Heh I think I have found a little trick that helps with blanking out the room. I haven't tested it very much though but I want to change my listening environment someday and use it.
Basically the idea of limiting early reflections and ignoring late ones works with visuals as well. If you have your LCD monitor on a desk right now the chances of this working are very small because of all of the early reflections off of the desktop - this is the exact same problem that is present with most mixing consoles and sound. But if you get rid of your desk and wall mount an LCD so that all you see is the direct light. You effectively blank out the room and all that is left is the LCD. This seems to distract you enough to help with sound as well - although early reflections of the sound must be minimized of course.
Basically the idea of limiting early reflections and ignoring late ones works with visuals as well. If you have your LCD monitor on a desk right now the chances of this working are very small because of all of the early reflections off of the desktop - this is the exact same problem that is present with most mixing consoles and sound. But if you get rid of your desk and wall mount an LCD so that all you see is the direct light. You effectively blank out the room and all that is left is the LCD. This seems to distract you enough to help with sound as well - although early reflections of the sound must be minimized of course.
This is exactly why DVD concert recording will soon come of age. A 2 channel recording with DSP created ambiance for the surrounds is fine. If they can get 5.1 right it will be even better. Certainly many of the rock concert DVDs provide a far superior experience that 2 channle audio alone.
For large format music I agree, but there are studio recordings - quite common actually - for which there is a very real image and precise instrument locations and "imaging" for these recordings in paramount. But for classic music playback where a "auditorium" sound is desired "image" is not a criteria, its all about spaciousness. This is were Floyd Toole and I part ways. Floyd is interested in the large venue sound reproduction and never discusses or listens to the kinds of recordings that I am talking about. (Maybe not never, but its NOT a high priority with him.)
I think with recording techniques you can have both diffuse (ie random phase or reverb based) or pin point imaging. The wet sound is a hard thing to deal with since I think in real life your brain tends to want to put all the pieces back together into an intelligible signal. And well on recordings the wetness is just there in your face and doesn't seem to go back together - maybe a lack of proper cues. I guess my point is that I think this is more to do with the recording and mixing end than the speakers exactly.
Unfortunately this is not correct. Of the three only a monopole will have reflection spectra that are uniform. The other two will always exhibit a changing directivity with frequency. And you left off the most important: CD waveguides, which truely are the only way that HF reflections can be spectrally uniform (excluding an omni since a HF omni is almost impossible to do.)
Yeah his ideas do seem to be more theoretical than realized beyond a certain HF as far as I can tell. I was more repeating his opinion not mine. Basically my way of shooting a hole in his hypothesis is to include CD.
I think that there were several confounding problems. First was a limited selection of source material, all played at "average" levels, there was no real dynamic pieces. Second was the test did not have a very good resolving power in terms of differentiating the speakers. The point that I made at the time was that no one syuspected that the Summa was a waveguide and not a direct radiating tweeter even when play right next to the Gradient. Everyone noted the JBL coloration and down graded it as such. And finally that was a phase-one prototype of the Summa that was not even close to what I make now. I had not even decided on the drivers to use, which was a major reason for the test. Those speakers are the exact same enclosures that I use in my own system today, but they have been completely redesigned and rebuilt about three times.
The Orion's indirect sound field should be pretty uniform because of the rear mounted driver. Probably more uniform than the indirect sound field of the Summa.
Best, Markus
Markus
I don't see how you can believe that. No piston source has a uniform directivity/power response, forward facing or not. Its going to change with frequency. Above about 1 kHz the Summa does not. If you are talking about below 1 kHz, that would be different, but thats not very important compared to the HF stuff.
*cough* perfectionism *cough* Haha just sayin'. Does it have to be exactly uniform? You could also argue that the reflective source itself will not be uniform and will most likely not be flat but does it matter?
I don't think that you quite grasp the significance of what I am talking about. The collapse in directivity of a piston source IS NOT an insignificant thing, its a major effect. This kind of misunderstanding comes from not looking at much polar data, because if you did, you would recognize how the piston effect dominates the directivity of any system that uses pistons. Perfectionism! I think not, more like a serious problem with direct radiators IMO.
The audio world needs to start actually looking at directivity - only then will people come to realize how significant the differences are between good and bad and how the axial response is a vitually useless measurement by comparison.
"Perfectionism" - no, its called "good engineering" and virtually 95% of the loudspeaker systems out there today don't get it right, or even close.
When I designed the original NaO (about the same time the Orion was designed) the prototype was without a rear tweeter. The sound field was not well balanced. It sounded dull. This was more evident on some types of source material than others, but it was very apparent. As result, I added a rear tweeter right from the get go. This was at the time when Linkwitz was still holding fast to the position that the rear tweeter was not required.
My measurements showed the obvious problems: First, at and just above the x-o point an unbaffled tweeter fairly omni-directional. The baffle restricts most of the higher frequency radiation to the front hemisphere. At the same time the midrange driver is both in a dipole format and beginning to become directional. Thus at the crossover point there is a sharp transition form "directional dipole" to baffled omni source. The result is a ballooning of the response at 90 degrees off axis form a dipole null to almost equal to the on axis response. Additionally, due to the baffle, the tweeter does not radiate much to the rear. However, the spacious usually attributed to a dipole system is largely dependent on the sound reflected off the wall behind the speaker. Without a rear tweeter this reflected sound is void of high frequency content and is not well balanced. Adding a rear tweeter serves to bring spectral balance back to this reflected sound and removed the otherwise dull sound I found without it. Additionally, while not truly a dipole due to the frequency and separation between front and rear tweeter, adding a rear tweeter does help reduce the ballooning of the high frequency response just above the crossover point. Linkwitz stuck to the front tweeter only until he designed his Pluto omni speaker from which he realized that the rear tweeter would improve the Orion.
The thing is, while the rear tweeter does bring balance to the spectra of reflected sound, the front and rear tweeter act as uncorrelated sources over much of their operating range and the radiated power just above the crossover point actually is considerably more than a dipole source. That is, it is not CD.
Wow John, a great disertation on exactly what I have been saying, thanks. Before you know it you'll be using waveguides and - with a license - stuffing them with foam. 🙂
PS. I don't get it, I'm in China so its not an abnormal time for me, but for you its God early to be on the Forums.
PS. I don't get it, I'm in China so its not an abnormal time for me, but for you its God early to be on the Forums.
Well no doubt I just mean he was trying to answer a very specific question and it seems like he is working backwards from the results. Basically why do these two speakers seem to operate independent of the room. I think with all things comes a point of diminishing returns on your investments - a point where things will benchmark better sure but are you really getting any more effect out of them?
I'm an east coaster. It was 7:30 when I posted. I'm usually up by 6 AM. When my eyes open I am alert! No coffee needed. After lunch I sleep. Been power napping since high school. Good again by 3PM. By 10 or 11 PM > 😴
You were generally talking about reflection spectra of monopole, dipole, cardioid and waveguide. That means looking at the sound power from 20Hz-20kHz. All of their isobar diagrams will look like christmas trees - thick, thin and unproportional trees. None of them has a power response curve that is horizontally flat.
The big question is: which contour is optimal? None? The contour the mixing/mastering engineer's loudspeaker had?
John, do you have 360° data of your NaO?
Best, Markus
Whose fault was that?🙂
First, let me be clear. I share your preference for high dynamic capability, realizable only with "pro" type transducers, perhaps so that the "liveness" of the sound is not loss due to compression effects. I use them myself.
However, I have also attended such group listening sessions and have come to realize that very few share our needs, hence the material and levels that were agreed upon at your test. No statistical data, but I would guess that for the majority of "audiophiles", the dynamic capabilities of the Orion/Revolution type loudspeaker is sufficient and does not diminish the listening experience.
I've seen you mention this before. Is this what a "direct radiator" looks like?
IIRC, you state that above 10k doesn't matter. A slight bump at 8k?😉
Then perhaps it's time for another round of testing, with the Orions thrown in?
Let me know when 😉.
cheers,
AJ
p.s. a link to the full test the above measurements were drawn from, including some interesting in room FR (similar to a different reviewers findings)
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