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Posted by Vasyachkin on
11-02-2008
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fiogf49gjkf0d actually this is not so much about horn loading ribbons as it is about curving them, but also horn loading.
look at this horn:
http://www.pioneerelectronics.com/pio/pe/images/portal/cit_3442/35960TH-4003_s.jpg
now imagine a ribbon of approximately same dimensions as Raven 3.2 MMX but placed sideways.
now imagine that this ribbon is not straight but curved into an arc. and finally that it is loaded into this horn.
only problem with this is obviously what's going to hold the ribbon up in such a position but i think it can be suspended on thin elastic bands - really thin.
another question is - why ?
well because normal ribbons have too much horizontal dispersion and not enough vertical. my proposed solution is to extend dispersion along one axis by curvature and limit it along the other by means of waveguide/horn.
it doesn't really matter if the resulting curved, horn loaded ribbon is horizontal or vertical but i think that a horizontal one would be easier to integrate with the rest of the speaker ( for example with a midrange horn by allowing for a closer CTC spacing )
what do you think ?
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Posted by Romy the Cat on
11-02-2008
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fiogf49gjkf0d I had a number of discussions about ribbons loading into horns and I generally do not welcome this idea. There are a few reasons why it never work properly and one of the most convincing is that in order to develop enough output from a ribbon you need to have some ribbon radiation surface that usually larger then a desirable throat size for a proposed horn rate. If one need to EQ a few DB with horn with upper ¾ of the ribbon response then it is OK. However to make a fully functional horn for a ribbon is not fruitfully thing to do. There are many other complications with no gain, so why to bother?
What however I very much object is a need to cure limited Ribbon’s vertical dispersion with horn – why would anybody need to do it? Second is the curving of throat. The throat curving is absolutely not necessary; in fact it is even ridicules. You can curve ribbon with DC but what the purpose of a curved ribbon if it sits behind a virtual back chamber (chamber is always there) of a horn, the back chamber that has no geometrical dimensions but only pressure dimensions? It feels that you did not experiment with speakers yourself. I do not know who you are and what you do but I wonder – are you just talk about speakers subject or you actually practice some kind of sound and some kind of objectionable playback?
The Cat
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Posted by Vasyachkin on
11-02-2008
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fiogf49gjkf0d expertise = experience X intelligence
a cockroach needs millions of years of evolution worth of experience to have the expertise necessary for it to be able to do find food. leonardo da vinci didn't need to experience flying in a helicopter in order to invent it.
of course it is important not to overestimate your abilities but i don't think i am overestimating mine. i need very little experience to be right when others with a lifetime of experience are wrong.
to answer your question no, i don't have experience horn loading ribbons and the only horn i own is the HF section of some JBL DJ speakers that i have ( 1.75" titanium tweeter ). but i do have an EE degree and i have been involved in DIY audio for about 10 years.
knowledge is impossible without experience but in this day and age the experience doesn't always have to be your own. if that wasn't the case technological progress would have been impossible as every generation would have to start from scratch. i think i have more than enough second-hand experience to talk about the things i talk about.
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Posted by Vasyachkin on
11-02-2008
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fiogf49gjkf0d i will give you this much - horn loading ribbons is fundamentally not as advantageous as horn loading dynamic drivers. this is because ribbon mass is already close to airload mass (in theory could even be less) and little extra efficiency can be extracted by means of an acoustical impedance transformer as the impedance is matched to begin with.
power handling however could be increased by making the ribbon thicker and then restoring the efficiency with a horn, but that would be ridiculous indeed - creating a problem and then solving it.
my ONLY motivation in horn-loading a ribbon is directivity control. perhaps i should have used the word waveguide instead of horn.
i would not use any kind of compression ratio. the horn could be almost a constant directivity or with some mild progressive rate of expansion. again it would not be used to boost any frequencies but merely to shape directivity.
you say that extra vertical dispersion is BAD. yes it is. but that entirely depends on what you call extra ? if you have 3 inches of vertical sweet spot at first and you expand it to 3 feet then i don't call this extra. i call this just enough.
the point is to be able to specify PRECISELY the size of sweet spot both vertically and horizontally and my configuration allows that. on top of this it allows for easy integration with any sort of a midrange horn due to similar geometry.
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Posted by Romy the Cat on
11-02-2008
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fiogf49gjkf0d  Vasyachkin wrote: | | expertise = experience X intelligence a cockroach needs millions of years of evolution worth of experience to have the expertise necessary for it to be able to do find food. leonardo da vinci didn't need to experience flying in a helicopter in order to invent it. of course it is important not to overestimate your abilities but i don't think i am overestimating mine. i need very little experience to be right when others with a lifetime of experience are wrong. to answer your question no, i don't have experience horn loading ribbons and the only horn i own is the HF section of some JBL DJ speakers that i have ( 1.75" titanium tweeter ). but i do have an EE degree and i have been involved in DIY audio for about 10 years. knowledge is impossible without experience but in this day and age the experience doesn't always have to be your own. if that wasn't the case technological progress would have been impossible as every generation would have to start from scratch. i think i have more than enough second-hand experience to talk about the things i talk about. |
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I see, you are the guy who is in own crusade against wrong application of science and who feels that you know right scientific ways. You are certainly free to have this point of view, however I would like to remind you that this site is centered around the subjects of advanced audio and evolved music reproduction techniques and if you do not mind I would like to keep it this way. If you recognize audio as a modeling playground for your scientific superiority then you are in a very wrong field. There are very many limitations in scientific applications, as least in the way how science understood commonly, and something does suggest me that you do not have the grasp how to apply the “other rules” to your audio views. Yes, there is a very weak, completely unknown but slowly growing and exceptionally successful community of people who practice the “thin side of science” in audio but looking at what you advocate in audio as a solution I conclude that you are not one of them. (I am not one of them but the 7th Macondo channel will be designed by those rules). So, I would propose to stick to more applied audio repodaction content if you have any interest in it.
The Cat
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Posted by Romy the Cat on
11-02-2008
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fiogf49gjkf0d | Vasyachkin wrote: | | i will give you this much - horn loading ribbons is fundamentally not as advantageous as horn loading dynamic drivers. this is because ribbon mass is already close to airload mass (in theory could even be less) and little extra efficiency can be extracted by means of an acoustical impedance transformer as the impedance is matched to begin with. |
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Well, in most of horn to accomplish effective EQ the virtual dynamic mass of the driver need to be co-measurable with horn’s air-mass applied to the throat surface (let call it throat’s reactance). That is why the very-very-very shallow horns might be used with ribbons (like the Water Drop tweeter) but as soon you need to EQ with horns lower frequencies then you are in troubles.
| Vasyachkin wrote: | | my ONLY motivation in horn-loading a ribbon is directivity control. perhaps i should have used the word waveguide instead of horn.
i would not use any kind of compression ratio. the horn could be almost a constant directivity or with some mild progressive rate of expansion. again it would not be used to boost any frequencies but merely to shape directivity. |
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Why would you need it? BTW, I generally do not undesired the whole idea of waveguiding… I think it cames from people who practice too wrong science…
| Vasyachkin wrote: | | you say that extra vertical dispersion is BAD. yes it is. but that entirely depends on what you call extra ? if you have 3 inches of vertical sweet spot at first and you expand it to 3 feet then i don't call this extra. i call this just enough. |
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I do not call extra vertical dispersion is BAD but I was asking why do you need it. Conventional ribbons have 30-40 degrees, even the Water Drop that insultingly tall and thin has 20 degrees. If you are at 8 feet for instance then what 3 inches of vertical sweet spot are you talking about? Do not bend the axis of your drivers and you won’t have any “3 inches of sweet spot”. BTW, the dimension of sweet spot has nothing to do with dispersion patters of a tweeter.
The Cat
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Posted by Vasyachkin on
11-03-2008
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fiogf49gjkf0d waveguides as far as i can tell are designed to equalize the power response.
for example if we are talking about a typical 2-way speaker with a 7" midbass and 1" tweeter then there will be a discontinuity in the power response around the crossover. because just below the crossover the woofer is quite directional and just above the crossover the tweeter is radiating in all directions.
on the other hand if you use a waveguide like this:
http://www.windovertheearth.com/Images/Mackie/HR824.jpg
it will flatten the power response around crossover frequency because it will make the tweeter equally directional at those frequencies as the woofer.
since we don't listen inside a black hole any energy that leaks into the room ( at any angle ) is likely to find its way into our ears. equalizing power response thus i think makes sense if you can do it without compromising the response on the listening axis.
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Posted by Vasyachkin on
11-03-2008
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fiogf49gjkf0d when you say conventional tweeters have 30 - 40 degrees - at which frequency is that ? probably not at 20 khz.
sure at some low enough frequency a ribbon in effect becomes a point source. but at higher frequencies it should become more and more directional.
at around 20 khz it seems as if the response should quickly fall off as you begin to move off-axis vertically ( as you move either above or below the top or bottom of the ribbon ).
i mean at some high enough frequency the ribbon should be launching a cylindrical wave front so if you're either above or below this cylinder your treble should be attenuated. and this cylinder may only be a few inches tall.
obviously depending on how much treble attenuation you're willing to accept you can say it has more or less dispersion but what if i don't want to accept ANY attenuation ? what if i want to have absolutely flat response at any angle ? i believe that with my configuration that is exactly how it would work.
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Posted by Romy the Cat on
11-03-2008
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fiogf49gjkf0d | Vasyachkin wrote: | | waveguides as far as i can tell are designed to equalize the power response.
for example if we are talking about a typical 2-way speaker with a 7" midbass and 1" tweeter then there will be a discontinuity in the power response around the crossover. because just below the crossover the woofer is quite directional and just above the crossover the tweeter is radiating in all directions. |
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Well, Vasyachkin,
I did not say that I do not know what waveguides are I said that I do not understand it and I said that people who pitch it in my view practice what you call “wrong science”. The wave guiding ideas have in my view absolutely no correlation with auditable experiences and explain absolutely nothing. The wave guiding is sell-serving idea for speaks theorists to think and to talk about speakers and nothing else. With my exposure to the subject I have mane a rule: as soon people begin to talk about waveguiding, power response, and management of speaker’s “energy” then I lose interest and walk away. I know what will following next – the sonic nothingness.
| Vasyachkin wrote: | | when you say conventional tweeters have 30 - 40 degrees - at which frequency is that ? probably not at 20 khz.
sure at some low enough frequency a ribbon in effect becomes a point source. but at higher frequencies it should become more and more directional.
at around 20 khz it seems as if the response should quickly fall off as you begin to move off-axis vertically ( as you move either above or below the top or bottom of the ribbon ).
i mean at some high enough frequency the ribbon should be launching a cylindrical wave front so if you're either above or below this cylinder your treble should be attenuated. and this cylinder may only be a few inches tall.
obviously depending on how much treble attenuation you're willing to accept you can say it has more or less dispersion but what if i don't want to accept ANY attenuation ? what if i want to have absolutely flat response at any angle ? i believe that with my configuration that is exactly how it would work. |
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Well, you were pontificating about wrong application of science and suffer from the very disease that you were warning against. Why do you feel that your brain is a spectral analyzer and that you need to have 20kHz and 0dB at your “3-inch sweet spot”. Go to live consort in the very best hall and in the very best sit and run spectral analyses from there. You will have -3dB at 6-7 kHz but you am sure will not be complaining about a lack of HF. Partially (only partially) what you say about the cylindrical nature of HF coming from ribbons is true (but there are cases where it is not is true) but so what? People who want are looking for motivations to do their things; people who do not want are looking for excuses not do the things. Try to find out what you are looking. If you are willing to use ribbon, know what you would like to get as a result then there are ways to accommodate ribbon, hiding its problem and capitalizing on ribbon’s benefit. If you use nothing and have no well-defined objectives then what is the point to chew over empty recitations of rumors about technologies? I do not mean to sound rude but I see no tangible practicality in your commentaries.
The Cat
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Posted by drdna on
11-03-2008
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fiogf49gjkf0d Well,
I will say that different people hear different things, which I have suggested before is the reason for different sounding stereo systems and why we sometimes thing someone has wooden ears or golden ears.
After all some people proclaim there is no difference with different wires; clearly not true. BUT, it is a difference that is important to only some people. Is it possible Romy cannot hear the sonic problems that are solved by the waveguides?
I will hope to hear Vasyachkin make some comments on the problems he was encountering with the sonics that may be solved with this novel solution of waveguides. Of course the other question is what compromise this produces and what will be lost for the sonics with this novel system.
Adrian
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Posted by Vasyachkin on
11-03-2008
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fiogf49gjkf0d so your design philosophy is essentially to listen to good designs and components, determine which sound best, modify them to sound better and assemble systems out of parts that compliment each other well.
correct ?
your philosophy may ensure that at any given time in history you have the best sounding system, but it won't allow to ADVANCE the science as a whole. your concern is advancing the art of riding the wave of science. i am more interested in the wave itself than in riding it.
my article was about limitations of science. i didn't suggest that science should be held in contempt - which seems to be your perspective.
without having a solid grasp of theory you cannot INVENT NEW technologies. merely using existing ones to the fullest is not exciting enough for me.
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Posted by Vasyachkin on
11-03-2008
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fiogf49gjkf0d | drdna wrote: | | I will hope to hear Vasyachkin make some comments on the problems he was encountering with the sonics that may be solved with this novel solution of waveguides. |
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to be honest listening to stuff is not my thing. it's not that i don't hear things - i just don't find listening as interesting. i became interested in engineering when i was about 7 years old and in hi-fi when i was about 15. it was only recently when i even realized that listening has any value in design process at all, but even though i realize this now it's just not how my head works - for me designing is still separate from listening.
everybody should use their head the way their head naturally works. i like to think conceptually. i like to rotate 3D shapes inside my head and visualize dispersion patterns more than i like to listen to them.
i understand the problem Romy has with this - his argument is that i didn't even hear the problems that i am trying to solve, and i am not saying that's not the case. but i see no reason not to solve a problem if know how to do it simply because i haven't experienced the problem.
i mean lets say i have never starved and never had AIDS that doesn't mean i can't worry about solving those problems.
bottom line is i don't see any conflict between the two approaches to design. theory has to be used to formulate new ideas and designs and practice has to determine which of these have any merit.
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Posted by Romy the Cat on
11-03-2008
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fiogf49gjkf0d | drdna wrote: | | After all some people proclaim there is no difference with different wires; clearly not true. BUT, it is a difference that is important to only some people. Is it possible Romy cannot hear the sonic problems that are solved by the waveguides? |
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Romy is trying do not create problems that need to be addressed by the ideas of waveguides. Let see a perfect waveguide – a transmission prorogation into continually-falling lower acoustic impedance. Is anything like this is in existing in reality? Yes, it is a horn. Any other waveguides imply step-impedance, which means absolutely unpredictable resonances. In the VERY simple case try to bend a J-horn and to get the same sound as strait. It is VERY complex, possible but very difficult. But then I see some kind of so called “transmission line” that is fractured from multiple labyrinths where each of section acts as different resonant chamber… then I do not want to hear about “energy releasing and the rest crap. BTW, most of the “big” supporters of waveguides do not recognize nether contribution of cables, nether the contribution of sources not the contribution of electronics. (Courtesy to Earl Geddes and otheres)
The Cat
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Posted by Paul S on
11-04-2008
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fiogf49gjkf0d The most interesting thought to come out of this thread for me is surfing the wave versus making the wave (or, making a part of the wave...).
Personally, I just enjoy listening to great music in my home, and I am happy any time this can happen. Since this is what motivates me, I have to admit I am really not concerned about anything but results (tempered by cost/benefit...), and this is for me the ultimate measure of both the theory and its application. I truly aim to stay "loose" and keep my ego out of the equation where particular means are concerned. Meanwhile, I always hope that those who are more absorbed with a particular aspect of audio theory are also getting what they want out of their involvement, even if in the end they are more concerned with, say, visual images than musical experiences. I have been given to understand that Vladimer Lamm is a "concept guy", who dismisses the notion of "listening evaluations", and as far as I am concerned, some of his ideas were largely successful, at least for my purposes. Still, in the end, its the results I support, not the "theories", which I see merely as tablature written in chalk on a blackboard.
It would probably be fair to say that I have in some way messed with/adapted everything in my system, meaning everything I use has been modified from "stock" by me for my own applications. This is because I do not love the means in and of itself, but rather I love the Music. And no matter what others say with respect to how something "should" be in terms of any criteria they may isolate, still the Music endures, at least for me.
As an aside, I happen to go back to the early days of consumer stereo, and I have messed with the terrible-sounding "wave guides" that "Vintage" guys still drool over. Keeping just music in mind, I certainly hope that modern wave guide "proponents" can do better than "classic" JBL, etc. If they come up with something that gets close enough to something I'm after, I'll gladly adapt it.
Best regards,
Paul S
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Posted by drdna on
11-04-2008
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fiogf49gjkf0d | Vasyachkin wrote: | | without having a solid grasp of theory you cannot INVENT NEW technologies. |
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This is a common error that many, many people make, becoming so wrapped up in the theory that they begin to treat theory like a self-sustaining reality.
And this is where it all goes wrong.
Here is an example. Acupuncture works. Surgery has been performed with acupuncture as the sole anesthetic. BUT it is not because of a meridian of energy streaming from the gallbladder etc.
We must be very careful when we build on theory because rely on making assumptions that may be wrong. We must make a theory and then TEST it, comparing it in the real world to see if the theory is sound. AFTER ALL, all theories started out based on observations of some phenomenon that was occurring in the real, physical world. In the case of sound and audio, this means listening. If you are a real scientist of audio, thus, you must listen to test your theories. If you do not listen, you are not practicing good science.
Adrian
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Posted by Vasyachkin on
11-04-2008
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fiogf49gjkf0d | Romy the Cat wrote: | | I see some kind of so called “transmission line” that is fractured from multiple labyrinths where each of section acts as different resonant chamber… then I do not want to hear about “energy releasing and the rest crap. |
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lol. yes i think people who are into back-loaded transmission lines are simply bored, at best. first they invent problems that don't exist. then they create real problems to solve imaginary ones. then they try to solve the real problems and fail. then they pat themselves on the back for their relative degree of success in addressing the problems they have created. finally they compare the sound to a regular box and observe that it is indeed different. they then conclude that because it is different it must be more natural ... for some reason.
any kind of folding of a horn into a compact box shape is not a path towards high fidelity. it can only be justified, imho, by crushing SPL when that is the goal and also the result. for example when i was in a certain hip-hop club in manhattan they had some EAW folded horn subwoofers playing 50-Cent ... i was actually worried about getting dismembered by SPL from them. now i believe this is the way to cover 15 hz - 40 hz or so where fidelity is ultimately of little concern. the problem with the back loaded transmission line people is that most of the time they don't even achieve SPL levels of an average sub in circuit city.
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Posted by Vasyachkin on
11-04-2008
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fiogf49gjkf0d | Romy the Cat wrote: | | Romy is trying do not create problems that need to be addressed by the ideas of waveguides. |
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well the way not to create problems is have a giant electrostatic panel.
starting from that point we create problems in an attempt to make the speaker smaller and more practical.
certainly i am creating problems by curving the ribbon and loading it into a waveguide - but it is not without a reason. it allows for a smaller ribbon. if cost was no object i wouldn't do it. i would simply run a ribbon from 1 foot above floor level to about 8 feet above floor level. i hope you agree that a ribbon that is maybe 6 inches long is potentially cheaper than one that is 7 feet long.
i definitely believe that line source will always outperform a point source ( and a plane source will outperform a line source ) but point source is just CHEAPER.
my idea of a curved ribbon is intended as a COMPROMISE between a point and a line source which allows for a certain degree of optimization via differeing degrees of curvature as well as different shapes of waveguide.
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Posted by horny on
11-04-2008
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fiogf49gjkf0d | Vasyachkin wrote: |  Romy the Cat wrote: | | Romy is trying do not create problems that need to be addressed by the ideas of waveguides. |
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well the way not to create problems is have a giant electrostatic panel.
starting from that point we create problems in an attempt to make the speaker smaller and more practical.
certainly i am creating problems by curving the ribbon and loading it into a waveguide - but it is not without a reason. it allows for a smaller ribbon. if cost was no object i wouldn't do it. i would simply run a ribbon from 1 foot above floor level to about 8 feet above floor level. i hope you agree that a ribbon that is maybe 6 inches long is potentially cheaper than one that is 7 feet long.
i definitely believe that line source will always outperform a point source ( and a plane source will outperform a line source ) but point source is just CHEAPER.
my idea of a curved ribbon is intended as a COMPROMISE between a point and a line source which allows for a certain degree of optimization via differeing degrees of curvature as well as different shapes of waveguide. |
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Mentioning line and plane sources (and dipoles) at Romy`s site is sort of forbiden. I believe Romy`s Macondos are the closest to the perfect horn loudspeaker, but are they the closest thing to the perfect loudspeaker, whatever that may be? I am not sure. Although I experimented with a similar configuration for about a year, just to get a taste of it, I changed the route to 2m tall ribbons that differ from the breed in some specific construction details (works in progress). They do offer some advantages that horns have problems with (no nasty harsh breakups and hardening of sound in the upper midrange, along with loss of separation on orchestral climaxes and choirs), but of course may have other drawbacks. Speaking in general, I feel true full range ribbons have the greatest potential of all technologies, but are of course nowhere near exploited.In any case, I intend to further investigate Macondo style of horns in the future, when new L`cleach horns are ready but I fear the results are predictable. Well, that`s it, I`ve just said it...
Cheers!
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Posted by Vasyachkin on
11-04-2008
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fiogf49gjkf0d | horny wrote: | | I believe Romy`s Macondos are the closest to the perfect horn loudspeaker. |
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is there a definitive description of what these Macondos are? pictures? i duno. i asked for a link already so far nobody wants to help me.
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