NEO Accident

[dvrmstrng 5,000+ posts]

so why buy magnets like that...just to have them?

 

[MakeshiftAudio 10+ year member]

Lifting projects, magnetic projects.

I have quite a few large ones, they're contained in wood crates lined in a high percentage bismuth alloy to help with containment. I'm tempted to contact my neo supplier and build a similar sub to 99z series, since it's stupid simple, and I have a lathe to make the back/top plate with. Only problem is, I know how strong these things are first hand, and I do not think I'll be able to place them on the plate. It makes me think that the neo in such large motors are magnetized post assembly or something. That also explains the low grade and ability to lose such magnetism.

Edit: Read after posting. Well, you can slowly negate the field of any magnet, neo's especially. Not much material to change polarity of, when compared to the super high peaks of an electromagnet compared to a permanent magnet. All grades will lose strength when used for a such an application. It depends on their permeability pretty much.

Now that I think of it, I've never heard of a N45 or N42 lose strength under the power mentioned. Hmmm... Again, leads to post-assembly magnetizing.

 

[joeboxer5876 10+ year member]

did think about how graphic those pics could be:furious: wish i didn't look at those pictures:crap:

 

[mrogowski 5,000+ posts]

Glad you didn't quote me on that.

Subs need higher grade neo because neo will lose its strength when exposed to high heat levels. The higher the grade, the hotter it needs to be for it to lose it's strength.

If by material type, then yes that is right.

But by simply going with the number rating because it has a higher flux density is not accurate.

 

[MakeshiftAudio 10+ year member]

More then likely. Putting the blocks that close together will definitely cause them to attract. And the plate will for sure not cooperate.

Yeah, imagine putting 20+ 6"x4"x1" N52 blocks on a single plate, same polarity. That's where fingers get crushed. On the second magnet, it will want to flip when you get it on there, if it does, it will take you fingers with it, wedging it to the plate or the other magnet.

I'm picturing an aiding dual rod design, so that it would help prevent it, and those rods would bolt into the top plate. Pretty much lead screws. It would bend them I think, but it would help. That would mean one would need to drill into the neo blocks though... Or... //content.invisioncic.com/y282845/emoticons/smile.gif.1ebc41e1811405b213edfc4622c41e27.gif Order it from the supplier. xD Since you're having the poles on the 1"x4" sides, it wouldn't be too bad. I like where this is going in my head. I'll have to mess with it on a scaled down side.

See, this is the next thought. The magnetic field is only as strong as the magnetizer, the reason for neo is the ability to accept a stronger field with less material. Hmmm...

Edit: You're talking about the Curie point when it comes to temperature. Not exactly right, and has nothing to do with moving to neos over ferrite. You're moving down actually, lower curie point.

See here:

http://www.armsmag.com/neodymium.htm

 

[terra 5,000+ posts]

I'm working with N52 Neo rings and they are incredibly forceful. I considered having the rings magnetized before assembly before I realized I wouldn't physically be able to assemble it.

 

[MakeshiftAudio 10+ year member]

Well, if you find a place to get them magnetized, let me know. //content.invisioncic.com/y282845/emoticons/biggrin.gif.d71a5d36fcbab170f2364c9f2e3946cb.gif

 

[MakeshiftAudio 10+ year member]

Yes your correct. But the grade is a good starting point, higher flux will also in terms relate to higher energy product. No one really sits with a spec chart of neo in front of them. So they give the grades for us to go off of.
And //content.invisioncic.com/y282845/emoticons/fyi.gif.9f1f679348da7204ce960cfc74bca8e0.gif you don't have to be so anally correct.

Yes you do. If you know, it kind of entitles you. I mean really, for the sake of comprehension.

 

[mrogowski 5,000+ posts]

You do around here. Especially when you get dorks spreading FUD saying lower grade magnets make the driver crappy compared to ones of higher grade. Once those types of statements have been burned in people's brains, it is difficult to correct it.

Kind of like the whole inductance thing with subwoofers...

 

[Lakota 5,000+ posts]

Wow.

 

[MakeshiftAudio 10+ year member]

You do around here. Especially when you get dorks spreading FUD saying lower grade magnets make the driver crappy compared to ones of higher grade. Once those types of statements have been burned in people's brains, it is difficult to correct it.
Kind of like the whole inductance thing with subwoofers...

What inductance thing are you talking about? //content.invisioncic.com/y282845/emoticons/smile.gif.1ebc41e1811405b213edfc4622c41e27.gif

 

[mrogowski 5,000+ posts]

What inductance thing are you talking about? //content.invisioncic.com/y282845/emoticons/smile.gif.1ebc41e1811405b213edfc4622c41e27.gif

Sorry, it has been a long day for me. I'm confident if you look around here or a couple of other forums you will see threads dedicated to the whole high vs. low inductance in subwoofer drivers.

I certainly did not mean to derail this thread..

 

[mrogowski 5,000+ posts]

Ive never really seen anyone make a comment saying "x sub uses n40 don't get it"
Neo by all means is superior then ferrite. Only if it weren't so dam expensive, and hard to produce. I also imagine a woofer company having to upgrade alot of equpt in order to produce a neo based sub.

I have and it is retarded.

 

[gymfreak101 10+ year member]

off topic a little but hasn't Diamond Audio been using Neo motors in the TDX for a long time way before the 99z.

 

[MakeshiftAudio 10+ year member]

Sorry, it has been a long day for me. I'm confident if you look around here or a couple of other forums you will see threads dedicated to the whole high vs. low inductance in subwoofer drivers.
I certainly did not mean to derail this thread..

Well, on the super technical side, higher inductance will create a stronger magnetic field for a given current. I'm not saying one is better than the other, but that is a fact. It's BL and inductance if I were to guess. There are really too many variables to really grade a sub.

Who cares? It's over the document that's pretty old. It was posted quite a while ago in a technical forum I visit.

If the OP cares, say something. Elsewise why ruin a possibly okay discussion? //content.invisioncic.com/y282845/emoticons/tongue.gif.6130eb82179565f6db8d26d6001dcd24.gif

Edit: Well, the only reason why I got to N42 etc grades, is because I have N52 blocks in my head. I actually have 3(possibly 4 if I get it back from a friend that used it in a now dormant project) 6"x4"x1" N52 blocks that I could try a test design with.