In the last several weeks I've been bashed by the Lansing Heritage Forum and now, the GoodSoundClub of Boston - not to mention the continued high regard of the Audio Asylum High Efficiency forum.
hi Lynn
did you expect something different from the Goodsoundclub of Boston?
We have a dictate here in Brazil : who goes walking in the rain, has to expect to get wet. Sadly there are not many other Speaker developers with your kind of experience, that decide to share their knowledge the same way you do - so, from me at least, a big thank you, i am learning a lot at this thread , even if i go a other route.
Angelo
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http://www.audiovoice-acoustics.com/forum/
hi Lynn
did you expect something different from the Goodsoundclub of Boston?
We have a dictate here in Brazil : who goes walking in the rain, has to expect to get wet. Sadly there are not many other Speaker developers with your kind of experience, that decide to share their knowledge the same way you do - so, from me at least, a big thank you, i am learning a lot at this thread , even if i go a other route.
Angelo
---------------------------------------------------------
http://www.audiovoice-acoustics.com/forum/
Thank you for the link to the "GoodSoundClub". I thought this type of bunker-railer was an invention of mine (post 4078). Since he once chose to buy Advantgarde loudspeakers, I can only assume that the name, "GoodSoundClub", is ironic. Strangely this serial conflater holds you responsible for DIYers changing capacitors as often as they change their underpants... Well, I suppose we all like a clean sound.
Cilla
Cilla
Thanks for the pronounciation class
Altec is also a lengendary name here, but so many people pronounce it wrong, pity.
Back on track, why using 12inchers for midbass since the big compression driver above can play down to several hundreds Hz range?
Why not just using 15"ers all the way down? I think both 515 and TD15 can play up to 1kHz without problem, so let them play several hundred Hz would be even easier.
Altec is also a lengendary name here, but so many people pronounce it wrong, pity.Back on track, why using 12inchers for midbass since the big compression driver above can play down to several hundreds Hz range?
Why not just using 15"ers all the way down? I think both 515 and TD15 can play up to 1kHz without problem, so let them play several hundred Hz would be even easier.
Romy....AA....
He knows what he likes....and doesn't seem to care whom he offends.
Audio Asylum is nice in that if people want to carry on an online war of opinions it pretty much goes unmoderated. I haven't seen Texas over there.
Two thumbs up for Lynn for getting lots of attention and press.
Chris
He knows what he likes....and doesn't seem to care whom he offends.
Audio Asylum is nice in that if people want to carry on an online war of opinions it pretty much goes unmoderated. I haven't seen Texas over there.
Two thumbs up for Lynn for getting lots of attention and press.
Chris
When I look around at the audio world, there seem to be two opposing poles of audio design:
A) Working from a theoretical model, staying within the bounds of a rigorous double-blind-tested scientific framework. The subjective world of feelings, emotions, and esthetics is kept at arm's length, and not allowed to interfere with design decisions. Measurements are used to confirm fidelity to the theoretically ideal model.
B) An endless process of "tweaking" off-the-shelf solutions, or at most, minor modifications or adaptations of commercial designs, moving towards an esthetic target, using only the simplest of instrumentation. This is sometimes combined with an antiquarian esthetic, with rare objects of obscure desire. If only one in the world is ever built, just to satisfy one person, so much the better.
I want to understand how things work, so neither approach has much to tell me. Theory is only useful to me if it correlates with real-world experience, both measured and subjective. Esthetics is useful as a guide, but without an understanding of the systems being used, can result in a rigid collection of DO THIS and DON'T DO THIS commandments pronounced from stone tablets.
I wanted to be The Next Great Audio-Wizard 30 years ago, but Audionics burned it out of me. Any time I start feeling too clever, I recall what it felt like back then, and how it turned out - not that well. The whole Big Ego thing turned out to be a nasty psychological trap, one that keeps tripping up some of the best minds in the business. The scary thing about audio is you meet the same people 10, 20, and 30 years later - some become hard, cynical, and embittered by the industry, and others become light, almost playful, and no longer take the industry seriously. They're the ones still having fun - and I've been fortunate enough to have some as my mentors.
The one thing I kept from those dark days was a sense of curiosity - why do things work that way? Why do they sound that way? Is a different approach possible, or have they all been explored?
As I did more research into the history of audio - aided by the team at Vacuum Tube Valley - I was surprised by how many promising directions were abandoned because of intra-corporate politics, market pressures, or just plain audio-fads of the day. This started in the Twenties, and for every decade since - in fact, it seems to have intensified over the last twenty years, as the business has gotten larger and more dominated by large corporations.
The reason I go to the trouble of designing anything is that I'm curious how it will sound - good, bad, or indifferent. When commercial quadraphonic systems used gain-riding to give an illusion of greater separation, I designed and patented a dynamic matrix that kept gains constant. When the tube amp designer community was polarized into push-pull RC-coupled pentode and single-ended direct-heated-triode camps, I revived transformer coupling to do the phase spitting for an all-triode Class A PP amplifier - just to see what a 60-year-old technology actually sounded like, instead of theorizing what it might sound like.
I have no idea what a non-traditional Altec (or 18Sound or Lambda) system is going to sound like. It isn't going to be an A7 Voice of the Theater or a Model Nineteen, since the underlying concept is so different. But the drivers might indeed be unusable - I don't know, and am stubborn enough not to take anyone else's word for it. If I had taken anyone else's word for it, I would never have designed the Shadow Vector, the LO-2, the Amity, and the Karna, since they were heavily discouraged and discounted in advance by CBS Labs, Audionics, and the New York "Triode Mafia" who wrote for Sound Practices magazine in the early Nineties.
None of these were commercial products, but I heard what they sounded like, and my curiosity was satisfied. This "Beyond the Ariel" project is about curiosity - what will it sound like? All I can say for certain is that it will not sound like commercial products - beyond that I do not know.
A) Working from a theoretical model, staying within the bounds of a rigorous double-blind-tested scientific framework. The subjective world of feelings, emotions, and esthetics is kept at arm's length, and not allowed to interfere with design decisions. Measurements are used to confirm fidelity to the theoretically ideal model.
B) An endless process of "tweaking" off-the-shelf solutions, or at most, minor modifications or adaptations of commercial designs, moving towards an esthetic target, using only the simplest of instrumentation. This is sometimes combined with an antiquarian esthetic, with rare objects of obscure desire. If only one in the world is ever built, just to satisfy one person, so much the better.
I want to understand how things work, so neither approach has much to tell me. Theory is only useful to me if it correlates with real-world experience, both measured and subjective. Esthetics is useful as a guide, but without an understanding of the systems being used, can result in a rigid collection of DO THIS and DON'T DO THIS commandments pronounced from stone tablets.
I wanted to be The Next Great Audio-Wizard 30 years ago, but Audionics burned it out of me. Any time I start feeling too clever, I recall what it felt like back then, and how it turned out - not that well. The whole Big Ego thing turned out to be a nasty psychological trap, one that keeps tripping up some of the best minds in the business. The scary thing about audio is you meet the same people 10, 20, and 30 years later - some become hard, cynical, and embittered by the industry, and others become light, almost playful, and no longer take the industry seriously. They're the ones still having fun - and I've been fortunate enough to have some as my mentors.
The one thing I kept from those dark days was a sense of curiosity - why do things work that way? Why do they sound that way? Is a different approach possible, or have they all been explored?
As I did more research into the history of audio - aided by the team at Vacuum Tube Valley - I was surprised by how many promising directions were abandoned because of intra-corporate politics, market pressures, or just plain audio-fads of the day. This started in the Twenties, and for every decade since - in fact, it seems to have intensified over the last twenty years, as the business has gotten larger and more dominated by large corporations.
The reason I go to the trouble of designing anything is that I'm curious how it will sound - good, bad, or indifferent. When commercial quadraphonic systems used gain-riding to give an illusion of greater separation, I designed and patented a dynamic matrix that kept gains constant. When the tube amp designer community was polarized into push-pull RC-coupled pentode and single-ended direct-heated-triode camps, I revived transformer coupling to do the phase spitting for an all-triode Class A PP amplifier - just to see what a 60-year-old technology actually sounded like, instead of theorizing what it might sound like.
I have no idea what a non-traditional Altec (or 18Sound or Lambda) system is going to sound like. It isn't going to be an A7 Voice of the Theater or a Model Nineteen, since the underlying concept is so different. But the drivers might indeed be unusable - I don't know, and am stubborn enough not to take anyone else's word for it. If I had taken anyone else's word for it, I would never have designed the Shadow Vector, the LO-2, the Amity, and the Karna, since they were heavily discouraged and discounted in advance by CBS Labs, Audionics, and the New York "Triode Mafia" who wrote for Sound Practices magazine in the early Nineties.
None of these were commercial products, but I heard what they sounded like, and my curiosity was satisfied. This "Beyond the Ariel" project is about curiosity - what will it sound like? All I can say for certain is that it will not sound like commercial products - beyond that I do not know.
Amazingly, there are just too many technical aspects not explored to the detail it takes to get a good coorelation between measured data and estimated performance. It is much like exploring the technical aspects of a human body. I'm sure there will be lots of lifetimes spent and probably still nothing that tells the whole story, but the journey is still interesting.
When theory, measurement, and subjective experience fail to correlate is also when it gets most interesting. That means that there is something waiting to be discovered - now, whether you get to be the lucky discoverer is another question. Some problems are hard, and solutions could be decades in the future. Others are easy, and are just waiting to solved today.
The problem is that you really don't know how hard a problem is until you've solved it. It's like being trapped inside a box, and the instructions for opening the box are printed on the outside. Easy when it's solved, not so easy when it isn't. Curiosity, persistence, and a desire to understand are as good a way as opening the box as any.
The problem is that you really don't know how hard a problem is until you've solved it. It's like being trapped inside a box, and the instructions for opening the box are printed on the outside. Easy when it's solved, not so easy when it isn't. Curiosity, persistence, and a desire to understand are as good a way as opening the box as any.
Lynn,
You have no need to apologize for your approach and process in designing this speaker system. This thread is dedicated to your project and while it may not be the best solution for others, I have no doubt that it will turn out to be one of the best projects ever made and will appeal to many. Not to mention that it has probably been the single best thread ever encountered in DIY audio for an in depth discussion of speaker based audio and acoustic issues.
All to often good ideas of the past were thrown away because of the politics of profit which is the governing aspect of nearly all corporations and businesses and those at the top who want to own a dis-proportionally large piece of the economic pie.
Corporate America no longer has room for an open ended approach to problem solving as it will not fit into the development cycle and consumer/profit model. Getting gain has overtaken the need for knowledge in all large consumer based areas.
You have no need to apologize for your approach and process in designing this speaker system. This thread is dedicated to your project and while it may not be the best solution for others, I have no doubt that it will turn out to be one of the best projects ever made and will appeal to many. Not to mention that it has probably been the single best thread ever encountered in DIY audio for an in depth discussion of speaker based audio and acoustic issues.
All to often good ideas of the past were thrown away because of the politics of profit which is the governing aspect of nearly all corporations and businesses and those at the top who want to own a dis-proportionally large piece of the economic pie.
Corporate America no longer has room for an open ended approach to problem solving as it will not fit into the development cycle and consumer/profit model. Getting gain has overtaken the need for knowledge in all large consumer based areas.
Hezz said:
I appreciate your confidence, but I must honestly admit my success rate has only been about 50%. Most designers quietly bury their failures, although in a corporate environment (I know from direct experience) the marginal products occasionally make it to market. More often the really good ideas don't make it out of the lab, thanks to institutional pressures and corporate infighting.
In a big corporation, there's such a thing as "being too good", a product so good it would threaten the existing cash-cow product line. This is one of the commonest reasons truly excellent products are never made by large corporations - there's just too much invested in the existing product mix, marketing plan, and sales structure.
This whole "Beyond the Ariel" thing is mostly an experiment to see what is possible. Sometimes I ask for what isn't possible; the only way to actually find out is research the history and properties of the underlying devices, and get an understanding of what they can do and what they can't.
Specifications only reveal the most superficial aspects of the device, since they treat it as an idealized "black box" with a few deficiencies here and there. I prefer to understand the device itself, the context in which it was originally designed, what it was intended to do, and what the inherent limitations of the technology are most likely to be.
A good example are the plane-wave measurements of the 288B that Bjorn Kolbrek has on his page. The anomaly between 2.5 and 3.5 kHz is a little mysterious; what is it? It shouldn't really be there, considering how low the frequency is.
Is it the first breakup mode of the aluminum diaphragm? Maybe. It's definitely too low for the tangential surround to be breaking up - that should be 2.5 to 3 times higher in frequency. Is it a reflection from the rear chamber? Maybe, but the wavelengths aren't right. Removing the rear chamber would answer that question.
This is the sort of thing that needs time-domain analysis by MLSSA or ARTA to find what the source really is. This is a completely different approach than simply equalizing the problem and hoping it goes away - for one thing, if it really is a time-domain problem, equalization is the wrong answer, since it will make the time-domain worse. It's a lot better to solve the problem in the appropriate domain - in short, to see where it is coming from and resolve it.
Now, if the problem turns out to be the first mode of the diaphragm, well, short of switching over to the phenolic version of the 288 (the 290, which is also made by GPA), then notch-filter EQ might be necessary, although not really an ideal solution. It's a judgment call between choosing a more lossy diaphragm material versus equalization - both approaches have their own set of drawbacks and tradeoffs. Lossy diaphragms can be prone to side-to-side rocking, many small breakups instead of several large ones, and higher IM distortion at the bottom of the working frequency range; conversely, notch-filter equalization does not actually "cure" the underlying resonance, it merely withdraws drive power at that frequency, and does nothing for narrowband increases in IM distortion centered at the resonance frequency.
So something as simple-looking as the 2.5~3.5 kHz anomaly can have rather complex underlying mechanisms, and the solutions are not always clear-cut, despite what the measurement fundamentalists might say. The extreme example are Lowthers and AERs, which have pretty scary measurements, but sound better than they have any right to. What makes them sound good aren't the terrible measurements - if that were true, they could be replaced with automotive 6X9 speakers with no loss of quality - but the special aspects of the LOwther/AER driver, such as saturated pole-pieces in the gap, and thoughtful choices of VC former and cone materials.
Measurements are useful, but primarily as diagnostic techniques to improve the drivers and the overall system. For an entire speaker system, they can be fairly misleading, unless you have access to the measurements of the individual drivers without crossovers and equalization.
Yes, too bad about the banning - his last speaker had a lot of good ideas in it.
What's interesting is that people as different as Gedlee, Romy, and Magnetar all have great ideas, although they are coming from completely different places and have radically different goals. Why people can't just cherry-pick the best ideas is something I don't understand - it's certainly a common practice in the industry, going all the way back to Bell Labs and Rice & Kellogg. Some concepts are patentable, so you steer around those, but a lot of what we do is nothing more than re-discoveries of concepts that are many decades old. Much of the underlying technology has never written down and does not appear in the literature, but can be discovered by talking to the "old timers".
What's nice about this forum is that it mirrors the kind of open-ended, collegial discussions that industry designers have among themselves. DIYAudio isn't about winners and losers, it's about sharing ideas.
What's interesting is that people as different as Gedlee, Romy, and Magnetar all have great ideas, although they are coming from completely different places and have radically different goals. Why people can't just cherry-pick the best ideas is something I don't understand - it's certainly a common practice in the industry, going all the way back to Bell Labs and Rice & Kellogg. Some concepts are patentable, so you steer around those, but a lot of what we do is nothing more than re-discoveries of concepts that are many decades old. Much of the underlying technology has never written down and does not appear in the literature, but can be discovered by talking to the "old timers".
What's nice about this forum is that it mirrors the kind of open-ended, collegial discussions that industry designers have among themselves. DIYAudio isn't about winners and losers, it's about sharing ideas.