Hello all,
I apologize for this delayed response. Let me touch on a few issues.
Jerry, as with any Owner, you are welcome to contact me by phone. The magnitude of your peak in the midrange is an artifact, and I'd be happy to discuss what might be going on with the room or setup. Email will not work for this, sorry.
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Green Mountain is a small company, but not tiny. Also we are old, not new. For more than fifteen years we have had consistently wonderful reviews in all of the major US, Canada, and UK magazines, and by Soundstage and sixmoons on the internet. They were performed by the editor or a chief reviewer, many of whom are talented musicians, and most gave us their highest award.
Most reviews are on our website, along with Owner's comments. The reviewers' summations are always similar, concerning clarity and realism, and Owner comments are also consistent for many years now. This says a lot about what we are up to, and why we've been around for so long. People do hear the difference, and appreciate what it does for their musical enjoyment and involvement.
We receive many requests for reviews, and look forward to sending out more product.
However, by casting our enclosures, we limit our rate of production, and thus our distribution and reviews, for which I do not apologize. Quality is very important to us, something much easier to control in craftsman-workshop spaces than on a large factory floor (visitors are welcome). And I get to speak with most every Owner, which is great! I always appreciate their feedback and continue to learn from their experiences and their music.
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Unless I have mis-read some of the thrust of this thread, some believe we do not publish measurements. We do indeed, and do so more thoroughly than any competitor, on each speaker's Specs webpage. We use specialized signals for some tests, and list those too. If we do not post a measurement or graph someone deems important, sorry. The measurements I choose to publish are the most meaningful ones to share, in my experience. I also include measuring distances, SPL, and room-size where appropriate. One magazine that backed up many of our measurements was Audio Ideas Guide,
here and
here. On the second page, have a look at the room in which the measurements were performed. Nothing special, but still we yielded the good numbers I expected.
TLSGuy, regarding measurements, please know that those two Quad graphs show only what is happening from 1kHz on up. While slightly misleading, it is not an omission on their part, but a limitation of that style of test.
If one were to use pulses/square waves ten times wider than theirs, you would then be examining everything from 100Hz on up, not just from 1kHz on up. But one problem with that wider signal is that it destroys any home loudspeaker before being perceived as being 'as loud as music' at just eight feet away. Another problem is a room's reflections become significant at eight feet away, for tones below 1kHz, obscuring what is being measured. So Quad did the sensible thing by limiting their published tests to above 1kHz, and perhaps acknowledged that somewhere for you.
As a side note, since room reflections and standing waves interfere with most tests, one could place the speaker on a high post outdoors. But then all tones below ~300Hz will be far weaker than inside a room. Therefore, outdoors, we again can only learn about a limited range of tones.
One last aside is you are somewhat mistaken about a speaker's driver-separation being a problem for achieving time-coherence, and it is easiest to explain why by phone if you were to call sometime, thanks.
After years of research, which grew out of that performed by those before me, and with the aid of some very high-powered physics, and years of location recording, I developed many specialized methods to test for lower distortion, less resonance, and better time-coherence in most every frequency range.
While I cannot reveal all of those methods, I do give many of their results, their numbers, on our website. I also describe, with almost no math, the limitations of each measurement technique, each test signal, in that Letter to sixmoons, the link for which I posted, perhaps in another GMA thread.
An article I wrote for Audio Ideas Guide covers the sources of phase shifts in speakers. It is very technical, the only way to present the topic, and I am grateful to Andrew Marshall for publishing it back in 1997. The math in it is understood by anyone with a four-year degree in physics or electrical engineering, but not in computer science unfortunately. Link to it on our website:
Audio Ideas Guide article
I know this is good information for those truly interested in the fundamentals of speaker design, and I'm proud to make it available.
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For those who think our website is written in a pandering?? or less-than-useful manner, know that the bulk of it was written for the typical purchaser of our speakers, who bought them because of what was heard. These are non-technical music lovers who just want to know how we produce this clarity, so our website is not written for the technical junkie... until one looks at the design concept paper for each model. Then feel free to tear me apart if you disagree with what is in those.
Yet as one explores our site, I do describe in great detail for the technical folks what is going on in each area of my speakers' designs. Here is the main page for that:
Time-and-phase-coherent Design. I am not sure what any criticism someone would have of the technical information presented there. They are not claims but facts, and feel free to ask me questions if I did not make myself clear enough there.
I hope this helps, and I look forward to answering specific questions, thanks!
Jerry-- call me.
Best regards,
Roy Johnson
Designer
Green Mountain Audio
http://www.greenmountainaudio.com
