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In Reply to: RE: I don't know if you guys remember or not a few years ago I had gone on a buying binge of woofers and posted by Audio Mind on February 21, 2015 at 23:17:48
Altec woofer made into Field coil..Classic Audio ReproductionsSame drivers but with cover on backJBL Everest drivers and crossovers..Nice speaker at 70k a pair and it uses the Neo/Bery drivers.Those 18 inch JBLs my friend bought before he died as we were experimenting with different bass setups. Those are actually new in box but I think they are more for PA or band application but then again I've never used those so I don't know.
Give the NEO drivers time to break in and I'm sure you will love them..I didn't find any harshness in them and if you go to Classic Audio Reproductions he actually takes a version of the 2435H and puts a field coil o it but still kept the diaphragm which is Beryllium and then he took the Altec woofer and put a field coil on it and he came up with the best sounding dynamic type speaker I've heard to date.They sound like a Quad ESL 57 on steroids and this is what some reviewers have said.The problem is they are 68k a pair..
"If it measures good and sounds bad, it is bad; if it measures bad and sounds good, you have measured the wrong thing."
- Daniel R. von Recklinghausen
Edits: 02/22/15Follow Ups:
It would be interesting to use a variable DC output power supply with field coil speakers.
Also wondered if vintage field coil speakers sound good and if a re-cone would be a plus assuming new cones are available.
The whole big thing about the field coil rage for the new designs is
having an adjustable "field".
Saying "do field coil speakers sound good?" is like saying "do speakers sound good?" Do cars go fast?, do all birds fly....I think you get the drift.
Now if you are saying taken the identical cone and using an alnico and a field coil side by side then it is possible for the field coil to outperform the alnico but not always. There are many variables that could be messed up building a field coil power supply as with building any power supply, obviously all are not created equal.
The topic on field coils is so complex and in depth you should start another thread. It would be interesting as compared to 20 years ago there are a bunch more people playing with field coils these days.
Frankly, speakers either sound good or do not. And, the lower midrange is especially critical. I received a free pair of new 12" Pyle speakers and the sound was horrible.
Agreed, it does not matter if a driver has and alnico, ceramic, field coil, etc., if the cone or diaphragm is a bad design it is going to sound pretty bad.
Exactly
There is no one size fits all..I have had alinco sound better than ferrite and I have had my ferrite sound better than my alnicos...It all depends on the sound you are looking for and what equipment is driving it and what room conditions are. Now the field coils to me sound incredible..I like the ESLs the most but I also use them with dynamic drivers for the bass. My ideal system would be ESL panels for the mid and high frequencies and a pair of 12 inch field coil drivers in folded horn for the bass on each side.The Great Alnico / Ferrite Debate
The subject of Alnico vs ferrite magnet drivers comes up fairly regularly on our site. The following is my attempt to clarify some of the issues involved. Before I get into a discussion on the merits and disadvantages of each magnet type, it is important to separate fact from fiction. To understand how this debate began, it is necessary to know a bit about loudspeaker history. Up until the late 70’s, most high end speaker manufactures used Alnico magnets due to their greater energy/weight ratio. Starting in 1978, all major manufactures (JBL, EV, Altec, Tannoy etc.) switched to ferrite drivers. That was when the myths began.
Myth #1 – Speaker manufactures switched to ferrite as a way to lower their production costs and cheapen the quality of their drivers.
Fact – The switch to ferrite was in response to a crisis situation whereby Alnico became totally unavailable. A civil war in Zaire led to the complete embargo of the world’s only source of commercial cobalt used in Alnico. There was no choice but to switch. This is why, in less than one year, every major Alnico speaker manufacturer had switched to ferrite.
Myth #2 – Due to the lower energy/weight ratio of ferrite, drivers using this material have lower total flux and lower flux densities compared to the previous Alnico drivers.
Fact – The initial ferrite conversion had the exact same magnetic energy of Alnico drivers they replaced. For JBL, the initial conversion effort focused on bass drivers since that represented their largest consumption of magnets. They had sufficient magnet stock on hand to continue Alnico compression drivers for a number of months.
To be able to continue production of the speaker systems in their catalogs, the ferrite bass drivers had to be the exact sonic equivalents of the Alnico drivers they replaced. Otherwise, the entire systems would have to be re-engineered and there was no time to do this. To give you an example, the L300 Summit, both before and after the ferrite bass driver conversion, used the exact same Alnico tweeter, Alnico compression driver, enclosure and network. The only change was that the 136A driver had its Alnico motor replaced with a ferrite motor to become the 136H. The basket, cone and suspension remained identical. The only way this could work was if the ferrite motor had the exact same magnetic energy as the Alnico motor.
As the demand for high power drivers increased, the magnetic energy of the ferrite drivers began to exceed the former Alnico systems. As an example, the last ferrite version of the Altec 515 had a flux density of 15kgauss compared to the 14kgauss of the Alnico version. The Alnico embargo proved short lived. Alnico became available in limited quantities after a year or so, but at a much higher cost. This happened before the compression drivers were converted and it was decided to continue their production to save the costs of redesign. Therefore, Alnico HF drivers remained in production for another three or four years, until it became too cost prohibitive to continue. Around 1983, they were converted to ferrite motors as well.
Nonetheless, the costs of the ferrite replacements in constant dollars remained about the same as the Alnico drivers before the civil war broke out in Zaire. Any savings in cheaper magnetic materials were outweighed by the sheer size of the magnets and the need for a large pole piece to accommodate the external magnet topology.
Now to factual differences. There are three main advantages of Alnico over ferrite:
1) greater immunity to flux modulation
2) greater heat stability.
3) greater suitability to shielded applications
There is also one significant disadvantage – Alnico is susceptible to demagnetization due to large voice coil currents.
None of these differences are absolute. It is possible to design out all of the limitations of each material. However the issue becomes one of cost.
Ferrite designs can equal or exceed an Alnico magnet’s flux stability with the addition of a copper shorting ring around the pole piece. With the use of vented cooling and heat sinking, you can manage the heat build-up on a ferrite driver to where it stays below the threshold of non-linear response. Finally with the addition of secondary magnets, you can shield the motor of a ferrite driver to the same degree as an internal ferrite equivalent.
In the same manner, Alnico drivers can be engineered to be immune to demagnetization from overpowering. JBL has done this though the use of a series of flux stabilization rings in their new 1500AL driver. However it is extremely expensive.
All in all, the major speaker manufacturers have found it more cost effective to engineer out the limitations of ferrite drivers than to do so with Alnico drivers and hence the dominance of ferrite designs.
In conclusion, I believe the modern ferrite drivers are superior to the vintage Alnico designs. This is not because ferrite is inherently superior to Alnico. Instead, manufacturers have been able to engineer out any limitations of ferrite and apply the advantages of 25 years of technological progress in driver designs unrelated to magnets. For example, cone materials, suspension design and construction has progressed significantly since the last Alnico drivers were made.
Regards
Don McRitchie
"If it measures good and sounds bad, it is bad; if it measures bad and sounds good, you have measured the wrong thing."
- Daniel R. von Recklinghausen
Edits: 02/24/15
Michael the more I read your post the more errors I find and I
feel the whole post is in some ways more detrimental than beneficial
even if you do have some true facts in there.If you have actually worked behind the closed doors of any speaker company
and have any first hand knowledge of marketing and engineering stories that can legally be released to the public I want to hear about but I think some the info you put in the post is just parroting somewhat true info and beaten to death legend stories mixed with marketing crap companies have fed us for years. Sorry if I am a little confrontational here but Michael what you are saying is just harmful information and utterly false and I can prove it:Michael's post states:
"To be able to continue production of the speaker systems in their catalogs, the ferrite bass drivers had to be the exact sonic equivalents of the Alnico drivers they replaced."
So company lit says ferrites are exact sonic equivalent as alnico, huh? I urge all to try the simple test I outline below.
If you ever have an alnico and ceramic woofer, mid, tweeter driver that have the same factory model designation and no cones or diaphragms in the drivers it is a really quick and easy eye opener.1. Carefully take a smallish screwdriver or other metal object with a grip
and lay it horizontally on the ceramic driver. Move it around so you can feel the shape of the magnetic field that is present all around the gap.2.Now carefully take the same screwdriver, etc and repeat on the alnico driver. Even if the alnico is discharged a little that field is going to feel quite different and way more tight and focused than the cermic model with the same model designation.
You say, but....the company assured me the drivers were the same!!! How come these fields feel so different? That radically different field shape and density couldn't possibly have an effect on the sound? right?!
This pretty much is black and white science here and not my subjective opinion in any way, just a cold hard fact easily verifiable.
Edits: 02/25/15 02/25/15 02/25/15
I didnt have time to check the thread in a few days. But am catching up now.
IMO Mike was simply trying to add further takes on the matter which other credible folks have wrote. Nothing wrong with that. I wish it happened more often.
Approaching this as a right or wrong / good or bad stance is often futile in such a subjective matter. Im not trying to say either is head and shoulders over the other. I like Mike are simply saying theres good and bad examples on both sides. Quite often this is case with anything in life.
Personally I also like to the think the "semi" free market will tell a tail over time. No reason to think if the great strengths of Alnico continue to reveal themselves, we may well see more of them on the market for us enthusiasts and then some.... who knows...
Again, your knowledge and input is wonderful IMO. I simply think when folks get overly heated and polar in a good natured exchange of ideas it often proves to be unproductive. Plenty of examples of this in all our fine forums. I dont mind heated to some extent. We are often overly passionate. Myself included. I just dont see Mike as posting anything overly bias or ill willed... Ill go as far as saying Mike is one of the best natured folks in this hobby who tries to help others more than most Ive seen.
All the best.
And I did shoot you a couple emails and fixed mine. Happy to send you more info and pics of the horns if you like.
2ch, thanks for pointing out what has happened and now I see the cause of the confusion. Now everyone can laugh at my story below but if happened to me I will bet there others may have experienced confusion as well.
I admit I was a little churned up because I really thought Michael was mindlessly paraphrasing the real article/post not realizing it was the exact article. (Had not read article/post in a few years so I did not realize what was going on at first)
1. Michael, your posting text just ran in to the text of another article/post titled "The Great Alnico/Ferrite Debate" with no quotes and no citation of where the text came from. Most people are not going to catch that.
2.Please, Michael and everybody else do not forget to use "quotes" around text that is not yours or no productive debate is possible. Also citations help greatly because there was also an important follow up to that post where Greg Timbers states plainly and scientifically states why ceramic is a lousy magnet material which you won't find on Don's "Lansing Heritage" post.
3.Yes I was a little bone headed not realizing Michael was not Don and I remember at the bottom of Michaels post thinking hmm ...Michael Samra is a really odd handle to use as a forum name. Maybe Michael Samra was an infamous character from a novel or something? And why would he use his real name in the post as Don McRitchie. Ok you can laugh at me for being such a goof ball but I just hope that brings to everyone's attention the
importance of quotes and citations.
Well said! You can't tell someone that they are not enjoying music through their system, even if you wouldn't like it. When I sold audio equipment, I found that different people had different cues that would tell them that the sound was real. I have yet to hear a speaker that does everything right. If I could figure out what the persons cues were and I could find a speaker in their price range, I got the sale. Most salesman sold what thy liked. I managed to do considerable better with my method.
Dave
1.Psychology-Crazy Dave makes a good point that there is no perfect speaker and we do have to pick our poison when choosing any audio component. This is where psychology comes in. A person that likes death metal may very well LOVE the ceramic magnet sound and think that alnico is too pretty sounding. Sales is actually kind of easy if realize that we have TWO ears and ONE mouth. So first you listen to the customer and when they are done talking, you say how many of those would you like and in what color? Although it is my belief that alnico comes the closest to reproducing the most realistic sound than any other permanent magnet so far, some people don't like reality....who am I to argue with them?
2.Science unfortunately is not something the average user gets to do unless they have the time, knowledge and/or money to run tests and research on their own. So most of us are left to rely on the science given to use in white papers and sales lit from a company. Only when we do our own tests can we read what was left out between the lines.
3.Business- Unfortunately for the the music and sound industries so many industry leaders have given us the more profitable choice and the science of the better choice is downplayed to the detriment of the enjoyment of music lovers everywhere.
At one point I even pondered the idea that musical and hifi equipment manufacturers should all be required to be non profit and maybe then we all could have gear that no compromises for greed and be affordable to all as well? I will probably get flamed for this thought and given a one way ticket to see how well Russia is doing with that concept but hey, I am trying to help the gear junkies out there with audio nervosa, I feel your pain as I was one of you at one time.
Even in the heyday of audio, I doubt I would have sold many alnico speakers, even if I had then to sell. The majority of what we sold were entry level or one step above entry level. Cost is a very important factor. The price of alnico drivers would have kept them on the fringe then, as it is now.
TAD, JBL, and Fostex have modern alnico drivers, but I doubt that they are keeping those companies afloat. The market is small, perfectionists are few, and even those don't agree.
Dave
Yes I think that even though the amount of alnico drivers sold even by the big boys in speaker manufacturing is probably very small, the psychology behind offering exotic drivers definitely works in a company's benefit.
C'mon how many out there can say they didn't wonder about the crazy priced alnico models when they were buying an entry level driver? Say another company had an equally as good entry level model but offered nothing exotic, would you still think it as good as the company that offers exotic drivers? There is something in the back of your head probably saying, well the company that offers really expensive alnico drivers must know what a decent driver should aspire to and the company with just an entry level driver, well what is their standard of reference other cheap drivers???
Psychology for sure in offering pricey alnico drivers and in the end good for their business for the cheaper nod as good sounding non alnico drivers.
The whole switch to ceramic mags really seems to echo the switch to solid state. All the companies scrambling to get rid of those pesky expensive tubes and telling the public solid state will be cheaper in the long run.
Get hip with this new solid state technology, it is so much better because you won't have the expense of tubes.Here buy these ceramic mag drivers, we have engineered them on paper to be equivalent to the alnico that you can no longer afford and these new fangled ceramics don't have to be charged up like alnico.
Man did that take a long time for them to "engineer" out the problems of solid state! Gawd please don't anyone start a ss vs tubes on this thread.
Quality tube gear is not for everyone and neither are quality alnico speakers or field coils, I suppose.
The problem with people not understanding alnico is just plain a better magnet material than ceramic,period is that it seems a whole generation has grown up with cheese whiz (ceramic mags) and discussing the merits of how cheese whiz has improved so much compared to that fancy expensive aged cheese (alnico). "Yeah that expensive aged cheese doesn't have the same engineering as the latest cheese whiz"...
But seriously folks, you have to ask yourself if you are happy with cheese whiz level of gear, if you are maybe ceramic drivers just might be for you....they sound just as good as alnico just like cheese whiz has been engineered to have the same flavor as that expensive aged cheese.
Edits: 02/25/15
I just want to say field coils can be great and yes can out do alnico most of the time but not always. If the power supply is mediocre and the power in you area dirty the sound will suffer and all the extra science project stuff is for naught. Field coils are like a race car, you better know what you are doing when you use them...or else!
Michael you spent quite a bit of time on your post, (I know because I have made some long posts on this thread myself). and you seem to have a little bit of experience with quite a few drivers, at least more than the average person but in the most respectful I do not agree with there being any technolgy that has allowed ceramic to react to signal like an alnico magnet even though there is quite a bit of marketing propeganda out there that says it has been done.
I am very interested to know the exact make and models of the ceramic mag drivers you preferred over any alnico models? Did you realize that some ceramic drivers actually have different cones and diaphragms to attempt to compensate for ceramics mags lower resolution? Some of the GPA compression drivers come to mind.
Let me make a guess on one model you preferred a ceramic driver on as I said in an earlier post, "you had some Altec 416's with cones as soft as toilet paper and magnets in need of a charge?" The only reason I could guess a person would prefer ceramic over an alnico might be an attempt to cover up something bad in the signal chain, yes lower resolution helps sometimes, I have a TV going through a strategically chosen low rez stereo myself.
I will state again that if all is equal on two drivers, same cone and equivalent motor strength and alnico is charged to the same level as the ceramic, the alnico will have higher resolution, handle the transients more naturally and generally sound more pleasing and more life like to any signal put in it over the ceramic even with ceramic having shorting rings, and all the supposed things to make it as good as alnico etc, etc...this statement is from my direct experience and not a sales brochure.
Now as far all the talk about some new drivers being better than old alnico models that may have worn cones, too soft or too brittle cones, also possibly having burned and deformed paper voice coils, etc., this may be so for the preference of a newer driver, but you should check out troels gravesens JBL L26 page where he shows the gap on a 40 year old JBL alnico woofer having a way tighter tolerance than anything made today by Scan Speak or other super high end driver makers he has seen.
One last thing, when newer drivers trade sensitivity for power handling over the old models it is really a tragedy and not an advance in technology at all but a huge step backwards because now the driver is less sensitive and has more power compression to deal with. You also need a bigger and usually more crude sounding power amp for your "new and improved" lower sensitivity driver.
All my JBL neo drivers are well broken in and I am not slamming them at all, they just lack a little "tonal color" or something, I can't put words on.
Kind of like a star student that lacks a personality and problem solving skills you can't argue with a 4.0 average but there is something not quite right.
If there was one place I think neo drivers excel it is definitely on the highest frequencies.
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