Tannoy Horn loading question

[pinkmouse]

Hi folks

Just a quick question for research for a future project. Is anyone aware of the Horn geometry used for the Tannoy 12" co-axial system? As most will know, it uses the bass cone for horn loading for the mid/high driver, and am just curious as to if it is designed to a certain geometry, (and if so, what?), or if it sounds good purely by chance.

Anyone any ideas?

Thanks!

[mikee12345]

u cud draw it up as a table in excel of the wooden expansions,and see what sort of curve it is,then make equivalent exponential etc flares to compare to

[usekgb]

These are fun drivers to work with. I don't know the exact horn geometry, but the LF section looks sort of like an exponential horn geometry. Steep in the center, and gradually flattenting out towards the edges. The biggest advantage to the Tannoy Dual-Concentric TM drivers is that they create a good time-aligned point source driver. You don't have to worry about driver spacing causing comb filtering and phasing issues. And, I can tell you, those HF sections in the Tannoys are plenty efficient without horn-loading them.

Cheers,
Zach

[pinkmouse]

Hi folks, and thanks for your replies

The reason this came up was that I have just started a Part time degree in Design, and the workshops in college are fully equiped for plastics and ceramics, as well as the usual wood and metalwork stuff, and to me the obvious easy thing to have a play with would be a mid/high horn.

Having owned a pair of Tannoys years ago, I remember well the sweet sound of the horn loaded co-ax, and I thought this would be a good place to start playing with my own designs. The idea of simply copying the flare rate of the cone looks do-able, but what I would really need for that is a photo of one of those half sectioned drivers that used to appear in marketing stuff.

I will probably be using a JBL pro compression driver for first experiments, maybe upgrading to the TAD if successful!

However, to broaden the subject, if anyone has any info on making compression drivers, that might be fun to have a go with as well

[Brett]

Originally posted by pinkmouse
what I would really need for that is a photo of one of those half sectioned drivers that used to appear in marketing stuff.

Your wish is my command.

[Brett]

And another....

[pinkmouse]

Spot on mate!

The second pic is the one I remember, but the first one looks even better, as it is a straight on shot, making curve tracing easier.

Cheers!

[Da5id4Vz]

Ceramic horns?

That is just too cool.

If you come up with a design you are particularly fond of you should consider making positive and negative profiles for making molds and being able to hook up some of us other DIY guys.

Ceramic besides making a nice horn in itself also seems like it would make a nice mold for gypsum plaster or resin.

Which Tanoys did you own? Ive placed sets in a number of broadcast and studio environments. They are one of my favorite brands.

The curve in the section looks kind of like a section from an ellipse. Are you thinking about tractrix at all?

[panos29]

Hey Brett great pic! Since I own 3 of these beauties HPD385) I would love to have tis pic in higher resolution(to my email ) as I am about to totaly dissasemble it for cleaning and adjustment but the mafnet is hard to open, I thought a pic of the inside might help me to se why.

Regards,

Panos

[Brett]

Originally posted by panos29
Hey Brett great pic! Since I own 3 of these beauties HPD385)

I used to own some HPD385's, but I sold them about 18 months ago, when I went to horns. Now I only own a single Red 12, which I might get a friend to design a TL cab for and put it in the corner of my bedroom. Unless I ever find a mate cheap enough.

I would love to have tis pic in higher resolution(to my email )

Send me a PM with your email addy and I'll send them off later.

as I am about to totaly dissasemble it for cleaning and adjustment but the mafnet is hard to open, I thought a pic of the inside might help me to se why.

If you go to the Keiwa site, and scroll down to "Roll Surrounds, Driver Construction, Crossovers, & Curiosities" there are a couple of links where an HPD has been disassembled for surround replacement. These might show you in more detail what you're looking for. Lots of other cool Tannoy stuff on the site too.

There is also another cross-section pic here