Alnico VS Ferrite

[speakerlust]

Those damned Roto-Rooter plumbing ones never come off.
Maybe they should make speakers out of fridge magnets ???
:lmao::lmao::lmao::lmao::lmao::lmao:

 

[Tom Brennan]

Maggies use refrigerator magnets. Really.

 

[speakerlust]

Do They Taste Like Chicken Too ???

 

[Charivari]

Maggies use refrigerator magnets. Really.

True, but so does every speaker that uses ceramic magnets. Magnepan magnets are regular ol' ceramic magnet strips attached to a perforated metal sheet with a squashed voice coil over it as opposed to shaping the material into a donut and sticking the VC inside. However, once you get into the ribbon elements for like planars, the magnetic material switches to samarium cobalt or neodymium.

- JP

 

[speakerlust]

REALLY ??? --- NO JOKE ??? --- I want my fridge door to be a Magnapan !!!
Well, it is looking like everyone pretty much likes alnico ???

 

[Tom Brennan]

My Maggies had those rubberish strip magnets, just like refrigerator ones, they probably came off a roll. Between that and the saran-wrap diaphragms......

 

[jblmar]

JBL, for one, over came the flux issue with Ferrite buy way of SFG (Symetrical Field Geometry, IIRC) which focused the magnetic flux in the gap. That's the good news.
Ferrite, for the same flux level as Alnico uses a much heavier magnet. This became an issue with touring groups that had to lug their gear after every gig.

One of the downsides of Alnico is that it will lose it's magnetic strength if droped or played at very high levels over time. Most if not all Alnico JBL drivers bought used will need their magnets 'recharged'.
As for sound, from what I've heard on JBL systems using both types of magnets, I've found the Alnico to have a 'darker' sound compared to Ferrite. Not saying that one is better than the other, just different. The L300 I heard sounded very nice with Alnico. The 4435 and my own 4671 which are Ferrite based, had, IMO, a much more open sound. Similar jazz played on both systems.

Ron

 

[speakerlust]

What is a darker sound ???

 

[Charivari]

Between that and the saran-wrap diaphragms......

Magnepan diaphragms are made of biaxially-oriented polyethylene terephthalate film, such as most often sold under the trademarked names of Mylar, Hostaphan, Dacron, etc. This material is known for its superior mechanical and chemical properties and finds a great deal of use in the high tech sector. The standard NASA "space suit" employs five separate layers of this material to protect the astronaut within from the extremely low pressures of the outer limits of the atmosphere, stellar and interstellar radiation, providing strength to the contained breathable atmosphere, as well as providing abrasion resistance and some protection against micrometeroids. All in all, a superior material.

Saran wrap, on the other hand, at least that of which you speak, is composed of low density polyvinylidene chloride. It is a material not the least bit related to PET and would be difficult for the educated eye to confuse the two.

Now, how exactly is boPET inferior to the pressed toilet paper scrap cones of your avatar speakers? Or how about the compression driver diaphragms made of phenol formaldehyde resin -- a chemical reactant of embalming fluid?

Hmm, NASA space suit and scientific equipment approved film as opposed to compressed toilet paper and embalming fluid diaphragm. No wonder you draw the conclusions you do.


- JP

 

[Tom Brennan]

Cherry----A long winded reply to a joke you evidently missed. My fault.

 

[jblmar]

What is a darker sound ???

To me the difference is a more open sound with ferrite v a 'darker', more colored sound with Alnico. I heard the al and ferrite based systems on different systems at different times, but judging from my own L 100s and 4671, I can hear a difference. A neighbor has the L 101 speakers which are Alnico. Still not as clear as the ferrite based system.
I may be wrong and by no means are my findings scientific, but I did hear a difference. I used my L 100s and 4671 with the same amp so at least that was consistant.

Ron

 

[speakerlust]

Yeah, I have three pairs of alnico speakers and two of the pairs I have out
of the cabinets to ad some metal to the cabs. They are 15's and 12's both
pairs with horns. They did sound a little dark but I believe that is a function of me needing to replace the caps for the horns which are over 30 years old.
I say try turning up the treble and repeat the test that you performed and see if the alnicos don't come to life ???

 

[tomt]

Each have their virtues, but I'd venture to say if both ferrite and alnico were made in the same manner (slug or other) with the same gauss ratios, voice coils and cones, that they'd both *sound* the same.

Ragnar Lian, co-founder of Scan-Speak,
said that speakers with alnico magnets had 10x less distortion than ferrite,
and neodymium had about 20x less.
If a copper ring is added to a ferrite magnet,
it can approach neodymium specs but only above a certain frequency,
below which the ring becomes ineffective.


http://www.audioroundtable.com/Speaker/messages/243.html

 

[Dan ʕ•ᴥ•ʔ]

Ragnar Lian, co-founder of Scan-Speak,
said that speakers with alnico magnets had 10x less distortion than ferrite,
and neodymium had about 20x less.
If a copper ring is added to a ferrite magnet,
it can approach neodymium specs but only above a certain frequency,
below which the ring becomes ineffective.


http://www.audioroundtable.com/Speaker/messages/243.html

Ah...that explains the copper ring I saw inside my FF165K Fostex drivers!

 

[tomt]

Ah...that explains the copper ring ...

some Philips drivers have copper on the pole piece ...

 

[speakerlust]

Ah...that explains the copper ring I saw inside my FF165K Fostex drivers!

FOSTEX DRIVERS ??? -----I'll take tw of em

 

[Dan ʕ•ᴥ•ʔ]

Madisound has plenty of 'em in stock I am sure... :yes:

 

[speakerlust]

What did your's cost you Celt ???

 

[Dan ʕ•ᴥ•ʔ]

Those sell for around $60 each.

 

[speakerlust]

How do you like the sound quality ??? would you buy them again, or choose
a different model same brand ???