Ok, so driving around I occasionally think about this Ambiphonics thingie...
So, now we want the speakers ~20 degrees apart, right? Otherwise it doesn't work. Yes?
Now, help me out with this does the effect work just as well when ur Xdeg off axis??
How far off the centerline?
Or, do you have to be sitting more or less on axis to the centerline between the speakers??
I'm still trying to get a handle on this. Of course I have not tried the experiment, mostly because I have no time to even consider it.
_-_-bear
So, now we want the speakers ~20 degrees apart, right? Otherwise it doesn't work. Yes?
Now, help me out with this does the effect work just as well when ur Xdeg off axis??
How far off the centerline?
Or, do you have to be sitting more or less on axis to the centerline between the speakers??
I'm still trying to get a handle on this. Of course I have not tried the experiment, mostly because I have no time to even consider it.
_-_-bear
Ok, so driving around I occasionally think about this Ambiphonics thingie...
So, now we want the speakers ~20 degrees apart, right? Otherwise it doesn't work. Yes?
Now, help me out with this does the effect work just as well when ur Xdeg off axis??
How far off the centerline?
Or, do you have to be sitting more or less on axis to the centerline between the speakers??
I'm still trying to get a handle on this. Of course I have not tried the experiment, mostly because I have no time to even consider it.
_-_-bear
The sound of an ambiophonic setup is noticeably wonky off-axis when you do the processing with DSP. This is the reason that I wound up ditching the processing and setting up a physical barrier.
I've notice that Bob Carver's new speakers use a poor man's version of ambio by intentionally creating out-of-phase reflections on the side walls.
Bear, I think it depends on the type of loudspeaker being used. With my dipoles, I have a foot or more of leeway (if you can call it that). After that, there's a transition where images begin to shift...maybe another foot or two... after that, it becomes mono in nature. Some of the leeway may be from the dipoles, I don't know. A speaker with a higher DI may be different.
Ambio is not much different than stereo as regards the above. In stereo the nominal angle is 60 degrees but in practice the tweak angle can be from 90 degrees to 40. Ambio can also work over a wide range of tweak angles say 18 to 30, but since there are two adjustments, for optimizing this (unlike stereo) Ambio is a tweakers delight. David Chesky insists on keeping his speakers at 60 degrees and using a far out version of Ambiophonic like XTC filters because he does not want to move his speakers and he thinks his audiophile customers will also only want Ambiophonics at 60 degrees even if this is not ideal.
Like stereo, Ambio does not work well off axis. But it works better than stereo or 5.1 in this regard. In stereo if you move sideways, you normally hear just one channel well. In Ambio if you move sideways you hear a perfect mono signal with both channels equally represented. Also in Ambio you can move backwards and forwards with little effect compared to stereo. In stereo if you move forward, you get a hole in the middle. If you move back you get mono. Neither happens in Ambio and you can stand, lie down, rotate the head, etc. For best results, where one still has a wide stage that is symmetrical, about one head width off center is possible. This is more than enough for car drivers and sitting comfortably when watching a movie. Other viewers can sit behind or in front as in a movie theater, or just listen in offside mono that is better than 5.1 and you never need a center speaker. I have had some six listeners at once at demos all on the center line. This is the proof that the angle to the speakers is not very critical compared to stereo.
Curved panel speakers like electrostatics can widen sideways area but more research needs to be done here on curvatures, line sources, etc. There are also other filters and speaker arrangements that can be used for multiple fixed listeners but you need to be a wealthy engineer to use them.
You can also use four speakers, two in front and two in the rear, and have two listeners sitting back to back. This is perfect for symphonic music or 2.0 jazz recordings where the rear facing listener does not object to the left right reversal of the stage. Most never even notice as the realism is overwhelming.
Ralph Glasgal
Ralph,
What I heard briefly on my laptop speakers was certainly of interest. The headphone experience was also interesting, although as I noted in my post the "unprocessed" versions seemed oddly "left-right" like old Beatles stereo releases. (any comment on this?)
I have yet to download a plug in and try it on a "real speaker system". Time is my enemy on that.
Regarding you post. My experiences with a properly set up stereo system do not mirror yours at all. Certainly I have no "hole in the middle"when one moves forward or back - and I am not talking about one or two feet, I'm including 0 to 20 feet in that. Quite the contrary, one gets a sense of being immersed in the sound stage closer in, and father back more of sitting in a concert hall venue in the audience. No hole.
Left-right can be more of an issue, but not so much that one gets anything resembling a "mono" listening experience off axis, out to the point where one is at least parallel to a given speaker. This is better, somewhat farther back than close in.
Right now my room permits the speakers to be spaced 13' apart and the listener to sit anywhere up to 25ft away. However that's just my room and set-up, what I'm saying is not unique at all to my room or system.
Clearly there needs to be a relationship between the polar response of a given speaker, the placement of the speakers, and the ratio of direct to reflected sound vs. frequency as well as a number of other factors for what I would loosely term "proper stereo imaging" to be possible.
The so-called "headclamp" requirement for imaging is not necessary.
Then too there are speakers that utilize the room acoustics deliberately to avoid the "headclamp" requirement, like the Beveridge and omni speakers like the MBL and the Ohm F as just two examples. (we can skip the Bose 901?).
On one hand I do like the potential of the ambiphonics type methods in so far as a sound stage reaching left and right beyond the speakers is a wonderful aspiration. On the other hand, if in order to accomplish that one needs again to in essence go back to a "headclamp" type listening position, that creates a limitation that is not so desireable.
It would seem to me that a properly recorded discrete 4 channel (4-corner) recording would obviate much of the need for after-the-fact processing... of course two things come to mind with that, first "they" have never seen fit to try to do that commercially or even on a "boutique" basis here in the bold new digital age, and secondly perhaps a software enhancement like ambiophonics would be of greater application in such a situation...
So, two things. My perception/experience with "stereo" seems at odds with your report. The apparent limitation in terms of the listening "sweet spot" is disappointing.
Regards,
_-_-bear
What I heard briefly on my laptop speakers was certainly of interest. The headphone experience was also interesting, although as I noted in my post the "unprocessed" versions seemed oddly "left-right" like old Beatles stereo releases. (any comment on this?)
I have yet to download a plug in and try it on a "real speaker system". Time is my enemy on that.
Regarding you post. My experiences with a properly set up stereo system do not mirror yours at all. Certainly I have no "hole in the middle"when one moves forward or back - and I am not talking about one or two feet, I'm including 0 to 20 feet in that. Quite the contrary, one gets a sense of being immersed in the sound stage closer in, and father back more of sitting in a concert hall venue in the audience. No hole.
Left-right can be more of an issue, but not so much that one gets anything resembling a "mono" listening experience off axis, out to the point where one is at least parallel to a given speaker. This is better, somewhat farther back than close in.
Right now my room permits the speakers to be spaced 13' apart and the listener to sit anywhere up to 25ft away. However that's just my room and set-up, what I'm saying is not unique at all to my room or system.
Clearly there needs to be a relationship between the polar response of a given speaker, the placement of the speakers, and the ratio of direct to reflected sound vs. frequency as well as a number of other factors for what I would loosely term "proper stereo imaging" to be possible.
The so-called "headclamp" requirement for imaging is not necessary.
Then too there are speakers that utilize the room acoustics deliberately to avoid the "headclamp" requirement, like the Beveridge and omni speakers like the MBL and the Ohm F as just two examples. (we can skip the Bose 901?).
On one hand I do like the potential of the ambiphonics type methods in so far as a sound stage reaching left and right beyond the speakers is a wonderful aspiration. On the other hand, if in order to accomplish that one needs again to in essence go back to a "headclamp" type listening position, that creates a limitation that is not so desireable.
It would seem to me that a properly recorded discrete 4 channel (4-corner) recording would obviate much of the need for after-the-fact processing... of course two things come to mind with that, first "they" have never seen fit to try to do that commercially or even on a "boutique" basis here in the bold new digital age, and secondly perhaps a software enhancement like ambiophonics would be of greater application in such a situation...
So, two things. My perception/experience with "stereo" seems at odds with your report. The apparent limitation in terms of the listening "sweet spot" is disappointing.
Regards,
_-_-bear
All these POV (and feelings) are relative.
I also thought my old stereo horn system was pretty good (or at least good enough for me) in imaging - no obvious holes, wide/deep enough, maintaining pretty stable images and tonal balance in quite a large listening area.... until I tried OSD.
Then I hit a bottle neck (again), and things turned to other direction....
Will I turn back to the old way? Not likely.
I also thought my old stereo horn system was pretty good (or at least good enough for me) in imaging - no obvious holes, wide/deep enough, maintaining pretty stable images and tonal balance in quite a large listening area.... until I tried OSD.
Then I hit a bottle neck (again), and things turned to other direction....
Will I turn back to the old way? Not likely.
Nice space! But judging from the walls, it must be warm all year round there??
Perhaps I need to come and visit for a good long while?
What are your subjective impressions compared to the same system set up as well as you can for stereo? I would think that with that size space the speakers could be spread quite a distance apart and toed in at ~45degrees, aimed in front of the center listening position for best image. Have you done that or tried it??
That space is very nearly what is needed... even if the room is live, the dimensions are such that the reflections do not interfere with the main sound... otoh you need to run higher average levels than in a smaller room...
_-_-bear
You got the point, Bear, it's an almost equatorial zone. Search for Tana Toraja, it's quite a touristic place. This ambient authorizes the use of flexible boundaries (walls, ceilings, floors, all...) and then a native dampening of the low frequencies. And of course all the rest of the spectrum is very well reflected, the room being empty on purpose.
Following the distance listener/speakers, the first side wall reflections arrive between 15 to 19 ms after the direct sound, and as you said, I listen at higher levels than the average people having neighbors.
I tried almost everything that I could imagine before using a centered distribution of the tweeters (OSD...), and I can guarantee that with the same level of competency (or incompetency as well) , never a two speakers configuration can give this feeling of reality. Of course, I agree that the actual configuration is not a silver bullet. It's just my experience.
With the rear group, it becomes more complex to set up but on some records, the envelopment is really 360°. I search to emulate a flawless cross talk cancellation without processor, managing either spaciousness and accurate imaging. But everytime I compare with a simple plug in like ambio.one, this last is still ahead.
It's a long way...
Following the distance listener/speakers, the first side wall reflections arrive between 15 to 19 ms after the direct sound, and as you said, I listen at higher levels than the average people having neighbors.
I tried almost everything that I could imagine before using a centered distribution of the tweeters (OSD...), and I can guarantee that with the same level of competency (or incompetency as well) , never a two speakers configuration can give this feeling of reality. Of course, I agree that the actual configuration is not a silver bullet. It's just my experience.
With the rear group, it becomes more complex to set up but on some records, the envelopment is really 360°. I search to emulate a flawless cross talk cancellation without processor, managing either spaciousness and accurate imaging. But everytime I compare with a simple plug in like ambio.one, this last is still ahead.
It's a long way...
Stereo is a sonic illusion and just as there are those who cannot see optical illusions that others see easily, so the stereophonic illusion varies with individuals. You are lucky that you can still resolve a center image as the stereo speaker angle goes to angles over 45 degrees. There are documented cases of individuals who cannot hear the center image at all at any angle. There is also no way to prove that the 60 degree angle is correct. It is just an empirical feeling that has evolved since Blumlein used this angle in 1931.
Usually one cannot get a good center localization experience if off center in stereo. You may still have some left right localization sense but humans have a problem localizing to anything but the two speakers when off center. If the speakers are directional, then an off center listener will hear mainly one channel only. Also if one is very much closer to one speaker than the other the precedence effect will make all the sound seem to come from just the one speaker.
With these dimensions the angle to the speakers does not change so radically and I would expect the stereo effect to still be reasonable at the 25 foot point. Try moving up to one foot in front of the plane of the speakers and see if you can still localize anything between the speakers. Then move back until you can. This will tell you the range over which the stereo sonic illusion is useful for your particular ears and setup.
Yes. Compared to a binaural loudspeaker technology like Ambisonics, WFS, or Ambiophonics, stereo is very sensitive to the things you mentioned. This is because it is a lucky flukey sonic illusion and not normal everyday binaural hearing. In optical illusions, (where a flat picture seems to be three dimensional) the lighting, your angle, etc. have to be just right to see them and some people just never see them. Stereo may not be this fleeting but it is similarly suseptible to tweaks and can never come close to the normal binaural hearing experience.
With Ambiophonics, you can move about as much as you can in a concert hall seat. But Ambiophonics and the other loudspeaker binaural technologies deliver a lot more than just a wider stage. For audiophiles it is the increase in depth, clarity, resolution, and presence that are of real interest. Obviously, if the soundfield reaching each ear is close to what one would have heard at the mic position during the recording session, then one is closer to the live experience and desirable if this is the definition of high fidelity. Of course, like black and white photography, one can view the stereo loudspeaker triangle as an art form to be savoured despite its limitations just as is black and white protography despite its lack of optical fidelity (no color, no depth, no motion)
There are plenty of good 5.1 recordings/movies out there that can be played back using 4.0 decoding of them. With a good front and rear stage on the disc one can have full 360 degree localization now in the home. But this will not work if the speakers are just arranged in a square. You cannot localize to the extreme sides this way. All you can have is 90 instead of 60 degree stereo in front and rear. There will be a gap of 90 degrees each side where no direct sound can be heard. (Yes I know about the mythical exceptions that keep circulating)
It is so easy just to put Ambiophonic speaker pairs front and rear and you then get a full 360 degree circle of sound from four speakers and you never need front or rear center speakers. Movies are great this way. Avatar especially. Games coming.
Everything is relative. Some will find the stereo limitations worse than the Ambio ones and viceversa. Mono has the least seating limitations. You can be anywhere in the room and listening to one speaker works great. This is why even today, along with other reasons, there is still more mono than stereo out there. (phones, newsbroadcasts, AM radio, etc.) I presume that a great many people find the use of stereo advantageous despite its limitations compared to mono. I hope that a similar attitude will make Ambio reasonably popular. But indeed, even if Ambio succeeds in finding an audience there will always be more stereo than Ambio.
Ralph Glasgal
so I'm not the only one...
same here! On my own system, with unprocessed stereo and my usual speaker placement I can walk around the whole room with very little changes on sound and image. And (at least with some recordings) image may extend well over the speakers (up to almost 180 degrees, same as what is usually obtainable with ambio). All this just with plain, unprocessed, 2 channel stereo.
I have tried (DSP-based) ambiophonics setups, too. In various rooms and systems (notice that I include the listening room as a fundamental "component" of an audio system!). In some "less-than-optimal working" (plain stereo) systems, changing to a ambio setup indeed may give a huge improvement. Not only on imaging but also WRT perceived details and overall "clarity". In such cases, what it does is really amazing.
But, on a well optimized and properly sounding system (perhaps due to a fortunate room-speaker pairing...) such as my own, ambio typical improvements were marginal, if any. With the (usual) added inconvenience of an extremely narrow "sweet-spot" listening area along the middle axis (which I find really very annoying). Moreover, with ambio there is also a small but clearly perceivable sound quality deterioration (perhaps due to DSP effects).
Of course, I quickly went back to my previous, regular stereo setup on my own system.
What does this means? I really don't know.
But I guess that the interaction between speakers and room (proper control of timing, intensity, etc of reflections, diffusion, reverberation, etc) is the key for a really satisfying stereo operation. IME I've noticed that in well-working setups the overall symmetry of room and even more so the symmetry of speaker placement in the room seems to be absolutely paramount. Speaker position and orientation is really extremely critical. Even a change of a few cm (or less than an inch, if you prefer...
) in their position and/or less than a few degrees on their angles may completely screw things up, changing from "audio nirvana" back to the usual average stereo triangle effect. That is (again IME), I've learned that rather than a "listener sweet-spot", one should talk (and must care) about the "speakers sweet-spot" in a given room!
It may literally take months of repeated trial and errors to find the right setup for a given speaker-room combination (if any exists for such pair). But, if found, you can forget about the system and just enjoy listening to music.
This is a general comment on several of the above observations.
Ambiophonics, like stereophonics is tweakable. Many of you have spent years getting your stereo systems just right. A similar process is appropriate for audiophiles in regard to Ambiophonics. Audiophiles need to put as much effort into tweaking Ambio systems as they have into tweaking their stereo systems. In the end tweaked Ambio will always sound better than tweaked stereo since the 60 degree loudspeaker triangle is not a psychoacoustic hearing mechanism that can deliver physiological versimilitude.
Of course, it is quite possible to enjoy stereo as an artform like black and white photography. Stereo crosstalk produces a level doubling in the bass/midbass region for central voices and instruments and one may prefer this to the flatter response of Ambio or normal hearing. Usually this is described as warmth. Sometimes the recording engineer corrects for this but this is only possible if all the center sound is on a spot microphone and is mono.
Finally, Ambiophonics comes in different flavors. I believe music is best with four speakers, and for classical music one should have the convolved ambience surround speakers going if you are a perfectionist. Also as manufacturers begin to make related products, audiophiles can select those varieties of Ambiophonics (or whatever name they use) that they think sound best.
As pertains to room acoustics. In general, Ambiophonics is less influenced by the room than stereo. When the speakers are close together, one can normally get closer to them and maybe even listen to them in the nearfield. Then the delay of the reflections from the walls are longer and even their relative amplitudes are less than is the case for stereo. If you use the ambience part of Ambiophonics then the surround speakers swamp the room sound, and the room does no more damage than the heads and seatbacks in a concert hall. But these are things that audiophiles will have to experience for themselves as they practice tweaking. Afterall this is a DIY forum.
Ralph Glasgal
glasgal@ambiophonics.org
Ambiophonics, like stereophonics is tweakable. Many of you have spent years getting your stereo systems just right. A similar process is appropriate for audiophiles in regard to Ambiophonics. Audiophiles need to put as much effort into tweaking Ambio systems as they have into tweaking their stereo systems. In the end tweaked Ambio will always sound better than tweaked stereo since the 60 degree loudspeaker triangle is not a psychoacoustic hearing mechanism that can deliver physiological versimilitude.
Of course, it is quite possible to enjoy stereo as an artform like black and white photography. Stereo crosstalk produces a level doubling in the bass/midbass region for central voices and instruments and one may prefer this to the flatter response of Ambio or normal hearing. Usually this is described as warmth. Sometimes the recording engineer corrects for this but this is only possible if all the center sound is on a spot microphone and is mono.
Finally, Ambiophonics comes in different flavors. I believe music is best with four speakers, and for classical music one should have the convolved ambience surround speakers going if you are a perfectionist. Also as manufacturers begin to make related products, audiophiles can select those varieties of Ambiophonics (or whatever name they use) that they think sound best.
As pertains to room acoustics. In general, Ambiophonics is less influenced by the room than stereo. When the speakers are close together, one can normally get closer to them and maybe even listen to them in the nearfield. Then the delay of the reflections from the walls are longer and even their relative amplitudes are less than is the case for stereo. If you use the ambience part of Ambiophonics then the surround speakers swamp the room sound, and the room does no more damage than the heads and seatbacks in a concert hall. But these are things that audiophiles will have to experience for themselves as they practice tweaking. Afterall this is a DIY forum.
Ralph Glasgal
glasgal@ambiophonics.org
Yes, and like sterephonics there will be many similar designs. Normally Princeton does not like to refer to Ambiophonics directly but see a few of their comments at
Ambiophonics 2nd Edition - Chapter 1 The Princeton crosstalk cancellation algorithim, although similar in concept to RACE, is a significant advance over RACE where proximity effects such as the bee buzzing at the ear are desired. RACE cannot do this. But RACE can easily deliver a full circle of sound with just four speakers, using existing surround movie discs at a low price with less compleixity than normal 5.1 which doesn't even work. For playing normal CD/LP music there is little difference in depth, width or clarity.
At the moment Ambiophonics can do full surround, is commercially available, free stuff also and no license is needed anymore than one needs a license to make stereo gizmos. There are at least five other similar systems being promoted and more rumored. I think one can firmly say that the simple stereo triangle is finally beginning to show its age after 80 years.
Ralph
Running a music server with lots of processing power I finally wound up and installed ambiophonics in foobar, using the vst wrapper and the free plugin.
I set my speakers at about 20 degrees, and started to listen.
The room seems to extend into the depth as well as in the width, far beyond the speakers,. The added information however seems to depend very much on the source.. Listening to the first track of "o brother were art thou" I noticed that in stereo the hammer hits mesh together in a few differentiable strikes, whereas in ambiophonics one can easily differentiate a whole bunch of individual hammers striking.
Reminds me of the "ping pong" stereo demos of the sixties, but there it is.
I set my speakers at about 20 degrees, and started to listen.
The room seems to extend into the depth as well as in the width, far beyond the speakers,. The added information however seems to depend very much on the source.. Listening to the first track of "o brother were art thou" I noticed that in stereo the hammer hits mesh together in a few differentiable strikes, whereas in ambiophonics one can easily differentiate a whole bunch of individual hammers striking.
Reminds me of the "ping pong" stereo demos of the sixties, but there it is.
I have google an old article in stereotimes from August 1999:
Once positioned in what looks like a cockpit, you're to put your nose centered about a couple of inches from the divider. Once you're seated correctly, Ralph readies three of what looks like the "Way Back Machines" I watched as a child on the TV cartoon show Sherman and Mr. Peabody. Actually, they're surround-sound processors. On the very first note of "Grandma's Hand" sung in splendid a capella by the group Take Six, I knew- strictly in terms of life-like and life-sized instruments in a room- that I was hearing something unlike anything I've heard anywhere before. When you have so many speakers in a room situated as Ralph has them arranged through a host of very rare JVC "Way Back Machine" processors, the images are no longer phantom in nature. Their presentation is life-like -- as in real life -- especially in terms of space. The believability quotient rose steeply due to speakers taking the place of phantom images. Done right, it just doesn't get any better than that. The array of speakers in the room appeared to recreate individual voices and instruments on a level that took on dimension and size I simply wouldn't have believed possible. You can think what you want, but two-channel stereo doesn't yet achieve, and I doubt ever, this level of performance. Conceptually, this is a system only someone with the mind of Glasgal could create in the first place. But as a clear example of what possibilities exist in the here and now, Ambiophonics serves as a portal into a sound that truly recreates the concert hall at home.
Greetings, H.
www.holophony.net
Once positioned in what looks like a cockpit, you're to put your nose centered about a couple of inches from the divider. Once you're seated correctly, Ralph readies three of what looks like the "Way Back Machines" I watched as a child on the TV cartoon show Sherman and Mr. Peabody. Actually, they're surround-sound processors. On the very first note of "Grandma's Hand" sung in splendid a capella by the group Take Six, I knew- strictly in terms of life-like and life-sized instruments in a room- that I was hearing something unlike anything I've heard anywhere before. When you have so many speakers in a room situated as Ralph has them arranged through a host of very rare JVC "Way Back Machine" processors, the images are no longer phantom in nature. Their presentation is life-like -- as in real life -- especially in terms of space. The believability quotient rose steeply due to speakers taking the place of phantom images. Done right, it just doesn't get any better than that. The array of speakers in the room appeared to recreate individual voices and instruments on a level that took on dimension and size I simply wouldn't have believed possible. You can think what you want, but two-channel stereo doesn't yet achieve, and I doubt ever, this level of performance. Conceptually, this is a system only someone with the mind of Glasgal could create in the first place. But as a clear example of what possibilities exist in the here and now, Ambiophonics serves as a portal into a sound that truly recreates the concert hall at home.
Greetings, H.
www.holophony.net
Stereo recordings vary a great deal in the amount of acoustic or panned ILD and ITD they actually capture. In the case of pop recordings these cues are often constructed through software and panning controls. Thus it is really unpredictable as to what they will sound like when all this artificial ILD or ITD is actually reproduced. But the controls on RACE components can be changed to reduce the ILD and ITD to make such weird recordings sound more like stereo i.e. without such a wide stage. One can hope that someday most recordings will be made with Ambiophonic reproduction in mind so that all recordings sound good in both stereo and Ambio.
Like anything, Ambio settings can be abused. If you use too little attenuation and too much delay you can actually amplify the ILD of a given recording. That is, if you cancel crosstalk that is not really there or in other words over cancel, you can hear what is described above. In general something that is panned with an ILD of say 3dB and is supposed to be at 20 degrees my be ILD amplified to 8 dB and seem to be much further to the side with the center depleted, if there is no actual mono (0 ILD) present.
New technologies are always hard to absorb and work with. When stereo first came out I used to measure LPs and notify the magazines which discs had one channel out of phase. There were quite a few and they had a similar effect of a very wide stage with no middle.
Ralph Glasgal
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