[xinoxide]

one of my friends father, also a friend of mine, has recently aquired a large stock of 5/8th" diameter x 1/2" thick neodymium magnets in a cylinder shape.

the grading of these magnets is N54 wich is the strongest grading of neodymium magnets.

i would like to know if there is a relation between magnetism and the rest of the drivers materials, such as the voicecoil and the number of times its wrapped.

does magnet grade effect how the diaphragms are driven?

say if i were to place a pair of these in a certain pair of drivers, would there be an effect in impedence or drivers tighness/clarity and detail achieved?

 

[cotdt]

you'll get less bass

 

[xinoxide]

thats easily countered through cup design though, at least to an extent, but is there any relation to impedence and linearity?

 

[cotdt]

Quote:

Originally Posted by xinoxide /img/forum/go_quote.gif thats easily countered through cup design though, at least to an extent, but is there any relation to impedence and linearity?

i would imagine the linearity would depend on the pole peice of the driver. the stronger magnet will only affect the impedance in the bass region. you will get better detail, though, because increased BL would increase the accelleration factor and extend the frequency response.

 

[xinoxide]

so it would basically make it faster in its adjustments to the input signal, at the loss of bass extension due to a shorter low frequency throw?

 

[cotdt]

Quote:

Originally Posted by xinoxide /img/forum/go_quote.gif so it would basically make it faster in its adjustments to the input signal, at the loss of bass extension due to a shorter low frequency throw?

you decrease the Q of the driver so you have less of a bass hump, but bass extension will improve with the stronger magnet. it will be tighter, higher quality bass, but less in quantity. in headphones bass quantity is more important than quality. but most headphones already have compact neodyium magnets. not all, though.

 

[xinoxide]

im not a bass head by any means, so far this sounds like it might actually suit my preferences, im going to have to e-mail a couple of headphone manufacturers to see about what streangth the magnets in some of their cans are. im also going to have to find something with a magnet comparable in size.

i must have over-interpreted what you meant by losing bass.

and not being a genius in the erea of physics and electronic engineering, think you could point me in a direction i can read up on some of the effects i should be expecting? i would like to figure out what exactly you mean by "Q of the driver" among other things i should know when venturing into this.

 

[xinoxide]

i mean, i get the general idea, i think, Q being the drivers resistance to the magnetic force right? but i think i need some equations to figure out impedence and such, since i will be replacing magnets in existing drivers, ill need to figure out what itll change to with these new magnets.

 

[cotdt]

sounds like an interesting idea, xinoxide. most of the magnets used in headphones are weak, but they picked weak magnets on purpose both because of the bass issue and to save cost. for more info on driver parameters, do a search on "thiele-small parameters". the expert on driver design is "Feyz" on various forums and he also has a personal website. You can contact him about your questions. He can also perform FEMM computer stimulations for you.

 

[xinoxide]

Thank you very much cotdt, you have been most helpful in this phase of my adventure.

Quote:

Originally Posted by cotdt /img/forum/go_quote.gif sounds like an interesting idea, xinoxide. most of the magnets used in headphones are weak, but they picked weak magnets on purpose both because of the bass issue and to save cost. for more info on driver parameters, do a search on "thiele-small parameters". the expert on driver design is "Feyz" on various forums and he also has a personal website. You can contact him about your questions. He can also perform FEMM computer stimulations for you.

 

[cotdt]

you can probably try messing with the Denon D2000. they use fostex drivers and it seems a stronger magnet would help them. don't worry if you mess them up, you can order replacement drivers for only a few bucks.

here's Feyz's website:
http://members.fortunecity.com/pirimoglu/

there is some useful basic info. it even shows you how to add a copper shorting ring to lower distortion. keep us updated on your progress! you are a brave man!

 

[zmorris]

I've recently done this with my modified D2000 and these 1" OD x 1/4" ID x 1/4" thick N48 neodymium magnets bought on eBay, which fit and attach perfectly to the back of the driver, and right off the bat I noticed a huge improvement in the SQ. It is much faster and leaner than before (tested with jump/techno tracks where fast, slamming bass is prominent) and the mids and highs have also improved, becoming less harsh and clearer at the same time. The transformation in SQ from stock to what I have now is simply amazing, and I highly recommend giving this a try. N48 magnets are VERY powerful, however, so be cafeful when handling them.

 

[Henmyr]

Quote:

Originally Posted by zmorris /img/forum/go_quote.gif I've recently done this with my modified D2000 and these 1" OD x 1/4" ID x 1/4" thick N48 neodymium magnets bought on eBay, which fit and attach perfectly to the back of the driver, and right off the bat I noticed a huge improvement in the SQ. It is much faster and leaner than before (tested with jump/techno tracks where fast, slamming bass is prominent) and the mids and highs have also improved, becoming less harsh and clearer at the same time. The transformation in SQ from stock to what I have now is simply amazing, and I highly recommend giving this a try. N48 magnets are VERY powerful, however, so be cafeful when handling them.

Can this in some way damage the headphone? Is the effect permanent or can you remove the magnet and the headphone is back to stock without problems?

 

[zmorris]

Quote:

Originally Posted by Henmyr /img/forum/go_quote.gif Can this in some way damage the headphone? Is the effect permanent or can you remove the magnet and the headphone is back to stock without problems?

If you are planning to remove the magnet and you haven't done the markl mod, I recommend placing a white washer that comes with the set (see the auction picture) in between the driver and magnet so that the paper filter at the center of the driver won't get damaged while trying to slide the magnet off. If two of these N48 neodymium magnets are stuck together, it's almost impossible to separate them without a set of clamps or a vise and they only can be separated by sliding them apart, so scraping will most likely occur. Since I already have Dynamat Xtreme covering the center part, I didn't need to use the washer and the magnet can easily be removed by sliding it to the side. As far as permanently changing the magnetic properties of the magnet inside the driver after the magnet is removed, I'm pretty sure that won't happen, provided that you only plan to attach it for a relatively short period of time.

 

[pearljam5000]

This is a little bit off topic but....
on the offical K-701 specs page it states : "NdFe magnets"
does anyone know what this means?