Right. Although most designers aim for a flattish on-axis performance, it is not guaranteed. So, as far as on- and off-axis performances are concerned, there is no certain correlation. Listening or measuring at a distance within the near field is not a reliable indicator of anything.
Why, Don? Does the Dr. have poseable maple or myrtlewood cable lifters with 4 inch human fingernails?As for "poseable mannequin hand cable lifters", and "wickedly posed" at that, well, no comment in an open forum. It does increase my desire to visit Dr. Toole's listening room at some point.
No argument that measurements matter, and more measurements matter more. I am guessing you haven't read my book. It is all there. Polar plots are useful, but collections of off-axis measurements are arguably more informative.
Torii, you gotta read my book. It explains that we use mono tests because listeners were more sensitive to loudspeaker flaws than they were in stereo, not because it is easier. When we did - and we really did - compare stereo vs. mono results the winners were the same. There is no magic to listening in stereo, except that it is more entertaining - not more revealing of loudspeaker problems. When extended to multichannel listening, we are even less fussy. As far as "stereo soundstage and imaging" are concerned the dominant factor is the recording itself. There is more to it, and it is all discussed at length in the book.a key question that alys confuses me is tests of speakers in mono 1 at a time vs the stereo sound...when I run rew on my speakers I see why mono might be ok as every individual speaker measures different...but when I run rew in stereo the results are totally different. I heard Dr Toole used mono for tests cause its easiest for science exam. but nobody listens in mono that I know...and stereo mesurements so different....anyways sure its in the book.
Dear Dr. Toole, although one wouldn't need a double blind test to tell that those Yammy NS1000s are indeed bright sounding (again, just how much is largely dependent on the kind of amplification used), the big 11.8in paper woofer crosses over to the beryllium midrange dome @ 500Hz (not 1kHz), which in turn extends its operation range up to 6kHz, allowing a very soft transition to the beryllium tweeter. Thus, being it a dome and a dome of such rigidity and lightness, one should have expected a very good/even sound dispersion characteristics and, hence, a very good off-axis frequency response in that range from a relatively small (only 3.5in) midrange dome.At the time, in the 1970s, the Yamaha NS1000M was a significant technical achievement, albeit flawed. The designer of it, and the more famous (infamous?) NS10M visited me at the NRCC and we had a fruitful exchange. Some anechoic measurements of the NS1000 are shown in Figure 18.3(e) in my book. The engineering was superb, but the target performance was wrong - a flat sound power. This was influenced by the east coast (AR) philosophy of the time, as was the driver configuration (a large woofer extending to about 1 kHz before transitioning to a much smaller midrange). As a result there was some midrange coloration and aiming for flat sound power inevitably created a tendency to sound too bright (which many erroneously attributed to the metal diaphragms). A bit of tone control tilting made a big difference. It had very low distortion which the designer modestly attributed to "good engineering" in the motors.
That said, the NS1000M was a good performer at the time, something which cannot be said of its smaller brother the NS10M. As shown in Figures 12.10 and 12.11 the choice of a flat sound power target, which they achieved, meant that the on-axis performance was dreadful.
Google it, sounds like some have tried it and there are problems with itDear Dr. Toole, although one wouldn't need a double blind test to tell that those Yammy NS1000s are indeed bright sounding (again, just how much is largely dependent on the kind of amplification used), the big 11.8in paper woofer crosses over to the beryllium midrange dome @ 500Hz (not 1kHz), which in turn extends its operation range up to 6kHz, allowing a very soft transition to the beryllium tweeter. Thus, being it a dome and a dome of such rigidity and lightness, one should have expected a very good/even sound dispersion characteristics and, hence, a very good off-axis frequency response in that range for a relatively small (only 3.5in) midrange dome.
What exactly made the NS1000 not as flawed as the NS10M (?), since they both had the same target performance - a flat sound power, as you say. Beryllium anyone?!
I'm sure that if Kevin Voecks and Mark Glazer had that beryllium midrange dome at their disposal, theirs and their team's enginnering effort would be greatly reduced. I guess one had to be an awful engineer to mess up a speaker design having such good drivers.
BTW, now that I'm on this, I must say I have the answer to a better Salon design, being it a cost no object loudspeaker... The Salon3 should have carbonfiber drivers instead of metal ones!!! In fact, I don't understand why isn't such a readily available material nowadays, used for loudspeaker drivers manufacturing. Carbonfiber is getting increasingly cheaper, even my sports salo(o)n have it all over the place! Very stiff, very light and easily modulated intrinsic damping characteristics. No metal, can touch it, not even beryllium!
Harman must now pay me for such brilliant idea!
But, I'm talking about something without paper, only pure carbonfiber!The high-compliance, low-compression drivers, custom-built to Sonus Faber's specs by Scan-Speak, consist of two extra-rigid, lightweight, 8" paper/carbon-fiber cone woofers, with the cone material "hand-thrown" to randomize the fibers (and break up resonances) and individually damped; a high-compliance, 7" multiple-coated paper/carbon-fiber midrange cone with a hyperbolic titanium phase plug (to break up high-frequency beaming); and a 28mm, non-ferrofluid, multiple coated soft-dome tweeter protected by a grate
And, an old vid of its manufacturing process by BMW:When impregnated with a plastic resin and baked it forms carbon-fiber-reinforced polymer (often referred to as carbon fiber) which has a very high strength-to-weight ratio, and is extremely rigid although somewhat brittle.
What kind of room correction do you have at your disposal? I don't like correcting above the schroeder frequency but if you have one that lets you limit the range you could try it. I personally use parametric EQ and only use filters up to 200Hz.Oh no no no....I hate you terrible room.
I was correct in what I was hearing. Lots of resonance in the ultra low frequencies followed by a steep drop at 40hz, another around 65, and another just above 80.
I tried the low frequency adjustment on the Salon 2; but, that seems to affect all frequencies below 200hz fairly evenly so it doesn't resolve anything here.
Definitely interested in thoughts. I've tried adjusting the seating position and speaker placement in increments; but, my room doesn't have a ton of flexibility. I will say that moving the speaker forward about a foot or backward foot led to no real change. In fact, it was a bit worse.
I'm thinking that if I can tame the resonance below 40hz, it might help bring everything else in line.
What kind of room correction do you have at your disposal? I don't like correcting above the schroeder frequency but if you have one that lets you limit the range you could try it. I personally use parametric EQ and only use filters up to 200Hz.
I'm going to try more placement adjustments today. Then room treatment. Any form of EQ will be last. It's not that I'm anti-EQ; it's simply that EQ has some pretty strong limitations and I'm sure to be better off working on the physical space before manipulating frequency response.Might need some room treatment too, kill the corners.