Soundstage Width cannot extend beyond speakers

[STC]

Why is that the soundstage never extends beyond the actual location of the speakers? Unless, there is phase manipulation it is impossible to hear stereo sound going outside the speakers outer boundary. Thoughts? 

[STC]

15 minutes ago, adamdea said:

Why should it?

Because most classical orchestra soundstage is beyond 60 degrees. 

9 minutes ago, PeterSt said:

 

Uhm, not correct at all ?

Unless you 

a. have directive horn speakers;

b. treated to the room (side walls) to completely dead.

... almost amused to death ('s Q sound - haha).

 

No. It cannot go beyond the speakers boundaries unless phase manipulation with SdSP like QSound. Occasionally,you get slight extension due to side wall reflection. 

[STC]

6 minutes ago, PeterSt said:

What I always noticed (and people may reject this just the same) is that the sound does not go behind the speakers. At least in all my life time I never ran into that.

 

Another far more crucial "claim" would be that the sound never can get beyond the room's walls. That too I never experienced, also not from the sides. Unless with, as you say, phase manipulation.

This is all logic because we hear reflections just the same and outer most boundaries of that are the walls. Or a cabinet in between (you and the wall).

 

In my previous house I could easily have the sound being sheer behind me. Q-Sound was made for it but I also have examples of Jimi Hendrix, De La Soul which was no Q-Sound at all. This never got to work again in my current house (listening room).

 

Ok. I didn’t read this post before my previous post. So we agree on most things except the part about sound going behind speakers. It is possible. 

[STC]

1 minute ago, PeterSt said:

 

Are we being ignorant ?

Even if I am 2 meters (!!!) in front of the speakers which are 6 meters apart, the room being 8 meters wide, it happens. Always.

But I understand I must go find my hidden DSP machine, right ? 

 

Maybe someone can do some math about the "damping" of soundwaves which radiate to the side walls and are reflected there. In a normal living room ? nothing damps and the only thing what matters is the propagation distance. So day that the speaker is 1m from the wall then possibly each reflection towards you travels 2 meters further/longer and is therefore attenuated by, what ? 6dB (2x 3).

 

How does it come that you are so definite / persistent on your claim ?

 

Are you saying that you hear sound outside the speakers boundary because of side wall reflection? If so, I agree. 

[STC]

1 minute ago, adamdea said:

No. Why should the sound coming from two boxes appear to come from an area outside the two boxes? I do hope this isn;t going to be a tedious ambiophonics plug. The issue relating to stereo speakers is pretty obvious assuming one starts with how you hear and proceeds to how stereo creates an illusion.

 

It is about speakers soundstage. Ambiophonics got nothing to do with this. 

 

I never heard sound outside the boundaries in a well treated room with 60 degrees setup. However, many says they could hear the soundstage is wall to wall. Is this depends on ones perception. And this is about normal stereo setup. 

[STC]

3 minutes ago, PeterSt said:

 

Are you outside in the field with your speakers then ?

 

But if the side wall reflection is strong enough to alter the position of the instruments then it introduces coloration. 

[STC]

43 minutes ago, PeterSt said:

 

And then still I dare say that it can happen (though harder to prove for me) because of how we (our ears + brain) work with phase and how the recording just incorporates phase. .....

 

 

Does this mean that even if the stage is less than 60 degrees In the orginal event projected a wider stage than 60 degrees?  @gmgraves May have something to say about this. IMO, your playback cannot exceed the physical location of playback. 

[STC]

19 minutes ago, Nikhil said:

STC,

 

The sound stage can and does position itself outside the speakers.

 

At Munich 2017 there was the BACCH SP seminar by Theoretica Applied Physics in which Prof Edgar Choueiri repeatedly demonstrated the abilities of his remarkable Bacch SP processor to - on the flick of a switch - expand the sound stage from within the speakers to outside the speakers.  It was a stunning experience to say the least.    The demo as I heard it clearly placed a singer at 9:00 o clock and an instrument 2 o clock which were clearly outside the speakers positioning (speakers were at 11 and 1 o clock so to speak).  The theory I believe is in the elimination of cross talk to some extent but also involved some calibration of the digital processor to the listening seat.   

 

Here is a picture of the demo.  There is one limitation in that you have to be seated in line behind the listening seat to experience the 3D soundstage. 

 

 

This is of course not the only way to experience this but as they say there are many ways to Rome.  Do look up the Theoretica website for more info.

 

Regards.

 

 

  

 

Yes. That’s possible with crosstalk cancellation which what BACCH is and I am doing that with Ambio. Here the issue is with stereo setup because some hear sound outside the physical boundaries of the speakers and I am curious what really triggers that.    

[STC]

36 minutes ago, PeterSt said:

 

I don't think it will be helpful for this context, but at least it testifies that I actively work(ed) on the subject; the screenshots I referred to were here :

 

 

 

But never mind this really. It is the upside down application from your subject. But when reading deeper, it is the follow-up of that project (which I did for a couple of years together with someone else) bodied into (the name) Phasure. That summarized : when waves are sufficiently sharp limited (in mid space) the phase relation as caught by stereo microphones (hey, them being maybe 20cm apart) can be brought back by two (not even more) transducers like loud speakers in the exact same fashion if only those phase relations are unique for the space those transducers reside in. This can NOT work for audio because the wavelengths are too long to uniquely imply phase angle equality (coherence ?).

Envision a LF wave of 10 meters long and anywhere on that wave you want to find the phase angle (crossing zero being a definite problem to begin with, but this can be solved). It would be tedious because each next cm would show practically the same phase angle (while you'd want (sub)cm accuracy). Now compare a HF wave of 10KHz. Thus envision again. ... Much more easy. But still a problem because together with all of the other frequencies spit out by e.g. the violin, it should form a picture of the proper size and uniquely in space (in your room). The lower frequencies won't work, but if the higher do, your brain will do the remainder. So say that all the frequencies together lead to one unique point in space, it works. But would I let lose my math on it (like used in those screenshots) then several positions come forward and no violin will be pictured in space.

With microwave frequency this works (say WiFi frequency of 2.4 GHz). But these waves are so sharply angled that it is an easy job. That project used two adjacent of such frequencies and two antenna's only (like 10cm apart) and it detects objects of IIRC 2cm diameter unique in a 12 x 4 x 3m space, accurate to 0.1mm.

The only upside for audio is that we possibly can use 20 different frequencies because the instrument of concern exhibits that. The more frequencies radiated, the longer the frequencies are allowed to be to form one unique localization point in (3d) space.

 

And so I am always working on better delimited (boundaried) sound waves ...

 

 

 

I should read the whole thread to understand better. My understanding of stereo microphone capturing sound is :-

1) timing difference.

2) level difference. 

3) phase difference. 

 

I have reasonable understanding of 1 and 2 but not 3, although I can see how it works. 

[STC]

19 minutes ago, adamdea said:

You are curious as to what triggers the event which you claim in your OP is not possible? Did you deliberately set out to have a muddled-thought festival?

 

Again, it is a simple question. In your 60 degree speakers setup, it is impossible to hear soundstage extending beyond the 60 degrees in a standard stereo recording such as using ORTF mic setup.   That’s law of physics and yet some hear them. The question is why and how?

 

Feel free to click the ignore button if you suspect I have other agenda. 

[STC]

1 hour ago, adamdea said:

That does not mean that it could not produce an illusion it just measn that there is a good reason why that potential illusion might fail and why its success will be listener and room dependant. Hpow much colouration?

 

Stereo illusion is based mainly on timing and level difference. So the accurate recreation of the event requires the accurate recreation of the exact position of the instruments in the illusion. The alteration of the position of the instruments is no longer representative of the recorded live event in regards to the exact location or the fidelity of the original sound. 

 

Having said the above, I do not consider the coloration or the altered position of the instruments matters. What is important is recreation of the playback that is good enough to fool us that it is a real event.  

[STC]

28 minutes ago, PeterSt said:

My system explicitly has been made to NOT require a sweet spot. And so it does not. I don't even have a listening chair.

 

So now we got stereo system where everywhere is sweet spot?

are we still talking about stereo sound?

[STC]

2 minutes ago, miguelito said:

Only with phase. But "manipulation" is not necessary - if you have a pair of microphones properly aligned it would come naturally from the distance from the source to each mike.

 

Consider for example Amber Rubarth's "Sessions from the 17th Ward". No processing whatsoever in this recording.

 

I need the check whether I got this album. IOW, this recording will have soundstage beyond the equilateral triangle? And if you don’t mind, what’s your reference to say that no whatsoever processing done to this recording? I ask because one famous audiophile label which claimed not to have any processing appears to have added ambience. My email query wasn’t replied. 

[STC]

Maybe, more can suggest different true stereo recordings. Amber is a good start. Anything else?  Maybe we can list the room dimension and speakers position and describe the soundstage. 

[STC]

14 minutes ago, PeterSt said:

Do you or anyone seriously think that there is one place only where one can listen decently to a stereo image ? (or listen casually to a decent stereo image ).

 Yes. See sweet spot and stereo. Dolby manual is a good reference. See wiki too. 

[STC]

7 minutes ago, PeterSt said:

 

Seriously.

 

Maybe you can explain to me that phenomenon then. Don't paste too much from WiKi pages.

 

 

 Peter, stereo works because of inter channel time and level delay. That is recorded from the center of the stage.  The reproduction must also be between the center of the two speakers. 

 

The simplest example of sweetspot is your headphones. Place on on over your ears and pull the other one about 2 or more inches away. 

 

Or or an example of a guitar recorded 60 degrees to the left of a stereo microphone. This sound will be at 60 degrees when the delay is about 250microseconds between left and right speakers. 

 

If if you move towards the left speakers, your sound will not come from 60 degree to your left but from the direction of the speaker. 

[STC]

Let’s rephrase the question - why soundstage cannot extend beyond the speakers spread in an anechoic chamber?  This will be easier to discuss as room interaction is eliminated. 

[STC]

11 hours ago, PeterSt said:

 

I hear you. But you forgot the reason of why.

That something is recorded from the center of the stage is irrelevant to begin with. Shift it to the left a little (2 meters, seen from the listener) and it will show up more to the left of the center (of your stereo speakers).

You make it sound like I now must sit 2 meters (or so) more to the left or else there is no stereo image ? This just doesn't make sense.

Of course you said that the mikes must be in the center of the recording. No wait, you don't say that either.

 

What are you saying ?

 

 

Aha, this gives some clues. You work with time delay.

No.

Nothing in your body works with time delay that I know of. It is all phase. And that per frequency. You obviously think that if you move your head (left / right) for one degree (but say your nose moves 1 cm and with that each of your ears 0.5 cm in opposite direction) that you suddenly are able to catch a time arrival difference between left and right ear of this one cm, which is at 340m/s how few ?

Of course with this you are also saying that for a nice stereo image your nose must point dead-center to the speakers (and must be in the middle of it) ?

 

All works with phase angles and differences between them. From that we derive angle (to the source). And just saying : might you move your head mentioned 1 cm (left/right) you can still envision the angle of where the source is. Or would you say that the source moves ? or that its distance changes ?

 

If a guitar was 60 degrees to the left of a stereo microphone setup (seen from the listener who is in the center of the stage) and you play this back through loudspeakers, if all is right the guitar shows up 60 degrees to the left of an imaginary center, which btw was created by the microphone's distance (to the guitar and all). So the distance is related, and not by means of time again. Just measurable distance by "meter". So if you approach the speaker, the angle to the guitar gets wider. This would happen in reality just the same if you only approach from the middle and keep on that center line.

In some mysterious way when you are at say 5 meters from the speakers and walk sideways, the guitar goes ... where ?

I think the problem with your reasoning could be that you see that 60 degrees as fixed. This is obviously not so.

 

To the latter I should add that your perceived sweetspot also has a defined distance. And Oh, I already know, this is related to the toeing of the speaker, right ?

Wrong. The toeing of the speaker isn't related to a thing, except for waves meeting at another place. Waves of which a kazillion exist in parallel to begin with (just look at your loudspeaker driver(s) and how it radiates sound). If that total beam, thus of one speaker, would be 3 meters wide at the middle position at the distance you reside, you'd have 1,5 meters left/right margin to stay in both beams and perceive stereo image. With a somewhat longer room this 3 meters does not make sense and will merely be the total width of the room and you can be anywhere, sideways.

 

 

This one again; yes you are correct. But this is only because the guitar, where-ever it resides, does not move. So if you sufficiently walk to the left then at some stage the guitar is in between you and the speaker. And it doesn't matter whether at first the guitar was in between the speakers somewhere at first, or that it was outside of it to begin with (which is harder to believe for you anyway).

The whole image shifts of course. This is because you're making the angle of "perceivement" smaller. The very same would happen when you'd walk sideways of the real-live stage. Be at 90 degree angle and you'd have all in one plane (longitudinal for you), assumed all the players stood/sat on one line (that line 90 degrees opposed to the normal audience).

 

By now I am not sure why I need all this explanation. I am not making up anything of what I perceive and what I regard normal. Come over and have a listen.

 

Quote

 

You make it sound like I now must sit 2 meters (or so) more to the left or else there is no stereo image ? This just doesn't make sense.

"..two-channel stereo is an antisocial system: Only one

 

listener can hear it the way it was created. If one leans a little to the left or right,
the featured artist fl ops into the left or right loudspeaker, and the soundstage
distorts. When we sit up straight, the featured artist fl oats as a phantom image
between the loudspeakers, often perceived to be a little too far back and with a
sense of spaciousness that is different from the images in the left and right
loudspeakers (see Figure 8.4 and the associated discussion).
This puts the sound image more or less where it belongs in space, but
then there is another problem:" - Toole

 

" To hear the phantom center image, and
any other panned images between the loudspeakers correctly located, listeners must be on
the symmetrical axis between the loudspeakers. Away from the symmetrical axis, as in
cars, and through headphones, we don’t hear real stereo; we hear a spatially distorted, but
still entertaining, rendering."  - Toole.

 

You are referring to quote 2 situation.

 

Quote

Nothing in your body works with time delay that I know of

 

Hearing works with time and level delay. If you don't get this then rest of this discussion is not going to yield any meaningful conclusion. Human hears timing difference in microseconds to determine the location.

 

Quote

By now I am not sure why I need all this explanation. I am not making up anything of what I perceive and what I regard normal. Come over and have a listen.

 

Same to you. People have listened. That's  including a reviewer who thought it was a surreal experience. 

 

[STC]

13 minutes ago, STC said:

Hearing works with time and level delay. If you don't get this then rest of this discussion is not going to yield any meaningful conclusion. Human hears timing difference in microseconds to determine the location.

 

https://www.coursera.org/lecture/human-brain/lecture-4-2-s-deducing-the-location-of-sounds-P2gbi

[STC]

58 minutes ago, MetalNuts said:

but in fact a sizeable area that allows movement of your head your body. 

 

Even in live performance head shifting happens all the time and the stage (or object ) changes position. It is understood sweet spot is not a pin point area but a reasonable spot where the sound sounds the best with correct perceptive. In a concert hall a sweet spot is subjective as you can choose anywhere which sounds best to. In stereo reproduction, the whole idea is to recreate the stage accurately and that can happened when both speakers energy directed to a spot to arrive at exact timing so that a solid phantom centre image is created.

[STC]

31 minutes ago, PeterSt said:

Yes. And I am afraid that @STCis all about that and that he does not really like to see his hard work debunked.

 

Nothing there to debunk. It is a valid and accepted method. "The most recent, and the most ambitious, attempt to extract the maximum from legacy stereo recordings is Ambiophonics (Glasgal, 2001, 2003; www.ambiophonics.org). It has gone through several phases of evolution, incorporating binaural techniques as well as complex synthesis of spatial effects to provide optimum sound delivery." Toole ( Sound Reproduction: Loudspeakers and Room ).

[STC]

10 hours ago, Abtr said:

I'm quite sure this must be caused by the bass overtones (sympathetic vibration) which can be localized even with a (single) subwoofer. A plain 24Hz source can't be localized. 

 

It ranges from 150Hz and below. I could locate 80Hz. 

[STC]

16 minutes ago, PeterSt said:

If I browse quickly through the Ambiophonics article/guide I (personally) see mistakes only. Almost a commercial for the phenomenon.

 

Wow...you can see mistakes that others who reviewed his AES papers couldn't? @Ralph Glasgal will be interested to know. But I am sure you wont able to point out here. For the record, the pioneers of the institute that went commercial but it is still a non profit institute.

 

You have not answered any of my replies to your and I wonder if this is all about what is contradicting what you have been for your commercial interest. I will wait for Mr.Rao to rebut. It will be interesting to see what he can come up with.

[STC]

18 minutes ago, PeterSt said:

 

Please. I wasn't talking about the debunking of the method. Don't draw my text out of context by quoting one line only.

The remainder I dedicate to language problem. You don't like to see your hard work debunked. ... Which would happen when others would be able to achieve the same but outside of ambiophonics. No re-read my text to see better that I don't debunk the method at all.

 

But not to forget : you debunk the other possibilities implicitly. See your OP. No big deal because it doesn't make the discussion less interesting.

 

Stereo is stereo. There is only one method to retrieve the spatial information contained there. What other methods are there? If its there then it can be heard by everyone. And nothing there to debunk. It is based on solid scientific principles and can be objectively and subjectively tested. There is no gray area that only can happened in some unique situation. 

[STC]

5 minutes ago, PeterSt said:

 

I suppose my English is too lousy. But I recall talking about it all the time.

 

PHASE RELATIONSHIP

 

 

You want to talk about MQA perhaps ?

 

 

I already did, so I won't again.

 

 

Me contradicting ??

Shouldn't you read back on your own first 10 posts or so ?

 

 

You seem to have some 2nd agenda with this. It won't be a commercial one, but things don't fit.

You have your thing with it, which is fine. If others can do it too by different means, you get angry ?

 

 

 

Yes, it will not extend beyond the speakers boundary unless there is phase manipulation like the QSound. All other sound that you hear outside the speakers already answered by quoting Toole. Too busy defending your interest?  

 

And whats the big deal of quoting MQA papers. Has that not been criticized?  I am asking for a valid criticism.