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? 

[adamdea]

Why should it?

[PeterSt]

29 minutes ago, STC said:

it is impossible to hear stereo sound going outside the speakers outer boundary. Thoughts?

 

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).

[PeterSt]

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).

[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. 

[PeterSt]

1 minute ago, STC said:

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. 

 

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 ?

[PeterSt]

6 minutes ago, STC said:

So we agree on most things

 

I can't see it. We disagree on everything.

But never mind, I will leave you to it. Maybe you will find a few contenders which help you with your quest.

I thought you had a problem to work out. But it appears to be a claim.

Strange ...

[adamdea]

6 minutes ago, STC said:

Because most classical orchestra soundstage is beyond 60 degrees. 

 

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.

[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. 

[PeterSt]

Just now, STC said:

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

 

Are you outside in the field with your speakers then ?

[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. 

[PeterSt]

2 minutes ago, STC said:

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

 

Technically you will be correct there. But practically ... I don't think so. This is because of (the ever vague subject of) our brain interpreting this correctly. I mean, the live double bass player will color as hell because you have walls ? No. For your brain this is just the interpretation of the room. And if the double bass player goes into another room in your house, his play will sound different.

Up to, of course, when he plays in the bathroom. That was one step too far ...

 

Anyway, I see that your pose should be :

 

1 hour ago, STC said:

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

 

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. IOW, there's a vague boundary between phase manipulation and all else which is not that but which in effect technically works the very same. It also works out the very same.

 

Didn't you see my screenshots (4 weeks or so ago) about two antenna's which are able to localize a point source to the outside of them ? it's exactly the same thing but in upside down fashion. There is no reason why we should not perceive a happening which was outside of two stereo microphones, there all the phases (of all frequencies !) coming together to provide you with the point source information of that single location. Of only the phase relations are unique (and with the far too low frequency in audio this usually is not unique at all, making the location vague up to smearing into the dead center (because it is everywhere but the center now is the loudest / closest by).

 

[adamdea]

For a normal sound source in a room you would expect to hear it where it is. If you take two sources and manipulate the inter channel amplitude you can fool your ears into thinking that the sound comes from inbetween them. This should not in itself make you think tha tthe sound comes from anywhere outside the two speakers because in the most extreme case you will be hearing all the sound coming from one speaker which will mean that you locate it precisely at that speaker (unless somkething else confuses your perception). So the starting point is that its going to be tricky

There are other effects at work which can also affect where you locate sound  in a room though. But how will these replicate the inter aural time differences,  spectral differences  and acoustic cues you might experience if the sound were coming from way left or right? Will these be the same for all rooms and all listeners?

[adamdea]

16 minutes ago, STC said:

 

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

So what? 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? Will it by chance resemble or markedly differ from what the hrtf would do? Your brain will just have to muddle through with forming a conclusion basd on less than perfect infromation. even if the sonic information  were perfect there would still be a potential problem from the fact that you (probably) know where the speakers are and you can;t actualy see a double bass player. 

btw I sometimes hear the sound coming from outsdie the speakers and sometimes I don't. In my old house I used to hear the sound coming from the right of one speaker often but hardly ever from the left of the other.  

[PeterSt]

19 minutes ago, adamdea said:

if the sound were coming from way left or right? Will these be the same for all rooms and all listeners?

 

FYI : if there is a sound profoundly at some point in space (in my listening room) I can walk around it.

I also once did a test with someone else who was at an inordinate angle (opposed to me and the room itself) at 4m or so distance from me (he say 2 meters closer to the speakers) and I asked him where he heard a sound and the other way around. We always pointed to the same location ...

[Nikhil]

STC,

 

The sound stage can and does position instruments and singers outside the speakers. But it requires a tremendous system to do it.

 

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.

 

 

  

[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. 

[PeterSt]

24 minutes ago, PeterSt said:

Didn't you see my screenshots (4 weeks or so ago) about two antenna's which are able to localize a point source to the outside of them

 

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 ...

 

 

[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.    

[adamdea]

8 minutes ago, STC said:

 

Yes. That’s possible with crosstalk cancellation which is 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.    

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?

[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. 

[fas42]

What I call a competent system is always capable of having sound subjectively coming from outside the speaker span. A clearly defined example of this is using a true mono source over the two speakers; if one steps to the left of the left speaker, then the sound originates from beyond the plane of the speakers, in line with one's lateral position - if one moves laterally the sound image tracks one, being always directly in front.

 

This obviously happens because the brain 'measures' the phase difference between the two sources - but requires high quality rendering for the brain not to be drawn to be becoming aware of nearest speaker being the true source - one of the markers for convincing playback.