The compression driver is behind the woofer magnet, waveguide is say 1 15/16th's od to clear mid vc of 2" inside diameter.
Post 18 of this thread has a picture.
Post 18 of this thread has a picture.
post18 is not a dual concentric of the "old" style.
post18 has a dome driver for the HF and the diameter is much smaller than the the bass/mid VC.
In the old style dual concentric, the VC of both the bass/mid and the HF are ~2" and the HF is a compression driver with the dome inverted as in all other compression drivers.
The Kingdom Royal post61 (very different from the Westminster Royal) has an HF VC that is bigger than the mid VC. This seems to be a 3rd variant of the dual concentric. I have not seen a cross section of this driver pair.
post18 has a dome driver for the HF and the diameter is much smaller than the the bass/mid VC.
In the old style dual concentric, the VC of both the bass/mid and the HF are ~2" and the HF is a compression driver with the dome inverted as in all other compression drivers.
The Kingdom Royal post61 (very different from the Westminster Royal) has an HF VC that is bigger than the mid VC. This seems to be a 3rd variant of the dual concentric. I have not seen a cross section of this driver pair.
The 10" Monitor Gold had a 2.5" VC for the treble and a 2" for the woofer.
The 12" and 15" used 2" VCs for both.
http://www.hilberink.nl/tannoy/flyer/tannoydcflyer1968.pdf
The 12" and 15" used 2" VCs for both.
http://www.hilberink.nl/tannoy/flyer/tannoydcflyer1968.pdf
I have some 8NFMIIs and I wouldn't call the HF driver a compression driver...not like any I have ever used. Looks more like a tweeter firing through the voice coil as there is no phase plug. So IF it is a compression driver, it is a REALLY low compression one.
I had not noticed the difference between the 10" and the larger models before.
The Hilberlink pdf for the 10" 16ohms Gold driver does indeed show the LF VC as >2".
Does it say 2½"?
Could this be a misprint in the export brochure?
My mistake it's the LF coil that is 2.5", the HF one is 2".
This is confirmed on Troels Gravesens site.
I always wondered about this myself as Tannoy used one magnet assembly for both LF and HF until they introduced tulip waveguides in '91.
This is confirmed on Troels Gravesens site.
I always wondered about this myself as Tannoy used one magnet assembly for both LF and HF until they introduced tulip waveguides in '91.
Tannoy introduced dual ferrite magnets long before "tulips".
The new range of HPD after the "fire" all went to ferrite instead of alnico. and used twin ferrites.
As far as I know these dual ferrite assemblies still used the same VC diameters and still used the pepperpot leading into the throat. That was from about 1978.
I think this also coincided with moving the manufacture to Coatbridge.
The tulip came in later and then the Westminster went back to alnico and finally back to pepperpot.
The new range of HPD after the "fire" all went to ferrite instead of alnico. and used twin ferrites.
As far as I know these dual ferrite assemblies still used the same VC diameters and still used the pepperpot leading into the throat. That was from about 1978.
I think this also coincided with moving the manufacture to Coatbridge.
The tulip came in later and then the Westminster went back to alnico and finally back to pepperpot.
My two pairs of K-series (the model which replaced the HPD) made in '81 and '87 use a single ferrite magnet for both HF and LF. Never heard of a ferrite HPD. As far as I know both HPD and HPD(A) use AlNiCo magnets.
The only twin magnet DC with pepperpot rather than tulip I've ever seen is one very, very late model 12" K series driver on Hans' site.
There are also a few Gold/HPD hybrids around which Tannoy sold during the switch over from Gold to HPD.
The Gold III-LZ is the 10" Monitor Gold. Same goes for Reds. I have no idea why Tannoy did not call the 10" models Monitor Red or Gold but III-LZ.
The only twin magnet DC with pepperpot rather than tulip I've ever seen is one very, very late model 12" K series driver on Hans' site.
There are also a few Gold/HPD hybrids around which Tannoy sold during the switch over from Gold to HPD.
The Gold III-LZ is the 10" Monitor Gold. Same goes for Reds. I have no idea why Tannoy did not call the 10" models Monitor Red or Gold but III-LZ.
As I said the K series still used a single magnet.
Twin magnets were officially introduced to their monitors together with the tulip waveguide when the K series drivers and the SuperRed/SuperGold series of monitors were replaced in 1990.
For domestic use the first twin magnet driver was the 8" 2008 introduced in '86.
tannoy
Twin magnets were officially introduced to their monitors together with the tulip waveguide when the K series drivers and the SuperRed/SuperGold series of monitors were replaced in 1990.
For domestic use the first twin magnet driver was the 8" 2008 introduced in '86.
tannoy
The Tulip structure is the phase plug. But yes the 8NFMII and most of the later Duals use lower compression ratios than one might find in a standard CD.
In an old interview Tannoys technical director Alex Garner said they reduced the compression ratio from 14:1 to 7:1 in the 8 and 10 inch models and to 4:1 in 12 and 15 inchers with the introduction of the tulip waveguide.
Just re-read (again) my post69.
the date and the omission of Kseries and the the move to Coatbridge are all mixed up.
Ignore my post.
the date and the omission of Kseries and the the move to Coatbridge are all mixed up.
Ignore my post.
Charles,
Thank you for posting the 'Tannoy - Back to Basics' link.
I have a pair of humble 609's and have often wondered 'whats going on' inside.
Thank you for posting the 'Tannoy - Back to Basics' link.
I have a pair of humble 609's and have often wondered 'whats going on' inside.
You're welcome!
Got it from Hans Hilberink's site which is always my first stop for anything Tannoy.
http://www.hilberink.nl/speaker.htm
Got it from Hans Hilberink's site which is always my first stop for anything Tannoy.
http://www.hilberink.nl/speaker.htm
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Ahhh, I've been on that site quite a few times, my brain's addled with a horrid 'cold' atm.
I'm following this thread because I've had my 609's for 7 months now and have had no 'honeymoon period' - I bought them, hooked em up and felt like they'd been there all along... I've never experienced that before!
So I'm looking into buying a pair of 10's or 12's with a leaning towards the HPD units.
I'm liking the look of these cabinets: tannoy
Shame there's no plans for them 🙁
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