Speakers using rare earth magnets?

[Durski]

I have been playing with rare earth magnets this afternoon. I came up with the idea of using them in speakers. These magnets have been around long enough that someone else certainly has thought of using them for speakers. My question, any one here have speakers with rare earth magnets? Anything interesting?

 

[frankxbe]

your post prompted me to read wiki link
http://en.wikipedia.org/wiki/Rare-earth_magnet
I`ve seen Neodymium advertised in speaker ads including JBL, Jensen, Eminence etc and on JBL website
These guys have a lot speakers with Neodymium Another type of magnet is Samarium cobalt mostly used in electric motors .
there are probably quite a few modern speakers using Neodymium magnets . as they are the strongest speaker magnets
anyways link is an interesting read.

 

[electronjohn]

AK sponsor Parts Express has a number of drivers w/neodymium magnets.

 

[jt45]

I believe the Emits in my Infinity QLS1s use a rare Earth element Samarium-Cobalt magnets
of wich I can vouch for being the strongest magnets I have ever seen. They are very small thin strips with enough strength to snap the 2 halves of the emits together like
a steel trap. Working on them is a lesson in caution for sure.

 

[DougMac]

I have some Infinity Qe speakers with EMIT tweaters. They are really nice little speakers, but they don't play really loud.

 

[ThanatosOfOn]

Some newer klipsch tweeters use neodymium, and Aura has a few subwoofers that are rare earth. My car stereo tweeters from ample use neodymium as well and i had a set of MB Quart 5 1/4's that used samarium cobalt IIRC.


There are also plenty of bass guitar cabinets that use neodymium for the woofers.

 

[srinath]

N60 neo bar magnets will turn your heil into a 130 db spl monster. N62 even is available now, in comparison, the old school ceramics are somewhere near N5.

You can make one no thicker than your hand ... heck it could be under 1/2 inch, and that diaphragm in the middle will be a threat to the whole state you are in.

Somethign like this - Make a wood frame, like a little photo frame, fit magnets on the thing rows, like 5-6 of em 1/4 inch wide, 1/4 inch gap between each strip, and put the heil in the middle and watch a 1 watt tube amp turn deafening (or atleast my imagination tells me it would be) ...
The problem would be the woofer. Where you gonna get a genuine 130 spl woofer.

Cool.
Srinath.

 

[tchuck]

...
There are also plenty of bass guitar cabinets that use neodymium for the woofers.

I have one. A 2x12 ported cab made by a company called Avatar. It's made of voidless 13 ply Baltic birch plywood and is only 56lbs. Those Neo woofers are uber light! :thmbsp:

 

[M Jarve]

As mentioned, rare-earth magnets have been in use for quite a while. Many planar-magnetic tweeters have used them since the mid 1970's at least, and they're now found in everything from el-cheapo "Shelf-system" speakers to ear-buds.

The main attraction to rare-earth magnets (pardon the pun) is that you get a very high magnetic density in a small package. You can put a powerful magnet in the center of the VC on conventional drivers, much like they used to do with Alnico V magnets back in the day. This is also why they're very popular in planar tweeters, where you want to keep things as thin, yet powerful as possible. Additionally, there are cost savings, particularly in transport and material usage, as you can substantially cut the gross weight of the unit in question without materially affecting performance.

The downside to rare-earths, particularly neodymium based ones, is that excessive heat can cause the magnet to loose magnetism, and the effect is cumulative. So you often see high-power drivers with rare-earth magnets sporting cooling devices on the magnet. Ceramics are more resilient in this regard, and "recharging" Alnico magnets is a viable option.

 

[Arkay]

I have a pair of "Sonic" mid+tweeter speakers that use Neodymium speakers. I believe they were originally sold as hi-fi speakers for use with computers. The drivers are housed in small enclosures shaped a bit like half of a (USA-style) football, but much smaller (perhaps 3-4" long and about 2-3" wide) mounted on a tripod of legs that extend and contract like a radio antenna. The overall effect is almost like some kind of eyeball on legs, a bit like an invading Martian from an old sci-fi flick. The tripod-leg arrangement allows you an almost infinite adjustment of exact height and angle of the speakers, up to the full extension of the tripod. I think they might have been paired with some kind of (sub)woofer to fill in the low end, but for mids/highs, they do a remarkable job for such tiny speakers. The best speakers I've ever heard in their size range.

As others have noted, some of the Infinity drivers also used Samarium-cobalt magnets.

Of course, the Beryllium domes on the NS-1000Ms are also fairly exotic.

All else equal, the more powerful the magnet used, the better the driver is likely to be. Rare earths are used in making some of the most powerful (for their weight/size) magnets known... it's no surprise they show up in some audio speakers, despite the cost.

 

[sfox52]

Rare Earth, they did "Get Ready", didn't they? Seriously, these things won't get any cheaper.

 

[Ruxman]

All decent headphones use those magnets.

 

[automojo]

I think you would need to pad the Heil.
The Heils do seem to work fairly well with the stock magnets.

N60 neo bar magnets will turn your heil into a 130 db spl monster. N62 even is available now, in comparison, the old school ceramics are somewhere near N5.

You can make one no thicker than your hand ... heck it could be under 1/2 inch, and that diaphragm in the middle will be a threat to the whole state you are in.

Somethign like this - Make a wood frame, like a little photo frame, fit magnets on the thing rows, like 5-6 of em 1/4 inch wide, 1/4 inch gap between each strip, and put the heil in the middle and watch a 1 watt tube amp turn deafening (or atleast my imagination tells me it would be) ...
The problem would be the woofer. Where you gonna get a genuine 130 spl woofer.

Cool.
Srinath.

 

[srinath]

Yea

I think you would need to pad the Heil.
The Heils do seem to work fairly well with the stock magnets.

Yea they do, but there was a swiss or german made speaker called the aulos and even one called a Kithrin or somethign like that, if I recall that had the 4.5" heil diaphragm and a neo magnet.
But we can make one flat as a pancake with the power of a freigt train whistle. Anyway if we need to tone it down for fear of shredding the heil by drowning it in 30X the max magnetic flux in existence when it was conceived, maye we should put fewer neo's bars and maybe have more open air space to get more of the compressions and rarefactions into our ear. I wont pad it, fewer magnets or maybe even a bit more room between the diaphragm and magnet.
Anyway my imagination says it would be phenomenal.
I'll see what I can google up.
Cool.
Srinath.

 

[srinath]

http://www.precide.ch/eng/english.htm
That has the speakers, I think it says somewhere it uses neo magnets.
Cool.
Srinath.

 

[automojo]

I think the Oskar Heil speaker may use the neo's also-but I don't think they have a 130spl. Except for sound reinforcement-I'm not sure what the advantage would be in home audio.

 

[danielpeng]

There are a lot a speakers with rare earth magnets, especially high precision speakers.

 

[hnash53]

Audio Nirvana speakers also can be built with them.

 

[60 Cycle Hum]

My P.A speakers, monitors and bass cabinets all use neo magnets. This weekend warrior is getting to old and crafty to carry all that heavy gear around:

http://yorkville.com/loudspeakers/nx/product/nx35-2/

http://www.genzbenz.com/?fa=detail&mid=1435&sid=426&cid=96

http://www.markbass.it/product_detail.php?id=37

 

[RobInONT]

My JBL monitors use neodymium in both drivers. The sub is neodymium as well.
Here's the 8" woofer from the 6328p's How's this for a strange looking woofer?