Hi,
one can observe very easily that speakers rather often are literally praised as "Alnico" speakers. This obviously has to be related to the alloy the magnet has been made from.
As the magnet's only job is to create a strong magnetic field within it's air gap and to interact with the voice coil's own field, I'm wondering whether the same field can't be created by any other magnet of suitable properties, being it e.g. a ferrite, a neodymium one or even a solenoid?
Or has an Alnico created magnetic field got some snake oil properties?
Best regards!
one can observe very easily that speakers rather often are literally praised as "Alnico" speakers. This obviously has to be related to the alloy the magnet has been made from.
As the magnet's only job is to create a strong magnetic field within it's air gap and to interact with the voice coil's own field, I'm wondering whether the same field can't be created by any other magnet of suitable properties, being it e.g. a ferrite, a neodymium one or even a solenoid?
Or has an Alnico created magnetic field got some snake oil properties?
Best regards!
Yes, the energy of magnetization at different electrical fields have a major impact on the sound.
Ferrite has a nice smooth curve like a transformer core, magnetize relatively slowly and demagnetize slowly.
Alnico is more lively but still has some curve. Neodymium is like Alnico on steroids. For an audio signal it would seam the most able to recreate almost any signals.
But don't get it wrong, ferrite speakers can sound as good but different.
The main strength of Alnico vs ferrite is when matched to a SET for some reason the match is perfect, take the same alnico and use a SS, all magic is gone. Take the SET on ferrite speakers, bass is dull. It is very complicated to explain, no one really dived into the thing seriously.
Ferrite has a nice smooth curve like a transformer core, magnetize relatively slowly and demagnetize slowly.
Alnico is more lively but still has some curve. Neodymium is like Alnico on steroids. For an audio signal it would seam the most able to recreate almost any signals.
But don't get it wrong, ferrite speakers can sound as good but different.
The main strength of Alnico vs ferrite is when matched to a SET for some reason the match is perfect, take the same alnico and use a SS, all magic is gone. Take the SET on ferrite speakers, bass is dull. It is very complicated to explain, no one really dived into the thing seriously.
What does hysteresis have to do with a given and constant magnetic field, as it is concerned in (to be more precisely: after) the magnetization process only?
Next question: How are speakers with Alnico magnets discerned from others in case you don't have a datasheet and/or the sheet doesn't specify the magnet's material (which is the case mostly)?
Best regards!
Next question: How are speakers with Alnico magnets discerned from others in case you don't have a datasheet and/or the sheet doesn't specify the magnet's material (which is the case mostly)?
Best regards!
A while ago I read an article about the difference between ceramic and AlNiCo magnets, but I can't recall the source. The shape of each type was analyzed in particular. Ceramic (ferrite) magnets are flat discs, AlNiCo magnets are high "pot" shaped. The reason lies in their magnetic properties (B-H curve). Apart from the shape, the color is also characteristic: ferrite is greyish black and smooth, AlNiCo is shiny (often painted grey or whatever) and sometimes has rough outside surface. Due to the shape (flat disc vs. tall cylinder), AlNiCos are in general longer throw. AlNiCo is conductive which is not good. Both are sensitive to shock and heat. This is all I know about them.
it's no magic - science:
http://www.diyaudio.com/forums/multi-way/105136-putting-science-loudspeakers.html#post1254379
http://www.diyaudio.com/forums/multi-way/105136-putting-science-loudspeakers.html#post1254379
I saw 30 year old ceramic magnet speakers whose remaining magnet strength has been maybe a third or fourth of the original value, maybe even less.
Hi,
You will know by the price
Any Alnico driver looks different from a Ferrite, they are easily discernible by appearance, you can see a ferrite magnet is big, round and flat, a Alnico magnet usually is small, the motor is open square or cylinder semi closed as Nirvanas.
Dont hurry an Alnico driver manufacturer have all the interest to shout to the four winds that his speaker is Alnico.
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Ya, and alnico demagnitize only if the amp can send a strong enough current to do this. 20 watts tube amplifiers cannot.
So this is a non issue, even at 90% the speaker will sound perfect, I heard 12 inches alnico speakers 50 years old and sounded perfect. They sounded **** with solid state.
Only Alnico magnet dont grant good sound.
Please note that the magnetism created by these 3 magnet types are all different each other, so when one add a paper VC with afew grams of a paper cone more a electric music signal the subject become very complex to explain how they do a different sound field.
The way to project a Alnico speaker is very different from an Ferrite driver project, if the Alnico driver is not well designed it will have a bad sound.
There are various types of Alnico, some them have good sound for hi-fi, others do not, from what I remember those who have good sound are:
Alnico 5
Ticonal
Alcomax ?(used by Lowther)
Alni, Alnico, Alcomax, Ticonal - Magnet Alloys - Ireland Alloys
Applications: Permanent Magnets
Co Cr Ni Fe Mo V Cu Al W C Others
Alnico 1 - - 24.5 BAL - - 6 12.5 - - -
Alnico 2 13 - 17 BAL - - 6 10 - 0.1 -
Alnico 5 24 - 14 BAL - - 3 8 - - -
Alnico 8 35 - 15 BAL - - 4 7.5 - - 5.0 Ti
Alcomax 2 21 - 11 BAL - - 4.25 8 - - -
Alcomax 3 24.5 - 13.5 BAL - - 3 8 - - 0.75 Nb
Alcomax 4 24.5 - 13.5 BAL - - 3 8 - - 2.0 Ti
Ticonal 25 - 15 BAL - - 3 8 - - 2.0 Ti
3% Co 3 9 - BAL 1.5 - - - - 1 -
6% Co 6 9 - BAL 1.5 - - - - 1 -
9% Co 9 9 - BAL 1.5 - - - - 1 -
15% Co 15 9 - BAL 1.5 - - - - 1 -
35% Co 35 6 - BAL - - - - 4 1 -
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Incorrect!
Alnico also belongs to the group of permanent magnets.
Old speakers (Altec 604 coaxials for example) are often remagnetized, that's why I thought
We have to talk also about the pole piece which is made of iron, and its magnetic field is saturated. So no matter how strong is the magnet, there is a limit of the field strength.
There is an interesting remark regarding to metal (AlNiCo, neodymium) magnets in "Loudspeakers: For Music Recording and Reproduction" by Philip Newell, Keith Holland:
"... there is a tendency for many of the of highest resolution devices to use metal magnets, and explanations have been put forward to suggest that the magnetic domain jumps which take place in non-conductive materials can give rise to effects not dissimilar to digital quantising distortion. These jumps are smoothed out by large eddy currents flowing in the electrically conductive magnets. In some loudspeaker designs the central pole-piece of the magnetic assembly is fitted with a copper ring to provide a very low electrical resistance - less than that of steel - to effectively short out any flux-modulation currents"
There is an interesting remark regarding to metal (AlNiCo, neodymium) magnets in "Loudspeakers: For Music Recording and Reproduction" by Philip Newell, Keith Holland:
"... there is a tendency for many of the of highest resolution devices to use metal magnets, and explanations have been put forward to suggest that the magnetic domain jumps which take place in non-conductive materials can give rise to effects not dissimilar to digital quantising distortion. These jumps are smoothed out by large eddy currents flowing in the electrically conductive magnets. In some loudspeaker designs the central pole-piece of the magnetic assembly is fitted with a copper ring to provide a very low electrical resistance - less than that of steel - to effectively short out any flux-modulation currents"
Perhaps the reason is rather more basic.
Put AlNiCo into a speaker, and you're already making an expensive speaker. The manufacturer would be rather commercially unsuccessful to make an expensive speaker that sounded worse than cheaper ones.
Hence AlNiCo speakers that actually made it to serial manufacture tended to sound 'better' - and now that they're rare the legend lives on mostly by word of mouth.
Put AlNiCo into a speaker, and you're already making an expensive speaker. The manufacturer would be rather commercially unsuccessful to make an expensive speaker that sounded worse than cheaper ones.
Hence AlNiCo speakers that actually made it to serial manufacture tended to sound 'better' - and now that they're rare the legend lives on mostly by word of mouth.
Thanks for your replies so far, fellas!
Perhaps I should have questioned more precisely: Given two (or more) speakers of exactly the same cone, suspension, and voice coil construction and the same magnetic field strenghth within air gaps of identical dimensions and pole pieces of the same material, but their magnetic field created by magnets of different composition. Do they sound differently, and why?
Best regards!
Perhaps I should have questioned more precisely: Given two (or more) speakers of exactly the same cone, suspension, and voice coil construction and the same magnetic field strenghth within air gaps of identical dimensions and pole pieces of the same material, but their magnetic field created by magnets of different composition. Do they sound differently, and why?
Best regards!
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