I have been observing High-Efficiency loudspeakers for a while. I think I have seen/heard many of High-Efficiency endeavors and I think that I did develop acquired taste and some experiences about High-Efficiency results. So, I would like to pass some of my observations about the general state High-Efficiency Loudspeakers, particularly the horn-loaded loudspeakers.

In my view the High-Efficiency idea experience good publicity last years and good popularly memento. Some negative and not completely groundless prejudges that horns had years back got softer and High-Efficiency horn-loaded installations pop-up here and there more or less frequently, by private efforts and by various manufacturers. However, did the admission of horns as one of the viable topological opportunity made the High-Efficiency notion better? Hmmm... Nope, it did not, and in my view the today’s state of horns is very said. In fact the more popularity horns get the more bogus horn installations are being built. Even though at each trade show you will see a lot of horn-loaded speakers practically all of them sound horrible and made with very indispensable mistakes that assure their improper operation. So, over 100 years we build horn-loaded playbacks and we still build crap.

In this thread I will upload my general bitching about the state of today horns. Warn you that it will be highly negative. We do not make good horns, we do not make doo drivers, we are mostly absolutely clueless about system organizations with horns and we are absolutely dead on a subject of proper setting up of horns in our listening rooms. The industry offers practically nothing in times of horn systems, in terms of more or less comprehensive theory, in trims of good tools or in trims of any useful critical analyses. The fate of horns thinking is outsourced not the hands of off the wall enthusiasts and if the industry allows itself to dive into horns then they do it for very sad for consumers cost per transition ratio.

If we presume that High-Efficiency loudspeakers shall deliver better result die to their multiple benefits (with what I agree) then would it be correct to assume that High-Efficiency loudspeakers shell sound better? It would be correct to assume but the reality indicates that generally High-Efficiency loudspeakers do NOT sound better then Low-Efficiency loudspeakers. Go to many trade shows or in the homes of many private owners and listen the actual sound. Not the BS they will tell you but the actual sound. All that you will experience will be mostly crap, undistinguishable if it was 88dB sensitivity or 20 dB higher? What does it say?

It said that the sadly implemented High-Efficiency loudspeakers are in pare with their Low-Efficiency brother and all alleged advantages of High-Efficiency loudspeakers are killed by our stupid and inept use of horn topology. If the “horns are better” then why the most horns installations sound as bad as anything else? This single question is nailing the state of High-Efficiency Loudspeakers..

Well, whatever you do with your loudspeakers of with you whole playback system is kind of irrelevant if your drivers are not right. In my view the drivers are the very much heart of playback but in case of High-Efficiency and particularly horn-loaded driver the situation is kind of more interesting.

To simplify everything - the Efficiency of driver is it’ surface by exertion by radiation angle. A horn shrinks radiation angle and makes the driver able to exert less, taking of many advantages of the low- exertion designs. Of course it is very simplified view but basically the right view. Now, here is the key to understand if you wish to listen and to understand what I have to say. A low exertion driver that produced some kind of pressure, would it be a compression driver of a regular driver, got equalized being loaded in horn. If the scale of this equalization might be more or less accurately predicted by different characteristics of the horn but the scale of TTH (tone-transient-harmonic characteristic) changes of the driver-horn tandem are absolutely not predictable. The common know of horn design teaches us to observe the propagation of pressures but atmospheric pressure is not executable force of music, the TTH of the timbral  pressure is, and you will not see any single manufactures or individual who is able to forecast accurately the TTH equalization or the rate of the timbral  changes when a driver is loaded to a horn.

So, based upon the said above is it clear that we in High-Efficiency world des with random and absolutely accidental drivers. I do not even mention that 99.9% of the companies that make driver do not even recognize the difference between atmospheric pressure and tonal  pressure of drivers and they do divers with the vise of a blind man play golf – that got the consumers are mostly low demands fools who would swallow anything….

I have to admit that in the world of direct radiation the situation is much better. People takes a driver, load it into an open baffle and whatever sound they get as a result is pretty much the sound of the driver.  People even to a degree learned to associate the sound that the drivers make with many objectively measurable parameters. In the case of horn-loading the story turns ugly as a driver loaded into a horn changes sound. How it changes is answerable in the realm of atmospheric pressure but not answerable in the realm of TTH characteristic. Therefore we in absolute darkness and uniformity about the sound we are getting out of horns.

So, what the stage of current High-Efficiency horn drivers?

I discard the low sensitively drivers, let discard anything that is below 100dB sensitively. I also discard any drivers that use in the wide-throat horn as I do not consider it as proper horn-loading. A driver shall have at least a half or a third of the bandwidth equalized by a horn. If not, then it is direct radiator with “leaves”.

There are few pro companies that make today high quality compression drivers that are more or less useable for home playbacks. Probably JBL and TAD are leading among them. This drivers are expensive and made with substantive R&D , which not necessary mean the right R&D. Thos drivers are not free of faults and one of the maggot is that those companies do not produce serious home-targeted horn insulations. This own horns and horn assemblages are garbage  and if you have their driver load into right horn that you might not have the “right” driver anymore. So, regardless how good of bad the newest JBL and TAD are they are still a food that need to be defrost and waked before eating. The older JBL production (that include Altec)  looks no more interesting as the story with them is very much the same -  no one cared at that time about the “right horns” and no one cared about anything more than atmospheric pressure.

There is a an army of the second echelon compression drivers – TOA, Selenium,  BMS, Eminence, Mccauley,  Beyma,  Emilar, B&C, Renkus, Radian, Ciare, B&C, Fostex, P-Audio, Gauss, Electro-Voice and a few others. They make different High-Efficiency drivers but again they have no reference of how they will be used and therefore the drivers are just situation of totally random results.

The second echelon of High-Efficiency drivers are no name drivers. They exist, there are many of them and they are cheap. Unfortunately they all use poor ceramic magnets that are not optimum in the case of minimum currents, so it is very problematic to use those drivers for a serious sound.

As a separate class there are expensive arrays of mostly Japanese High-Efficiency drivers: GOTO, ALE, YL and a few others. I have a big problem with those drivers as I do not like the consents that a driver might be made with any respect to the way how it will be loaded. The people who use them looks like them but I less care what many ignorant people like and more care if the same GOTO, ALE, YL drivers to be more accommodateable for proper loading. Unfortunately the system design ideas of those who made, sell and used those drivers are absolutely foolish, and therefore I do not see that any reported advancement in driver in this case leads to advancement in final results.

The separate class of the High-Efficiency drivers are vintage drivers made before the era of powerful SS amp hit the market– before the 60s. Here are WE, RCA, Vitavox, BELL, Klangfilm/ Siemens, Telefunken, Magnavox, Jensen, Goodman and a few others. The advantages of those drivers that many methods of the barbaric design the manufacturing, that are a norm today, were not invented back then and some of those vintage (no all of them but just a few of them) drivers do have interesting TTH characteristic. Again, those drivers were not design to be use in proper horns and in prosper systems. The design, precession and stability of those driver making was horrible to begin with, the condition of them after 50-70 year is mostly very pity. Thos driver are just not up to level of contemporary demands, they are like driving a car from 50s – it is fan but you would do it more than 10 minutes just to experience this ride and then will drive away in your BMW X7…

So, do we, the High-Efficiency people, have today a stable, predicable and good quality part of drivers that we might use in our playback? Nope, we do not. The drivers we all, all of them are pain in ass and if the people who design amplifiers would have the same situations with tubes or transistors then it would be a ridicules situation.  Taking a transistor a person more or less has a basic idea what might be taking out of this devise. In case of Low-Efficiency drivers, the direct radiators, the same concept might be applied to a degree. With the Low-Efficiency drivers - the driver’s result is black hole as it is absolutely not know where the sound of this driver will lead you and what the driver might need to be able to do what you expect.

It is not surprising that the subject of horn is as screwed as the subject of drivers. It is understandable as driver must be made for specific horn loading, not one make drivers properly, so what the horns are made for?

A horn is a very simple devise but if you have money and desire to build or buy a horns for you playback then you will have a lot of problem to find where the sores them. Do not take me wrong. There are a couple dozens of custom horn makers in today words and there are perhaps a hundred of manufactures that in one way of or other use horn-loading in their playback. However, all of them do whatever is convenient for them to make not what is need to be done and not what you might would like to have (if you have a sense of identity regarding to what you want).

So, let have general overview about horns as we have it today.

The Pro-Audio. The horns and the horn-loading principles that pro-audio industry offers today are very much garbage and must be discarded for home use. The pro-audio solution might work in cases of furnishing sound for large spaces and high power but this is totally different universe of sinking and it used totally different certain to define success. I personally did not see any single pro-audio horn that was made or design up to the point what I would consider acceptable, trust me - neither did you.

The Vintage horns. There is a big array of all possible horns starting from 20s and ending with 60s what the ported designs begin to show up. I found ALL vintage horns very much not acceptable. I laugh what I wee people pay tens thousand dollars for old RCA or WE horns. The Klangfilm had not bad idea with their own MF profile but they never implement it in a way it needed to be done. We need to clearly understand that 70-50 year back there was no today’s demands for quality of sound and all vintage acoustic systems, if you experience then in this original form, sound very sloppy and very sub-demanding. As I always wrote, it requires a lot of understanding, sense and audio intelligence to make vintage playbacks to sound properly. Mostly audio people do not have it and if they do then the “horn” ingredient of the vintage systems is one of the first to go.

Today.  I would leave aside the commercially available complete horn systems for now as I will be make a next write up about them. In this section I would like to talk about the individual horns available for today horn user. Generally speaking the HF horn shall have faster opening and LF horn shall have slower opening. Of cause in my mind all horn mish be spherical.  There are many variables that might interact with this rule; I will not go over them here.

There are quite a few horn makers who would do custom 5kHz horn.  We might have a good selection of profiles, materials, finishers.  Germany, France, Australia, Russia, USA, Belgium juts atop of my head has a few makers who would be very accommodating and would do whatever you wish.

As soon we move to lover 250Hz-1000Hz horns then the satiation is change. It is more difficult to found makers for those horns. We still have 10-20 pleases where the things might be done but people mostly do not do what is necessary but have own set of cookie-cutters solution that they are willing to execute.  When we are at 250Hz-1000Hz range then the materials and the profile of the horn become matter. Materials are available: various plastics, various metals, various woods, various pressed armatured paper. All of the materials might work out well if they are sensibly done. As rule a customer has no chose in material as one maker uses only one type of manufacturing, and if you deal with a maker who does wood then you have a section of different type of woods but you would hardly be able to get out of this manufacture a metal horn. In this range there are 4 profiles available. First one is all slow opening profiles – I am not a big fun of it for this range, let live it alone. Second is Le Cleach profile that is better for HF knee with right driver but in my view the Le Cleach very controversial from a perspective of whole system design as it has very low real-estate per frequency compliance. The there is Tractrix. It has fast opening and low size but in my view needs a further revision of profile termination in the direction of Le Cleach does.  The last one is conical profile. This is also a divisive profile; there is only one manufacturer who insistently promotes it. I am familiar with the argument to support the conical profile, I degree with them. Even though I do have high respect to the manufacturer who promote the conical idea I have to admit that by very peculiar confidence any single conical profile user that I know is a fucking idiot. This fact itself discouraged me to look into the conical idea personally. The last but not least I have to note that with 5kHz horn we, the users, can do whatever we wish but with 250Hz-1000Hz horn we exposed very much to the manufacturer’s egos that not always in  compliance with our design intentions.

Moving to lover 80Hz-200Hz horns opens a gate to hell when it is practically imposable to get out of horn maker anything beside what they have done before. You will have a lot of difficulty to found makers who will LISTEN YOU and to comply with what you would like to have.  The implementation patters of 80Hz-200Hz horns are greatly depend of environment of a give system, so most of generalization will not work. The horn makers seldom agree with it and they try to promote themselves as they own some “secret” in horns making. Well, the best their secret is that their customer are Moron and it is about it.

The sub 70hz how are the beast on it’s own and it usually more a labor of love. The properly performing sub 70hz horn is very seldom, there are many badly performing surrogates but they just devaluate the concept and prove that any technology in hands of barbarian will produce a barbarian result.

That is about it regarding the horns. I would add that very few people are able to view horns in context of the drivers’ need and to recognize a driver and a horn as a homogenous unity.

This is the last article in the planed overview. Here I would like to cover options available among commercially available High-Efficiency systems. As you might expect it will not be too exiting.

In a ways commercial systems inherent all problems of my previous two articles – hard to get truly good sounding drivers and hard to get sanely performing horns. However, there is much more problem with the whole systems. The integration problem, the architecturing problem, the shipping problems, the cost restrictions, the installation problems and many other issues really kills the horns setups or make them less attractive as commercially-successful systems.

Horns in a way enjoy today some popularly and public expectance but I see the picture very far from celebratory.  Today any Moron implementing any indentation in a baffle proposing that his acoustic system became horn-loaded. The amount of fools who is willing to pontificate foolishness about horns and make absolutely insane bloopers with horns design is ridicules. That all leads to many-many horns attempts but it also leads to very poor actual results from all those attempts as Good Sound does not obey the rules of egos and dire taste but follows its own principles. The good things for many “bloopery” horn manufacturers is that most of their “customers to be” have very low demands and absolutely no sense of what they need to hear from speakers. As the result the idiots-consumers do buy bad acoustic systems not because of their sound but because of many other reasons, mostly to get a satisfaction to the frustration that was implanted into buyers by the marketing bullshit.

Generally speaking a CES-like audio trade shows are a good indication of common tendencies in speaker building and the High-Efficiency horns are not an exception.  Each year brings more and more horns but they are generally not better but worse and mostly they are improperly made in different manners.  I very attentive observe what is being made with horns over the years and I did not see any interesting and inspiring horns-centric ideas. People just re-render various dreadful designs and demonstrate badly performing installations where they in different way recite the faulty but “convenient” mistakes. The common tendencies of all commercial horns miss-aliments of drivers, use of poor drivers, improper migration ideas, overloading horns with LF, improper channel slicing, improper selection of horns, improper horn-driver integration, improper horns making, under-loading of the drivers, improper use of channel and many others. In most of the cases the designers themselves are just too ignorant to understand what they do, why they do what they do and in some cases the products designers go for consciousnessly wrong directions because the cost and marketability of their products.

I need to make clear that the fact that some kind of product out there did not comply with my idea of “proper horn setup” do not automatically make the speaker bad. There are plenty of good direct radiator systems (or other topologies) out there and no all acoustic systems must use horn-loading.  However, the targets of my observations are the systems with over 100dB sensitively and mostly horns. So, I have no problem to put myself on the position of being horno- snob and say “if you do horns then do it properly”. Very few do, and very few among those that do are coming out of closets with commercial systems.

I certainly am not familiar with everything that is done out there but whatever is exposed publicly on internet I am well familiar and I do pay attention. I admit that I enjoy re-thinking again and again about the “stimulating elegancy” of an abstract horn installation and I always look for new inspirations. Unfortunately my definition of elegancy does not imply compromises of the things that I believe are important. I know what is important in horns systems and what is not important and I know how the important/unimportant things sound. There are practically none of the commercial horn systems know to me that do not slip in what is important. Why I said “practically”? Well, there are 1.5 exceptions.

The only one full exception from the long list of the boring, ignorant or juts idiotic designs I would grant to a German speaker:  Cessaro Gamma. This speaker, despite having some things that I do not appreciate, but it still is the most accurate approximation to the proper design of horn-loaded acoustic system commercially available. The 0.5 exception goes to an American from Tennessee Jeffery Jackson. From a few post that he made in past at this site it was obvious that he is not a Moron in the horn thinking and since he put himself as CES vendor last year then he declared his intend to commercialize his design ideas. I think his designs are premature so far as products. He has good ideas and good intend but they did not compile themselves yet to a complete expression in a shape of merchandise. What he did so far was “not there yet” but I feel that he is in the right direction and soon on later he might come up something interesting commercially-available.

It is about it. I do not see any other serious commercial adventures out there. If you know about any that were missed from my attention then let me know.

 Someone at the Audio Sewer posted a question about horns and while Tom Danley was trying to reply he shaped a brilliantly-simple postulate:

“ … loudspeaker flaws increase faster than the level does so that as the level increases, the flaws become louder faster than the signal. “

http://www.audioasylum.com/forums/hug/messages/15/152000.html

I’m kind of pissed and jealous that I did not pronounce the concept myself.