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neodymium vs ferrite magnets in loudspeakers

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neodymium vs ferrite magnets in loudspeakers

Postby AdrianTatar » Thu Feb 19, 2015 1:04 pm

Why the manufacturers of speakers/loudspeakers have not switched to production of speaker with neodymium magnets (especially, those for low freq). In the past two years, are producers who have won several international awards, some even innovation awards, with speakers that use ferrite magnets.

I know there are manufacturers who use neodymium magnet but represent a small percentage.
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Re: neodymium vs ferrite magnets in loudspeakers

Postby Hugh Robjohns » Thu Feb 19, 2015 1:10 pm

If ferrite can generate the required flux density within acceptable size and weight constraints, why go to the expense of neodymium?

H
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Re: neodymium vs ferrite magnets in loudspeakers

Postby shufflebeat » Thu Feb 19, 2015 1:21 pm

While we're at it, can we agree a pronunciation?

...of the N word, that is.
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Re: neodymium vs ferrite magnets in loudspeakers

Postby Hugh Robjohns » Thu Feb 19, 2015 1:23 pm

neo·dym·i·um \ˌnē-ō-ˈdi-mē-əm\
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Re: neodymium vs ferrite magnets in loudspeakers

Postby Logarhythm » Thu Feb 19, 2015 1:50 pm

Hugh Robjohns wrote:If ferrite can generate the required flux density within acceptable size and weight constraints, why go to the expense of neodymium?

It makes a huge difference to the sound... of marketing communications ;)
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Re: neodymium vs ferrite magnets in loudspeakers

Postby shufflebeat » Thu Feb 19, 2015 2:06 pm

Hugh Robjohns wrote:neo·dym·i·um \ˌnē-ō-ˈdi-mē-əm\

Ta.
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Re: neodymium vs ferrite magnets in loudspeakers

Postby Folderol » Thu Feb 19, 2015 5:19 pm

Logarhythm wrote:
Hugh Robjohns wrote:If ferrite can generate the required flux density within acceptable size and weight constraints, why go to the expense of neodymium?

It makes a huge difference to the sound... of marketing communications ;)
It also makes a huge difference to the manufacturers bank balance.. coincidentally, yours too in the opposite direction.
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Re: neodymium vs ferrite magnets in loudspeakers

Postby IvanSC » Thu Feb 19, 2015 9:56 pm

I can lift my 2x10 bass speaker box with one hand since I swapped the original ones for Celestion neos.

Same reason I have swapped out a lot of my gear. Size and weight.
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Re: neodymium vs ferrite magnets in loudspeakers

Postby Folderol » Thu Feb 19, 2015 9:59 pm

IvanSC wrote:I can lift my 2x10 bass speaker box with one hand since I swapped the original ones for Celestion neos.

Same reason I have swapped out a lot of my gear. Size and weight.
It makes a huge difference to your general fitness, as you don't get so much exercise :tongue:
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Re: neodymium vs ferrite magnets in loudspeakers

Postby AdrianTatar » Fri Feb 20, 2015 7:51 am

IvanSC wrote:I can lift my 2x10 bass speaker box with one hand since I swapped the original ones for Celestion neos.

Same reason I have swapped out a lot of my gear. Size and weight.

if we talk about weight, IMO line array systems used for mobile scene, have the most benefit from neodymium
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Re: neodymium vs ferrite magnets in loudspeakers

Postby BigRedX » Fri Feb 20, 2015 2:44 pm

The main market for Neodymium loudspeakers are musicians who gig regularly and have to move their own gear without the benefit of a road crew. So full-range powered PA cabs and bass cabs are where all the innovations are being made and where you'll find people being enthusiastic about the technology.

It's not really an issue with permanent installations like studios, or bands who are successful enough to be able to employ people to move all their heavy speaker cabs about for them.

Also remember that neodymium speakers are not simply conventional ones with lighter magnets. As soon as the chassis no longer has to support the weight of traditional magnets, the designers have a lot more scope for saving even more weight and improving the performance of the speaker. This means that that neodymium based speakers are never going to sound the same as "traditional" ones. And as we all know in the field of audio, what is technically better is not always as pleasing to the human ear that has years of being attuned to a certain type of sound.
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Re: neodymium vs ferrite magnets in loudspeakers

Postby AdrianTatar » Fri Feb 20, 2015 6:26 pm

Image

If we take the speaker "A" and turns into a speaker with neodymium magnet "B" the only possible change that I see is some holes marked in red.
If you reduce the size of the chassis, will start to vibrate.

What other changes do you think are possible, to make it sound different?
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Re: neodymium vs ferrite magnets in loudspeakers

Postby IvanSC » Sat Feb 21, 2015 10:18 pm

Chassis does not necessarily have to be made of sheet material.
A cast spider-style chassis would still be rigid enough without having to support the weight of a large magnet.
This has already been done many times in the past to very good effect.

In the early 60's my bass cabinet had a 22" speaker out of a juke box, which had a rigid spider fame made of cast aluminium.
Mind you it DID break pretty easily when I dropped it down a flight of concrete stairs leaving a gig! :lol:

I replaced it with two huge 1x18" Goodmans Audiom 90 reflex boxes! 50 watts handling capacity each!
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Re: neodymium vs ferrite magnets in loudspeakers

Postby AdrianTatar » Sun Feb 22, 2015 9:00 am

I agree that "Chassis does not necessarily have to be made of sheet material."

But chassis has a dual role.

Besides the support of the magnet which is very obviously, has one that is "hidden" must maintain the distance between the the voice coil, top plate and the bottom plate core. This distance must be as small as possible for high efficiency, so it is not possible for the chassis to vibrate neither 1 mm / 0.039 inch even at max output, because it would damage the coil and an variable magnetic flux would have negative consequences.

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Re: neodymium vs ferrite magnets in loudspeakers

Postby Wonks » Sun Feb 22, 2015 9:43 am

But it doesn't take much to make a rigid frame to support a lightweight magnet. The forces involved aren't huge. Don't forget that most cones are made from paper and they don't break down under the forces involved. The same finger push that can poke a hole in the parer cone will only distort a sold chassis by a few microns.
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