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:
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.
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:
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…..
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….
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:
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…
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
"I wish I could score everything for horns." - Richard Wagner. "Our writing equipment takes part in the forming of our thoughts." - Friedrich Nietzsche