dual concentrics? where can i get some?

Do you like dual concentrics?

Stereophile: Tannoy Churchill loudspeaker

http://stereophile.com/images/archivesart/tanfig7.jpg

John Atkinson:"In the time domain, the Tannoy's impulse response (fig.6) looks typical of a design that uses a high-order crossover. Indeed, the step response (fig.7) confirms my suspicion from the impulse response that the Churchill is not time-coherent, despite its use of a coaxial drive-unit that places the tweeter diaphragm close to the acoustic center of the woofer. The tweeter output arrives at the measuring microphone first, followed by the woofer output."
 

ra7

Member
Paid Member
2009-02-07 6:47 am
Davis, CA
I heard the tannoy dual concentric in a voight pipe at a diy speaker contest. Sounded quite good... it definitely had the coherence of a good full range driver. Produced good amounts of bass too.

The drivers were obtained from ebay... like James says, you can buy the ceiling speakers and pull the drivers from there.
 
Do you like dual concentrics?

Stereophile: Tannoy Churchill loudspeaker

http://stereophile.com/images/archivesart/tanfig7.jpg

John Atkinson:"In the time domain, the Tannoy's impulse response (fig.6) looks typical of a design that uses a high-order crossover. Indeed, the step response (fig.7) confirms my suspicion from the impulse response that the Churchill is not time-coherent, despite its use of a coaxial drive-unit that places the tweeter diaphragm close to the acoustic center of the woofer. The tweeter output arrives at the measuring microphone first, followed by the woofer output."

The treble arrives first despite the tweeter coil physically being behind the woofer coil?

I don't know much about the Churchill as it is an export-only model but the typical Tannoy xover consists of a 12dB lo pass and a 6dB high pass, is that considered high-order?

Once upon a time Tannoy employed an all-pass filter to make their speakers time coherent. According to Tannoy engineers this was merely done to pander to the north-american markets obsession for time coherence at the time as it created more audible problems as it solved.
 
Heard Alpair 7 or 12 (10 will slot right in between -- i'm one of the lucky few that have heard them)?

dave

unfortunately ive not heard ANY of the MA drivers, and if i were to just go the whole hog and go FR im sure I would probably go with one of the MA drivers, since the few Fostex ive heard, whilst not coloured, have a certain 'flavour' to their sound. This is fine for acoustic/classical music, but i found them tiring to listen to.

I have to say im not all that au fait with the driver models, but i have looked at alpair5 or 6, for a wideband tweeter. This is mainly as im reluctant to increase the physical size too much, mainly due to the propensity of cones to break up and beam at HF. whilst a narrowing of polar response is a good thing, if implemented correctly, i feel that (maybe) a driver of more than about 3 or 4 inches could be larger than would be optimum (for me) with respect to beaming (or rather excessive beaming). hence my next project may be a 12 sub plus alpair 5/6 x-o about 300hz.

However, without a listen I couldnt say either way and what im saying is purely conjecture.

Is there any data available on the polar responses of the various MA drivers, so i could compare them? I have looked before but it turned up little, but that was some time ago
 
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Btw and AFAIK the term 'DualConcentric' is owned by Tannoy, all others are co-axials.

luckily the term 'Dual Concentric' is also an actual, literal english term, typically formed from latin:concentric and greek:dual respectively.

In fact the term applies to windings in some electrical generators and motors...

I tend to define dual concentric as a tweeter NOT pod mounted, like many automotive speakers, and mounted either tied to the poleplate, (static concentric) and attached to the 'woofer' cone and inductively driven, (floating concentric).

strictly, what you say may well be true, since i only know of Tannoy inductively driven dual concentrics.