Green Mountain Audio Europas

[RoyJ]

Hi, Jerry

We all can (phase coherency), and for a while (the 70s) the builder community thought it was (notice that most "time aligned" speakers are from that era). Then someone (Toole IIRC) actually did a lot of blind listening tests and discovered that it wasn't.

In particular, a question about this and then a correction, thanks. I apologize in advance for the length of this post, but it is pertinant information about which I've not seen much written. So, again, your quote:

We all can (phase coherency) [why use this term here? = Question, thanks], and for a while (the 70s) the builder community thought it was (notice that most "time aligned" speakers are from that era).
Then someone (Toole IIRC) actually did a lot of blind listening tests and discovered that it wasn't.

Well, this last line sounds plausible Jerry, but I'm afraid you've been told someone's complete speculation. I was there from the early 70's and onwards, including being the principal buyer for stores at the trade shows, and I still retain many friends working at all levels throughout the industry. Thus, I think the following analysis is accurate:

Two important aspects of the USA hi-fi market changed between ~1982 and the early 1990's (all prior to the influence of Floyd Toole).

1. The overall number of hi-fi units sold steadily grew as the USA big-box stores came about and later on, from the demand for home theater gear. Falling prices and new features kept the unit-numbers up even through the several recessions in that period. The average price/unit went down from pressure by competition between the big-box stores (and from the several recessions), so manufacturing for most hi-fi moved from Japan to Taiwan, then to Thailand, Hong Kong, Singapore, China. Someday we'll see 'made in Congo'.
   
   
2. While the major electronics mfgs benefited from the big-store sales' volumes and thus greatly damaging specialty retailers, the major speaker companies could not accommodate the low-price business these USA box stores offered. Yet, they felt pressure to lower prices because of those recessions, which reduced sales of their status-oriented/expensive models. Those never did sell as well as expected when they were first being designed in the early 1980's, like the Celestion SL-600 speaker that came out in the mid `80's.

Therefore, these large speaker manufacturers asked what would best sustain or perhaps enlarge their own portion of the specialty-market share?

This would be frequent and positive reviews of 'innovative products' in all of the new hi-fi magazines then hitting the stands. And that decision caused them to shorten their R&D cycles in order bring out a wide range of new speaker models each year. Which costs more. Which meant there was going to be a move to Asian parts and assembly when possible.

To this day, a big side-benefit of bringing out new models every year remains using these new models as leverage on their exclusive retailers to have them always order at least X-amount each year. So the manufacturer knows how many to build and warehouse ahead of time, while work begins right away on the next "next-year's models".


The easiest way to shorten their R&D cycle was to design higher-order crossovers with the new help of computers, since one only designs for a proper acoustic roll-off, such as fourth-order, out of each driver with its crossover, and then checks for phase coherency when combined (by looking for holes in the overall response).

-- With these crossovers, tweeter voice-coils would be less expensive, a low resonance from a proper suspension less critical, and a rear chamber apparently 'not required'. That left $$ to cover the greater expense of metal domes.

-- With these crossovers, the emerging hard-plastic and metal 'high-tech-looking' cones would have their nasty breakup resonances better suppressed (so is commonly believed).
And they looked hi tech (and were the only part of a speaker that could do so. Other than the picture of a horribly complicated crossover.).


First-order speakers take a lot longer to design, and their raw parts cost a lot more.

Also, the math for getting time-coherence out of piston drivers, while not having coverage and lobing issues is not known by most speaker designers, as it cannot be self taught and emerges only in grad school for physicists. And while I make every attempt on our site, I don't think the math and physics can really be communicated to the public.

Thought you'd want to know. Time-coherence was simply set aside by most companies (and reviewers, and specialty retailers) for the reasons above, and not because golden-ears thought better.

It was about business foremost but also about designer skills, fortified by research papers that claimed we couldn't hear time-delays below about two milliseconds in the midband.

Poppycock. They used the wrong sounds for one, but this is a discussion I will not have time for on the internet, sorry. Anyone can get the papers from the Audio Engineering Society and form their own opinions after reading about the methodologies employed and how the conclusions were actually drawn.


Best regards,
Roy

 

[RoyJ]

Roy this last post of yours makes no sense at all.

I am sorry you did not understand it (post #367). I don't think I have anything more to say to you about this, sorry. I hope you get to hear our speakers someday.

Best regards,
Roy

 

[RoyJ]

I was fine with your statement until this part. And no, I'm not saying that different amps and speakers don't have different sounds - however, there can only be one right...

However, if you're saying that amps can impart anything other than "extra" sound (note I didn't say "better") with the exception of more power enabling better control over the transducers involved at the speaker - then I totally disagree.

One simply hears more musicianship and more clarity between the artists from an especially good amp. It is someone else's problem to figure out how to measure 'that', but people here (non-audiophiles) hear it all the time.

Speakers are definitely a series of compromises - on this fact TLS, Roy, and pretty much everyone else agrees. In an amplifier - there is no reason to not have a totally flat and completely time-coherent sound... as it is merely voltages.

Agreed, but know that it is current that matters to speakers, doing the dirty work in the voice coils, which we cannot measure directly. All we can do is look at the voltage and make educated guesses about what the currents are achieving, which is why education and experience both matter.

Best,
Roy

 

[GO-NAD!]

With all due respect, it seems this tells many here there is somehow a conspiracy afoot, moles everywhere... Yet, since these Owners are all saying similarly positive things, there might be technical reasons those might be true, which are indeed found on our site. And some of those I have endeavored to explain here.

By the way, since few here have apparently heard of us, search for "Green Mountain" on Audiogon and Audio Asylum, to see these same comments made by a whole lot of Owners over and over. As with any 'possibly good' product, this uniformity of opinion is about our only hope of finding the best gear via the internet, I think.

Best regards,
Roy

Well, I would think that after 380+ posts on this topic, there's nothing left for it, but to stage a head-to-head DBT with other well-regarded loudspeakers and let ears alone tell the tale.

With all due respect to owners, I don't put a whole lot of faith in their opinions - including my own. Why is that? Well, if you look at owner reviews of the Bose Wave radio, you would think that we should all take our piles of large complicated equipment to the dump! The Wave radio apparently does it all! Now, as a clock radio, I'm sure it's a wonderful piece of equipment, but to be able to replace a "conventional" audio system?

My point is, in isolation, pretty much any piece of audio equipment may sound wonderful (or we can convince ourselves) - until you set it beside something better. Then, shortcomings become apparent. IOW, sound quality is relative.

If, as TLS has stated (IIRCC), implementing time-coherence introduces other problems, this may become recognizable when directly compared to other speakers. If it appears that your designs are indeed superior, that will also become apparent.

I don't imagine that Jerry will be able to stage a proper DBT with some of his other speakers, but in the end, he might be able to give us at least an honest subjective comparison.

 

[Dr. Parthipan]

Also, the math for getting time-coherence out of piston drivers, while not having coverage and lobing issues is not known by most speaker designers, as it cannot be self taught and emerges only in grad school for physicists. And while I make every attempt on our site, I don't think the math and physics can really be communicated to the public.

Best regards,
Roy

No this attitude is not right Roy. Firstly why cant it be self taught? Secondly you keep speaking of the mathematics yet you have never presented any math evidence for the claims. There are mathematicians on this very site so do not be afraid to present it. This sounds condescending to claim that you have this special knowledge about time coherence which cannot be communicated to the public because it's too difficult. That's unacceptable.

Jerry himself is a computer expert I'm sure he understands some mathematics.

 

[RoyJ]

No this attitude is not right Roy. Firstly why cant it be self taught? Secondly you keep speaking of the mathematics yet you have never presented any math evidence for the claims. There are mathematicians on this very site so do not be afraid to present it. This sounds condescending to claim that you have this special knowledge about time coherence which cannot be communicated to the public because it's too difficult. That's unacceptable.

Jerry himself is a computer expert I'm sure he understands some mathematics.

Thanks for your thoughts.
Some of the math is four-dimensional calculus involving vector equations. The components of those equations come from almost areas of physics-- mechanics, electromagnetics, hyrodynamics, thermodynamics, optics and acoustics (similar 'basic' math) learned in just the first two years of university as a physics major, followed by the advanced courses. Plus the math itself- calculus, differential equations, multi-dimensional geometry, vector/matrix calculus.

One has to adapt the math to the physics involved, which means using it to understand concepts such as the radiation resistance of pistons. And one does not learn that math until grad school and even then, only the basic version that describe what to expect from a piston mounted flush into an infinite wall. Vastly different equations emerge when that is adapted into describing what comes from a 'naked piston', out in the room.

There are terms added to already-advanced equations that describe the non-linear viscosity and the non-linear pressure/density relationships in gas (air). The usual equations ignore these to make them more-easily solved.

There are other equations that show what to expect when trying to measure how cone-breakups and distortions arise and decay.

There are the non-linear absorption coefficients to deal with for any interior acoustic padding. Some acoustic materials are isotropic in their absorptions; others are not.

There are the very basic equations for a damped harmonic oscillator that attempt to be our guides on tuning the cabinet and port correctly, but the presence of the absorption materials inside modify those equations, and when the equations are re-formulated, they accurately predict the measurements when proper internal damping of the enclosure is achieved at each frequency (!).

So no, I cannot post the math here. I wish I could, and I do go over the subjects on our site, so anyone can see what courses are required.

It cannot be self taught to perhaps 99% of the population, in my experience, including when I was teaching while in grad school. I know it takes grad school to first learn the advanced math, the multi-dimensional calculus and differential equations, and then years after that to figure out how to adapt that 'all-purpose math' to real-world materials and to the problems specific to speakers and to acoustics. So I know how to make better measurements, and to help guide my ears.

And so all that math has to be put onto something physical, not just left on a blackboard. That comes out of applying it in all of the physics-major courses taught in undergrad and in graduate classes, and in physics lab courses, but never in just a math class.

Finally, all that math and physics is sometimes only a guide for further experiment and measuring. Coupled with psychoacoustics, of course.

Best,
Roy

 

[highfigh]

FYI- all of those math courses are taught to engineering students- at least, they were when I started college in '75. We have several engineers here- give it a shot. We, as a group, may not be as uneducated as you think. If the general population is any indication, some here may even be in the 'gifted' group.

 

[digicidal]

Thanks, and I would remind you that they are on my site, in great detail, including how the measurements were made with what signals.

OK - I've spent more than an hour going all over the place on your website. I've read long chronological lists of audio history, I've encountered numerous pictures - most of which were 'psychological equivalents' of the sound presented supposedly and uploaded by customers of yours as well as your own. I've seen guys on radio towers, wind surfing, etc...

I did find a really faded couple of pages about the Continuum 1's that has a FR chart - however it's so faded and small that I can't see anything of use on it at all... I can barely make out the db values and I have no hope of determining the scale at all. It does appear to be relatively flat with some early bass boost I think ~80Hz and rolls off at something that looks like maybe 15kHz but can't tell... then there's a gob of lines that look like off-axis plots on the same chart but 40db lower and extremely wide in the fluctuations.

Could you please provide a couple of links to these charts that I'm obviously too inept to find? Thanks.

Having the NRC make measurements would not change my sales. I have no technical need for the NRC or their equivalent, nor do my customers.

OK - then I guess I have no possibility of becoming your customer - since having something other than a owner-recommendation is a requirement of mine since I've had numerous recommendations for both KLH and Bose over the years... and since they're cheaper if that was all it took to get me to write a check I'd just get their speakers.

I invite anyone to have a detailed look at the independent measurements performed on my 13-year old retired design, the Continuum 1, on my site. Have a look at the room it was measured in, too!

I found those - reminded me of a photocopy of a photocopy that had been faxed to China and then faxed back here. Do you have a scan of just the chart at a high enough resolution to read any of the values?

I didn't find anything about the room except a small picture with about 5-6 different speakers and a chair in it. Is this what you're talking about, or am I reading the wrong thing (I'm hoping that's the case).

Check out our Eos model's measurements recently performed by the UK's most experienced reviewer, Keith Howard. I forgot the ones that Home Theater Magazine did on our first two-way, in 1999. I think those might be on our site for the retired Continuum 0.5. Done by the founding editor, and a drummer, who went on to work for Dolby Labs for several years.

Couldn't find anything on any Continuum 0.5 listed anywhere on your site. The retired section under Continuum only lists C-1,C-2,C-1.5,C-3 and under each of those only the C-1 has anything resembling a review. I was able to find something from SoundStage Network regarding your C-3s pair with Flying Mole monos at RMAF that was a flattering paragraph (congratulations on that!) however, there was nothing even remotely close to a measurement or analysis.

Our dB +/- is clearly stated on our site, and how we obtained that.

OK, on the one hand, yes they are but no, in most cases they are not adequately described - or more to the point: they are not described in an manner consistent with other speakers or even to each other necessarily.

Here's something I found for the C-3 off the spec PDF:

Response +/- 0.75dB from 40Hz to 21kHz, -3dB at 35Hz and
23kHz, from 2.5 to 6m, on Soundfield Converged axis, on firstarrival
tone bursts, across approx. 80dB dynamic window.

If you have measured +/- 0.75db response from 40-21k, the for the love of all that is music... why would you NOT want to publish the chart to prove that?!?

That's freakin' magical indeed - in fact, it's more than that...

Most of the specifications say things like

In-room, typically +/- 2dB from 50Hz to 20kHz

or something similar. I realize that we don't live in anechoic chambers, and it is helpful to know what kind of room gains may be expected of a speaker we're researching before we buy and/or audition them... but there is a reason why we use them. It is clear that you do not want your speakers compared directly to another speaker - or at least that's how I feel now that I've spent more than an hour reading through your site.

 

[digicidal]

With all due respect, it seems this tells many here there is somehow a conspiracy afoot, moles everywhere... Yet, since these Owners are all saying similarly positive things, there might be technical reasons those might be true, which are indeed found on our site. And some of those I have endeavored to explain here.

Not at all, Roy. You seem to have misjudged my response. I do not mean to say that I believe there "are moles everywhere" but simply that I confused what came across as "rabid fanboyism" in two out of about 20 posters in this thread. I think you seem to have done exactly the same thing as far as I'm concerned and confused me with the people accusing these two of being "GMA Moles" - I made no such accusation - I was simply responding to what I read as accusatory vitriol based in "golden eared" justifications... nothing more, nothing less.

By the way, since few here have apparently heard of us, search for "Green Mountain" on Audiogon and Audio Asylum, to see these same comments made by a whole lot of Owners over and over. As with any 'possibly good' product, this uniformity of opinion is about our only hope of finding the best gear via the internet, I think.

Best regards,
Roy

And that is exactly the problem - and the reason why I will always consider uniformity of opinion about anything subjective to be highly suspect. In anything there are always detractors - especially in music and music reproduction.

There are many on this very site that are fairly uniform in their praise of Paradigm's higher-end lines. However, that does not automatically mean that I would think they are great. There are other speakers that are very highly and universally well regarded that I've not cared for that much - just as there are some that have been denegrated in numerous threads that I quite enjoyed.

I quite enjoy my Polk RTi A1's for 2ch listening, I think they're amazing for the price (note the qualification - I don't think they're perfect). Other than a short "I actually like those speakers - perhaps you should hear them" or even a "yes the FR looks bad at first glance, but if you look at the 30deg off-axis response you see that tipped-up treble suddenly becomes ruler-flat" and leave it at that. Everyone is more than entitled to belittle those speakers - I don't care.

Just like I don't care how many people on other forums have 100's of threads about how bad Windows is... I like it, I've used *nix, MacOS, etc... it doesn't matter - but I don't feel the need to go making posts which amount to "well, that's because you're just too stupid to make it work correctly" because that's rude and doesn't help move everyone to a better place technologically.

 

[RoyJ]

FYI- all of those math courses are taught to engineering students- at least, they were when I started college in '75. We have several engineers here- give it a shot. We, as a group, may not be as uneducated as you think. If the general population is any indication, some here may even be in the 'gifted' group.

Hi highfigh.
Please understand that I cannot present my math for many reasons- the most important one being I haven't the time. I've said why but anyone is free to speculate. There was no slight intended.

Which is a true statement because I am not afraid to reveal where the math I adapted for my needs came from: it's already on our site, in the Library section under Speaker Design, with nothing 'about GMA' anywhere in it. And the latter half of it is still under construction, as they say.

Proceeding through that Library from the top down, each subject is presented by explaining why I (and others you'd find) think it is important to consider. I go on to describe how 'it' is best considered (that is, the best technical approach to 'it'). Anyone is free to jump off from there and perform their own research, as those are the real basics of design. Without knowing those intimately, then the math I could present makes no sense. Not even its symbols would be understood without lengthy explanation, and even then many of the interactions they have in those equations take a very long time to explain, but at least each came from considering those basics I do present. I don't think that information can be found on any other website, also written for anyone with a science or engineering mindset.

Do note the Library's section on Math and Physics lists the specific areas of study required in each, and again WHY. Then the 'best' physics textbooks that very many universities have used for a long time are listed for your convenience. Many of them can be read through without doing their math, which is not an education, but at least will be thought-provoking when applying those basics to what is being commonly communicated/marketed about audio and sound. Helps anyone to more quickly separate bunk from reality.

Thanks for your thoughts,
Roy

 

[digicidal]

...Without knowing those intimately, then the math I could present makes no sense. Not even its symbols would be understood without lengthy explanation, and even then many of the interactions they have in those equations take a very long time to explain, but at least each came from considering those basics I do present. I don't think that information can be found on any other website, also written for anyone with a science or engineering mindset.

Fair enough to simply say that you chose not to reveal your equations and specific research as a protection of your IP as a speaker designer-builder... To state the above is not only presumtive but egotistical and condescending.

It reminds me of a humorous quote attributable to Albert Einstein (I think - but I could be mistaken - been awhile):

If you are out to describe the truth, leave elegance to the clothier.

I guess I have to brush up on some solid state physics before I can adequately participate in this discussion further. Since I have neither the time nor the inclination to do so without a better compensation than further argument... I will simply have to resign from the discussion.

Good day to all - I'm going to go really enjoy some horrible speakers now.

 

[RoyJ]

OK - I've spent more than an hour going all over the place on your website.

Thanks.

I did find a really faded couple of pages about the Continuum 1's that has a FR chart - however it's so faded and small that I can't see anything of use on it at all...

Please click on the image itself when it comes on the screen.

OK - then I guess I have no possibility of becoming your customer - since having something other than a owner-recommendation is a requirement of mine since I've had numerous recommendations for both KLH and Bose over the years... and since they're cheaper if that was all it took to get me to write a check I'd just get their speakers.

OK.
However, I wrote only that numerous and similar Owner comments on any product I think ups the odds in finding something worth exploring further. I regret you did not get that.

Couldn't find anything on any Continuum 0.5 listed anywhere on your site.

Look under the bookshelf speaker section, since I said it was a two-way. You went only to the floorstanding-speaker section. Both sections were clearly marked. On the C-0.5 page, its Testimonials section is linked and active. I look forward to our site's completion, but to this day, other things still require my time.

OK, on the one hand, yes they are but no, in most cases they are not adequately described - or more to the point: they are not described in an manner consistent with other speakers or even to each other necessarily.

Right. Since I cannot continue to go on with you or anyone else about this, please read the specs, and you'll see HOW they were determined. So then THINK about that, and if you don't know what that test means, please refer to that Letter I wrote to sixmoons concerning Measurements.

Here's something I found for the C-3 off the spec PDF:

If you have measured +/- 0.75db response from 40-21k, the for the love of all that is music... why would you NOT want to publish the chart to prove that?!?

That's freakin' magical indeed - in fact, it's more than that...

Most of the specifications say things like or something similar. I realize that we don't live in anechoic chambers, and it is helpful to know what kind of room gains may be expected of a speaker we're researching before we buy and/or audition them... but there is a reason why we use them. It is clear that you do not want your speakers compared directly to another speaker - or at least that's how I feel now that I've spent more than an hour reading through your site.

Sorry to know you feel that way. One last time: There is no single FR graph to be run that is accurate in what we hear from a speaker playing music in a room.

However, the closest approach are the test Andrew Marshall developed, and employed in our Continuum 1 review. He definitely measures unlike any other magazine and the NRC, but he knows his tests reflect the tone-balance heard in real rooms on music, and I would agree. He does not disagree with the NRC, but only feels they are not accurate enough.

He also goes to the trouble in each issue to explain exactly WHY he uses these tests and HOW each is conducted, much like I do. And you may choose to dismiss his qualifications too.

My +/- numbers on our specs pages are the result of splicing together many perfectly-valid tests, ones that have been known for decades to circumvent room issues.

If there was a single FR-curve that could be accurately run, then all you would learn from it is the speaker's tone balance and dispersion, assuming the speaker did not have a 'spiky' curve, which comes from resonances and noises that should have been addressed. You would have no idea of its response to dynamic changes (which are in music), nor how the distortions not revealed by that FR graph sound.

And by the way, perhaps I could have explained that "+/- 2dB in-room" spec better. It is usually what would be read from that speaker in a room without serious resonances or echos/reflections, on pink noise via a third-octave analyzer, at the listening position, with a carpet on the floor and the listening chair moved out of the way. Which anyone can do.

Best regards,
Roy

 

[RoyJ]

Not at all, Roy. You seem to have misjudged my response. I do not mean to say that I believe there "are moles everywhere" but simply that I confused what came across as "rabid fanboyism" in two out of about 20 posters in this thread. I think you seem to have done exactly the same thing as far as I'm concerned and confused me with the people accusing these two of being "GMA Moles" - I made no such accusation - I was simply responding to what I read as accusatory vitriol based in "golden eared" justifications... nothing more, nothing less.


And that is exactly the problem - and the reason why I will always consider uniformity of opinion about anything subjective to be highly suspect. In anything there are always detractors - especially in music and music reproduction.

Then how in the world are you to find good gear? By looking for the most detractors? I fail to see your logic.

There are many on this very site that are fairly uniform in their praise of Paradigm's higher-end lines. However, that does not automatically mean that I would think they are great.

So, be specific. What does their praise make you think?

I quite enjoy my Polk RTi A1's for 2ch listening, I think they're amazing for the price (note the qualification - I don't think they're perfect).

Of course no speaker is perfect.
And using your logic, why are you even telling anyone? Unless you also have something negative to report. Oh... you did:

continuation of the above...
Other than a short "I actually like those speakers - perhaps you should hear them" or even a "yes the FR looks bad at first glance, but if you look at the 30deg off-axis response you see that tipped-up treble suddenly becomes ruler-flat" and leave it at that. Everyone is more than entitled to belittle those speakers - I don't care.

OK. So, we now know you have spent some time 'investigating'. Good. When you can write about WHY that treble changes, then you'll be doing everyone a service.

Just like I don't care how many people on other forums have 100's of threads about how bad Windows is... I like it, I've used *nix, MacOS, etc... it doesn't matter - but I don't feel the need to go making posts which amount to "well, that's because you're just too stupid to make it work correctly" because that's rude and doesn't help move everyone to a better place technologically.

You seem to be implying I think people are too stupid to understand my math or my designs. If so, then that means my non-technical explanations on our site serve some purpose other than to introduce the concepts. Backed up by specific technical explanations in each speakers' Design Concepts pages. And then the origins of those explanations are given in my section on speaker design.

But perhaps the section with the history/timeline of speaker-related technology is there just because our server wasn't full enough. Too bad you did not learn anything about speakers-in-general from your visit, since that's why all that additional information is there. For you and anyone, except for me.

I do think there are far too many speaker designers that lack advanced math skills and knowledge of more than the basic Physics taught to non-majors and no more than basic Filter Theory. Doesn't have to mean they are stupid. Just not educated enough, for sure.

I've posted all I can think of to you that's appropriate to this site, so good luck and take care!

Best regards,
Roy

 

[RoyJ]

Originally Posted by RoyJ
...Without knowing those intimately, then the math I could present makes no sense. Not even its symbols would be understood without lengthy explanation, and even then many of the interactions they have in those equations take a very long time to explain, but at least each came from considering those basics I do present. I don't think that information can be found on any other website, also written for anyone with a science or engineering mindset.​

Fair enough to simply say that you chose not to reveal your equations and specific research as a protection of your IP as a speaker designer-builder... To state the above is not only presumtive but egotistical and condescending.

Again, good luck. Especially with such an attitude to someone who was open and honest about the scope of the issues involved. I GAVE you their details and also WHY I thought they were important, since we all know "SPEAKERS DON'T MEASURE LIKE THEY SOUND!"
And if you didn't go through them, I know that's work but there's no way around that, as with any education. Can't be handed to you on a plate since my research, my math can't be presented in that manner, much as you might like.

Best,
Roy

 

[highfigh]

Hi highfigh.
Please understand that I cannot present my math for many reasons- the most important one being I haven't the time. I've said why but anyone is free to speculate. There was no slight intended.

Proceeding through that Library from the top down, each subject is presented by explaining why I (and others you'd find) think it is important to consider. I go on to describe how 'it' is best considered (that is, the best technical approach to 'it'). Anyone is free to jump off from there and perform their own research, as those are the real basics of design. Without knowing those intimately, then the math I could present makes no sense. Not even its symbols would be understood without lengthy explanation, and even then many of the interactions they have in those equations take a very long time to explain, but at least each came from considering those basics I do present. I don't think that information can be found on any other website, also written for anyone with a science or engineering mindset.

Do note the Library's section on Math and Physics lists the specific areas of study required in each, and again WHY. Then the 'best' physics textbooks that very many universities have used for a long time are listed for your convenience. Many of them can be read through without doing their math, which is not an education, but at least will be thought-provoking when applying those basics to what is being commonly communicated/marketed about audio and sound. Helps anyone to more quickly separate bunk from reality.

Thanks for your thoughts,
Roy

I'll take a look- thanks for the heads up on where you posted this info.

 

[Dr. Parthipan]

Hi highfigh.
Please understand that I cannot present my math for many reasons- the most important one being I haven't the time. I've said why but anyone is free to speculate. There was no slight intended.

Which is a true statement because I am not afraid to reveal where the math I adapted for my needs came from: it's already on our site, in the Library section under Speaker Design, with nothing 'about GMA' anywhere in it. And the latter half of it is still under construction, as they say.

Proceeding through that Library from the top down, each subject is presented by explaining why I (and others you'd find) think it is important to consider. I go on to describe how 'it' is best considered (that is, the best technical approach to 'it'). Anyone is free to jump off from there and perform their own research, as those are the real basics of design. Without knowing those intimately, then the math I could present makes no sense. Not even its symbols would be understood without lengthy explanation, and even then many of the interactions they have in those equations take a very long time to explain,

My question is how can you say you have no time when you have already spent a very long time and effort in writing responses on here and on your own website?

Can you understand why I feel cheated and why this seems evasive?
On one hand you are a proponent of time coherence and go to great length using words and pictures to give evidence but when asked to provide the mathematical details, you are not committed to doing so. Ultimately we cannot discuss time coherence properly without those details.

 

[Rickster71]

396 posts in a thread about a pair of used speakers that aren't manufactured anymore. To what end?

And people complained about political threads.

 

[MinusTheBear]

396 posts in a thread about a pair of used speakers that aren't manufactured anymore. To what end?

And people complained about political threads.

Partially, but what this thread has really become is a debate on loudspeaker design philosophy/engineering. Quite fitting for an audio forum, though I'm sure it will suffer similar fate of a political thread.

 

[davidtwotrees]

I think Roy J has been very forthcoming in spending a large amount of his time in this matter and I for one thank him. Many posters have seemed argumentitive and accusatory. I wouldn't have stuck around for such brag and abuse.
I have also found that I am not a total objectivist, whose proponents here seem totally absorbed in measurements. Music for me is personal. A good pair of speakers makes the music come alive for me and makes me feel good.
Do I want my rig and my speakers to be well made and something for which I can be proud of? You bet. Will I wring my hands wondering if my off axis response doesn't measure up? Nope.
To me, worrying endlessly about numbers and measurements is not being objective, but obsessive.
Roy sounds to me like he hopes to make the music come alive for his customers. I don't think he is snake oil. Thanks for taking time from your day to share your thoughts with us, Ray.

 

[JerryLove]

FYI- all of those math courses are taught to engineering students- at least, they were when I started college in '75. We have several engineers here- give it a shot. We, as a group, may not be as uneducated as you think. If the general population is any indication, some here may even be in the 'gifted' group.

I know I had to take calc / analytic geometry two and calc-based physics before I could complete my 2-year. I'm pretty rusty, and I know there are those far more knowledgeable than myself here, but I do actually have a pretty solid background in math (my minor from college). (Ive done some side-work in chaos-oriented math when that was a passion, but in the end that's typically algebra).