New cabinets for Tannoy M15?

[OzMikeH]

the M15 is a large 2-way bookshelf speaker.
An 8 inch bass reflex with a tweeter, crossover is 3kHz.
the 8 incher has a horn shaped cone and appears to be made of textured plastic. it has rather substantial cast frame. There are dual-concentric versions of this driver with a tulip shaped waveguide but mine is the one with a separate tweeter.
I bought them about 1994

I stumbled over this:
http://www.yildiz.edu.tr/~ilkorur/ILKORUR/Tannoy.html

which made me think perhaps I should look at doing something with them. My cabinets have bashed corners, so I'm looking at new cabinets, preferably something quite large that extends very low. perhaps a double big-vent reflex or a transmission line.

I searched for theile-small specs of the drivers, and can't find them. can anyone assist?

[OzMikeH]

Here'a a couple of largish pictures of the whole speaker. I have no idea what the site is, maybe a Japanese audio marketplace.

Mine are in a lot better condition than these, looks like disintegrating cabinets are common.

www.avbuzz.com/bbs/hand/hand-thread-85364.html

If anyone thinks they can assist I'll pull mine out of storage and dismantle them for some detailed pictures of the drivers.

[OzMikeH]

Well i finally got around to it. Photos to come tomorrow.
I dragged out the old Tannoys and gave them a run, When pushed hard they have some issues with turbulent airflow out of the ports. the curtains blow around and you can feel puffs of air across the room (vortices). Not particularly graceful.

Baskets are not cast as I said earlier, they are pressed steel. 4 legs. ferrite magnet, very large diameter spider with 4 small vent holes through the frame around the magnet. Wires are run along the spider. They're clearly designed for quite a bit of excursion. They look like quite cheap drivers actually, Small ferrite magnet, flimsy basket, plastic moulded cone.

The baskets rang nicely when flicked with a fingernail. So I wrapped the legs with foil backed bitumen and packed & streamlined the magnet-basket interface with some dense poster putty leaving some room for the spider's rear vents.

I lashed up one channel into a singular cabinet, extending the midbass wires from the original crossover and standing the tannoy cabinets upside down on top of the singulars. Bass was much, much lower and better behaved. they sounded less boxy and less stressed.

They definitely don't have that fostex fullrange magic in the midrange but they are much better than I expected. Metallica's S&M was never that involving with the Fostex drivers in these cabinets. It's quite enjoyable now with quite a few goosebump moments.

I'll be listening to these for a while, enjoying some different parts of my music collection.

If anyone has the equipment in Western Australia I'd be interesting in determining the Theile-Small specs to design some proper big cabinets for these.
Alternatively is there way to get a reasonably reliable estimate by reverse engineering the Tannoy cabinets?

Edit: I've been shuffling the cabinets on top around all afternoon, trying to get the time alignment right. These lash-ups image very well.

[alan-1-b]

Mike,
which specific Tannoy model is it ?
There were various M15, M20, M30 models in the 1980s and 1990s.
Some had descriptive names added to the M numbers.
Does yours ?
Is yours a dark greyish cone, like in the photo, or a light whiteish cone ?

Are you sure it is an 8" cone ?
So far as I remember the M15 models had 6.5" cones in 8" across outside circumference of chassis diameter.
The model in the Japanese photo looks like the 6.5" cone version.

If you can Post any of the above I may have some other information for you.

[OzMikeH]

black cone. No description other than M-15 and Made in UK.
The driver in the cabinet next to it is Fostex FE207E to give you an idea of scale.

It fits in the same cutout but a bit loose, Mounting bolts are very slightly smaller circle.

[OzMikeH]

the spider and cone shape.

[OzMikeH]

the back of the driver. Note the little vent holes.
Edit: hard to see without adjusting contrast.
they are aprrox 5mm diameter, in line with each basket leg.

[OzMikeH]

Close up of cone.
Again Fe207E is nearby for size comparison.

[OzMikeH]

Another voew of the back.

[OzMikeH]

And a shot of the my lash-up.
Note the magnet brace in the original cabinets on top.
that lump stick on there feels like plasticene with some kind of dense grit kneaded in. As the driver is screwed in the plasticene compresses to about 5mm thick.