . I’m looking forward to making the grilles - with the correct badges these should look almost genuine!

 

[cooky1257]

I went for pretty much the same clean 70's aesthetic as at the end of the day they have to be house-able, the church furniture look of many offerings including Tannoys Prestige range is not for me(says a bloke with 2 huge arses staring out from a pair of JBL's ;-).

 

[calorgas]

Wow, that looks terrific, wish I had the woodworking skills to build cabs like that.

I may be embarking on something of a Tannoy cabinet project in 2021, but if it goes ahead than I guarantee that it won't look as good as yours.

 

[cooky1257]

I really like the way these are thought through.
The K 3128 usually come with a cast iron magnet cover so coupling the rear of driver to the floating brace, in keeping with the now well established DMT construction method, is straightforward.
In the case of Gold or HPD the brace is easily be modified to account for the AlNiCo magnets( the plastic covers would need to be removed and the damping compound applied to the hf top plate).
I look forward to seeing the removable terminal/ crossover panel, another neat idea from Fray, this can be customised to accommodate various external, bespoke etc set ups.
I'm waiting for someone to ask how much?
PS do I get a discount?

 

[ToTo Man]

I really like the way these are thought through.
The K 3128 usually come with a cast iron magnet cover so coupling the rear of driver to the floating brace, in keeping with the now well established DMT construction method, is straightforward.
In the case of Gold or HPD the brace is easily be modified to account for the AlNiCo magnets( the plastic covers would need to be removed and the damping compound applied to the hf top plate).
I look forward to seeing the removable terminal/ crossover panel, another neat idea from Fray, this can be customised to accommodate various external, bespoke etc set ups.
I'm waiting for someone to ask how much?
PS do I get a discount?

How easy is the damping compound to remove? e.g. if was applied directly to the back of a crinkle-finish Gold HF diaphragm, would it potentially distort it out of shape if you attempted to separate the driver from the brace again?

 

[cooky1257]

How easy is the damping compound to remove? e.g. if was applied directly to the back of a crinkle-finish Gold HF diaphragm, would it potentially distort it out of shape if you attempted to separate the driver from the brace again?

Like most mastic type compounds it dries out over time so I wouldn't apply to diaphragm cap, I wouldn't fancy crushing 'putty' using the back of a diaphragm..... use the hf top plate that surrounds the dia assembly instead.

The outer rim/ top plate:

 

[Cesare]

I'm confused by this talk of bracing the back of the driver - are you saying the back of the driver should be coupled via mastic to the bracing? A picture of the arrangement would help me understand. My current build has the driver only connected via the 4 front screws to the baffle, but I can easily add something more sophisticated here if it's an accepted improvement (i'm guessing to the hf response?)

 

[Cesare]

All here;http://warehousesound.com/r/tannoyMONITORmanual.pdf

I can't read that, is there a better source of info?

Aha, maybe this link which looks similar has the right info - https://www.hilberink.nl/codehans/tansys215.pdf

 

[cooky1257]

That's it.

 

[fraserking]

Here is the view behind the driver - I left a gap of around 5-10mm behind the mag cover .I`m thinking of using Blu Tack unless there is a better suggestion?