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Horn-Loaded Speakers
Topic: Cart, horse... chicken, egg...

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Posted by Romy the Cat on 10-25-2006

It was The Rocky Mountain Audio Show a few days back and I LOVE it. The best things about the show that I wasn’t there, thanks, thanks, thanks, God!!!

But it was not actually all. I had even more pleasure today when I went on-line to The AA Sewers ™ and read those typically idiotic posts and looked at those pictures. Holly could! How primitive it is all and how full of themselves those people are! Furthermore how correct was I when I liberated myself from the visitors of those shows.

Interesting that as much the show portrays the unfortunate stage of High-End as much the online comment portrays a Moronity of the shows visitors. To me the audio people who cruse around the shows (other whose who make money there) very much symbolized in AA’s whore Jonathan Weiss from Pennsylvania. There are Cogent guys who are trying to do something with horns and there is Jonathan Weiss who spins around the Cogent boys and Tampax with his idiotic, ignorant or fraudulent comments any conversation about Cogent - I call it the “Jonathan Mills Syndrome“. What is interesting is that most of the in there are not very far from the Jonathan’s state: few buzz words, few deception and few badly hidden demonstration of stupidity, sponsored with glossy pictures and the … another show is done.

Anyhow, I posted it in my “report” about the last show I ever attended, as I do not want to create a thread on the subject. In the end: what I read, openly laughably, the AA Sewers ™ posted about the RMAF Show the image of a wonderful guy was popping in my head: A few year ago I met at CES a very well know and widely reputed manufactures who was running his room with airplane’s isolated earplugs in his ears. He most likely did not know me; I did not know him and I asked him why he uses the earplugs. His reply astonished me with it’s honesty and friendly speaking with it’s bravery. He said that the sound in the rooms sucks, the music in the rooms sucks, the people that he meet and deal within the show sucks and therefore he prefers do not react to anything that it going on in there. So, why we, the people who do not do business on the shows, can’t do not react to the Audio Shows from homes?

Rgs,
Romy the caT

Posted by clarkjohnsen on 10-31-2006
There are Cogent guys who are trying to do something with horns.

 And what they were doing, at CES 2006, was fine indeed.

clark

Posted by Romy the Cat on 10-31-2006

 clarkjohnsen wrote:
 And what they were doing, at CES 2006, was fine indeed.

Nope it was not. Cogent sound was not near as interesting as it could/should be, and the Cogent boys know it, or at least they are slowly learning it.  I do not know if the entire notion behind the Cogent’s RCA drivers is worthy, I do not say that I “bad” I just do not know. I wish the Cogent guy sometimes were be able to learn it themselves and educate others. Certainly their pursue in thir direction is commendable but … but, but but…. unit they stop render archeological concepts and begin to build “Sound of their minds” then I think they will not reach anything better then a juts a cheap audiopseudophile  publicity.

Rgs,
Romy the caT

Posted by Paul S on 10-31-2006

I recieved and accepted an invitation to hear an earlier version of the Cogent speakers, and I was subsequently asked for a considered opinion of the sound.  I guess the designers had read from my posts various criticisms of horns in general and they liked the idea of getting an "outsider" opinion so as to not get too cozily hunkered down in their own bullshit.

Anyway, the system was so flawed that I am loath to try to get it all out.  However, it did one thing in one small (un-"loaded") portion of the midrange that is as good a rendition as I have ever heard, and that is the "ragged edges" of music.  That was simply uncanny.  Everything else was all over the place, from absurd scale to bass trombone dynamics, to combing, etc., etc.  As I recall they were using 300B amps (of course...), but pretty good, for all that.

The thing that struck me, though, was that they were simply committed to their method and direction, and NOTHING was going to make them go back past a certain point of no return to re-evaluate and try something else.

FWIW, I have NEVER heard big plywood horns I thought were worth a crap, so if you love those, these Cogents may be just what you are dreaming of.  But get in line.  People are beating the doors down for the old stuff, especially the properly pre-hyped old stuff.

Best regards,
Paul S


Posted by Romy the Cat on 11-01-2006

 Paul S wrote:
I recieved and accepted an invitation to hear an earlier version of the Cogent speakers, and I was subsequently asked for a considered opinion of the sound.  I guess the designers had read from my posts various criticisms of horns in general and they liked the idea of getting an "outsider" opinion so as to not get too cozily hunkered down in their own bullshit.

Anyway, the system was so flawed that I am loath to try to get it all out.  However, it did one thing in one small (un-"loaded") portion of the midrange that is as good a rendition as I have ever heard, and that is the "ragged edges" of music.  That was simply uncanny.  Everything else was all over the place, from absurd scale to bass trombone dynamics, to combing, etc., etc.  As I recall they were using 300B amps (of course...), but pretty good, for all that.

The thing that struck me, though, was that they were simply committed to their method and direction, and NOTHING was going to make them go back past a certain point of no return to re-evaluate and try something else.

FWIW, I have NEVER heard big plywood horns I thought were worth a crap, so if you love those, these Cogents may be just what you are dreaming of.  But get in line.  People are beating the doors down for the old stuff, especially the properly pre-hyped old stuff.

Well, Cogent speakers are the subject of a separate conversation perhaps in a different thread and perhaps with Cogent bois in attendance.  However, I will droop a few words in this thread, primary because my trip to CES 2006 was to interested to hear Cogent.

I do not think that the “system was so flawed” or “everything … was over the place” is a last judgment about the Cogent loudspeakers. I herd them only once at CES, where the entire installation did quite poorly, adding to your description probably large trunk-bass sound as it was coming from a sewer pipe. However, a deferential snapshot of poor Sound has little meaning and it is more important the objectives of the system builders instead of the semi-accidental results that there got. The “objectives” is exactly where I do not get what Cogent guys do.

Cogent guys are fixated and obsessed with idea of electromagnetic drivers. Electromagnetic might be fine, though my personal evolution on the subject does not necessary suggest that the electro-magnets is undoubtedly winning direction to go.

http://www.goodsoundclub.com/TreeItem.aspx?postID=1929#1929

The RCA suspension-type is another major advance in the Cogent drivers. I never used RCA suspension and I can’t say. However, as far Cogent guys took serious and far-going in their evolvement into making own drivers as much shallow they are in any other aspect of playback installation, at least it was what I seen, and what I head from them. This way, my major complain about Cogent would not be the Sound that they got but rather the very primitive level of efforts at which they have chosen to operate. Within those generally-low demands the Cogent’s  really serious efforts (drivers) could not be exposed and could not be really assessed. 

I think Cogent need time to learn what they do. It takes personal evolution to underused sound and to teach own awareness to react to reproduced sound adequately. So, far the Cogent guys operate withing a framework of concepts but not within a framework of Sound – they make driver but they do not feel ownership over the sound that they accomplish in room. It is exactly where they are and it is completely upon them how serious chose to be.

The only negative thing that I can see in what Cogent do now is in the very cheap and very idiotic positive publicity that they are getting from the typical Internet Audio Morons. Years after years the primitivism of customers was destroying Bruce Edgar’s ability to make seriously sounding horn installations. Bruce is brilliant and very able guy but look at his clientele – 99% of them are idiots –this fact, I am sure, does not inspired Bruce to do anything more serious then just satisfying the primitive interests of his typically-idiotic, low demands customers. I afraid that the very same might happen with Cogent in future. I have seen a large amount of absolute cretins who passed their glorious observations about Cogent’s sound and it makes me very scare. Cogent also have “almost in staff” that Jonathan Weiss from Oswald’s Mill – a brainless, fealty, lie-spreading whore that defiantly does not adds values to the Cogent operation or to Cogent publicity. Form a different perspective Cogent’s Rich and Steve do not promote anything as “done and available to ship” and they are keep working – so far I fine it commendable. As I said before, if the Cogent’s boys start to pressure Sound then they very much could end up with something very much worth very serious attention.

So, so far I feel, Cogent demonstrate promising, controversial but non-interpretable result. I do not see Rich and Steve have problems with methods of knowledge and it is completely up to them what level of sound they would like to accomplish. They my stay pleasing the AA-level Morons ™ and it would be fine – I wish them to become successful in this and wish them a lot of driver with Harry Olson autographs to sell to many Morons around the world. Or they might try to push an envelop and to go for an eximious Sound for the given topology. It will be interesting to watch where Cogent will be landing….

Rgs,
Romy the Cat


Posted by Paul S on 11-01-2006
The big RCA field coil is the best thing about the Cogent system.  It has great "promise", based on what I heard.  Although their methods of "developing" this driver seemed confused to me, they do have truly encyclopedic knowledge of it, from both technical and historic perspectives.

While I was there, they were trying a rather rough looking diaphragm of their own manufacture (or derivation) that looked pretty uneven and unnecessarily heavy to me, but likely it was pretty ridgid.  Still, something about the driver worked quite well.  I mentioned to Steve that I found the best part of that driver's range very good, indeed, and I wondered aloud how it would sound if tuned to just that narrow part of its range, perhaps without the horn.  He said he had wondered that himself; but I imagine they must  hear the recklessly-spewed opinions of at least 1/2 dozen people per day, as their house is like Grand Central Station.

One thing that often hurts this sort of "rennaissance" endeavor, as far as I am concerned, is that the folks most interested are usually "vintage" folks, generally content just finding, acquiring, trading and working with the "special" vintage stuff, happy to simply own, restore or produce variations, or perhaps they might settle on "something" as a "product" and just stay with it, having found a comfortable niche.

Which is all well and good, I suppose.  But as far as audio evolution is concerned, I am not sure where I would start with a pair of those raw drivers.  Based on what I heard I'm guessing they would probably wind up rather less efficient if manipulated and tuned for their best possible sound; or at least I would ask them to do considerably less than they were trying to do when I heard them.

If nothing else, Steve's and Rick's work has resulted in their position as ground zero for the equipment they are interested in.  If you wanted a pair of those drivers you could probably save time by talking to them first.

I would be very interested to hear someone else's version of that driver.

Paul S

Posted by rdrysdale on 11-02-2006
Thank you Sir.
Rich

Posted by Romy the Cat on 11-02-2006

OK, I split the thread: “Best of the HE2006!!!” there extracting the Cogent’s related posts into a separate thread….

 Paul S wrote:
The big RCA field coil is the best thing about the Cogent system.  It has great "promise", based on what I heard. 

Yes, it “might” be a great promise, but did you ask yourself why it is great promise? I do not mean to undermine what Cogent guys do but I would like the people who argue the Cogent to have some clarity on the subject.

 Paul S wrote:
I wondered aloud how it would sound if tuned to just that narrow part of its range, perhaps without the horn.  He said he had wondered that himself; ….

And this is VERY loaded sentiment…. I would have a LOT to talk about it and the Cogent boys should have a LOT of to think about it.

 Paul S wrote:
One thing that often hurts this sort of "rennaissance" endeavor, as far as I am concerned, is that the folks most interested are usually "vintage" folks, generally content just finding, acquiring, trading and working with the "special" vintage stuff, happy to simply own, restore or produce variations, or perhaps they might settle on "something" as a "product" and just stay with it, having found a comfortable niche.

Yes, I would not even discuss it. There are plenty of people out there who worship audio archeology and they keep reinstating the Sound that they experienced during those glorious years when they were abused by their local priests. Let pretend that Audio is about Sound but not about use of audio methods to cure own psychological deviations….

 Paul S wrote:
I would be very interested to hear someone else's version of that driver.

Actually it is not what I feel. Why someone else's would be more informative then Cogent? What I feel Cogent did was dive into very specific area of drivers making but unfortunately they do not explore the area with necessary level of seriousness (sonick seriousness).  Electromagnets, from what I have seen, have own quite unique sonic structure. I would not argue that it is positive of negative stricture. However, I do insist that anyone who deal with any unique sonic structures should be able top capitalize on them and incorporate the uniqueness of the given topology into objective positive result. Whatever method of topology we use, if we use it properly, we end up wit the very same result. Otherwise we dive into the amateuristic idiocy about”everyone has own taste”…  So, my wish would be not someone else does the Cogent’s drivers but rather the Cogent does whatever they do but under umbrella of more interpretable results.

Rgs,
Romy

Posted by Dominic on 11-02-2006
I find this project so fascinating. I find it particularly interesting because one of my first experiences of good sound
 involved a field coil driver. Many years ago my grandfather
 bought an old hammond chord organ(predates the b3 and other tone wheel models), eventually it found its way to our appartment when i was around 6 years old. The sound of this thing was sooo cool. It was full of life or something.
Anyway it got sent to live with some friends for some years. When it came back it remained unplayed and unplugged untill one time a couple years ago when i was getting into fidling with sound i decided to plug it in and take advantage of its rca input. It pretty well stunned me. It was doing something that no other piece of audio gear had ever done in my presence. Particulary it had great attack. Anyhoo the moral of the story is that i thought it was really cool and when in my online adventures i referred to Steve Schell's adventures on the loonie bin i started hanging on every word. But like you, other than some optimism -and a perhaps unreasonable fetish about materials and toplogies- i've found the cogent project dificult to interpret. From abruptly terminated conical horns to really odd bass horn foldings and what seems to be really shitty time alignment efforts, to using a digital crossover with a really high end turntable. then there's the impressions by the guy at Audio Federation who's gone in two showings from 'wow this is the future!' to 'um, this kinda sucks'.
I think their horn designs are theoretically so compromised nothing can really be said. But it still would be nice if it does work out, i'm pulling for them.

Posted by Paul S on 11-02-2006
I'ts not that I feel "someone else's would be more informative than Cogent".   Rather, even though I know what I heard from the Cogent version, I cannot at this point say I understand how much and what part of what I heard is the generic field coil sound you refer to and what part is unique to Cogent.  I'd like to know and I'd like to hear for myself how different approaches affect the sound.

My own ideas about that field coil just sprang to my mind as a result of many years at hi-fi, but I was absolutely hearing and reacting to generic horn problems while remaining fuzzy about anything I could cite as "field coil specific" problems, because I simply have no other experience with these drivers and/or their immediate permuations.

I can say, however, that I feel no allegiance whatsoever to any hi-fi component for any reason other than what it brings me in terms of sound.  I am not smitten by the idea of field coils, per se, or the history of field coils, or anything like that.

The Cogent RCAs are the only such drivers I have evaluated.  They just do some thing very special.  My curiousity was piqued, and I wonder if there are other drivers of this type out there, to give a listen to.

To dig in a bit, the special thing I heard from them was that they put music in the air, as opposed to putting air around, on or into the music.  They had phenomenal resolution over about two octaves, and they also did effortless dynamics over that range, micro and macro.

My impression at the time was that they MAY BE the "best" drivers I have ever heard over those two octaves.

But you know how these things go.  Maybe next time it's not like that.

So I'd like to get more familiar with that type of driver.

Best regards,
Paul S

Posted by Romy the Cat on 11-04-2006

Well, when we are talking about Cogent we need clearly differentiate two things: the Cogent’s drivers and the Cogent’s installation. The problem is that since Cogent’s drivers are something so called “compression drivers” then their performance might be viewed only in context of the rest installation. Therefore it is imposable to look at the Cogent’s drivers as a non-encapsulated entity but only in context of total sound that the drivers, horn and the systems produce....

This is what I love about hors: there is no room to BS with them and everything in horn world is omni-connected and honest. You see: any acoustic system, and practically as complex as multi-coned horn installation, is a very delicate and very fragile system. It is like a violin - it could be tuned, and could be played but horns require a lot of sensibility and a lot of time to learn how very minute elements within acoustic system affect out ability to feel Sound. There is a lot of thing that Cogent’s guys do that suggests that they do not indulge that violin as a virtuoso- violinist, or even as violin connoisseur-collector, but rather they handle horns like plumbers-bureaucrats. I do not mean to be offensive: actually I appreciate the Cogent Steve and Cogent Rich but my respect to the Cogent boy’s effort has nothing to do with the said fact of Cogent’s Sound. Also, on different note, it would be worth to note that I put “compression drivers” in the quotes, because the phrase symbolizes that a driver is made to me loaded into a horns but reality is much more complicated and “compression drivers” is, in fact, a bogus combination of words. Unfortunately many people do not understand it…

To me, observing somebody else’s efforts to build playback is like reading the person dairy or novel. As like while you tasting food is it not difficult to decipher what was in the mind of a cook, it is as much while looking what person does to recreate sound it is not difficult to cruse around the person’s mind and figure out his intention, objectives, evolutionary patters and many other things. Unfortunately In the world of the “Stupid Audio” no one talks honestly and openly about other’s people results following a faulty sense of political correctness:

http://www.goodsoundclub.com/TreeItem.aspx?PostID=2546

However, I do not think that it serves any purpose for ANY of participants and defiantly this political correct belabor does not advance a familiarity with the actual subjects.

So, let look at the Cogent. Let look separately what Cogent’s drivers are and what Cogent’s system is. I will not describe how I see the Cogent’s Sound - most of the people who read this site in one or other format heard it. Theoretically it is possible that in controlled environment of their homes Cogent’s installation do better but I have my doubts. I looked very carefully at the exuberant and enthusiastic reaction of many different people on the different Internet sites and I realized the some of them are familiar how Cogent’s system performs in controlled environment. Those people did admirer what they heard and did not differentiate their admiration between the Cogent’s home and the Cogent’s public presentation. Therefore I made a conclusion that there is “no difference” not to mention that the Cogent’s system in “controlled environment” will use the same “Cogent’s default installations”.

The last thing that I would like to mention that the stupid dominating dishonesty and fear that conquer audio people hardly serves audio people. I know personally many audio manufacturers with whom I might be honest. I have witness in many-many occasions at the audio Shows (and I do not mean the Cogent) when a typical audio-writing marketing Moron was sitting at the vendor's room and was in awe from the sound in the room. As soon the reviewer was leaving the room the vendors practically always laugh because they know that they demonstrated very unfortunate result and the idiots-reviewer loved it. This is defiantly is good for vendors as they will have a positive mentioning in press. However, I still wait when sometime a manufacturer with integrity and with courage shows up. I still wait when a manufacturer will react to another glorifying-brainless and empty reviewer’s feedback about the manufacturer feeble demonstration at the show.  I still wait when a manufacture say publicly: “Shut up! The sound that I demonstrated was very poor and if you disabled not understand it then you are not qualified to writhe about my Sound”…

Anyhow, let return back to my sober view on Cogent True-to-Life Horns. Let start from the Cogent’s worst: the horns.

COGENT HORNS

The Cogent’s Steve and Rich are eaten by the same illness as many other horn people – something that I call “horn avarice”.   Even if one has no ears and can not hear a horn geting chocked with sound then a reference to Harry Olson “Elements…” should help them. In paragraph 7.3 Mr. Olson describes the “Distortions Due to Air overload in the Horn”. In reality 99% of the horns out there pretty much “greed-dead” due to the horn’s overload. How many of you heard about the infamies “horn sound”? How many of you know that lifting a crossover point slightly up in most of the cases (there are exceptions thought) resolves the problem? Invigorating? Nope, just plain stupid – why people go for the last 1/3-1/2 octave of a given horn bass extension of it kills the sound of the ENTIRE INSTALLATION? I never was able to figure out an answer to this question but I am sure many of you know how congested and hard, not to mention “honky” horn might be.  Now you know the answer why….

So, why I mentions the “pressure overload” in context of my Cogent’s criticism? Let see…

Cogent climes their MF driver is 200Hz to 20.000Hz. First of all it is very bogus and very FUNDAMENTALLY INCORRECT objective EVEN TO PURSUE such a driver. Nevertheless even if you use such a bogus driver, a driver that can go down to 200Hz then it requires a certain horn to support this extension. (And this horn will have severely compromised HF by default). Ok, since a J-upperbass-horn is useless at around 300Hz I would not be surprise if Cogent cross their MF channel at ~400Hz, that is awfully low for a horn that Cogent’s presents. The horn looks more like 300Hz horn, but it is conical. The Conical horns have lower LF equalization that makes people go for lower crossover point, believing that they get “more bass” out of horn. Nothing could be further from truth people juts overload the horn and get the consequential “nozzle” sound

Actually the Cogent’s MF horn is kind of funny.  Most like it was made by Bill Woods aka RCAfan. I have addressed the conical infatuation that the Bill Woods subscribes:

http://www.goodsoundclub.com/TreeItem.aspx?PostID=2324

I  personally do not like conicals but a jury still could be out for other people. However, what makes me to question RCAfan-Cogent sanity (and I do not mean to be insulting) is the shape of the Cogent’s MF horn.

Looks at the image above. (BTW, the images of this post are kidnapped from Audio Federation’s Blog). The MF horn is 12 sections horn. It is fine to make sectional hors. However, when people make such a complex metal work they not “juts do it” accidentally but spent a lot of time, thinking, labor and money. I wonder what king thinking Cogent – RCAfan used whan they end up with 12 sections shape? One of the ideas to go for more sections then a regular quadrilateral shape is to prevent the standing waves and get rig the parallel surfaces within a belly of horn. I always suggested to people who find spherical too complex go for pentagon horns. Why not the hexagon or octagon - because the parallel surfaces. So, if the  Cogent – RCAfan have already go for expensive and labor-intensive multiple sections then why they have choose the 12 sections but not the problem-free 11 or 13 sections? I really have no answer to this question.

The upperbass horn. This is a major pain. As I understated Cogent use a driver with 4” throat and they try to push out of it 50Hz-60Hz. The 50Hz demands 1500cm by 2400cm mouth and near 3000cm length. You might slightly lower month if horn is coupled to floor but still it is should be larger that Cogent does. Apparently Cogent is combining profiles. The combination of the profiles combined with curved horns and in addition with the non-gradually opening is not a recipe for disaster- it is the disaster itself. Those chambers inside act like resonating cavities and it is nastier then even talking into a long pipe because the resonances are completely not predictable.  Ad to it the very light and very “ringy” material of the Cogent horns and the picture become very depressing.  You this it is it? Nope, there is something even worst: the effect that I call “sonic horn boom” and the Cogent upperbass has it in it’s full glory. The “sonic horn boom” is a situation when sound echoed inside of the badly made curved horn and those inner horn chambers act as a horn’s front chamber where the undersized mouth of the horn act as … throat! I hope any person who does practical horns  (instead of recitation the stupid horn literature) know about the evil of any front chambers…  So, how about in the case of Cogent to have a 3 meters front chamber? It is not juts a front chamber but rather a front grotto!!! This is what I call a “distributed throat effect”. What happens then? The upperbass “sonic horn boom” builds itself up, overload the horn but …has difficult time to pass itself out because the profile near the mouth is too small. Therefore sound lives horn with very recognizable character that you can hear from 95% of the upperbass horns, raisin a decolorized atonal pressure before it passes tone.  Let me give you an example how you might understand it. Do an experiment: close your lips and try to count to  very loud…..

1,2,3,4,5,6,7,8,9…

Did you try it? That is exactly what the “sonic horn boom” is in poor horn. Ironically in odder to make the “sonic horn boom” more “musical” the audio Morons drive the upperbass drivers harder and claim that “it sound better”… Very unfortunate….

Interesting that what Cogent did at CES this year was much better from my perspective then this new horn during the last show,

Still, eave thsi “white” upperbass horns had a lot of sonic issues with sound and the Cogent CES system did a wonderful job of converting Mahler into Buckner… I would not even mention the time alignment… this is whole another topic… and I feel Cogent’s horns design is not at the level when time should be addressed.

So, what the experience of the Cogent horn teaches us. The biggest and the most prolific conclusions that I might propose would be the very same as I always do:

1) Do not be greedy with horns. Use horn where it sounds problem-free but not were you would like it to.

2) Abandon a foolish idea that it is possible to make 2-way full-range horn installation. It is imposable and the more people try the more imposable it becomes.

3) Horns do not forgive mistake. Badly made direct radiators sound like poor speakers. The badly made horns sound like crap.

4) Stop “register” with your senses the stupid acoustic pressure and learn how to “register” Sound…

Finally: what concussion about Cogent horns should I make? Pretty much no conclusion - as horns or the Cogent systems are not the Cogent’s area of expertise. However, because of the irrational implementation of the Cogent hors (and the complete system – I will talk about it later) it made completely imposable to have any more serious conversation about the Cogent drivers. Still, drivers are hugely important and talking about Cogent it is impossible to escape the  conversation about the drivers. So, I will try….

COGENT DRIVERS

First off all it will not be a conversation about the Cogent drivers but rather about the Cogent’s drivers concepts. I did not heard the Cogent’s drivers is condition where they were not compromised and therefore I will not speculate. There are two major design differences that set Cogent drivers apart from others: RCA suspension and the electromagnets. I personally have no experience with RCA suspension, so I would avoid this subject all together.  However, I would like to talk a little about the electromagnets.

Generally when Audio people hear about field coils they dive into amnesia and behave like a hypnotized mouse that look at cobra and can’t move. In fact, I would like to bring up an argument questioning the benefits of electromagnet. I do have personal experience with the subject. If you are serious then read the long thread:

http://www.goodsoundclub.com/TreeItem.aspx?postID=1929#1929

So, let ask ourselves again: why the electromagnet is not necessary “better”. No one argues this argument for whatever reasons and people just blindly accepted the “believe” that “nothing could beat the filled coils”. I read/heard again and again the comments by all imaginable Morons claming that it is a self-evident fact. Ok, let look at facts not at the hype. Any magnet has own signature. There are a number versions of AlNiCo and they ALL have different sound (I did tried it). The electromagnets are juts one of the version with own sound signature – is it better? Who knows???!!!

Let look for instance the Shindo Laboratory loudspeakers.  The Shindo’s opaque electronics is very problematic but it looks that Shindo made some experience with converting the Altec 288, Altec 802, Altec 604, Altec 515, JBL 375 and JBL 150-4C into field-coils. So, I presume that he is very few of us who did the METHODOLOGICALLY CLEAN experiment comparing THE IDENTICAL DRIVERS WITH THE DIFFERENT MAGNETS instead of comparing different drivers with different magnets.

 Shindo wrote:
The most sought after drivers for "Ultra-Fi" home audio playback are the field coil Western Electric 594A, Altec Lansing 287 and Lansing 801. These drivers are the best performing speaker components ever produced.

OK, give me a break with this bogusness! So, far not one using the “the best performing speaker components ever produced” was not able to get any more or less serious applied practical sound. To make those drivers to perform well it requires employing them it VERY different ways then they meant. The Altec and WE driver “as is” are not useable for series sound.
 Shindo wrote:
  The main advantage of field coil designs is the extremely high flux density, or magnet strength, which allows playback of music far beyond what non field coil drivers are capable of.

False. An electromagnet in speaker drivers does not necessary delivers higher flux density. Also, everyone who dealt with electromagnet use them at very moderate flux density, not higher then it is possible to get with permanent magnet. Not to mention that today magnet do 2.4T in gap… good lack to accomplish this with electromagnet - your driver will melt first… It is also important to understand (and the Morons ™ do not understand it) that the flux density could not be changed in electromagnet by adjusting current that flows through the field because changing flux changes Sound of the driver very substantially. The Morons think that a higher flux is better. It is incorrect and the necessary amount of flux is a complex derivation form many factors. The notion thst more flux would be better is a stupid notion that came from the stupidity of the ignorant of deaf of the brainless marketing cheerleaders.
 Shindo wrote:
  Why go through the trouble and expense of a field coil?

Primary because they are “tweaky”, forgive the mistakes and it is ease to manufacture and to assemble them in small quantities.
 Shindo wrote:
Speakers are the primary source of distortion in the play back chain, field coils can drastically reduce these distortion levels. With a field coil magnet system the driver is controlled much more accurately than with a permanent magnet speaker. Field coils can trace the signal much more closely to the original. Field coil drivers designed properly have magnitudes less distortion than the permanent magnet counterparts.

Why, what kind bogus statements are they? There are no tangible evidences that flux modulation, temperature compression or any other typical distortions are lover with field coils. With current that flows in horns drivers at fraction of a Watt and at near 2T of flux in gap any conversations about flux modulations are worthless.
 Shindo wrote:
There is a harmonic richness, ease, dynamic tracking ability and naturalness that is achieved with field coils.

I do not know. My field coiled Vitavox S2 sounded much harmonically weaker then when the same driver with perm magnet. The Klangfilm field coiled drivers sound also with much less “harmonic richness” and “dynamic tracking ability” then the same drivers with perm magnets. I really do not know if the Shindo-guy means anything when he says “harmonic richness” …
 Shindo wrote:
  Instruments and voices float in space in an envelope of air, with breadth and life. Notes develop, bloom and decay in a life like manner.

In fact I have opposite experience. Since S2 electromagnets were harmonically challenged I feel the sound from them too thin and has problems with “space”. The very same I felt with Cogent and the very same I felt with original electromagnets RCA drivers. Still in Cogent case the sound of the drivers was “buttered” with “sonic horn boom” and it is very default to say anything DEFIANTLY…
 Shindo wrote:
Hearing a properly designed field coil for the first time is mind blowing. The reduced levels of distortion are heard immediately making all other speakers sound "dirty and grainy" by comparison.

Disagree, it is very far from “mind blowing” and I assure you that for 95 % of audio people the differences field coil will not even auditable. Bring the damn field coil to the stupid CES and do not tell that they are electromagnets – not one will note it. In fact it did happen as I remember that one of cretins who run AA’s Sewer was writing a grooving comments about the sound of David Karmeli’s Bionor because as he elegantly put “it clearly proved that nothing can compete with filed coils drivers”   – the irony is that David Karmeli’s Bionor use perm magnets…. Anyhow, returing back to the Shindo’s comments - it does not make “other speakers sound dirty” - it screws harmonics, the same OTL does – and THAT make them to sound “less dirty” and particularly for crappy music. Nevertheless where I completely agree withShindo is that field coil makes SOUND  MUCH LESS GRAINY.
 Shindo wrote:
Basic advantages are; A) Much more fatigue free playback B) Magnitudes more perceived inner detail C) An amazing ability to sort out the musical information and detail D) A more relaxed feeling while listening E) Better perceived dynamic contrasts or "Dynamic tracking ability" F) A total reduction of all smearing of information G) More realism and presence H) A greater sense of involvement with the music I) Far less perceived dirt and grain in the playback J) A greater sense of the meaning and soul of the music or greater communication

It looks like it was written by the Shindo’s distributor because it sounds too stupid. Whatever it was I endorse ONLY the claim about the “less perceived grain”.

 Shindo wrote:
Why doesn't everyone use field coil drivers and why did they go out of production? Unfortunately these designs add great expense to speaker production due to the need for a dedicated power supply.

Really? Cogent uses Radio Shake PS that cost $30. I used that one that cost $100, including 4.7 Farade capacitance. In the past people use input choke filters that were actually …the field coils on the drivers (and did not bother about ripples). The irony is that for single production there is no “great expense to speaker production” - all the same pain in ass would it be field coils or perm magnets. In fact, field coil qute simplifies magnetic assembly because, contrary to the perm magnets, the field coil ‘s cores are shapeable.

What I heard in the field coil sound (My S2, Cogent, Klangfilm, Telefunken, the RCA from which the Cogent took the idea) was (beside the VERY glorious lack of granularity) some “ease” and effortlessness that… I do not like. THAT ease was different then I would like to and the effortlessness was more like the “slippage of seriousness”. When was listening the electromagnets I feel that I am a sportsman who is running for a short distance but across an ice filed and consequentially I have no good traction with ground.

Anyhow, my explanations might go on and on but honestly I do not see any convincing justification at this point that field coils are a perspective direction to do. I have no hard evidences. In fact the real evidences I am expecting coming…. from the Cogent boys…

COGENT EPILOG

There are no good or bad components but there are interestingly sounding installations. To accomplish this “interestingly sounding state” an audio a person should act like an ugly woman. Smart ugly women know how to make up themselves and how to dress themselves in order to hide the bad thing in their appearance and how to highlight more attractive or “saleable”.  The same should be done with playback.

I do not think the Cogent guys lack stamina to accomplish more interesting sound then they do. But I am convicted that in order to do so they need to change the ways in witch they approach “Making Sound”. It is not about their or anybody’s else drivers, their horns or their electronics but rather about their unitization of any tools that we audio people have in our disposal to accomplish a sound of our minds. It is not about getting sound from an electromagnetic drivers or sound from a MC cartridge but it is about HOW to make a given electromagnetic driver or a given MC cartridge to perform at its best in order to serve the purpose of a person’s sonic objectives. What is boiled down: I would like Cogent stop building drivers and start to building Sound. If within their vision of Sound their field coil driver will be beneficial then it would be a prove that the concepts of those drivers were worthy. Then, ONLY THEN, it would be educational to hear the Cogent’s ideas how the specific unique attributes of their driver let them to accomplish their unique sonic objectives.

So far Cogent does not demonstrate any somber sonic objectives and did not indicate any efforts that would imply that they have any. To use good amplifiers, drivers or cables is very far from to be sufficient in audio. The Real High End Audio requires an evolution of views, as well as a growth of listening intelligence and reference points about the nature of reproduced sound. Leopold Stokowski one said that when a listener listens Sound he hears only the Sound that he is able to hear. So, I see a lot of technical activities in Cogent actions but I do not see so far any more then the ordinary Sonic aims.  Could ordinary objectives deliver more then ordinary or let call it “reference” conclusions? I do not think so. I feel that until Cogent get sound “near properly” I think the debates about the Cogent’s methods (RCA suspension and electromagnets) will remind controversial and wide open.

What could be more convincing then a first-rate sound from a playback installation? When we experience the real series reproduced Sound we ask: ”How it was accomplished?” and we extend credibility to the people who accomplish it, regardless of their methods. When we experience Poor Sound then we really do not care about the methods and techniques that were used...

Rgs,
Romy the caT

Posted by Dominic on 11-15-2006
I hooked up that old organ yesterday and listened to some stuff i remember listening to through it before.
Before i get any further it's the only thing with tube amplification in the house, pp6v6 ~6w, driver is 12" Rola. My observation was that it was sharp as a mofo, hit doesn't acurately describe it, maybe 'hard and fast' is better. romy you might be right about the 'something missing' but i'm not sure what it is, aside from the thing being run on its own and having all frequencies thrown at it- it's not a fullrange driver so missing bandwidth. Actually i noticed that your graphs from the S2 experiment showed a narrower native bandwidth with the field coil driver, and mainly on the low end, so that may be part of it, sounds like a similar phenomenon here. Next on the list of observations is that it was nowhere near as clean as i remember, the source is crappy(iMac DV) but is the one i used before (possibly, it may have been the g4 cube, which has a tripath amp), it was certainly not a whitewasher and was also kind of shouty, this sucked balls in this room but wasn't a bad thing in the tiny superdamped basement i first tried this experiment in. The shoutiness i found interesting, first because it reminded me of lowthers' (which i'd very much like to hear at the very least as reference) reputation, it puzzled me because often it's been said that this is due to too much magnet power for the cone weight which seemed counter to my earlier impressions of this thing. When i noted it didn't go very high all that time ago i thought of it as soft and chalked it up to not being as strong a motor as was needed and begrudgingly accepted that perhaps 'field coil' did not mean 'powerful motor'. I'm starting to think otherwise. It definitly saounded different from anything else i listened to but did have an unnerving similarity to the little Harmon drivers in the Mac. possibly last on that list was that it filled the space (14'x8'x28') very well, the sound i was getting was kinda crap in some ways but the darn thing despite being a shitty impersonator of an infinite baffle filled the space with a realness. I wonder if one can make an annalogy to the magneto-rheological fluid dampers (ferrofluid shocks) in some cars. I think maybe the map of the theoretical improvements versus actual effects relative to common practice might look similar because of the similar relative way they work.

my overall un-concrete conclusion is that my first impression of this thing got me excited because it gave a very strong hint of 'what can be done' not much more, and not much less. The idea to actually post something came from comming across this post: Damn Speakers where Antonio speaks about his adventures. Mine seem to have been exactly the opposite, everytime i try something or listen to something new i eventually hear a moment or remember the sound in a way that makes me think of what can be done -if only. i've yet to hear much that gets more than a kind of moment right. the 12" rola in the organ has a couple of them but makes no sense in a live room as a fullrange driver at all as it stands. Interestingly those dorky little speakers in the computer somehow manage to give a sound with a feel of space, it's not great sound and sometimes it foo-king sucks so much i get depressed but it is one of those sometimes humbling little 'what could be done' moments. I wonder also how much of my impression has to do with the amp in the system being exactly what it is.

before i go i thought i'd write down that i think trying the Rola in a very much fullsized upper-to-lower-mid midbass horn might not only drop the shoutiness by being in a tighter acoustic but harness all that excess juice to show kick rather than just hardness. This whole thing warrants much more experimentation though so nothing i wrote here today can be taken as final in any way, just what seems to be the most effective way to verbalise what i think i'm understanding about it so far. And i hope all this give a bit of added perspective to the whole field coil idea.

Posted by guy sergeant on 11-15-2006

Hi Dominic,

I have some Rola's. Although intended (in organs etc) for quite widerange use I'm not sure that for listening to music they should be allowed to go too high. The other thing I found was that what lower frequencies they produced were more natural (and relaxed) when the current was turned down a bit.

I lent another pair to a friend who is a session guitarist who finds them hugely preferable to practise with in comparison with the more usual Alnico equipped vintage Celestion G12's etc.

They do have some very desirable qualities but incorporating them in a good sounding loudspeaker design is tricky and may require more modern diaphragm/surrounds to be fitted while preserving their sensitivity.


Posted by Romy the Cat on 11-15-2006

 Dominic wrote:
i thought of it as soft and chalked it up to not being as strong a motor as was needed and begrudgingly accepted that perhaps 'field coil' did not mean 'powerful motor'. I'm starting to think otherwise…

Yes, it is exactly the point! Electromagnet is not a stronger or better motor it is juts different type or magnet. There are a dozen different Alnico magnets. All of them are combination of aluminum, nickel and cobalt but vary with some other ingredients added. There are different anisotropic grades of Alnico and they all sound different. Interesting that in may vintage drivers, the manufactures used whatever they have available and did not differentiated between the Alnico grates. However, the same driver with different Alnico grade produce different sound, practically at HF. Then there are Ceramic or (Ferrite) magnets. They also available in my grades but they have less sonic difference between the types. Let me to explain: the difference is mostly auditable at HF but Ceramic magnates must not be used for upper then I would say 1000Hz… (actually is possible but then the drivers should be driver by SS PP electronics… whish is very different subject), Then there are Neodymium magnets, there are Samarium magnets, there are powdered magnets and few other - they all have own sound. The electromagnets are juts one of the different type of magnets with, like anything else, own sound. I did not see anybody trying to talk intelligently about Sound of electromagnets. Usually as soon the “freaks” see electromagnets then these yeas flip upside down and they behave like typical idiots: This is the field-coiled drivers and therefore it is the “best”. I still feel that the best is what sounds better and unlit I hear a properly sounding installation with electromagnets I would refuse to admit that  field-coil has any advantage over permanent magnet. I do not say that it does not have it. I juts say that the the people who advocate the electromagnets did not make their case yet conversably.

After my experimentations with Vitavox S2-fieldcoil I designed the how I need modify the S2 in odder to get from it what I needed in non-compromised manner. I called that driver  “Quartopuss” because it had 4 active polls. I have a pretty clear view of magnetic stricture (reuse the S2’s phase plug and diaphragm) and it would take ~$4000 to make the driver. However, what I heard so far from electromagnets did not convince me to go into the new round of hassles and expenses. The answers about the electromagnets are still pending but unfortunately I do not see any players out there who would cover the electromagnets question with a demanded level of seriousness. I personally have no motivations to build up around the project a necessary for me crew and to dive into the nuts and bolt of electromagnets…. because “so far” my S2 perfectly fulfills my needs.

Rsg,
Romy the Cat

Posted by cv on 11-15-2006
Romy,
Care to elaborate on the design you had in mind for this?
Sounds very interesting indeed - might be possible to get it made cheaper...
Thanks,
cv

Posted by Romy the Cat on 11-15-2006


Posted by Dominic on 11-15-2006
That would certainly be an interesting driver.

a couple of the dynavector cartridges have coils around the polepiece apparently to 'soften' the circuit, this kind of goes someway to explaining the FC sound but other times like the little session i mentioned above, it seems counter to experience. i'm going to try the experiment again and try bypassing the amp in the organ and try different imputs and report back again.

Posted by cv on 11-15-2006
Allo
I'm confused, but I just need to sit down and figure out what is going on here - geometrically speaking, that is. Never was good with 3d...

Having said that, what would you expect the sonic impact to be, and what's the reasoning behind it?

Cheers
cv


Posted by Romy the Cat on 11-15-2006

What the sonic impact will be? I clearly have no idea.  I was slightly desponded and warned that my excremental S2 with electromagnet did not have the “sonic impact” that I find useful.

Regardong the Quartopuss... Chris, you're confused because the front panel made transparent just for sake of the illustration.  The front side is not just a circle but a solid plate with a hole in a middle that short the coils. So, we have 3 coils on return pass and one coil around the center poll piece. The reason to go for multiple coil is because I would like to keep the driver shorter, effectively reducing the begging of the horn form 190Hz to 400Hz

(as I told in the http://www.goodsoundclub.com/TreeItem.aspx?postID=1929#1929)

Form one side I need to have enough core mass for the coils but from another side I do not have enough length between the exit of the horn as a diaphragm. So, I figured out that I have 3 options:

1) Go for a multiple coils (it is expensive as it should be disableable to mount the coils, but is effective for cooling)

2) Made another horns for 2’-3’, making the driver longer (too mach hassles)

3) Do inverted driver, or what Cogent does, putting the diaphragm on front and the putting field-coil on the drivers back. This is the most propionate direction to go but it is basically will force to make a completely new driver.

Frankly speaking the objectives of mine were not to built a new driver but to see what S2 will be able to do with electromagnet – juts a delta between the magnet types. There is a lot of unexplored grounds in making own drivers but it is not what I have interest in, I am comfortable with what my normal S2 do. I was looking for inspirations to find something “out there” when I was flying to Vegas last year - pretty much to hear what Cogent ended up was my main reason to visiting Vegas last year. The Cogent was not conclusive and I went to my own S2 electromagnet modification. What I heard was good or bad but defiantly NOT at the level what might suggest me to modify my entire Macondo in order to accommodate a field-coil driver.

BTW, if you wish, as I told, I might send you the field-coiled S2 (with the cone) and you can play with it yourself. Regardless that I did not find it prospective so far I still assure you that it will be an educational experience.

Rgs,
Rom

Posted by Romy the Cat on 10-16-2007

Another Rocky Mountain Audio Show went  on and Cogent dragged this filed-coiled asses :-) to the show. I was wondering is any changes with Cogent during the last year took place.

The unfortunately-famous whore : Jonathan Weiss - has become Cogent’s East Cost dealer – who would ever believe? Ok, it was sarcasm - the world does desperately need another empty- headed cretin with long tongue to become an audio professional. Frankly, the association of Cogent with Weiss level of pop-waste does paint Cogent in a very questionable light.

I do not know if Cogent went for better electronics this year, I hope they did. What however I do know is that Cogent decided to demo in a very large room this fact I think does deserves attention.

If the Cogent  boys have ears and if they not turn deaf from the zillion voices from the typical idiots around then who scream to them that Cogent speakers sound “magnificent” then we see Cogent for the very last time in the  architecture as it exist now. A large room and at larger listening distance should alert the Cogent boys that this speaker needs a tweeter and I think the next Cogent step will be to use one. I see a LOT of complexity and problems to employ a tweeter in context of the current Cogent’s horns. So, let see what the Cogent  boys will come up with…

Rgs, Romy the CaT

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