AlNiCo vs. Ceramic Ferrite... Observations?

[Multiplex]

First and foremost, I am not trying to start a "this is better than that" thread... I'm not interested in which is better, I just would like to see if your observations are similar to mine.

...And yeah, I know this has been discussed before, but to me it is still an interesting topic. Many speaker manufacturers started to switch to ferrite as early as the mid-60's, but some stuck with AlNiCo until the late 70's. Obviously, Ferrite magnets are cheaper to make, so that was undoubtedly the motive behind the switch for many manufacturers. But, why did some of them hold out for so long? There must be a difference in tone...

Here are my observations: It seems to me that most AlNiCo speakers are very efficient, and tend to thrive at lower to medium volumes. They tend to be dynamic and punchy at low power levels. Most will also have a notably rich, clear midrange, which seems somehow different than what I've noticed from most ferrite speakers. However, AlNiCos tend to compress and "thin out" when pushed hard, whereas ferrites will usually have more punch, and even "warm up" at higher volumes. Is this what you've noticed, as well?

Somewhat of an exception to this rule would be the higher powered "West Coast Speakers" such as JBL, Altec, and Trusonic. They tend to like more power and push more air than most of the AlNiCos of the era. This is probably because their original designs started out as professional PA and instrument speakers, with those durable cast baskets, rather than lighter-duty constuction of most Hi-Fi speakers. However, even the most powerful AlNiCo speakers of yesteryear don't handle the power of their more modern ferrite counterparts. (For example, AlNiCo JBL D/K series vs. Ferrite E series.) It is pretty hard to top the ear-bleeding SPLs of those vintage West Coast speakers, however.

Another question... Do modern Neodymium speakers have similarities to that vintage AlNiCo sound?

 

[Nikko75]

The various types of magnets will offer the desired BL strength needed, but sizes and weight will depend on the respective material. What really changes the parameters of efficiency and flux density is the shape and design of the magnet that is build for the voice coil. In the 1970's, companies started using finite element analysis and computerized modelling to devise ways of focusing the strength and reducing stray magnetic fields. The shape of the gap, the gap height and strength combine with the suspension compliance and mass to form the electromotive parameters that we use to model and design a speaker system. As far as sound, I have found no correlation between magnet type and perceived or measured performance. The speakers that used AlNiCo magnets usually have a vastly different motor structure, which in itself changes every parameter of the driver. Another thing that we do today is insert the copper farady ring to drop the inductance and distortion at higher frequencies. This again changes the sound by providing additional damping, but no great advancements have been made. Rather, the knowledge and design of that time can now affordable be produced for the consumer market. It's a lot like enclosure design, 3D modelling and fluid dynamics were a staple in engineering even in the mid '70's, but the cost for the computers restricted it to few companies. Today, we can actually build what was once a dream. Motors are changing slowly and becoming lighter and more efficient for the desired strength, and there are a variety of topologies used in loudspeaker drivers today.

 

[mhardy6647]

You can make as powerful a magnetic motor with ferrite as with AlNiCo; pound for pound, of course, neodymium can be used to make an even more powerful motor.

Sensitivity of the speaker isn't related to the magnet material per se but rather to the motor (and, indeed, the whole speaker) design.

AlNiCo does have some interesting "linearity" properties which might be related to the Cult of AlNiCo. Who knows?

 

[rusomon]

I've never heard a specific set of attributes that suggests one or the other to me. So there you go. Kinda makes it hard for me to make generalizations. Not questioning what others hear, just not hearing it myself.

 

[Adda]

You have to look long and hard to find a ribbon tweeter with Ferrite magnets.
In a ribbon tweeter you only have three components, a transformer, magnets and the ribbon.
Stronger magnets means higher efficiency, to get small yet strong magnets, you need Neodymium or AlNiCo.

 

[Gang-Twanger]

First and foremost, I am not trying to start a "this is better than that" thread... I'm not interested in which is better, I just would like to see if your observations are similar to mine.

...And yeah, I know this has been discussed before, but to me it is still an interesting topic. Many speaker manufacturers started to switch to ferrite as early as the mid-60's, but some stuck with AlNiCo until the late 70's. Obviously, Ferrite magnets are cheaper to make, so that was undoubtedly the motive behind the switch for many manufacturers. But, why did some of them hold out for so long? There must be a difference in tone...

Here are my observations: It seems to me that most AlNiCo speakers are very efficient, and tend to thrive at lower to medium volumes. They tend to be dynamic and punchy at low power levels. Most will also have a notably rich, clear midrange, which seems somehow different than what I've noticed from most ferrite speakers. However, AlNiCos tend to compress and "thin out" when pushed hard, whereas ferrites will usually have more punch, and even "warm up" at higher volumes. Is this what you've noticed, as well?

Somewhat of an exception to this rule would be the higher powered "West Coast Speakers" such as JBL, Altec, and Trusonic. They tend to like more power and push more air than most of the AlNiCos of the era. This is probably because their original designs started out as professional PA and instrument speakers, with those durable cast baskets, rather than lighter-duty constuction of most Hi-Fi speakers. However, even the most powerful AlNiCo speakers of yesteryear don't handle the power of their more modern ferrite counterparts. (For example, AlNiCo JBL D/K series vs. Ferrite E series.) It is pretty hard to top the ear-bleeding SPLs of those vintage West Coast speakers, however.

Another question... Do modern Neodymium speakers have similarities to that vintage AlNiCo sound?

That's pretty-much my take on alnico. I'm a musician, and I found alnico guitar amp speakers to be just like you said (Very-much-so). Better at the lower volumes I like to work at, but also better with old-school vintage-style, all-analog effects like the kind that Hendrix, Page, Clapton, and others used back in the day (And this doesn't really apply to hi-fi, but they sounded smoother when closing in on/reaching that breakup point). And I TOTALLY-prefer alnico magnets for guitar pickups (My main guitar has Alnico II magnets, which are a bit bloomier in the middle than Alnico V, which has better extension... It all depends on what sort of tone you're going for with your guitar... Alnico II's were used in the earliest PAF pickups from the mid '50's, like on the old gold-top Les Pauls... Gibson started using Alnico V magnets around '58-'59, such as on the sunburst Les Pauls from those years).

Whatever the case, my main speakers (Wharfedale W90's from 1963) have alnico drivers all around. The ceramic W70's and W90's seem to be very-smooth as well, although I have to wonder why they were still using an alnico mid-woofer in the W70's from '66-'68 if there wasn't a good reason. Who knows. But what I DO know is exactly where this thread will go: ..... Nowhere.... At the end, we'll be no closer to a consensus than we were when this thread was started.

 

[Gang-Twanger]

You have to look long and hard to find a ribbon tweeter with Ferrite magnets.
In a ribbon tweeter you only have three components, a transformer, magnets and the ribbon.
Stronger magnets means higher efficiency, to get small yet strong magnets, you need Neodymium or AlNiCo.

That's something I did not know, although the alnico magnets in my Wharfies seem quite-huge compared to what I would see in equivalent ceramic-loaded speakers. I figured alnico ones had to be bigger for some reason.

One thing about alnico drivers, the magnet resides WITHIN the voice-coil structure whereas it would be OUTSIDE it (usually around the outer-edge) if you were looking at a ceramic driver. Don't know why that is, but it is.

 

[Nikko75]

If I could upload a picture here, I could demonstrate why that is done. It's a very simple and practical means of creating a small motor. The AlNiCo forms the center pole piece, with the bottom forming one pole of the motor which is complete by the magnetically conductive frame. The circuit is completed across the VC gap, where it meets the top pole.

 

[Gang-Twanger]

If I could upload a picture here, I could demonstrate why that is done. It's a very simple and practical means of creating a small motor. The AlNiCo forms the center pole piece, with the bottom forming one pole of the motor which is complete by the magnetically conductive frame. The circuit is completed across the VC gap, where it meets the top pole.

But what I don't get is why they don't do this with ceramic drivers as well. Why the drastic difference in design philosophies?

 

[Adda]

That's something I did not know, although the alnico magnets in my Wharfies seem quite-huge compared to what I would see in equivalent ceramic-loaded speakers. I figured alnico ones had to be bigger for some reason.

One thing about alnico drivers, the magnet resides WITHIN the voice-coil structure whereas it would be OUTSIDE it (usually around the outer-edge) if you were looking at a ceramic driver. Don't know why that is, but it is.

The motor in your Wharfedales might look big, but the magnets aren't necessarily very big, maybe it's just overbuilt.
Many AlNiCo woofers sport small diameter voice coils (small dust caps) and have the magnet on the inside of the coil.
Not a lot of room for a big magnet.

Since Ferrite magnets are weaker, they need to be bigger to be as strong.
So many ferrite woofers have a large ring magnet around the voice coil, on top of that, a lot of ferrite woofers tend to have large diameter voice coils, enabling even bigger magnets.

But you already said this your self

 

[Nikko75]

Here's why- Ferrites have a lower magnetic strength, and in order to achieve the flux field strength that is needed, it takes a larger quantity of magnetic material. The most practical means to go about this is to develop a ring that encircle the voice coil and is glued in place. The top place that form the gap is then glued on top of the magnet to complete the circuit. The entire magnet is then inserted into the magnetizer that realigns the magnetic particles and develops distinct poles. In the end, it can achieve the same strength at a lower price but at a higher weight penalty.

 

[Multiplex]

That's pretty-much my take on alnico. I'm a musician, and I found alnico guitar amp speakers to be just like you said (Very-much-so). Better at the lower volumes I like to work at, but also better with old-school vintage-style, all-analog effects like the kind that Hendrix, Page, Clapton, and others used back in the day (And this doesn't really apply to hi-fi, but they sounded smoother when closing in on/reaching that breakup point). And I TOTALLY-prefer alnico magnets for guitar pickups (My main guitar has Alnico II magnets, which are a bit bloomier in the middle than Alnico V, which has better extension... It all depends on what sort of tone you're going for with your guitar... Alnico II's were used in the earliest PAF pickups from the mid '50's, like on the old gold-top Les Pauls... Gibson started using Alnico V magnets around '58-'59, such as on the sunburst Les Pauls from those years).

Whatever the case, my main speakers (Wharfedale W90's from 1963) have alnico drivers all around. The ceramic W70's and W90's seem to be very-smooth as well, although I have to wonder why they were still using an alnico mid-woofer in the W70's from '66-'68 if there wasn't a good reason. Who knows. But what I DO know is exactly where this thread will go: ..... Nowhere.... At the end, we'll be no closer to a consensus than we were when this thread was started.

Interesting observations... I play guitar as well, and I can definitely hear the difference between AlNiCo and Ferrite in instrument speakers. FWIW I am a big fan of JBL AlNiCo speakers (D or K series.) Otherwise, I usually tend to prefer ferrite. With my vintage stereo gear, I have recently found myself tending to gravitate towards AlNiCo speakers from back in the day. Right now I am really enjoying some old 12" EV Triaxials.

...And I don't really expect a consensus on anything, mostly just the sharing of opinions and observations.

 

[bluesky]

All 4 pair of my speakers have AlNiCo magnets.

AlNiCo, to me, sounds better...much better.

AlNiCos sound warmer, more life-like, natural. Not so brash and in your face.

AlNiCos sound much more like 60s and 70s music. (I wonder why) As mentioned: Stones, Hendrix, Clapton, all the early bands LP sound better with AlNiCos.

AlNiCos are preferred by many musicians for their sound quality. There's a reason why all those old Fender speaker systems, like tweeds and blackfaces, are so highly sought after and command such high prices. Granted, they are tube amps...but they also have AlNiCo magnet speakers. It's a total package deal for the sound of the era.


** Also, I've noticed, for me anyway, that AlNiCo speakers really help CDs sound warmer, just much 'better'. It tames digital down a notch. Not so much in your face and more natural, more like an LP sound if that makes any sense. 'Smoother'. They take some of the harshness out of the digital playback and it just makes CD sound better. Anyone else notice this???

Guys are buying better CD players, new high priced DACs, etc., and are trying many different things to make digital sound right, more like analog. Maybe...just get a pair of AlNiCo magnet speakers. I may be totally wrong but it works for me! CDs sound ok, let's say...better. Warmer, smoother.

It appears to my hearing that there is a big difference between ferrit and AlNiCo magneted speakers. But 'most' foks will say there is absolutely NO difference. So be it.

I'm an AlNiCo guy. All the way. Always have been...always will be.

But...AlNiCos may not be for you. If you play your music 'loudly', like crank it, blast it...you many not want AlNiCos. The magnets will need to be re-charged, re-aligned, whatever it is, from time to time, at the speaker repair facility. But when re-done...good as new. If you don't 'crank' your music...then there's no problem. You know, pushed to distortion. I read that somewhere.

I also read that the reason they went from AlNiCo to ferrit is because of the limited supply of AlNiCo (which only came from one place I believe), the increasing price due to rarity and whatever other problems (there was problems getting the stuff), and ferrit magnets was easy to make and were just cheaper anyway - more cost effective for production. So they made the switch.

So they sound better? It's the 'old school' sound. They sound nice!

 

[bowtie427ss]

Alnico outside the voice coil:

 

[Uncle Paul]

Some good information on Alnico vs Ferrite and why manufacturers switched: http://www.audioheritage.org/vbulletin/showthread.php?4031-The-Great-Alnico-Ferrite-Debate

 

[Adda]

AlNiCo magnets contain Cobalt, which became quite rare and expensive during the 70's.
So they switched to ferrite.

 

[Copa1934]

AlNiCo magnets contain Cobalt, which became quite rare and expensive during the 70's.
So they switched to ferrite.

^ what he said. Though switched may not be correct for the industry as a whole. But likely MOST did switch. Just pure economics (or greed if you will).

My AR3a speakers have ferrite magnets. Huge freaking ferrite magnets. My speakers are "warm" sounding, or put another way are not "bright" like JBL speakers I own, have owned and have on loan. Nor bright like my HPM's, Mach One's, etc. I have other speakers that I would also call "warm" and they too have ferrite magnets.

Only real answer to this is the typical blind test, like with wires, interconnects, etc. Play some music through multiple makes and models of speakers and ask people which they think are one of the aforementioned magnets. Then ask which sound warm, bright etc. Likely after the results have been tallied the data will be useless. Take the preconceived out of the equation entirely.

I'm not at all convinced the magnets play a role in the final sound. I'd be more inclined to believe that a driver can be designed to sound either bright or warm by way of the components used and how they are implemented.

 

[Gang-Twanger]

Part of me loves the way they look just as much as the sound. I dig the look of alnico magnet-structures (like the Super 3 and W12's used in my W90's).

 

[Copa1934]

Part of me loves the way they look just as much as the sound. I dig the look of alnico magnet-structures.

35lbs of awesome, and that's just the driver. Got a couple EV 15's, heavy freaking beasts.

 

[Gang-Twanger]

35lbs of awesome, and that's just the driver. Got a couple EV 15's, heavy freaking beasts.

Yeah, the W90 highboy is 125lbs, and I wonder how much of that is the 6 drivers. They made an alnico 15 back in those days that has a huge, square magnet-structure. Never heard one, but I'd love to find one of the big 3-way '50's cabs they made that did (This was one of two models used at the live/recorded demonstrations). The Altecs from that era were even heavier. And University made big honkin' alnico drivers back in those days. The build-quality was no joke back in the '50's and '60's. Goodmans was crazy-overbuilt as well (The old Vox AC15 sometimes came equipped with an alnico Goodmans driver inside).

Here's one of the W12's in my W90's (This is the one with the polystyrene dampener over the front of the cone... The W90 had W12's that were tuned specifically for that model... And these both operate in full-range mode in the W90's I have [EDIT: I don't think that's true now, actually... I think 3500hz just sounds a lot higher than it actually is]):