haralanov wrote:

Romy, I have never said you have to listen to only one channel during your regular listening sessions. I just mentioned it is the most difficult TEST to pass for any system, including your Macondo. Of course you will listen at both of your stereo channels. But their absolute performance strongly depends on the quality of your left and right channel alone.

haralanov wrote:

“Audio window” – that is property of sound that belongs entirely to the reproduced sound and it is strongly system related. It doesn’t exist in reality (when listening live music), because in reality it is totally unlimited in size. Despite the fact it is sound related, it directly affects the musicality. I’m not a good descriptor of sound in context of English language, so I should give you very simple example of that playback’s related phenomena, despite the fact I am perfectly sure you already understood what I’m talking about. Take any accidental midrange driver and let your amplifier to feed some signal to it. What you should hear is a sound pushed inside a very tiny spot – that’s what I call small “audio window”. As I already gave an association somewhere within your site – it is the same like watching a movie on the display of your mobile phone – you get the idea of the event, but it is totally artificial – you are completely disabled to feel the physical aspect of the event. So there is a critical size of that “window” and if it is not achieved, one can never have the physical aspect and the greatness of a given recorded musical event. The physical aspect makes the recreated event believable and real, so if the listener could not get in touch with it, he cannot feel that physical directness of the musical messages, because he rather feels the sound like a the memory of the music popping up from the "head" of his acoustic system, but not the super expressiveness of the music. So the system should be able to reproduce the music with the same amplitude as the originally performed music, in order to affect the listener in the same, and IF is possible – in even more influencing way. So with improving the quality of the system, the audio window should get larger and larger, until it lose its meaning as a sound related artifact (in the best case scenario with top level acoustic systems) – it should be completely transparent window of unlimited size, that allows you to be and to feel like a part of the original music event. In other words – there should be no window at all. So until that window is part of the system’s type of sound presentation, we are faced with something artificial, which makes the reality not so believable and not so physical. Too pity that almost no one cares about that…

haralanov wrote:

I have been thinking for the last few days that maybe my initial description carries a terrible mistake:  The Harmonizing effect comes before the Spherical soundstage, since this soundstage Sphere is a very important part of the Boilling effect. Romy, can I get some confirmation from you on this.

Jorge wrote:

some of the bigest strenghs of horns is indeed power and dynamics

Hiroyasi Kondo wrote:

Cone speakers have sometimes been characterised as "boneless sounding", but such disadvantaes were elliminated by these improvemnts, and more over, this cone type achieves an obedient sound that cannot be gained from horn type units.

Jorge wrote:

IMHO horns do have the ability to image better than direct radiators.

Jorge wrote:

you dont get highs or lows, just extended midrange.

Jorge wrote:

It is spherical because you feel like you could bend downwards and look infinitely beyond the sphere,  on bass,  and also lets say stand up and get a clear view on top,  like the "poles" of this sphere being highs and lows,  not evidently present but seemingly infinite in extension.  Hard to describe,  but clear if you have heard it before.

Romy the Cat wrote:

I am not sure why you associated it with MF and HF. From my point of view your definition of “Audio window” is more managed by upperbass and lower MF.

Romy the Cat wrote:

The presentational geometry is very important but only for audio not for listening to the message.

Romy the Cat wrote:

Sure, no one would argue and as I said when speaker is design, tested, calibrate or tuned then only one right or left channel is used.

haralanov wrote:

So if they do the things I already mentioned several times, the owner of these stereo channels will experience different, much more advanced type of recreated reality (which could NEVER be achieved if the channels have any deficiency of “space” when listened separately, no matter the room integration efforts and no matter if they are placed according to DPoLS rules)

haralanov wrote:

Yes, you are right. Power – you have almost unlimited power. Dynamics – you have as much dynamics as you want. But there are a lot of associated problems with that kind of dynamics. The following illustration is taken by Wolfgang Klippel’s technical paper "Loudspeaker Nonlinearities – Causes, Parameters, Symptoms":

I am not sure that I agree with Wolfgang Klippel. Yes, I heard that at high amplitude sound theoretically propagates faster, so at different temperature, pressure and horn geometry. However, how much practical significant it has I do not know. In the Wolfgang Klippel illustration the waves that are coming from compression driver are some kind of perfect waves that then get deform into changing geometry of the horn. I am sorry but it is ridicules. The deformation of the waves in a compression driver and in the phase plug is order of magnitude higher than anything that might take place in the horn. Also, the change of sound speed at high amplitude happens only at the highest amplitude. Perhaps this is why the high compression driver are not sound good. If a driver has 100% efficiency then 1W of electrical power is converted to 111dB of acoustic power. Yes, because of that or because other reasons (I believe into other reasons) the compression driver that do 111dB sensitively sound very bad. The drivers with moderate compression and with moderate acoustic pressure are way more “human” in my estimation. JBL/Altec/Vitavox and many other drivers do max 108-110db loaded and from there you need to take 6-8dB of horn gain. So, the moderate compression drivers are not at the max compression and max amplitude. There are inhalations that are made to archive 130db-150dB and in there the problem with high amplitude might take place but no one think to pay attention to sound at those systems. So, I do not feel that at moderate pressure that we use in home system the effects that Wolfgang Klippel describes is so significant or even meaningful.

haralanov wrote:

As Paul perfectly put it in words – “trombone dynamics”! So that inherent steepening of the reproduced signal makes your brain to believe the sound is very dynamic. And it really happens! BUT – you have that kind of very dynamic behavior even when you play music where that dynamics are originally not there (!!)

I disagree with Paul definition of “trombone dynamics” and I disagree with idea of contrived dynamics. Even the most dynamic playback the one can imagine no where even close to the dynamics that need to be accomplished.  Even with the best compression drivers we are nowhere near the dynamics of live sound.

haralanov wrote:

So how could this topology pass the musical messages in completely transparent way without affecting their original meaning? Yes, you already guessed – it cannot. You can also read Kondo’s observations on the subject:  Hiroyasi Kondo wrote: Cone speakers have sometimes been characterised as "boneless sounding", but such disadvantaes were elliminated by these improvemnts, and more over, this cone type achieves an obedient sound that cannot be gained from horn type units.

I do not know what kind improvements Hiroyasi Kondo implies. Worn you that he was in the business of selling audio and he made all possible claim that not necessary had factual value. I do not recognize this argument as some kind of war between direct radiators and horns. I have seen the properly made direct radiators that had dynamics greater then horns and I have seen horns that were absolutely dead. If I use horns it does not mean that I advocate horns but since I know horn I would defend horns from the criticism that I feel is unreasonable.  I think the Haralanov/ Kondo attempts to find a justification of alternation of musical messages and the affect to original meaning of the musical messages coming from loudspeaker topology is a bit too marketing-like. I think it is not topology that deforms musical messages but an implementation of a given topology. I am sure that would it be horns, direct radiator, electrostats or anything ease – if they done sensibly the they would do the identical “deformation of musical messages”. The musical messages are being corrupted not by loudspeakers but by the people who makes loudspeakers and teacher loudspeakers to sound.
 

haralanov wrote:

Tone? Where is the tone of the compression drivers/ horn combos? If there is no tone deficiency, then why one needs injection channels?

Good question. I would like to have compression drivers/ horn combo with predictable tonal characteristics but do not forget that in the world of comprehension drivers we deal with EXISTING drivers. It is much easier to deal with direct radiator as it is easy to make your own driver. Suspend any material with VC between magnets and you have a driver. To make compression drives is much more complex  and much less predictable and therefore practically no one experiment with them

haralanov wrote:

Of course (!!) it is managed mainly by the upperbass and lower midrange, but it is deformed (the “space” is deformed, not the geometrical properties of the audio window; audio window is just responsible for the feeling of space to happen in the listener’s mind) by the tweeter (not by the HFs, but by the tweeter as a separate sound source). That’s the only reason why I put an accent on the tweeters and their integration. It is so important!

I do not share or do not understand your statement that “space is deformed”. Theoretically with horns you shall have more uniformed “space” as horns do less “beaming” then largest single cone direct radiators drivers. The radiation surface from horn is also much larger and horns produce more “clouds” of sound then the “source of sound”. Again, you are talking about “deformation of space” and Ima not sure that I understand it or at least talk about the same things.

haralanov wrote:

The musical message is also affected, because its authentic value and magnitude of it expressiveness is also a function of the audio message. If it is not audio related, then all of the existing systems would be musical to the same amplitude as if the listener is listening live music, but unfortunately it is not the case...

And why do you feel that the affecting of the musical message is the subject of ONLY topology of acoustic system. When you change topology of acoustic system you along with it change many other characteristics of your playback to accommodate the new topology. So, it might not be ONLY the direct radiator vs. horns deliberation. I juts would like you to understand it.

Romy the Cat wrote:

Yes, I heard that at high amplitude sound theoretically propagates faster, so at different temperature

Romy the Cat wrote:

I do not know. In the Wolfgang Klippel illustration the waves that are coming from compression driver are some kind of perfect waves

Romy the Cat wrote:

The deformation of the waves in a compression driver and in the phase plug is order of magnitude higher than anything that might take place in the horn.

Romy the Cat wrote:

the compression driver that do 111dB sensitively sound very bad. The drivers with moderate compression and with moderate acoustic pressure are way more "human" in my estimation.

Romy the Cat wrote:

I disagree with Paul definition of "trombone dynamics" and I disagree with idea of contrived dynamics. Even the most dynamic playback the one can imagine no where even close to the dynamics that need to be accomplished. Even with the best compression drivers we are nowhere near the dynamics of live sound.

Romy the Cat wrote:

I have seen the properly made direct radiators that had dynamics greater then horns and I have seen horns that were absolutely dead.

Romy the Cat wrote:

I think the Haralanov/ Kondo attempts to find a justification of alternation of musical messages and the affect to original meaning of the musical messages coming from loudspeaker topology is a bit too marketing-like.

Romy the Cat wrote:

I think it is not topology that deforms musical messages but an implementation of a given topology.

Romy the Cat wrote:

The musical messages are being corrupted not by loudspeakers but by the people who makes loudspeakers and teacher loudspeakers to sound.

Romy the Cat wrote:

I would like to have compression drivers/ horn combo with predictable tonal characteristics but do not forget that in the world of comprehension drivers we deal with EXISTING drivers.

Romy the Cat wrote:

It is much easier to deal with direct radiator as it is easy to make your own driver. Suspend any material with VC between magnets and you have a driver.

Romy the Cat wrote:

The radiation surface from horn is also much larger and horns produce more "clouds" of sound then the "source of sound".

Romy the Cat wrote:

And why do you feel that the affecting of the musical message is the subject of ONLY topology of acoustic system.

haralanov wrote:

I think you wanted to say reflection surface, not radiation surface, right? Radiation surface is the surface that is directly attached to the vibration creating element (the voice coil). So the radiation surface of the horns using compression drivers is equal to the surface of the dome of that compression driver. All the rest is reflecting surface.

haralanov wrote:

I’m not looking for a justification of alternation of musical messages and the affect to original meaning of the musical messages coming from horn topology – I only mentioned that all of the horns I have ever heard do affect the musical messages, making them too horny every single time. I will be glad somebody to demonstrate me proper horn implementation (because everybody knows most of the horn implementations sound like crap) that is free from those artifacts.

Romy the Cat wrote:

What does it mean “horny”?

haralanov wrote:

Notice how Vengerov starts to play at 0:25-0:40: http://www.youtube.com/watch?v=dk6tqaPLp5M&feature=relmfu  "You start being heroic - which is unnecessary" - he said :-))

Romy the Cat wrote:

do you mean that they had honk?

Romy the Cat wrote:

It is incorrect. There is no reflection surfaces.

Romy the Cat wrote:

Of cause in case of horns mouths are the active transducers…

haralanov wrote:

Take a look at the video:

haralanov wrote:

To have a situation where there are no reflection surfaces, the compression driver must be radiating directly in the air. Loading it with a horn is equivalent of placing reflective surfaces around the exit of that driver.

Sorry to disappoint you but you are absolutely wrong about it. Loading a driver to a horn does introduce a front contras peruse that is not linear and that has a well designated name – throat reactance. One of the definitions of compression driver is that the driver is designed to deal with throat reactance and can’t work without it properly. The throat reactance is NOT a reflection but permanent force that participates in balancing of diaphragm damping. If driver feel an actula reflection from horn then it is juts shitty horn design and shall not be used.

haralanov wrote:

That’s because the wave cannot escape until it reaches the mount of the horn – it is surrounded by all sides. But that happens only at the lower working range of the horn. When you play some HF tones in let say 440Hz MF horn, the wavelength of these HF is small in comparison to the horn’s diameter and you have a lot of random uncontrolled reflections. If you don’t want to have reflections in the upper part of the working range, then you have to eliminate the horn surface, which means to eliminate the entire horn or to use it no wider that 1 octave.

Yes, ideally a horn shall have 1 octave bandwidth and optimal horn rate is a single point not a wide bandwidth, very similar to optimal ani-scatting for tonearm – it is perfect only for one single point on the record surface. Still, there is reality of practical implantations and those realities do allow to use slightly wider bandwidth by losing horns equalization. Still, in case of too HF loaded into to too large horn the problem that you will not will be NOT “random uncontrolled reflections” but absolutely different problems. Again, forget about random uncontrolled reflections in the horn (with exception of reentry in LF horns). They do not exists. The HF propagates as light – where do you see light get reflected back from the horn?

Jorge wrote:

Romy said "I think importance is not in sequencing but in relationship between listening practice and sound presentational geometry. The presentational geometry is very important but only for audio not for listening to the message." We have been talking about this "mechanical" or Geometrical audio effects, but have not looked at the ….

It was not what I was talking about. Let me give you a clue. The simple audio term “soundstage” has a number of levels of understanding.

At first level person recognizes soundstage as a geometrical virtualization of performing space. Most of the people are there

At second level person recognizes soundstage as a geometrical virtualization of own perception to performing events. Not a lot of people get there.

At the third level person recognizes soundstage as a melt, sort of alloy between virtualization of playback imaging and own perception. Think about conductor positioning his musicians in accordance to his interpretive objectives. Very very few people in audio get there.

The forth the level give a person a freedom to have any soundstage and by the force of own mind and creativity to override it in own perception to whatever she/he wants it to be. I know just 2 people who are able to do it in audio.

The last fifth level is the level of ultimate peace and maturity with soundstage where the perception of first level with the geometrical virtualization returns back but this time a person knows where, how and how much reconstructive powers she/she willing to dedicate of it his perception and how much he is willing to get sound presentation as is. Mitigating in his/her mind the force of own observation the person might deal with absolutely any soundstage results.

This illustrative above is given as a pattern to understand my quote above.

Romy the Cat wrote:

It is quite banal things and those infomercials of Vengerov educating in front of camera the sentimental girls how do not play overly arousing of overly patriotic have become the annoying stamp of his marketing of himself.  Look for Menuhis teaching his master classed how do not play Paganini overly “heroic” and listen him to play Paganini’s concertos – you will hardly will enable to tolerate his attitude.

Romy the Cat wrote:

Sorry to disappoint you but you are absolutely wrong about it.

Romy the Cat wrote:

One of the definitions of compression driver is that the driver is designed to deal with throat reactance and can't work without it properly.

Romy the Cat wrote:

The throat reactance is NOT a reflection but permanent force that participates in balancing of diaphragm damping.

Romy the Cat wrote:

The HF propagates as light - where do you see light get reflected back from the horn?

Jorge wrote:

I would say tone and texture some of the most important aspects of an organic playback.

haralanov wrote:

Your response is a very good illustration of how you redirect attention away from the actual discussing subject and point it to a completely different direction that has absolutely no relation to that subject. You asked me what I mean by saying “horny” and I just gave you an example – nothing more, nothing less. The video link is not there to illustrate what Vengerov or Menuhin do, but to show you how I feel the horns sound like (!) – they always push the sound with unnecessary force.

haralanov wrote:

That’s why I am interested only in drivers which don’t need any throat reactance in order to work properly. But I will trash my drivers and replace them with compression ones in the moment when somebody demonstrates me really worthy horn loaded drivers. I do not belong to the group of people who are slaves to a given speaker topology and I can instantaneously change my concepts IF there is something that is going to provide better results in terms of sound.

haralanov wrote:

>

haralanov wrote:

This is the third you put words in my mount, words that were never told by me. Where did you read I have written that the sound is reflected back in the horn? I said it is being reflected inside the horn, not back in the horn.

haralanov wrote:

Now the owner of the injected S2s listen to this concerto, but is he able to hear the real colors of that violin, despite he feels his system has super tonal complexity? The answer is NO. I will tell you why. It is because the sound is now polluted by the algorithm that makes the injection channel to be saturated by colorations. That algorithm affects the sound always in the same way, because the injection channel does not have own intelligence to decide how to color the sound of the different instruments. It colors their sound with the same intentions every single time and that is the real problem. The sound of every note has the taste of that channel.

I think the usage of Romys Injection Channel has misguided you to think it was implemented because of a certian lack of tone or some sterile sound,  nothing of the sort,  I cannot blame you for not having listened to Romys system,  but theorizing around this sort of untrue assumptions is ridiculous.  I listened to Romys old system,  I am sure the new one sound better,  but let me assure you:  The sound comming from Romys system is packed full of information and tone, texture and color.  When I was at his place he disconected the injection channel for me to notice what it brought to the sound,  I could not really percieve any change in sound,  If anything it was ever so slight; at those levels, It would never be able to inject lacking tone into a system:  It is mainly the masteful adding of a specific spice into an already wonderful meal.  Romy explained: it adds certain notes of red color.

I studied painting for some years with a master, the use of black was forbidden;  you can get even deeper darks by using combinations of red, green and blue hues, the use of black gets color dirty.  Generally shadowing is done just using different shades of the same color: but when a painting comes to life is when hues of a diferent color spike the shades and make the image move.  I imagine Romy felt his systems color would appreciate some tones of red in order to spike the sound even more.  But trust me his sound is an explosion of color.

Most of us here are not newbies trying to get a good sound.  I have been into horns for the past 10 years,  before that I was using Lowthers on open baffle,  I was not a fad then like now.  I had DX3 on open baffle, running with its own amplifier with the xover placed at the coupling cap,  and another PLLXO at the input, under that there were a pair of Altec 416 on modfiied cabinets going from around 150 hz down to 35 hz run by its own EL34 PP amps with an active xover and EQ: Rel Stentor subwoofer under that, and supertweeters cut anywhere from 8 khz to 15 khz.  I played with a lot of old german alnico wide range drivers Saba green with the big magnets, Telefunken 10 incher but my favorite became the Oval telefunkens.  I played with different tweeters,  from paper ones Green Saba, Telefunken with the bolt in the center to Fostex, EV,JBL, Beyma... many others.  Open baffle helped me to learn a lot,  but IMHO they are far away from a horn system.   Now you can get a perfect resolution with that system,  I did  for a long time,  but soundstage is never where it should be,  and you cannot control the response of the speakers like you can with horns.

About horns,  when we choose a driver for its tone,  be certain it is not because it is the least compormised, but because the tone in that one is indeed better than in other ones,  is this hard to comprehend?   I took out Lowthers because I tried the Altec 802 with the 800 hz horns and it blew it away in every respect:  This was already a very good sounding system with the lowthers,  and the Altec 802 is not even one of the top compression drivers.

I agree with you that most of the horns systems around are lacking tone,  there is this generalized wrong usage of horns crossed over to a 15 inch driver at anywhere between 1.2 khz to 500 hz.  Now the tone of a 15 inch driver at 800 hz will never match or even compare to that of the compression driver and this makes for a terrible sound.  But please give us some credit here:  this is not the sound we have.  Without an upper bass horn all bets are off,  and this range is so important we all believe it to be the hardest working channel in a system.  Now the driver used inside this huge 120 hz horn is not a compression driver in my system and Romys,  it is a cone driver of specific qualities, that should match in tone and texture with the compression driver used on top of that.  This driver is used with a back chamber which reactance to the throat is vital for its work (check Romys Problems with horns upper bass),  so the volume of this sealed back chamber is extremely important to the sound.  What happens when a cone driver is placed inside a horn is explosive: its output is augmented by 6 or more db and the cone barely moves, this brings lower distortion with higher sensibility for softer tones, and great dyanimics.  One gets better detail at every level of listening and the real possibility of closer to life dynamics: Now we are always looking for a better driver to place inside a horn! it is some kind of vice we have,  either a compression driver that will go down to 50 hz or a huge magnet cone speaker... This is where I was drooling over a driver like the one you posted!!!

Once you get an upper bass channel; Horns are unbeatable, the tone is there, textures, detailing better that any cone driver plus dyanmics to die for:  Now if there was something better I would run for it,  and I have been looking for a long time.  Adding the Fundamentals Channel will bring in even more control over the color pallete, again; not that there is no color,  but the saturation of tone achievable with this is so incredible and even controlable to ones taste: I am already playing with an injection channel,  getting to know its tone, color, textures and extremes in order to build a perfect horn for it.  Still too far away from an injection channel.  And the sound I have is already very good if I might say so.

I believe we have not even grasped the extended abilities of this type of system and the pshycoacoustical effects achievable through sound:  This thread is an attempt to define what is beyond a Perfect Resolution of the recorded material. Now there are few systems capable of going there:  I know multiple horn systems can,  I hope other topologies could get there too,  but I still never heard them:  And believe me I listened to very well set up cone systems that do a wonderful job at presenting what is in the recording with exeptional soundstage:  I am looking for more input from  systems that can go beyond that.  Romys system is that far beyond,  and my first post was a blunt explanation of how far beyond that is, and an attemp to stat to trace a way of getting there.

Romy the Cat wrote:

Possible, but what is an alternative?

Romy the Cat wrote:

To use a good quality direct radiator that presumably gives all necessary colors? There are two problems with this approach. First, colors pallet is only one of the characteristic, there are many others.

Romy the Cat wrote:

The second: how do you know that with your driver you might not be benefited by what I call "injection?"

Romy the Cat wrote:

You might not know what kind result I get from my ejection and your assessment that your single driver gives a sufficient palette of colors might be inaccurate. It is very difficult, almost imposable to make those assessments without being familiar with the actual results.

Romy the Cat wrote:

One more thing. In my mind the injection that I use is more preferable solution then to use truly rich driver as you presumably use. The resosn is that using one good driver you have no control over it's color. The driver is what it is and you can't add or reduced colors. Using one driver you have no control over depth of colors, I do.

Romy the Cat wrote:

I am sorry, haralanov, but it absolute BS. To have a reflection as you depicted the wavelength shall be comparable with the radius of the throat.

Romy the Cat wrote:

I see absolutely no problems with any other type of reflections. Reflections is it how all sound works, so what is the problem with it?

Romy the Cat wrote:

Have you heard about the axis cancelations in direct radiators? Why do you feel that the axis cancelations in direct radiators are less damaging then alleged horn reflections?

Romy the Cat wrote:

The point is that I do not feel that forward reflections in the horns are a subject at all - it just not exists in my estimations any meaningful way.

haralanov wrote:

First of all, I want to note that when somebody lives on the principle of denying everything, he risks to live in his own encapsulated world, build according to his own principles in order to feel comfortable there.

It has nothing to do with fear or desire to live in “encapsulated” world. This exchange worth only as exchange of reasons, nothing else.  I do not see me “denying everything” but I only provide my reasons to agree or disagree.  I do not insist you or anyone else to subscribe my reasonings.

haralanov wrote:

OK, let suppose you are some kind of magician and you made your injection channel to be capable of changing its coloration algorithm according to the specific music material you play at a given moment.

It is absolutely not how it works.
 

haralanov wrote:

I have control over thousand parameters of my main driver (and not only my main driver, but also my tweeters, my upperbass/lower midrange drivers and my 23” bass drivers!) Choosing the type of magnet system, the geometry of the magnetic circuit, the hysteresis properties of the magnetic steel, the type of the voice coil, the material of the VC former, the INDUCTANCE of the voice coil, the type of the glue for the different joints, the way the sound energy coming from the VC is transferred to the cone, the type of the cone, the geometrical properties of the cone, the type of suspension, the combination of different materials for that suspension (for more complex tone) and literally zillion other variables – I am able to manipulate the tone to any degree I want – I have unlimited freedom to do so.

I have no control over all of those parameters and if I did I would not know how they might affect what I need to get in sound. You claim that you do? Good for you. If you share how they do then perhaps other would understand what you are taking about.

haralanov wrote:

“The driver is what it is and you can't add or reduced colors” – this is valid in your case, but I really wish you to start research in the field of compression drivers and to invent your custom driver which is able to kick your Vitavox S2 right in the ass! I know it is not easy, but I also do not see any reason that stops you not to try it! Only then you will have the sound that you imagine in your mind – your type of sound. But still keep in mind we have already concluded that the less the compression, the better the sound

I do not see why making custom driver would be a difficult and I do not know why it has to be compared to Vitavox S2. I am not sure why you have interests in compression drivers if you did not hear good sounding horns and if you do not recognize horns-loading as advantageous topology. Sure you are free to do whatever you wish but as in anything else I am looking for reasoning…

haralanov wrote:

The problem is that I hear them [reflections] as a specific type of sound signature that I associate with the mechanical device reproducing the signal coming from the amplifier. If I close my eyes and you play for me 20 different speakers, I will always tell you if there is horn type of speaker – my ear (actually brain) is very sensitive to that type of inherent sound signature. Maybe all the horn users have their brains wired differently and they are restricted by the Nature to recognize that type of specific signature. Who knows....

Can you describe more specifically what exactly you hear that indicate for you’re the “horn type of speaker”? What kind signature are you talking about? BTW, did you detect the very same signature in the sound of trained singer or in the sound of well tune symphonic orchestra?

haralanov wrote:

You can think of direct radiators as a kind of very fast expanding horns. They have very slight horn effect for the frequencies radiated by the center of the cone, but the cancellations that you are talking about are order of magnitude less compared to let say tractrix type of horn profile. The cancellations that you are talking about exist mainly in the controllable zone of the cone, so one can almost entirely eliminate them if he knows how to do so.

I do not think about front reflections, neither in direct radiators nor in proper horns (means no step pressure transition). The whole story about reflections is the subject of your invention and I do not mind if you live in that “full of reflections encapsulated world”

haralanov wrote:

If you are happy with the sound in your room, then everything is OK – this is the only important thing of all – to be satisfied by the sound you have in reality.

… and it is not about being “happy with the sound in room”. I was trying to debate the reasoning, nothing else. Frankly I did not now hear anything stimulating regarding horns. Your objections against the horn loading were not noteworthy in my estimation.

Jorge wrote:

I guess you cannot say you listened to a horn system if you dont have an upper bass horn.

Jorge wrote:

Once you have an Upper Bass Horn working properly with a good driver inside it, and getting at least 6 db extra output out of the loading (I just wrote about 2 pages of technical difficulties on this but let’s just stick to the sound) …

The best midrange comes from compression drivers, it has that minuteness, transparency and dynamics that no other topology can offer; the main problem with them is that they only cover a very specific mid frequency range.  Their sound is so distinctive that it is very hard to mix it with other speaker topologies.  They have been mistakenly used above a 15” driver with the terrible results by which we judge horns badly.

The only way to fill in the frequencies below the compression driver is with a bigger horn; the Upper Bass Horn.

Compression drivers work well from around 15 khz on the upper range to 800 hz on the lower rage.  Most are specified for 500 hz and recommended at 1,200 hz.  So let’s use this range as our upper range target.  About how low they should go, well; as low as physically possible!

Bruce Edgar designed his first Upper Bass Horn to go down to 80 hz, it was a square horn with a 12” cone driver.  I am very familiar with the sound of the latest more conical version.   It does have some horn gain but it gets down to 80 hz with almost no compression and dead sound.  Bert Doppenberg made a nice 150 hz Oris horn for Lowther drivers,  but with no compression,  the horn works mainly as an equalizer, I heard them a lot of times and built a few,  lowther drivers can cover a very long range inside a horn but their sound becomes very soft,  very listenable; but no match for compression drivers.  Adding compression to a Lowther driver will spike the sound but they will hardly go below 200 hz, and since we only need them up to 500 hz, they become redundant,  there are more powerful pro drivers that will cover lower frequencies with much more elegance and transparency than Lowthers will.

Of course the best thing to do is a Round horn that will cover as much range as logically possible.  80 hz will need a mouth size of ¼ of its wave length: That is about 110 cm, now the ear of a human being sitting down on a comfortable position is at 90 cm.  For good soundstage the compression driver playing the higher frequencies must be at ear level.  The normal horn size for a compression driver with a tactrix profile is around 28 cm.  If we smack it in the middle of our ear it will leave 76 cm under it, this is the maximum size our Upper bass Horn can have in order to allow the compression driver to play at ear level.  A mouth of 80 cm at ¼ wave length is about 110- 120 hz. My UBH is 82 cm high.

Now in order to make a cone driver work inside a horn and match perfectly with a  compression driver it should work with compression in order to have a sensibility gain from 6 to 9 db, making a readily available 8”, 10” or 12” driver with a sensitivity of 100 db go up to 108 db.  It is not so much as to match level, but manly to match output, speed and dynamics.  The properties for this driver may vary, but certainly you will need an FS close to the horn mouths cut off,  high sensibility, very light cone for faster transients, etc.

This all sounds very easy and logical; so you have to make your round horn of 76 cm in diameter with a cone driver inside it, add some compression, basically choking it with a throat around 50% smaller than its cone diameter, and hope it will get up to 500 hz and as low as we can get away without honk.  The driver you choose will have to go inside a “box” otherwise there will not be any pressure build up.  The size and volume of this box has to be specifically calculated for throat reactance, whatever the size will be, adjustments will have to be done when changing to another driver, so the best thing to do is leave it “movable”, either you can make it big in order to open it and add something inside it that will take up volume, or you can make it adjustable with a sliding wall.  I made the last and let me tell you ¼ of the turn of a bolt will make a big difference in sound.

Of course making the horn is no easy task,  and I wont even go there. Let’s say you already have the horn, picking the right driver and getting to the perfect back chamber volume will take you a long time and extended listening tests, I have literally chased a resonance on the horn from its lower range to its higher range, only to bring it back down again and eventually out of the horns cut off in order to get rid of it.  Once it is almost out of your horn; if you turn the back chamber volume bolt half a turn more the sound of your horn will die, put it back closer and it will just jump out of the horn with the most transparent and clean sound you ever listened this frequency at.

I have made several UBH, from 180 hz down to 120 hz, with exponential and Tactrix profiles.  The 140 hz horn will do most things nice but the cut off is still at a very sensible frequency.  140 hz will most probably bring you in room anywhere from 160 hz to 130 hz depending on the position in your room.  Once you get the sensibility to hear the resonances of the horn down low and where it dies out, you will notice this is a very bad range to let it die, a lot of fundamental frequencies of the voice and several instruments are still going strong, so a performance “step” will appear between your UBH and the channel below it, mainly if it is the same 15 inch woofer!  These were very time consuming an expensive tests to fail, 120 hz will get you just out of that range and still into the range a woofer that can go under 30 hz will cover.   Make it 140 hz and you will need two separate bass solutions, one that goes from 140 hz down to 40 hz and a subwoofer.

You want aggravations; let your woofers start a fight between them, when you can get a higher bass output by lowering the volume level on one woofer amp,  something is not right!

Once your UBH is running you have to listen to it by itself and make sure all the resonances are out and you still have the great dynamic sound.  Now get your RTA out and measure what you got.  Be sure to place a high pass xover below the natural cutoff of the horn, if you leave lower frequencies to be played by the horn they will mess up the sound, so unload the extra bass out of your horn. You will most probably be able to mix in your compression driver very naturally; the point where the UBH will be dying on the upper range will most probably be well within the range of your compression driver.  You can play around with low pass cuts on your UBH and high pass cuts on your CD in order to get the tone and timbre you like, make it sound a little fuller with more overlap or cleaner and drier with more separation between the drivers:  since both drivers are at the end of their natural frequency ranges you will be able to mold their sound properly with a first order xover.

If the sensibility of your UBH does not match the compression drivers one perfectly, you will need to use a separate amplifier for each horn, resistors at speaker level or Lpads here will kill a lot of harmonics and tone.  IF you need more sensibility, you can add compression to the horn or change the driver inside it.  Some drivers won’t be able to get a nice full tone and explosive dynamics once inside the horn with compression, lowther drivers don’t do very well, Fostex wont either, but even some drivers that develop nicely inside a horn can give way to a driver that will work wonderfully inside a horn.

In order to change the tone of both drivers, horn size changing is a very strong tool, drivers will most likely do what the horn demands of them, but they will pay little attention to crossover changes.

Mixing in the two horns, the UBH and the Compression driver is a lot of fun,  if you never listened to an UBH and CD playing together you will be so impressed,  you will probably just leave it on the most comfortable position and enjoy the sound as is!  Don’t, time alignments will bring the sound even closer together, and careful volume match will be the easier way to make those wonderful microscopic tonal adjustments that will make your system explode with color!

Jorge