I saw some on my last visit that looked like the Extremis from the front but instead of that beautiful trim Neo motor on the back there was a big chunk of ferrite!
A little OT but I thought it was interesting. This one looks like a mini-Extremis but I know it's not an XBL^2 driver 'cuz it's only got .5mm Xmax.
http://www.tb-speaker.com/detail/1230_04/w3-1335s.htm
A little OT but I thought it was interesting. This one looks like a mini-Extremis but I know it's not an XBL^2 driver 'cuz it's only got .5mm Xmax.
http://www.tb-speaker.com/detail/1230_04/w3-1335s.htm
Your output is pretty amazing Dan, designing something on a PC or paper is one thing but actually making a working production model is another nightmare It takes months for me and two of my friends to settle on a design and this normally takes hundreds of hours of listening time in panels, in tens of enclosures and different rooms and equipment and miles of notes and tweaks and its a long trying process with lots of arguments along the way, finite analysis can cut down on R&D but it can not replace empirical testing and listening, how do you quality control the sound quality of such a large output of newly designed speakers? Or are they variation on a theme? Or is it assembly of new parts?
hi
i found this interesting from jbl :-
( the text is a direct copy / paste )
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SOLVING A LONG-STANDING PROBLEM, LEADING TO DEEPER, MORE ENERGETIC BASS:
THE 1500AL ALNICO MAGNET WOOFER.
The magnetic circuit is a speaker's most fundamental component, the very engine of sound. Alnico magnets, prized for their lively, high-energy sound, were once widely used in the magnetic circuits of high-end speaker systems. But, because Alnico magnets tend to demagnetize at high power levels, they've all but disappeared since the 1970s, when amplifier power outputs increased ramatically.
Having successfully overcome the demagnetization problem, JBL's engineers are pleased to reintroduce the deep, energetic Alnico sound.
-------------------------------------------------------------------------
i have an aquaitance who manufactures high - end alnico magnets - permanent magnetics limited - pml , india
i will contact him about this development - and check if he backs this possibility and development
suranjan
i found this interesting from jbl :-
( the text is a direct copy / paste )
-------------------------------------------------------------------------
SOLVING A LONG-STANDING PROBLEM, LEADING TO DEEPER, MORE ENERGETIC BASS:
THE 1500AL ALNICO MAGNET WOOFER.
The magnetic circuit is a speaker's most fundamental component, the very engine of sound. Alnico magnets, prized for their lively, high-energy sound, were once widely used in the magnetic circuits of high-end speaker systems. But, because Alnico magnets tend to demagnetize at high power levels, they've all but disappeared since the 1970s, when amplifier power outputs increased ramatically.
Having successfully overcome the demagnetization problem, JBL's engineers are pleased to reintroduce the deep, energetic Alnico sound.
-------------------------------------------------------------------------
i have an aquaitance who manufactures high - end alnico magnets - permanent magnetics limited - pml , india
i will contact him about this development - and check if he backs this possibility and development
suranjan
One of the 'properties' that is often spoken about with regard to neo magnets is the demagnetization due to shock. How relevant is this in a PA application? Just how badly would a driver have to be handled in order to hear noticeable effects? Obviously PA speakers have a much harder life than regular hifi, studio, etc speakers but is this property of neo magnets not really relevant in the real world.
DanWiggins said:
No, this was not his intent.
http://www.audioroundtable.com/Speaker/messages/223.html
other speaker designer on this subject
http://audioheritage.csdco.com/vbulletin/showpost.php?p=110522&postcount=29
7428
Yes. One should try keeping one's knuckles off the ground when applying Alnico magnet drivers, and shouldn't overpower them beyond their specified operating parameters. I don't see that this is really so difficult to do in a high quality application. Then their greater resistance to flux modulation relative to other magnetic materials can be appreciated.
I've posted the numbers, which you have apparently accepted that demonstrate this. If you try blasting your alnico drivers into hyperspace with extreme amounts of amplifier power, then, yes, you will demagnetize them, but doing so would be inappropriate in a high sound quality application and abusive to boot, IMO.
I don't see why there should be any difficulty accepting this.
And another reply essentially consisting of :
"Well, I will blast them into hyperspace and demagnetize them if at all possible, therefore you're wrong."
is merely avoiding my point thus implicitly conceding it.
Incidentally, alnico driver magnet assemblies shroud the cone's back wave far less than large ceramic magnets do, much like neodymium.
tomtt-
Your second link expresses almost exactly the points I was making about alnico vs mud with numbers. I wonder why some here find these truths to be so offensive.
"Well, I will blast them into hyperspace and demagnetize them if at all possible, therefore you're wrong."
is merely avoiding my point thus implicitly conceding it.
Incidentally, alnico driver magnet assemblies shroud the cone's back wave far less than large ceramic magnets do, much like neodymium.
tomtt-
Your second link expresses almost exactly the points I was making about alnico vs mud with numbers. I wonder why some here find these truths to be so offensive.
So, if I understand your argument correctly, AlNiCo is superior to "mud" magnets (never mind ALL magnets are made the same way - a slurry of base elements that are formed and sintered - they're all "mud" at one stage) if you use them in low power applications.
So what about the other 99.99% of the speaker world? Literally. The market you just identified is essentially low power, high efficiency speakers. Which is probably a $5M/yr market - for the drivers, that is. Worldwide the audio transducer market is around $50B - that's a bit different, no?
Also, note that it's not the power level but the flux density that kills AlNiCo. Do a high-flux-field motor and your AlNiCo is toast - it loses it's charge. That can be done with 10-20W if you have tight clearances and tight winds.
Why use AlNiCo when neo is available?
1. Neo doesn't have the problems of demagnetization
2. Neo can provide more flux per cross sectional area than AlNiCo
3. Neo isn't as brittle as AlNiCo
Oh, and about those "mud" motors? They're vastly superior if you need to use 1000W of power with your driver. You now, subwoofers, prosound applications, box sizes that you can actually use around your house (i.e.: low efficiency designs in bookshelf speakers).
AlNiCo really doesn't have ANY advantage over neo, and the only one it has over ceramic is the same that neo has - a lot more flux per cross sectional area. It costs more than the other options, demagnetizes much more readily, can't stand flux compression, and is more brittle.
AlNiCo works well in small niche markets - high efficiency, low power. But outside that realm it's seriously inferior, which is why it's just not used (outside a few MI applications where the compression is actually desired as a sonic trait).
So what about the other 99.99% of the speaker world? Literally. The market you just identified is essentially low power, high efficiency speakers. Which is probably a $5M/yr market - for the drivers, that is. Worldwide the audio transducer market is around $50B - that's a bit different, no?
Also, note that it's not the power level but the flux density that kills AlNiCo. Do a high-flux-field motor and your AlNiCo is toast - it loses it's charge. That can be done with 10-20W if you have tight clearances and tight winds.
Why use AlNiCo when neo is available?
1. Neo doesn't have the problems of demagnetization
2. Neo can provide more flux per cross sectional area than AlNiCo
3. Neo isn't as brittle as AlNiCo
Oh, and about those "mud" motors? They're vastly superior if you need to use 1000W of power with your driver. You now, subwoofers, prosound applications, box sizes that you can actually use around your house (i.e.: low efficiency designs in bookshelf speakers).
AlNiCo really doesn't have ANY advantage over neo, and the only one it has over ceramic is the same that neo has - a lot more flux per cross sectional area. It costs more than the other options, demagnetizes much more readily, can't stand flux compression, and is more brittle.
AlNiCo works well in small niche markets - high efficiency, low power. But outside that realm it's seriously inferior, which is why it's just not used (outside a few MI applications where the compression is actually desired as a sonic trait).
Interesting discussion
I have a driver I like a lot- the PR65neo PR65 neo page
It's underhung, with an undercut pole piece, and uses some other nice features. Anyone want to describe the way the neodym is used with the ceramic in a motor like this? My inclination would be to think that it's designed to redirect leakage flux, but that's a guess.
I have a driver I like a lot- the PR65neo PR65 neo page
It's underhung, with an undercut pole piece, and uses some other nice features. Anyone want to describe the way the neodym is used with the ceramic in a motor like this? My inclination would be to think that it's designed to redirect leakage flux, but that's a guess.
Regarding this discussion of Nd vs. alnico, lemme just say that I'm not at all against Alnico magnets per se, though I generally prefer to design using Nd. At the end of the day, the important thing for me is the fun factor, and Alnico and Nd are both much more fun for me than ceramic.
I love the practice of transducer design--creating devices that sing to me and transmit truth and beauty to my mind--and I dig the design challenge that alnico's touchiness presents. That's why I say hats off to Doug Button for his work on the 1500AL, a device of intrinsic beauty. I also like alnico for its historicity and connection to the early days of audio.
While transducer design should certainly evolve technically and continue to raise the state of the art, I also think of the best transducers as objects d'art in their own right--their form, materials, and execution providing joy and value to their owners apart from their measured performance.
I love the practice of transducer design--creating devices that sing to me and transmit truth and beauty to my mind--and I dig the design challenge that alnico's touchiness presents. That's why I say hats off to Doug Button for his work on the 1500AL, a device of intrinsic beauty. I also like alnico for its historicity and connection to the early days of audio.
While transducer design should certainly evolve technically and continue to raise the state of the art, I also think of the best transducers as objects d'art in their own right--their form, materials, and execution providing joy and value to their owners apart from their measured performance.
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