Neo Versus Ceramic In Subwoofer Applications

[CarlosT]

I have read just about every possible voodoo explanation as to why ceramic magnets are better than neo magnets for low freq. applications.

Can someone explain this?

[MaVo]

i doubt there are differences from a pragmatic sound quality pov. of course, neo is less weight. and of course, there are allways people defending obsolete technology like vinyl.

[aznboi3644]

There is no sonic difference...magnetic flux is magnetic flux

[djk]

Neo is a poor choice for high power applications, the magnets cannot take the heat, ceramic can.

"There is no sonic difference...magnetic flux is magnetic flux"

Alnico is electrically conductive. Other materials will require shorting rings to reduce distortion and inductance.

Some of the netter neo woofers do have these shorting rings, and specially designed frames with heatsink fins.

Spending 2x the money to cut 10lbs off a 150lb~200lb subwoofer and have dubious powerhandling is an easy choice for me.

On a lightweight mid-high top that will be lifted onto a stand, that's another matter.

[Jack Hidley]

Using a neo magnet will almost always have less distortion due to less flux modulation at low frequencies. Shorting rings in the motor will reduce flux modulation some, but their effect decreases as frequency goes down. At frequencies below 80Hz, they have virtually no effect. Neo is the easiest way to fix this problem.

This assumes of course, that you can keep the voice coil at the same temperature with the neo magnet.

[aznboi3644]

A subwoofer will never produce enough heat to affect the neo magnets strength enough to make any difference.

[djk]

" subwoofer will never produce enough heat to affect the neo magnets strength enough to make any difference"

Then why do the better manufacturers buy the higher temperature grades? They are heavier for the same flux density, and cost more money too.

"The Neodymium materials do exhibit a temporary, or reversible loss of flux with increasing temperatures. The severity of these losses and the possiblity of permanent, or irreversible losses must be considered when the design is being developed. "

Magnetic Characteristics
3512 3517 3521 3814 322 355
**Recommended Maximum Operating Temperature
°F
176 248 302 212 248 230
°C
80 120 150 100 120 110

So we see that the highest grade neo is only recommended to 230°F, or 110°C.

** The maximum operating temperature of a magnet is dependent upon its magnetic characteristics, the magnet or assembly geometry, and how the magnet is utilized. The listed values are guidelines, please consult for your application.

[CarlosT]

Many live sound manufacturers are going to neo now...even more than when I started this thread. It reminds me on how titanium became common in motorcycle exhausts all of a sudden after the Russians flooded the market with cheap titanium.

Even Yorkville has recently moved their LS808/LS800P subwoofers to neo (these are already 140 lbs so weight savings was not the motivating factor). Some DJ/pro sound guys are jumping up and down that the new neo versions don't have the same the 'thump' or kick as the old ceramic magnet versions.

Can there be anything to this? Doesn't neo magnets generally have higher and tighter flux?

[Borat]

Originally Posted by CarlosT

Many live sound manufacturers are going to neo now...even more than when I started this thread. It reminds me on how titanium became common in motorcycle exhausts all of a sudden after the Russians flooded the market with cheap titanium.

Even Yorkville has recently moved their LS808/LS800P subwoofers to neo (these are already 140 lbs so weight savings was not the motivating factor). Some DJ/pro sound guys are jumping up and down that the new neo versions don't have the same the 'thump' or kick as the old ceramic magnet versions.

Can there be anything to this? Doesn't neo magnets generally have higher and tighter flux?

with Neo the way you build the motor ends up being different. more likely than not you end up putting the magnet under the pole. the difference in design we can logically expect to translate into a difference in sound.

however i consider ceramic to be a thing of the past already. even though the temperature is a concern i think it is a small price to pay for having 20 times the flux.

i think the contest for best sound quality is between neodymium and alnico. ceramic is not even in the picture.

[Glowbug]

Originally Posted by djk

" subwoofer will never produce enough heat to affect the neo magnets strength enough to make any difference"

Then why do the better manufacturers buy the higher temperature grades? They are heavier for the same flux density, and cost more money too.

"The Neodymium materials do exhibit a temporary, or reversible loss of flux with increasing temperatures. The severity of these losses and the possiblity of permanent, or irreversible losses must be considered when the design is being developed. "

Magnetic Characteristics
3512 3517 3521 3814 322 355
**Recommended Maximum Operating Temperature
°F
176 248 302 212 248 230
°C
80 120 150 100 120 110

So we see that the highest grade neo is only recommended to 230°F, or 110°C.

** The maximum operating temperature of a magnet is dependent upon its magnetic characteristics, the magnet or assembly geometry, and how the magnet is utilized. The listed values are guidelines, please consult for your application.

The ironic thing is that Neo seems to get used a lot for very high power SPL competitions, like the DD Audio Z:



Of course, the great thing about sponsorship is that they can just swap out the motors after every few runs