Seems too good to be true, magnet looks Alnico (?)
Amazon.com: Full Range Speaker 10 inch Hi-End 99dB HIFI Speaker For Tube Amplifier XIZI AUDIO 2PCS: Electronics
Amazon.com: Full Range Speaker 10 inch Hi-End 99dB HIFI Speaker For Tube Amplifier XIZI AUDIO 2PCS: Electronics
I stumbled across these on eBay. Australian price is $889 for a pair!! Pretty expensive for a 25watt full range driver. I passed pretty quickly.
I can get a pair of Fane 12-250TC for $280 inc shipping from Thomann (Germany) for $280. They get good reviews on this forum. And they can handle a bit more power. I am looking to get a pair soon (back in stock in 1 or 2 weeks).
Fane Sovereign 12-250 TC – Thomann Australia
I can get a pair of Fane 12-250TC for $280 inc shipping from Thomann (Germany) for $280. They get good reviews on this forum. And they can handle a bit more power. I am looking to get a pair soon (back in stock in 1 or 2 weeks).
Fane Sovereign 12-250 TC – Thomann Australia
Hmm. From the appearance of the cone, suspension, extended polepiece (plug) & colour of the basket they're clearly aping Coral. Not a bad idea in itself, although the Coral units had a lot of engineering behind them.
The advert states magnet material is Y35 (a grade of ferrite). Other than a small discrepancy in Vas, the spec. appears consistent with itself, with nominal sensitivity in the piston BW of 95.155dB 1m/w (96.627dB 1m/2.83v) appearing to agree with the FR graph before resonant action takes over. The 8mm stroke mentioned does not state whether it's mechanical travel or nominal linear, however you might want to take that; given the configuration & the inverse surround, the former seems likely. To be honest, I'm struggling to see anything I would consider 'too good to be true' for the price; a pair appear to be about 3.5x more expensive than, say, the equivalent Audio Nirvana model (Super 10 ferrite). It might be 'better', it might not, but it would be a rather pricy undertaking to find out.
The advert states magnet material is Y35 (a grade of ferrite). Other than a small discrepancy in Vas, the spec. appears consistent with itself, with nominal sensitivity in the piston BW of 95.155dB 1m/w (96.627dB 1m/2.83v) appearing to agree with the FR graph before resonant action takes over. The 8mm stroke mentioned does not state whether it's mechanical travel or nominal linear, however you might want to take that; given the configuration & the inverse surround, the former seems likely. To be honest, I'm struggling to see anything I would consider 'too good to be true' for the price; a pair appear to be about 3.5x more expensive than, say, the equivalent Audio Nirvana model (Super 10 ferrite). It might be 'better', it might not, but it would be a rather pricy undertaking to find out.
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You can ask this guy:
FAST_5" speaker
He got the FAST-5 version of your 10. He said they were cheap, clearly not on Amazon!
Looking them up on Taobao, the 5 is indeed cheap, and the 10 is much more expensive.
I tried a number of good-looking drivers from Asia, and pretty much all of them were disappointing, but I'm not saying this one is. I keep dreaming of finding the diamond in the rough!
FAST_5" speaker
He got the FAST-5 version of your 10. He said they were cheap, clearly not on Amazon!
Looking them up on Taobao, the 5 is indeed cheap, and the 10 is much more expensive.
I tried a number of good-looking drivers from Asia, and pretty much all of them were disappointing, but I'm not saying this one is. I keep dreaming of finding the diamond in the rough!
I think they're more than Aping them, those cones looks 100% identical to the cones in a Coral Flat 10 II, right down to the 4 decoupling rings on the outer of the large cone. (The smaller Flat 8 II like mine has only 3 rings)
The whizzer cone looks to be an identical size and taper as well.
A few possibilities come to mind:
1) A lot of Coral drivers were hand assembled from individual replacement parts (cones, voice coils, baskets, surrounds etc) in the early 2000's long after Coral had gone bust, including my pair of Flat 8 II's which are a model originally released in 1972 but mine were hand assembled in 2003 from as new parts! (I also have other pairs that were original factory assembled)
Maybe they got hold of another cache of replacement cones but there were no more baskets left so they put them into a different basket. The reverse roll fabric surround also looks genuine and the same as mine, however other modern full range drivers use the same style surround (although usually in black) so it wouldn't be that hard to source the surrounds today.
2) They got hold of some original moulds to make the cones.
3) They stripped a driver down and used it to make moulds for a cone press.
They're just too identical to be a loose knockoff copy.
As for engineering, there was a lot of hidden engineering in the Coral drivers that isn't obvious at first glance that could lead a copy that looks roughly the same not to work as well.
A few things that spring to mind are:
1) The decoupling rings - ok so these are clearly visible, but their exact mechanical properties (width, thickness, stiffness, spacing etc) are critical to tune the breakup behaviour of the cone in the upper midrange and give the flattest possible response from 2-5Khz.
The rings also provide some circumferential stiffness that help control breakup of circumferential modes the travel around the perimeter of the cone.
Most full range drivers these days don't have these rings at all and their breakup response suffers for it. Even so it's possible to improve further on them - I've added a special pattern of adhesive foam strips on the rear of the cone in the area of these decoupling rings to further tune the response.
2) The whizzer cone is not only curvilinear, it is a laminate of three different layers of long grain paper each with their grain patterns oriented at 120 degrees from the other. This is quite remarkable attention to detail.
(How do I know ? Because on one old moisture damaged one I had the 3 layers have de-laminated and are clearly visible, also shining a very bright light through the whizzer reveals the 3 different grain orientations)
This means the whizzer cone has an exceptional stiffness to weight ratio that isn't matched by the typical conical with edge flatted whizzer cone. It's so crisp that you can bend the edge inwards with a finger and then release it will snap forcefully back into place with a loud "snap"!
Unlike most other full range drivers I've measured, the whizzer cones on Coral drivers are free from resonances in the critical 2-5Khz region.
Making a whizzer cone that looks the same and is the same basic shape won't necessarily perform as well if the material and lamination's are not done the same.
3) The relative positioning of the whizzer cone in the Z-axis (forwards/backwards) relative to the main cone is a critical piece of tuning to tune the crossover between the two cones and their phase relationship. This position is critical +/- 2mm or so. If the whizzer cone sticks too far forward it introduces enough phase shift to cause a sharp notch in the summed response around 2.5Khz.
I know this because I've had many pairs of coral drivers and a couple were manufactured incorrectly with the whizzers glued too far forward, and those two had large notches around 2.5Khz that the others didn't.
Not sure where you're getting a stroke figure of 8mm (I can't find it in the amazon ad) but if that is peak to peak, it's perfectly reasonable for the driver, if it's peak, I'm quite skeptical.
The Flat 8 II series were all overhung designs with ferrite magnets, the Flat 8 II has an Xmax of +/- 3mm based on the voice coil/gap difference, and I can confirm this on my pair. Mechanical suspension limited travel is probably +/- 5mm.
They are also very "rub resistant" as far as voice coil gap goes - if I gently press one side of the cone on a Fostex FE206 it takes very little asymetry of force to cause the voice coil to rub, on the Coral driver it doesn't rub at all when pushing the cone back and forth indicating a good suspension/spider design and a relatively conservative voice coil gap. So they're probably relatively robust in the face of moderate over-driving with bass. I've certainly not managed to damage mine in nearly 15 years, and I've had a few accidents with the volume control over the years...!
So I can easily believe that the 10" model would achieve an Xmax of +/- 4mm.
They're certainly interesting looking (apart from the rather tat looking wooden phase plug) but even as a Coral fan I don't think I would be willing to take the risk on these at the price.
I'd rather put the money towards something like a pair of Tangband W8-1772 which are a readily available relatively well known driver with fairly comparable performance to the Coral drivers.
With this amazon listing you're taking a punt which even if it works out may be drivers that you'll never be able to get hold of again. (If they are indeed building them partially from left over Coral cones)
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Apparently aping them then, since this does not automatically imply copying badly. With only pictures in an internet advert to go on though, that's as far as I'm happy going.
True. And it's possible, although judging from the numerous Diatone lookalikes kicking around, I suspect it's more likely they've made something that resembles them rather than using NOS components.
Stripping down an original unit would be more likely.
Just so. That's why I said Coral units had a lot of engineering behind them.
Yes, decoupling rings were a popular means of controlling the transverse wave (the W.E. / Bell / Altec 755 comes immediately to mind) and are still used to varying extents & various ways. Not the only method however, and the existence or lack thereof is not necessarily a guide to quality.
Agreed, the Corals had one of the best performing whizzers of any wideband unit I can recall.
Attached screenshot; ringed in red. Without a a lot of extra information on this driver (rather than the units it resembles) I would be cautious about reading anything whatsoever into it.
The ones I've heard haven't been comparable to a good pair of Corals -but then, finding a good pair of Corals is not easy any more.
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I've done side by side measurements with a few other 8" whizzer cone drivers including FE206, FE207 and they don't even come close. In fact my FE207's are back in their original boxes for the last 12 years or so as I consider them un-listenable due to their incurable upper midrange resonances. (Wish I'd just sold them on once I decided not to use them! I tried a number of different damping tweaks, some destructive and nothing helped)
Agreed. As I said, I'd say +/- 4mm would be reasonable and I wouldn't expect any more than this. I've not seen "stroke" used in place of Xmax before, Xmax is usually (always ?) defined as peak displacement, but I suspect "stroke" is equivalent to peak to peak Xmax.
Yes.
I've had several pairs of Corals over the years of slightly differing models and quality including Flat 8A, which were factory original in original cabinets but whose surrounds had gone very stiff, 8A-100 - a rare, cut price version of the Flat 8 with black cones/surround and a paper dust cap instead of the regular metal dust cap, which was sold in NZ by David Reid electronics in the 80's, (and which I have never seen mention of online) and my currently in use Flat 8 II which are NOS hand assembled in 2003 which got from Canada.
I've had a watchlist on ebay for about 5 years now and only a couple of pairs of Flat10 have come up - I haven't seen any more Flat 8's and none of the projects I have in mind really lend themselves to a 10" driver. (Plus they are expensive)
So I have basically given up on ever finding another pair of Flat 8's, hence why I'm looking at the Tangband W8-1772 for future projects.
Disappointing to hear that you don't think they quite compare, but my intended use would be as a high sensitivity high SPL wide band midrange driver from 250Hz to 3Khz, in a large 3 way system and as such they would have a crossover which would allow me to equalise and shape their frequency response.
I already apply quite a lot of frequency response shaping to my coral drivers in a fairly complicated 2 way crossover to get optimal results as well as having performed damping modifications to the cones.
So whilst the W8-1772 might not sound as good "out of the box" naked and with no crossover, from what I've seen I feel reasonably confident that with a some similar foam damping strip tweaks as the ones I've used on the Coral drivers and suitable shaping in the network that I should be able to get a very comparable response from 250-3khz with similar directivity and equal or better dynamic performance. That's the plan anyway...
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Doesn't surprise me; it was a shame Coral vanished into history. I hadn't heard about the black cone versions; interesting bit of history there. 
Fair enough re the 1772s; you may well find them ideal, that was my opinion only, and many do like them. Be interesting to hear how you get on though, as & when.
Fair enough re the 1772s; you may well find them ideal, that was my opinion only, and many do like them. Be interesting to hear how you get on though, as & when.
Odd that they show an anaechoic chamber - but not the FR plot measured in that chamber.
The (brown) M6 has a FR plot that looks pretty honest. It measures like a good TV or radio speaker - HF is boosted, but with no horrible spikes, so it would probably sound pretty good (flat to ~8kHz, i.e. high enough for good vocal intelligibility) when off axis.
So at a guess, it would be an easy listening speaker, for applications like background music or listening to podcasts where you will be moving around a lot, rather than a critical listening speaker.
It'd also look the part when rear mounted in a retro radio style cabinet.
Just to try something different, or are you getting tired of your home-grown FR drivers?
Awwww ...c'mon the Reality of a largish cone FR driver is complete BS or more charitably; wishful thinking.
The geriatric and IMO now Borrring.. something for nothing world view.
IF one could manage it with any degree of credibility (as in it hasn't been Done Yet).
There would be a line up around the block wanting to buy.
Are you seeing one?
The geriatric and IMO now Borrring.. something for nothing world view.
IF one could manage it with any degree of credibility (as in it hasn't been Done Yet).
There would be a line up around the block wanting to buy.
Are you seeing one?
People have different design ideas and wanting of a different listening experience.
Some people don't have the space or possibility to stuff a big 15" driver inside their room, so, no, there are no line ups for a single kill-all design.
I, personally have more fun listening to a 15" woofer combined with 8" FR, than using that same 15" woofer, combined with 3" FR drivers. Even when both designs are EQ to my preferred listening curve.
And I ain't geriatric yet!
I'm glad you shared that you listened to all the big drivers designs in the world, saves us the trouble of finding out ourselves....
Some people don't have the space or possibility to stuff a big 15" driver inside their room, so, no, there are no line ups for a single kill-all design.
I, personally have more fun listening to a 15" woofer combined with 8" FR, than using that same 15" woofer, combined with 3" FR drivers. Even when both designs are EQ to my preferred listening curve.
And I ain't geriatric yet!
I'm glad you shared that you listened to all the big drivers designs in the world, saves us the trouble of finding out ourselves....
Once you are done with the 20's and have the basics set just so, it's almost like a prerogative to get grumpy and stubborn. No use for the social buzzing with uninteresting individuals, you get more stuff done if people jump out the way.
I am kidding ofcourse, but it does have some advantages.
Sometimes playing on peoples generalizations can't do any harm?
I am kidding ofcourse, but it does have some advantages.
Sometimes playing on peoples generalizations can't do any harm?
BS eh ?
40Hz to 15Khz with a single driver is perfectly possible with a really good 8" dual cone full range driver + a moderate amount of EQ. I know because I've done it...
The only real drawback that is somewhat unavoidable is they do become very directional in the treble above about 6Khz, leading to a relatively small listening sweet spot and a very "dry" sounding room reverberation that doesn't have much treble in the reverberant field.
Which is why I now use them with Ribbon tweeters for a better overall listening experience that has a more pleasant reverberant field and a much wider listening sweet spot.
But with suitable EQ the treble response at the sweet spot is just as good if not better than many tweeters, and the coherence of of the single driver is very difficult if not impossible to replicate with multiple drivers, and the result can be quite breathtaking on certain kinds of music.
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Hi HB
I'm still happy with my Boyd FR drivers, jist looking to have some fun. As you know I have listened to panel speakers for over 20 years so its time to learn some mew tricks.
I have some CTS,
15" FRs, from the 60's/70's.
Advertised as 2" voice coil, 30 oz, Alnico magnet.
I have No measurements,
'They will respond quite low, maybe mid 20's.
Cymbals seem to be well done.
As I recall, $35, each new, late 1970's ....
_------------------------------------------
Xizi -
Yudan Tool @ Amazon.com:
15" FRs, from the 60's/70's.
Advertised as 2" voice coil, 30 oz, Alnico magnet.
I have No measurements,
'They will respond quite low, maybe mid 20's.
Cymbals seem to be well done.
As I recall, $35, each new, late 1970's ....
_------------------------------------------
Xizi -
Yudan Tool @ Amazon.com:
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