(Rant warning!)What's the fuss over alnico?
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Gang-Twanger
Resident Wharfedaliophool
The speaker industry (and a lot of other industries) better hope we don't go to war with China anytime soon. I didn't realize that they're responsible for like 75% of the world's magnet-supply (and 95% of the ones we get here in the US).
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Wigwam Jones
Caesar non supra grammati
That was true a year ago; but it appears China's actions changed things.
http://online.wsj.com/article/SB10001424052702304692804577281572744017042.html
In the last couple days, China has tried to fix the problem they created by attempting to corner the market:
http://www.cnbc.com/id/49545975
We'll have to see how things end up, but it appears that US manufacturers will be coming online with rare earth production before long.
I imagine that if we go to war with China, buying speakers will probably be fairly far down on the list of priorities.
stereofanboy
Addicted Member
How do you even tell if your magnets are alnico? I don't think I've ever been aware of the type of magnet my speakers were utilizing.
frperdurabo
AK Member
Yeah, that's one area I haven't even READ about. Are those similar at all to the old field coil units they used back in the early 20th Century (prior to the introduction of the VOTT and all that)?
Right now, the "alnico cone-drivers in a big, ported, non-resonating cab" thing seems to be working out very, very-well. Things are really-clicking. I'll look into that stuff though. I've heard of Lowthers, but the Cogent name is new to me.
*EDIT* - I really-like the look of the Supravox drivers (I think they're Supravox... They have a kind of Goodmans look to them). I found what looks to be a great link on Supravox history. I'll give 'er a read...
http://http://www.supravox.fr/anglais/histoire.htm
I wonder how a pair of these 215 rtf 64's sound... Do all field-coil types have such a tall magnet structure (or whatever it is)?
In the late 90s early 2000s I experimented with most of the then currently available Supravox drivers. I like them a lot - much more than Lowthers (which I found shouty and unreliable). BUT ... in those days you had to deal directly with the factory in France (they had a little ad in Speaker Builder), and that was problematic. I believe things are different (and better) now.
If you're willing to live with 4-6 cubic foot bass reflex cabinets the 215 and 215 bicone are DEFINITELY worth checking out. You'll probably want some sort of supertweeter, to add off-axis treble.
And now, back to our topic.
Jef Bardsley
New Member
I can help you out a bit here...
Since a guitar pickup is essentially a Gauss meter with an audio output, it's no wonder the magnets make a big difference in the tone of the pickups. Different magnet sizes and materials make a difference in the shape of the magnetic field, and as the string vibrates in the field we hear different overtones being generated, especially as the note decays. Guitar players not only generally prefer alnico magnets, they get fussy about which kind of alnico is used. I replaced the alnico5 magnets in my JBs with alnico2, the same as you have in your Seths. The bass is fuller, and the top end sweeter.
As you say, guitar speakers are designed to distort. They have very little Xmax, and the paper cones are relatively light for the power applied. They also have variable rate suspensions so they don't go "clunk" when you 'pop' or 'slap' a string. That is, guitar speakers handle a much greater dynamic range than audio speakers and they do it by compressing the signal. According to Ted Weber, alnico magnets temporarily deguass when faced with a strong (opposing) magnetic field, and this is why alnico speakers compress even more than ceramic speakers. And, they seem to have the same looser bass and harmonically richer highs that alnico pickups do. (I own four different 100 watt alnicos, and for most things, prefer them to my ceramic speakers, such as Greenbacks, V30s and EVM12Ls.)
My guess would be this all relates to the audiophile's preference for alnico by providing a more euphonic experience, though I suspect JBL and the others designed their speakers to avoid alnico's more extreme non-linearities. No speaker is perfect, though, and myself, I'd rather have a speaker that was 80% accurate and euphonic for the last 20% than a speaker that was 90% accurate and got harsh and brittle when pushed too far. YMMV, etc.
mhardy6647
Lunatic Member
Just like vacuum tubes and vinyl, I think that most of the buzz arises from the cult of the arcane.
There are claims that AlNiCo has nonlinear properties that result in vacuum tube amp-like "compression" that may be euphonious.... but there are also claims that Jimmy Hoffa is still alive and well and presiding over an army of clones in South America, and that the Pentagon's $1000 toilet seats finance research into new directly heated triode technology at Area 51.
;-)
There are claims that AlNiCo has nonlinear properties that result in vacuum tube amp-like "compression" that may be euphonious.... but there are also claims that Jimmy Hoffa is still alive and well and presiding over an army of clones in South America, and that the Pentagon's $1000 toilet seats finance research into new directly heated triode technology at Area 51.
;-)
flavio81
Turntable technician
Isn't so difficult to explain.
Top manufacturers (JBL, etc.) knew how to do great speakers using AlNiCo. Once they couldn't source economically AlNiCo, they had to resort to other magnet materials, like ceramics; and they found many problems with non-linearlity, which means those non-alnico speakers weren't so good. Those problems were solved eventually.
Later exxxxcelent speakers have been made regardless of the magnet material, so, i woulnd't romanticize AlNiCo so much.
The best? The best is obviously a field coil.
Top manufacturers (JBL, etc.) knew how to do great speakers using AlNiCo. Once they couldn't source economically AlNiCo, they had to resort to other magnet materials, like ceramics; and they found many problems with non-linearlity, which means those non-alnico speakers weren't so good. Those problems were solved eventually.
Later exxxxcelent speakers have been made regardless of the magnet material, so, i woulnd't romanticize AlNiCo so much.
The best? The best is obviously a field coil.
Gang-Twanger
Resident Wharfedaliophool
Nope, he's currently-residing at the Renaissance Center Hotel in Detroit... underneath a whole lot of concrete.
mhardy6647
Lunatic Member
oh, and back on topic
AlNiCo is kiddie stuff... field coils (electromagnets) is where you really want to be.
Srsly.
AlNiCo is kiddie stuff... field coils (electromagnets) is where you really want to be.
Srsly.
Jef Bardsley
New Member
Anyone that offers a reconing service should be able to do it.
Gang-Twanger
Resident Wharfedaliophool
Yup. Very-true. I'm an Alnico II guy totally. If someone wanted alnico with a more-modern sound, Alnico V would be a better choice. Alnico II gives a more-open, honkier, midrangier kind of tone (like in the earliest PAF's). And what you said about guitar speakers and compression is true as well. But even at low levels, the alnico guitar speakers are generally-sweeter-sounding than their ceramic counterparts, for whatever reason (And I'm referring to NEW guitar speakers here). And I'm hearing that same sweetness in the alnico Wharfedale drivers I have from the tube era versus the ceramic ones from 5-10 years later. It's hard to say, really. The alnico ones were used in ported enclosures (and whatever design that SFB3 was) while the ceramic ones were put in sealed enclosures. Anyway, I don't know enough about this stuff to definitively-say what it is that makes a lot of alnico drivers so-special. Is the magnet material a huge part of it? I don't know. But I do know that I like the way a lot of the older alnico drivers are VOICED. Wharfedale, Goodmans, Altec (to an extent), University, Bozak (although they made great ceramic woofers as well), and even the old JBL woofers (It's their tweeters that I've never been a big fan of, but that's just a matter of personal taste). I also like the drivers they used in the Dynacos, especially the tweeter.
TerryO
Super Member
Musicians get their speaker's re-magnitiuzed from time to time. It's a very easy proceedure if a shop has a magnetizer.
Best Regards,
TerryO
Ceramic magnets tend to be larger in diameter and flatter than Alnico magnets, just as visual shorthand.
Copa1934
My ears are bleeding
Probably an oversimplification. One of the most obvious signs, for "exposed" Alnico is the "U" shaped metal piece over the pole piece. For many JBL speakers they have a Cover/Hood over the magnet so you don't see the actual magnet itself. If I recall, for a number of JBL speakers if the part number ends in "a" it's alnico, if not it's ferrite or ceramic. Not sure this is across the board though.
More often the non-alnico are round or square and sandwiched between a plate and the frame. Kind of like a burger, traditional and Wendy's.
Gang-Twanger
Resident Wharfedaliophool
In other words, Alnico magnet-structures (at least on the older ones) tend to be tall and narrow in comparison to ceramic ones... generally-speaking.
Here's an alnico woofer...
And now here's a ceramic woofer from the same company...
The top one is a 12"... I think the bottom one is an 8", but you get the idea. Ceramic ones are usually quite-flat, like he said.
That top one... Oooh, baby.
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