AlNiCo has superior coercivity to neodymium, which can be important in high power applications, especially those subject to continuous load. Losses depend on grade, since not all are created equal (as I recall, there are nine commercially available grades of AlNiCo). It is something of a moot point trying to compare magnets alone since they have no sound in and of themselves (humans not hearing magnetism), but different behaviours that affect the other components. Which in turn means that a competent drive unit design accounts for the behaviour of the magnet in the overall motor design, and it is extremely rare they will ever be like-for-like. Be that as it may, AlNiCo has its uses; much of the time today it is there for marketing, but this does not mean that it has no positive technical attributes.
...not to go too far off topic but talk about an expensive Fostex AlNiCo driver, Fostex W400-A-HR 15" Woofer 
Did you hear this joke on BBC? Here is a comparison of the characteristics of the coercive force of magnets at Alnico worst of all, even compared with ferrite, not to mention neodymium. If Alnico really had great efficiency, then this type of magnet would still be used in electric drives of cars, electric vehicles and other powerful industrial electrical equipment. The most valuable thing that can be in the old speakers is the magnetic core of permendur. Alnico magnet even loses its magnetization over five years by 20%. Then the loss rate decreases, but it is still there. Neodymium has no loss of magnetization at all. And this I am repeating a second time. Expensive magnetic systems from permendure are now successfully used by many manufacturers, but already in combination with neodymium.
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There is zero need for that attitude. Get over yourself.
I perhaps should have assumed it would be realised I was refering primarily to it as pertaining to thermal performance, or visa versa if you prefer (your lookout, I couldn't care less one way or the other). For the record:
-Typical maximum operating temperatures for neodymium magnets is about 120°C depending on grade with a few specialist types that can get up to about 230°C.
-Typical maximum operating temperatures for ceramic magnets is about 250°C depending on grade & geometry.
-Typical maximum operating temperatures for SmCO magnets is about 250°C - 350°C depending on grade.
-Typical maximum operating temperatures for AlNiCo magnets is up to about 500°C, depending on grade.
Hence the preference some have for AlNiCo magnets in high power applications with high continuous loads. This is just a fact. Nobody is insulting your precious Neodymium. Or ferrite, SmCo or anything else. You use what is optimal for your given functional design goals, costings and (as relevant) advertising. Live with it.
I perhaps should have assumed it would be realised I was refering primarily to it as pertaining to thermal performance, or visa versa if you prefer (your lookout, I couldn't care less one way or the other). For the record:
-Typical maximum operating temperatures for neodymium magnets is about 120°C depending on grade with a few specialist types that can get up to about 230°C.
-Typical maximum operating temperatures for ceramic magnets is about 250°C depending on grade & geometry.
-Typical maximum operating temperatures for SmCO magnets is about 250°C - 350°C depending on grade.
-Typical maximum operating temperatures for AlNiCo magnets is up to about 500°C, depending on grade.
Hence the preference some have for AlNiCo magnets in high power applications with high continuous loads. This is just a fact. Nobody is insulting your precious Neodymium. Or ferrite, SmCo or anything else. You use what is optimal for your given functional design goals, costings and (as relevant) advertising. Live with it.
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Neodymium has higher coercivity than Alnico. And Alnico are actually very weak magnet, e.g. LNG44 grade alnico or called alcomax 3 where the Br can reach 1.2T, but their low coercivity makes them loses magnetism easily if they are dropped or placed in a demagnetizing magnetic field.
I custom made for my products, alnico loses magnetism after first magnetized charged. And alnico 8 and above all subgrades has a diameter limit in making them. Max diameter for alnico 8 and above is around 70mm
To be honest alnico main advantage is it has Titanium content in them making them super tough and durable against corrosion.
And there are more than 9 grade of alnico. Each alnico grade is broken down into further sub grade from LNG34 to LNGT80
Casted or sintered
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See above clarification regarding to the point made. Re-stating (again) I assumed it would be realised the reference was as pertaining to thermal performance & limits.
I stand corrected re the number of grades available; I was aware of nine common ones, not of additions so thank you for the clarification.
Re diameter limit / dimensions, as I noted:
a competent drive unit design accounts for the behaviour of the magnet in the overall motor design, and it is extremely rare they will ever be like-for-like
This being a result of the different physical properties of the magnetic materials, and it is not always possible to provide identical (or sufficiently similar) results with different magnet types, making 'comparisons' with only a single variable change (magnet type, zero other changes) essentially an oxymoron since it's almost impossible to achieve.
I stand corrected re the number of grades available; I was aware of nine common ones, not of additions so thank you for the clarification.
Re diameter limit / dimensions, as I noted:
a competent drive unit design accounts for the behaviour of the magnet in the overall motor design, and it is extremely rare they will ever be like-for-like
This being a result of the different physical properties of the magnetic materials, and it is not always possible to provide identical (or sufficiently similar) results with different magnet types, making 'comparisons' with only a single variable change (magnet type, zero other changes) essentially an oxymoron since it's almost impossible to achieve.
I'm glad you almost understood what was happening.
I will tell you a secret that a voice coil during operation can only heat up to 250-300 degrees Celsius in a short time, no more. But why now, in your speakers, instead of the greater coercive force of Alnico’s magnets, did a magnet temperature of 500 degrees Celsius arise? In any case, the temperature of the magnet, even in the most severe conditions, does not exceed 65 degrees Celsius.
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25 years ago when I graduated from mid-fi and began my misadventures into high-end audio, a well-respected importer, dealer and audio review writer I'd chat will at audio shows and audio society shin-dings told me AlNiCo magnets were used back in the "Westrex" "golden age of audio" because AlNiCo focus the magnetic field into the gap better and with more strength than ceramic magnets. Part of the reason high-efficiency drivers achieve high TS parameter SPL ratings. That AlNiCo magnets are difficult to produce because the Cobalt in the mix is a very hard metal so AlNiCo magnets are a lot of work to machine on a lathe.
...and what a load BS that's all sounding like!
Thx again guys!
...and what a load BS that's all sounding like!
Thx again guys!
Are you tempted?Fostex FE103A 4" Alnico Full Range - Foster 70th Anniversary Limited Edition - Pair: Madisound Speaker Components
Wow! Thats a lotta scratch for a pair of Fe103's...
The frequency plots are not exactly world class either....
Indeed! I find it simply worderful that a company of their size takes the time these days to honor their roots and their customers with such an offering. It take quite a bit of dedication from the brass to go through the hoops to produce something like this and I would bet my hat that in 30 years these will be worth a mint!
As to all of the bickering.... I think they are missing the point of this thread.....
As to all of the bickering.... I think they are missing the point of this thread.....
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