If you have a good understanding of the limitations of any microphone, relative to how our stereo ear-brain mechanism works, you realize that "real" is actually not quite an option. Anything you do will only be so correct. It's like you're handed a painting that's mostly done, and your job is to turn it into something great. A fun challenge in my mind.I actually don't think people are looking for a more "real" experience with their stereos. I think people want an enhanced experience. Why would we want "real" when better can be had at the same cost and it's available anytime we want it? Most women look better enhanced as well.
Dan
Hum, it's apparent you are a musician(that's a good thing BTW). Check out my recording in my signature when you have a chance. Not the best horses in the race, but that's who I am(just a running son of a gun).
Anyway, I mentioned your point(but stated a little different of course) earlier in the thread. That's why playback, whatever is chosen(stereo as of now and likely a long time to come), needs to be standardized. Otherwise the intent of the artist(s) is lost. If that's important to the end user. I know it makes me crazy when I make a recording and play it back through a friend's system that took no care in its design. I need to learn more about the recording end of this gig for sure, but I can tell you recording has made me think about the playback end more seriously.
An ambiophonic system would work for one listener, but so does binaural and headphone playback. Ambiophonic might well be better d/t HRTF issues. If it excludes others, I'm not so sure it could ever be the standard. Humans for the most part are social still.
Standardization would still point to narrow pattern so that early spatial impressions could be removed from the equation yet the reverb remain intact. At least that's how I see it now though I use more typical speakers and love it.
Dan
You are referring to three statements by markus76 that you quoted in post #843. He says his speakers are set up like Gedlee's and he does not hear much spaciousness. Gedlee says he is listening to a his own setup and he hears spaciousness.
I think I can fairly say that gedlee's claim is subjectively disputed by markus76. All three of the markus76 quotes refer to his subjective listening impressions. Subjective.
Sure, but the standard speaker which Toole works with has directivity around 10dB in the high frequencies, which is similar or even more directivity than CD horns.
Hi graaf, do you have a personal investment in Stereolith® speakers? Or is it a case of you heard a pair and liked them a lot but did not buy them?... isn't it Ted Jordan's stereolith-like setup, not far from Elias' and also mine?
Is "yes, but" a good enough answer? Yes, but having massively enhanced bass or treble seems wrong, and having 'empty bathroom' reverberation seems wrong. Yes, but when someone plays piano in your room do you wish for sound enhancements? Maybe a speaker mounted on each side of the piano pushing out some extra width? ...or with a bit of delay for extra 'openness'?
Hi David, I'm right with you on all the above.
As you said, Toole is working generally with standard cone-dome speakers in boxes. Their dispersion generally starts at 360 degrees in the bass and, smoothly or not, works its way to about 60 degrees in the top octave. When he refers to wide dispersion he is not referring to omni, he means the speaker is free from beaming or cabinet interference effects due to cone drivers running too high in frequency, domes that beam and breakup excessively, crossovers that allow severe vertical lobing, and cabinets that diffract and reflect sound such that it interferes with the beamwidth of the drivers. And when he refers to narrow dispersion he is not referring to a CD horn or dipole, he means a cone-dome box speaker that exhibits some of the above issues.
Hence I see no need to defend dipoles or CD horns or to argue with Toole over his findings. I do see a need to use speakers with smooth dispersion that varies little or at least smoothly.
By restricting himself largely to standard speakers, Toole accepts their overall directivity increase from bass to treble, and suggests their design and application should be done in a way that 'manages' that directivity in a positive way. Here at diyaudio we have more freedom and can look at designing the beamwidth 'from the bottom up'. I see modern CD horns as a way to get even better directivity in the top end because they can be effectively constant directivity and can even be wider than a typical dome tweeter in the very high end. This is an opportunity. And Wayne Parham discussed a way to get more consistent and less variation in directivity in the low and mids. Like David I think the issue is moot below about 250Hz, but we can aim for 'better control by design' through the midrange too. Combined with careful control of the mid-hi crossover region, we hobbyists can consider the possibility of near-constant directivity over large ranges of frequency. For some this brings us back to dipoles and omnis, but they have measurement issues as David says above, and we don't have to go that way to get CD any more.
So you think Elias with his "two tweeter localization feature" already took the next evolutionary step? Looks like stereo soon comes to an end
As subjective as Earl's initial claim. He also said that his definition of spaciousness doesn't include early spatial impressions. Mine does, so does Toole's:
"Spaciousness or spatial impression can be separated into two
components:
- Image size and position: Strong refl ections have the ability to
shift the apparent position of a source in the direction of the
refl ection and/or to make the source appear larger. In live
classical performances, this is called ASW (apparent source
width), and audiences like it. In sound reproduction, there is
evidence that the tendency continues.
- Envelopment and the sense of space: Also called listener
envelopment (LEV), this is the impression of being in a specifi c
acoustical space. It is perhaps the single most important
perceived element distinguishing truly good concert halls. In
music recordings and movies, it is arguably the greatest
improvement contributed by multichannel audio."
Good remark markus. I was not thinking of these Elias particularities, but right now, I have done the stupid experience :
do two dome tweeters high passed at 1500 Hz and angled towards me make me describe a centered phantom image with a pink noise signal? Of course, all this without turning the head and with control of the Fr.
I'm afraid that no. These tweeters are really perceived as two individual sources, no hesitation. A panning R/L is not probant at all, almost a switch on-off.
Same conditions with 4" : when full range, there is a phantom image...but it's like if the Hf part of the spectrum comes from two sources, the speakers. Confirmation when adding a low pass 48 dB : there is a strong phantom till 1200/1500 Hz, after it explodes in two sources. Panning is much better.
Third iteration this time with the tweeters of my usual speakers : back to back side firing unit in the center of the room, with a screen that works like the famous pillow. This time, the phantom is perfectly centered for any high pass between 400 and 10000 Hz. Passed 10000, the source becomes dual and localized to the side walls. I have to say also that a R/L panning is perfectly smooth and progressive.
Very basic experience, anybody can do it, we are not mutants, stereo is alive and well.
do two dome tweeters high passed at 1500 Hz and angled towards me make me describe a centered phantom image with a pink noise signal? Of course, all this without turning the head and with control of the Fr.
I'm afraid that no. These tweeters are really perceived as two individual sources, no hesitation. A panning R/L is not probant at all, almost a switch on-off.
Same conditions with 4" : when full range, there is a phantom image...but it's like if the Hf part of the spectrum comes from two sources, the speakers. Confirmation when adding a low pass 48 dB : there is a strong phantom till 1200/1500 Hz, after it explodes in two sources. Panning is much better.
Third iteration this time with the tweeters of my usual speakers : back to back side firing unit in the center of the room, with a screen that works like the famous pillow. This time, the phantom is perfectly centered for any high pass between 400 and 10000 Hz. Passed 10000, the source becomes dual and localized to the side walls. I have to say also that a R/L panning is perfectly smooth and progressive.
Very basic experience, anybody can do it, we are not mutants, stereo is alive and well.
I responded to 851 in 858.
I meant the part about using the ratings of the ESL63 as prove that higher directivity is a bad thing. You didn't really go into that. However, you did in your latest post. I guess we're on the same page now
.This makes sense. Blocking early reflections probably adequately simulates the effect of listening to high directivity speakers. When people come to listen to my speakers, they all comment on the dryness of the sound. Especially in comparison to the 'juicy sound' of the full-range dipoles I previously had, the sound is very much drier. Some like it, some don't. It indeed sounds artificial. For me it's mainly a disadvantage, but it's probably the price you have to pay for superior cleanness, lack of coloration, better imaging and effortless dynamics. This brings me to another point: I feel under most conditions the sense of dynamics has more to do with directivity than power handling. Even small bookshelf speakers sound a lot more dynamic when listened to outside, although they are struggling a lot more to generate a given sound level than they would in a room.
Maybe even better is (I believe earlier in this thread already suggested by Markus) Dolby up-mixing to surround, although I must say I don't have a lot of experience with it thus far. By the way, too bad seemingly nobody has ever heard the magic speaker. Is it any good?
I used to be a polar idealist - superbly extended pure dipole behavior was what I was after - but I've decided to let go of the idealism in favor of some practicality. I think some others should too. That's why in the opening post I said psychoacoustics first!
LOL
Hopefully in the morning it will all come back to you!
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There is a chance that some thread subscibers have it in mail notifcations (sent by diyaudio) of a new reply in the thread
Unfortunately I haven't received it
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I'm absolutely baffled by this, as well as Elias's original claims in this and other threads that stereo speakers cannot provide a phantom channel at high frequencies, and that he hears even mono treble frequencies as coming from each side individually instead of localizing in the middle.
I've just done the first part of the same test above and I do not get the same results.
I tried mono (phase coherent L+R) pink noise unfiltered, high passed at 1500Hz, high passed at 4Khz, and high passed at 8Khz, listened to at a normal listening distance at a normal stereo apex and I do not perceive the source of sound to be coming from two sources at the sides with any of the high pass cut-off frequencies or unfiltered.
In every case when I'm equidistant from the speakers there is one apparent source of noise coming from directly ahead, and no apparent sound localized from the direction of the speakers.
What I do notice is that with higher and higher cut-off frequencies my head position does become more critical to accurately locate the image in the centre, and with those high cut-off frequencies there is some sideways "ripple" in the exact location of the phantom image as I move sideways, but it never collapses into appearing to come from both sides instead of the middle, it just moves around a little bit in the middle.
This rippling effect at high frequencies is due to comb filtering between left & right, and as my speaker separation is only about 45 degrees the effect is somewhat more noticeable than it is at 60 degrees. (I know this from past experience with the same speakers at a wider angle)
I can only conclude that either (a) some people don't perceive phantom images at high frequencies like the rest of us, for whatever reason, or (b) something about the speakers and/or room are interfering with phantom channel localization at high frequencies.
In the case of point a, I'm starting to wonder whether some people just aren't able to perceive a solid phantom channel image regardless of speaker, and that it could be no different than something like red/green colour blindness - you either have it or you don't.
For point b, I wonder whether a speaker with excessive horizontal dispersion at treble frequencies could damage the phantom channel localization at high frequencies, by "spreading" the apparent source width too wide ? Even placing speakers too far apart in a reflection free environment does, past some angle, start to cause the phantom channel to fail to form solidly, and eventually fall apart, perhaps excessive ASW due to large amounts of side-wall reflection can do the same thing with a more conventional angular separation ?
I just wanted to go on record to say that not everyone hears stereo imaging and the phantom channel the way Elias and Radugazon describe, although whether I am in the majority or the minority I don't know.
Certainly everything that Tom Danley has said about strong phantom channel localization in speakers with high directivity, or speakers listened to outdoors in a reflection free environment (with a 60 degree set-up) tallies with the way I perceive sound - I've found both situations provide extremely strong and realistic phantom channel images to the point that you could swear there is a speaker hovering in space in the middle, with no apparent output from either of the actual speakers. (on a mono signal, obviously)
In my experience, early room reflections only ever dilute the strength and definition of the phantom centre channel, they never make it better.
Has anyone ever done a study on the perception of phantom channel imaging to see whether there are a percentage of people that don't perceive it the same way as others ?
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I'm absolutely sure it was brilliant.
(Gee, I hope I haven't driven you to drink.)
David S.
You are actually precisely referring to the speaker you have built
Yes, and several times I've expressed the oppinion that CD horns are beneficial, not for the power response they have but because they tend to have better response at on axis and near on axis angles.
The paper we published to accompany the systems shows pretty well the poor polar curves and gross response variation of other horns of the era. In the midst of it. Mark Gander and John Eargle stated talking about the benefit of "flat power response" with regard to the system. I still have a memo I wrote giving a contrary oppinion, that flat power was not a benefit, nor does the system really have flat power. (Flat power or constant directivity in one drivers bandpass?) To this day JBL talks about superior performance through flat power response for their Theater and PA products.
With a 90 x 40 horn the system climbs smoothly to a d.i. of about +10dB.
David S.
Simon, thanks for your help. As I am puzzled too, I've redo the test with both types of pink noise, (and even a natural waterfall), with speakers between 0.5 and 3 meters from the back wall, different heights and toeings, and for finishing, flooder and beveridge configs.
All this helped by the DCX and its remote controls. The test goes fast, because in any case the results are evident : bilocalisation passed 1500 Hz.
No panic, maybe I'm still normal. Can I suspect other causes ?
1. result expectation : no, because my plan was to tease Elias on his own abnormality
2. very lively room : possible, but it's also wide, see also that the results don't change with different positions
3. listener not in the middle : no, my seat is a cockpit (for the XTC)
4. high distorsion : no, already three couple of different drivers tested.
5. deaf, too old, anatomic anomalies of the pinna : never know
6. evolution of the sensibility after one year of exposition to a center side firing system :
plausible but hard to believe. It's a fact that when I had normal systems I was never so much focusing on imaging perception. The possibilities of a DCX push also the listener to the limits of his perception. Training , perversion of the taste, deviance ? Dunno.
BTW, last time I was listening seriously some music in high end shops, I remember that almost all the speakers were sounding bifid.
I'm really surprised, maybe markus knows a good link.
edit : I don't say that pink noise and stereo music are totally the same thing for this issue .
All this helped by the DCX and its remote controls. The test goes fast, because in any case the results are evident : bilocalisation passed 1500 Hz.
No panic, maybe I'm still normal. Can I suspect other causes ?
1. result expectation : no, because my plan was to tease Elias on his own abnormality
2. very lively room : possible, but it's also wide, see also that the results don't change with different positions
3. listener not in the middle : no, my seat is a cockpit (for the XTC)
4. high distorsion : no, already three couple of different drivers tested.
5. deaf, too old, anatomic anomalies of the pinna : never know
6. evolution of the sensibility after one year of exposition to a center side firing system :
plausible but hard to believe. It's a fact that when I had normal systems I was never so much focusing on imaging perception. The possibilities of a DCX push also the listener to the limits of his perception. Training , perversion of the taste, deviance ? Dunno.
BTW, last time I was listening seriously some music in high end shops, I remember that almost all the speakers were sounding bifid.
I'm really surprised, maybe markus knows a good link.
edit : I don't say that pink noise and stereo music are totally the same thing for this issue .
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Very nice ! You feel no fear to experiment !
Excuse me, today my brain is moulded. What does this mean? Image split into two, or did not split? And this is with 1.5kHz high pass? How about for example 5kHz high pass?
- Elias
Excuse me, today my brain is moulded. What does this mean? Image split into two, or did not split?
And this is with 1.5kHz high pass? How about for example 5kHz high pass?- Elias
My results with pink noise left and right in phase, while I sit in the stereo triangle:
- With full spectrum I only hear the central phantom image. While I rotate my head, comb filtering makes the tweeters appear as individual sources, but the low frequency noise stays solidly at the phantom centre.
- With a 3 kHz highpass (tweeters only) I do hear them as separate speakers, but there is still a central phantom image at almost the same level. Only when I rotate my head, severe comb filtering will destroy the central image completely.
Rudolf
- With full spectrum I only hear the central phantom image. While I rotate my head, comb filtering makes the tweeters appear as individual sources, but the low frequency noise stays solidly at the phantom centre.
- With a 3 kHz highpass (tweeters only) I do hear them as separate speakers, but there is still a central phantom image at almost the same level. Only when I rotate my head, severe comb filtering will destroy the central image completely.
Rudolf
Were the mono tests a single speaker only playing, (located where ?) or playback of a mono recording on a normally set up stereo pair ?
If the latter, the fact that the Quad was marked down for poor imaging of mono signals should be a warning sign that just because it's a "directional" speaker, other directional designs like CD shouldn't be tarred with the same brush, as I think most (who have heard them) would agree that directional / near CD designs provide an excellent phantom mono image.
If the test was in fact a single speaker, ignore the last paragraph
This is where I think you may have fallen off the rails in your extrapolation of dipole panel results to other directional designs, for two reasons:
1) Directivity is about so much more than just a raw directivity index figure.
In fact overall directivity index vs frequency tells you surprisingly little about a speaker, since it gives you no idea in which directions radiation is reduced, and I think everyone agrees that the directions in which radiation is reduced within a room are of key importance, even if we don't all agree on what those directions might be. Obviously the dipole has its major cancellation axes at right angles, different to practically every other design on the planet.
2) The elephant in the room is the reverse phase radiation from a dipole, which I suspect is more likely the reason why Toole's listeners didn't prefer the dipole, even if they didn't know why.
Show me one natural sound source or instrument that is predominately a broadband dipole. I can't actually think of a single one, although I'm sure there must be something, such as some type of heavy machinery.
The reality is that almost every natural sound source on the planet that we're likely to record for music is a mono-pole, which is largely omni-directional at bass frequencies (if the sound source produces frequencies that low) and becoming more directional at high frequencies. This is what we're used to hearing in real life, not dipole sound sources.
There is just (to me) something unnatural sounding about a dipole sound source, and I know that will ruffle feathers in the dipole camp.
In my mind the major advantage of a dipole is the lack of "boxy" colouration in the vocal range due to the absence of a box for sounds to bounce around in and emerge time delayed through the cone, (and box walls) not the fact that it has a dipole radiation pattern. I actually think the dipole pattern and the anti-phase radiation from the rear is a drawback not a benefit, and that the directivity index achieved by the dipole is not beneficial because the nulls are in the wrong directions, with far too much rear firing output.
So I would contend that the Quad was not liked as much in the test for reasons other than just "high directivity", reasons such as the large anti-phase rear radiation, unusual 90 degree cancellation angle, and a probably not as smooth on axis response.
To lump CD designs (or other directional monopoles) in with a dipole and extend the lack of preference for the dipole to these other designs - which were not represented in the tests - seems to be groundless, and remains so until someone does some similar research that includes a whole bunch of modern CD designs which have top notch on-axis performance.
Again, I think you're coming to a misleading conclusion. What is "wide dispersion", "medium dispersion" and "narrow dispersion" exactly ? That's far too vague, and lumps all directional speakers into the same camps, even though they may have radically different polar patterns.
If nearly all the speakers in his comparison were cone and dome designs of various types, (other than the dipole panels) we can make a few assumptions about what a wide and medium dispersion design might be.
Comparing a wide dispersion cone and dome design with a "medium" dispersion cone and dome design, most of the reduction in dispersion is going to be towards the top end of each drivers frequency range, leading to a very non-flat off axis response which has a large hole below the crossover frequency and droop at the top end.
The reality is these "medium" and "narrow" dispersion speakers tested would have only been narrow at certain key frequency ranges, not uniformly over a wide range.
How is this equivalent to the off axis response of a CD design ? Perhaps what the listeners didn't like in the "medium dispersion" designs were large holes in the off axis response, large holes that would not be there in a CD design.
To extrapolate the lower rankings of the "more directional" cone and dome designs to a CD design doesn't seem to hold water to me.
I agree.
Again this is an area where I think a dipole is an interesting curiosity, but doesn't really solve the issue properly. Yes a bass dipole lined up with the room axis will theoretically avoid exciting 2 of the 3 main room modes, but in doing so you're throwing away a ton of potential performance from a given driver, or requiring a MUCH larger driver to achieve the same performance, along with requiring active equalization to achieve a flat response. (No passive designs possible here...)
It still doesn't address the 3rd room axis mode, nor does it address the large variations in response around the room due to non-modal constructive and destructive interference. So if you're willing to throw away a lot of performance and use a large baffle it half heartedly addresses some but not all of the room problems in the bass.
On the other hand distributed monopoles, eg the spatially dispersed sub approach can solve all problems at once. With a sub in each corner or side-wall two of the three room modes can be directly cancelled and the effects of the 3rd mitigated, uniformity around the room is far greater, and you get a lot more dynamic headroom because you're sharing the load amongst many drivers around the room, rather than throwing away headroom in the dipole case.
So I don't think polar characteristic at bass frequencies is that important - use monopoles but place several of them around the room in the right places.
Exactly my point earlier - if power response isn't a reliable indicator, DI curve with no other information like polar patterns isn't much of an indicator either. Therefore the listening results of a "directional" speakers with a certain DI can't just be extrapolated to another speaker with a similar DI which could have a radically different polar pattern - eg dipole vs CD.
(As well as one having reverse phase radiation and the other not...)
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"Yes, but" is a good answer. You'll pretty much never get the sound of the instrument captured on a recording that played back sounds like the instrument. I can't honestly say I have heard it--ever. I've heard bathroom reverb that sounds great. Several recordings of it. You might be surprised that you likely have too. I would just love to hear a piano in my living room. Never had the chance. My keyboard certainly doesn't cut it even though it sounds "good" and better than most pianos really. Sound enhancements can be nice.
When I play piano(or guitar, banjo, sanshin, bass, etc...), most of the time I do wish for sound enhancements(not necessarily that fault of the piano, but truly it often is). You do learn to play around the "faults" of the instrument eventually. Some people have less trouble than others at this and some instruments seem to sound beautiful regardless. Recordings certainly aren't perfect, but I'd argue typically more pleasant than the real thing. They are certainly capable of being so though the loudness wars rage on. Depending on the music you like, it can be hard to find decent recordings as well. I've actually never come home from a concert and thought the sound beat my stereo. Unamplified acoustic music or not, it's never been close. I still love concerts however. There is no doubt something about live instruments and the "moments"(hopefully extended) experienced while listening. The best part about music is that it's fleeting. Existing briefly in time. It's not generally the sound of a concert, it's the experience.Anyway, until there are standards for playback, any recording can be altered by the end user. Going by logic, I don't see how anything but a fairly narrow pattern could be best.
Dan
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