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[Scott Bolt]

Back on topic.....

The issue with Neo drivers was caused because China started dumping cheep Neodymium on the market.  This forced pretty much all other regions of the globe to close up their mines since there was no profit in it.

Faced with a monopoly on neodymium, China then jacked the prices up rapidly.

Sadly, pro audio OEM's had hitched their pony to this material and many rapidly had to redesign in order to maintain any profit in some markets.

Just some engineering points to make here.....

Neodymium is a superior material to make magnets out of.  For the same size and weight, it produces a flux density ~ 10 times greater than ceramic.

Now this doesn't mean that you can't make a speaker that sounds just as good and puts out the same SPL using a ceramic magnet, it just means that it is going to be heavier and bigger.

Bob is incorrect in that Neo doesn't transfer heat as well as Ceramic, but what I think he was aiming for was that Neo isn't as tolerant of high temperatures as ceramic or ferrite magnets.  In fact, Neo starts losing its magnetic properties at around 176 degrees F.  That isn't really all that hot when you think about it (although it is much hotter than most consumer grade electronics can stand .... which is around 140 deg F).

It is better than ceramic and ferrite with respect to keeping its magnetic field in the presence of time, shock, and other magnetic fields though.

If you are a speaker designer and given a set of design criteria that include size and weight, Neo is going to likely be your first choice.

[Bob Leonard]

What I said was "The neo drivers don't dissipate heat as well as the newer designed ceramic drivers.", and they don't. Additionally neodymium magnets suffer more irreversible damage when subjected to high temperatures beyond their working capabilities, even to the point where they can become un-usable. There are also many grades of neo meaning how do you know low cost speakers are using a quality grade neo, and finally, has the neo been coated properly with a layer of copper/nickel/copper after it has been machined. Just questions to ponder when you buy that neo driver based on it's low cost and light weight.

I'm not saying neo doesn't have advantages. What I'm saying is that neo isn't always the best choice, as many may seem to think. Many neo instrument speakers are considered to have poor sound qualities as compared to ceramic or ALNICO, and the same can be said for many speaker types used in pro sound, or voice applications. YMMV according to taste.

Anything you need to know about magnet types and properties can be found here.

http://www.ndfeb-info.com/
 
"Ferrite magnets are extremely popular due to their characteristics.  Ferrite magnets are corrosion free – for long term performance they are superb; if looked after they are capable of exceeding most products lifecycles.  Ferrite magnets can be used up to +250 degrees C (and in some cases up to +300 deg C).  Ferrite magnets are also low cost, particularly in high volume production runs."
 
"The magnetic output from the "Neo" magnet varies with temperature. The output falls with increasing temperature but usually returns as it cools (the degree of fall with rising temperature is dependent on the reversible temperature coefficients). It is possible to permanently reduce the magnetic output through too high a temperature (a permanent demagnetisation)."

[Brian Jojade]

What NEO magnets do is make for a lighter speaker.  Sound quality of the speaker has to do with the overall design.  Of course you can't just take a ceramic design and throw a NEO magnet in place of it and expect it to work and vice versa.  However, with the same design criteria in mind, an engineer could come up with the same output of each design.  The Neo would be lighter weight.

Now, working with NEO does require a bit more planning. If you're buying from a manufacturer that likes to take shortcuts, I'd shy away from NEO as they may not have designed the system in a way that can take the abuse of real world use.  With Ceramic magnets there's more tolerance available so the shortcuts won't be as detrimental.

[ProSoundWeb Community]