Neodymium magnets vs Ferrite magnets

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I always wondered about this but does a speaker like the Sony SRS-ZX1 that uses neodymium magnets sounds better than if the speakers had ferrite magnets? I know that the speakers I have use neodymium magnet but I was wondering if it had ferrite magnets instead what would happen?


Basicaly my speakers is a full range 57mm driver that puts alot of good bass for there size and they normaly cost $400 but I got them for $197 with shipping.



Here's a link to my speakers.

SRS-ZX1 | Stereo Speakers with Remote | Sony | SonyStyle USA
 
Neodymium magnets are an expensive rare-earth metal that can hold a very high magnetic "charge." As such they provide a much higher magnetic flux density in the air gap and so can generate a much greater action force in the voicecoil. The electro-mechanical parameter is called "Bl" or the product of the magnetic flux density and the length of wire in the voicecoil.

Changing magnets on a speaker would change "Bl" and likely mess everything up. A speaker sounds good because it finds a symbiotic combination of ALL the various parameters that produces a balanced sound.

It is possible to make excellent sounding speakers from both Ferrite and Neodymium magnets. Even the old-school Alnico magnets from WW2 era produced some beautiful sounding speakers that are still sought after today and Alnico has even less "B" than Ferrite.

P.S. and welcome to the forum. Great question!
 
Well I guess I was also wondering about this but if they can make speakers that use ferrite magnets sound as good as speakers that use neodymium then I wonder why did Sony decide to use neodymium magnets for the speakers. I remember reading on sony's website that it said something about neodymium magnet headphones for example they would say it would give clear treble and powerful bass. Also about my speakers on Sony's site it says "Neodymium Magnet Speaker Unit for High Quality Sound".


So that's why I thought that neodymium magnets speakers have better sound than ferrite magnets but I guess I was wrong and maybe Sony is wrong about saying that.
 
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Well, what do you want them to say? "Neo magnets for light weight!" ? Just doesn't sound as good, does it. ;)

There will be arguments about magnet types forever. But one thing is for sure, Neodymium isn't bad. And the light weight, small size can have many advantages.
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small size can have many advantages.
.

You mean like having more space fore thicker pole plates instead :p
Ok, small drivers will have the benefit of being less closed in by magnet
Older alnicos had that advantage too

Two pictures of 21" woofers of same make
The new model with neo is the cheaper one
Maybe because theres much less iron involved, and less work
Unfortunately still very expencive

Clouldnt resist showing it bottom up:)
 

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Yes, very pretty magnet!
In pro use the weight savings are very welcome. Anyone who has worked on the road can tell you that. :D
But neo can be helpful in other places. Headphones, microphones, maybe phono cartridges. All could benefit from strong, small, light magnets.
 
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Yes, but one problem could kill them very early...surface treatment I believe is crutial
They really dont like air, humidity, and the surface treatment isnt too good either, doesnt stick too good
Is there something about not liking bumps either
And neo quality may vary a lot
 
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Well I guess I was also wondering about this but if they can make speakers that use ferrite magnets sound as good as speakers that use neodymium then I wonder why did Sony decide to use neodymium magnets for the speakers.

Could be any number of reasons such as.

- OEM drivers used neo magnets so they didn't change the design.
- Reduced weight to save on shipping costs.
- Performance vs weight.
- Air flow in enclosure.
- Ticking marketing check boxes.
 
Hi Guys,
Coming from the makers point of view, Neo is primarily used on small drivers due to its high output relative to size. Usually as part of a size limited volume assembly (e.g. audio modules used in flat panel TV's).
Going large with Neo is mostly cost prohibitive + cooling issues as the magnetic output can be adversely affected by increases in moderate to higher environmental temperatures. The driver's output is potentially more variable.

Ferro remains the material of choice. Its magnetic properties can be varied according to the material grade and its less effected by temperature variation. Down-side is size and weight.

Some folks debate the relative acoustic merits but flux to flux D. output from either material broadly measures the same when size/output is proportionally applied to driver builds. I've built same 2" drivers both in Neo and Ferro motors, nothing much between them in anechoic and listening tests.

Mark
:)
 
i'm not an expert, anyway, differnet materials will take different amounts and then space to generate the SAME force: this will allow for different drivers geometries, and so for different proprietis of the field generated... but you are talking esotheric here, for example take a look at these fancy magnets:

Products
Parts-Express.com: Tang Band W8-1772 8" Neodymium Full Range Driver | Tang Band W8-1772 8" Full Range Driver full range tb speakers neodymium driver line array point source midrange home theater computer speaker center channel set tube amplifier

also different motor geometries will have different impact on the back-wave radiating behind the driver, expecially on small drivers, it has been said...

different magnets generating different fields will alter the way the cone moves and follows the signal, in this regard Alnico is claimed to be more natural (something like more symmetrical field, i don't know) and it's loved also for instruments like guitars and so.

field-coils seems to be the top, for it can be regulated and usually be stronger than a same-cost magnet can be taken (but it's my guess)

regarding you'r sony speakers the small magnets is certainly ideal to have more volume left inside the enclosure, but then more then the type of enclosure loading they are getting 50hz (witouth giving any db indication) because they are bringing it down to 78db sensitivity, which is adequate for near-field, and let figure out they are equalizing the whole thing... a single alpair-5 has been taken down to 20hz in selaled box this way... and hey, that's a ferrite :)
 
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for example take a look at these fancy magnets:

The neo magnets on the TB driver, anyone can buy those at a dollar each
In huge numbers price is hardly worth mentioning

As fore the Feastrex
It really is very special, and expencive, no doubt about it
But maybe most of the money that goes into the magnet design is just a waste
With the same cone design, surround, and careful assembling etc, I wouldnt be surpriced if it sounded just as good with any other good ordinary magnet design
And cost much less
But maybe thats just the point, price
 
Even the old-school Alnico magnets from WW2 era produced some beautiful sounding speakers that are still sought after today and Alnico has even less "B" than Ferrite.

Actually, the 'old school' alnico magnets have about four times the remanent strength that ferrite does, and their flux is more stable wrt temperature and even in the presence of an opposing flux (up to a point! Beyond that point, they can be 'permanently' demagnetized - until they are remagnetized, that is.). The ferrite drivers that replaced alnico versions were generally heavier due to the greater magnet mass required to give the same gap flux.

Neodymium magnets are even stronger for a given size than alnico and do not as easily 'permanently' demagnetize under extreme conditions, but their Curie temperature (where they lose all magnetism) is very low so they lose magnetic strength faster as they heat up and are also not particularly good at maintaining a constant flux in the presence of an opposing magnetic field.
 
So does this mean that all magnets have pros and cons? But if that's the case I wonder why for somereason most higher end speakers use Neo magnets. There must be something great about them more than other kinds. But is there not really an answer like yes the Neo magnets are the best or no there are not the best? I just notice you guys don't really give a straight answer on the questions I ask. You say like this magent is good for this but other one is not good for that.
 
Yes, as with everything in audio and acoustics, there are pro's and con's. I'll go out on a limb and say that there is never a "best" only a "least bad".

If we're honest, we'll never truly reproduce the same sound field as a quartet playing in your living room. It's all a compromise. That's why there's DIY and why we'll always be here:)

<edit> and thank you Mark & Thoriated for very educational posts!
 
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I wonder why for some reason most higher end speakers use Neo magnets.

A neo magnet assembly look way better than with clumsy ceramic

At other times you see shielded ones
Ofcourse the shielding has a practical purpos
But may also serve another purpos
If nude it might look so small or badly designed you wouldnt even consider to buy it

I would say magnet material isnt really that important
Better to look at pole plate design
And all the other farraday tricks
Impedance curves reveal much of this
 
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