BACCH4Mac "Absolute Sounds Product of the Year 2024"

[STC]

That is the nature of a hard-panned sound, whether you like it or not.

A sound object that is hard-panned is just played by either the left OR the right speaker, so the sound can only come from the exact position of that speaker as long as no effect is applied. It's as simple as that, and that is the reason why it can be used to determine if BACCH is fixing a problem or if it's just an effect. It is an effect as it often makes the sound object appear to be coming from a position outside the speaker.

XTC is fixing a known problem of crosstalk. hard panned is isolating the sound to the speaker so if you put the speaker 180 degree apart then you going to get sound from 3 and 9 o’clock; it is not what the mastering engineer intended. Most engineer work with a 60 degree angle so the width fixed by the position of speaker because you cannot extend beyond the position of the speaker due to crosstalk unless you use effects.

The crosstalk cancellation institute already cited several papers why the speakers should be in Ambiodipole position due to psychoacoustics reasonings. The hard panned sound when XTC is implemented by such configuration will extend outwards from the speaker’s position. The exact position will depend on your speakers position and your own HRTF. If you have the right speakers and you know of a recordings where the hard panned sound supposed to emit from 30 degrees from the side based on conventional stereo setup then the speakers width can be determined so that you get the exact placement as the mastering engineer intended. This is where the circle of confusion comes in. Whether it is conventional stereo or XTC the exact width is not known.

Proper crosstalk (not like BACCH) focuses on your HRTF and determines the position based on the shift you get due to pinna direction finding. often this will extend beyond 60 degrees width and depending on the frequencies. You can limit the XTC so that hard panned sound to come where you believe it should be but that would compromise on the crosstalk cancellation effect and this compromises the 3D experience. 3D is not about wide soundstage. It is about realism of the performance like real players Infront of you. It is difficult concept to comprehend unless you listen to a proper setup of XTc and compare best stereo setup side by side. most of the time it like explaining 3D TV to someone who has not seen one.

 

[Gwreck]

XTC is fixing a known problem of crosstalk. hard panned is isolating the sound to the speaker so if you put the speaker 180 degree apart then you going to get sound from 3 and 9 o’clock; it is not what the mastering engineer intended. Most engineer work with a 60 degree angle so the width fixed by the position of speaker because you cannot extend beyond the position of the speaker due to crosstalk unless you use effects.

The crosstalk cancellation institute already cited several papers why the speakers should be in Ambiodipole position due to psychoacoustics reasonings. The hard panned sound when XTC is implemented by such configuration will extend outwards from the speaker’s position. The exact position will depend on your speakers position and your own HRTF. If you have the right speakers and you know of a recordings where the hard panned sound supposed to emit from 30 degrees from the side based on conventional stereo setup then the speakers width can be determined so that you get the exact placement as the mastering engineer intended. This is where the circle of confusion comes in. Whether it is conventional stereo or XTC the exact width is not known.

Proper crosstalk (not like BACCH) focuses on your HRTF and determines the position based on the shift you get due to pinna direction finding. often this will extend beyond 60 degrees width and depending on the frequencies. You can limit the XTC so that hard panned sound to come where you believe it should be but that would compromise on the crosstalk cancellation effect and this compromises the 3D experience. 3D is not about wide soundstage. It is about realism of the performance like real players Infront of you. It is difficult concept to comprehend unless you listen to a proper setup of XTc and compare best stereo setup side by side. most of the time it like explaining 3D TV to someone who has not seen one.

Panorama vs 3D movies.

 

[STC]

Panorama vs 3D movies.

Panorama is hardly 3D. XTc is not about wide stage but that’s often used as a marketing tool because that’s what will be obvious. It is about definition, separation, clarity or simply like listening to headphones but sounds like binaural recordings irrespective whether they were made plain stereo or binaural.

 

[AudioJester]

That's an interesting question! I have done accidental measurements with uBACCH in the signal chain but I have never deliberately gone about trying to quantify the effect. I am guilty of enjoying uBACCH like an old-fashioned subjectivist I think you have two ways to measure it:

- Acoustic measurements with BACCH in the signal chain. Send the output of REW through a VST host with uBACCH installed, then out the speakers with capture through a microphone. With my accidental measurements I can tell you there is no difference in the frequency response. If I were to set out to deliberately quantify the effect, I would also do mono measurements (left and right playing together) since that is how xtalk cancellation works.
- Measurement of the digital output. Send the output from your VST host through Audyssey, with and without uBACCH. Then generate a difference file.

Let us know of your results! If I have time, I might go do this experiment myself.

I found something. PAZ Analyser is a waves vst plugin. (I got it free with one of there continuous sales a while ago).

It has a stereo position display! Can clearly see the change using xtalk shaper - adjusting the effect control, but more easily with the bypass button.
Very cool! Obviously have no idea how accurate or valid the measurements are.

 

[Justdafactsmaam]

So sitting somewhere in the middle will fit the angles of the stereo triangle, no?

Somewhere in the middle. Not where I sit. Where I generally sit it’s more like 75 degrees.

It’s a pretty big stereo triangle. That stage is about 50-60 feet wide. My speakers are about 7 feat apart. How far apart are yours?

And the hall is much much bigger than that. So you are getting early reflections that are much wider

 

[Justdafactsmaam]

I am only concerned with the validity of the claim. Long before BACCH came there were other DSP and no coloration was audible including the $10 AmbiophonicsDSP where I have personally done multiple demo comparing if there was any colouration that can be audible. I am genuinely interested in crosstalk when BACCH was not event conceived. Multiple users have reported that BACCH seemed better than other DSPs but better that doesn’t mean without colouration.

The website contains contact info. I asked Edgar directly about listening tests but that doesn’t really help you.

 

[STC]

The website contains contact info. I asked Edgar directly about listening tests but that doesn’t really help you.

I did ask Theoritica but received no reply but perhaps my inclination towards Ambiophonics could be the reason as we can see that no whatsoever reference to it despite was engaged by Ralph during the early development of XTC.

 

[LIΟN]

(I enjoy both XTC sound and non-XTC regular stereo.)
To sound widespread(wider stage) about XTC is a misunderstanding or a misrepresentation.

I make sure to include changing the music from "listen" to "feel" when I talk about my appreciation of XTC.

It is difficult concept to comprehend unless you listen to a proper setup of XTc and compare best stereo setup side by side. most of the time it like explaining 3D TV to someone who has not seen one.

I agree with this.

If you think of it as listening to the sound, the question will inevitably arise: does it widen or get better.
But if you describe it as feeling, the sound is there. It depends on your space, the listening distance to the speaker, and the initial reflection, and if it's originally mixed widely, it sounds wider.
Most important part is, the speaker is erased.

I don't think there's a need to exaggerate about Crosstalk, or conclude that it's unnecessary.
If you listen within about 1~4 meters,

(Yellow and Green is Crosstalk Information)
Crosstalk exists no matter what you do, no matter how room acoustic you do, no matter what DRC you use, that's how our ears and body,head hear.

And a distance of approximately 7 meters or more loses much crosstalk meaning. (But having such a listening distance in a typical home is very difficult. To adjust the direct/reflective ratio that suits your taste and purpose, as well as your listening distance.)

So I think it's hard to describe XTC by simply saying that it "expands the soundstage".
If you could correct that Crosstalk somehow, it would be simpler to think that you can hear as much as you can = as much as hear or feel you can in your space.

We can ask ourselves.
Are we listening to the sound coming from the speakers?
Or are we just feeling your space as it is, where sound exists?
Is the sound really there? Or are our brains and ears deciding it's there based on Crosstalk?

 

[Thomas_A]

Somewhere in the middle. Not where I sit. Where I generally sit it’s more like 75 degrees.

It’s a pretty big stereo triangle. That stage is about 50-60 feet wide. My speakers are about 7 feat apart. How far apart are yours?

And the hall is much much bigger than that. So you are getting early reflections that are much wider

Mine are 7.8 feet apart. How wide the hall is does not matter. It is the angles that is covered depending where you sit. The orchestra is not sitting "at my speakers" but much farther away. Creating such an illusion related to what is on the record, speaker construction, speaker setup, and room. Having directional speakers or damped room exaggerate the crosstalk errors during stereo reproduction. Having speakers that reduce the crosstalk errors makes them more invisible as speakers, including some other small tricks.

 

[STC]

(I enjoy both XTC sound and non-XTC regular stereo.)
To sound widespread(wider stage) about XTC is a misunderstanding or a misrepresentation.

I make sure to include changing the music from "listen" to "feel" when I talk about my appreciation of XTC.


I agree with this.

If you think of it as listening to the sound, the question will inevitably arise: does it widen or get better.
But if you describe it as feeling, the sound is there. It depends on your space, the listening distance to the speaker, and the initial reflection, and if it's originally mixed widely, it sounds wider.
Most important part is, the speaker is erased.

I don't think there's a need to exaggerate about Crosstalk, or conclude that it's unnecessary.
If you listen within about 1~4 meters,


View attachment 361985

(Yellow and Green is Crosstalk Information)
Crosstalk exists no matter what you do, no matter how room acoustic you do, no matter what DRC you use, that's how our ears and body,head hear.

View attachment 361986

And a distance of approximately 7 meters or more loses much crosstalk meaning. (But having such a listening distance in a typical home is very difficult. To adjust the direct/reflective ratio that suits your taste and purpose, as well as your listening distance.)

So I think it's hard to describe XTC by simply saying that it "expands the soundstage".
If you could correct that Crosstalk somehow, it would be simpler to think that you can hear as much as you can = as much as hear or feel you can in your space.

We can ask ourselves.
Are we listening to the sound coming from the speakers?
Or are we just feeling your space as it is, where sound exists?
Is the sound really there? Or are our brains and ears deciding it's there based on Crosstalk?

Frankly, I am unable to learn anything from the graphs. It is true that generally, we ( I mean RACE developers) never recommended to do cancellation below 100Hz but that was for another reason not because crosstalk doesn’t exist. Bass is Omni directional and ILD comes into play for frequencies below 700 Hz. But since the ILD difference is so small at lower level localization becomes impossible so that was the original reason for not effecting cancellation at lower frequencies and usually not above 7000Hz also since it is extremely difficult to suppress pinna natural direction finding with XTC. Having said that Ralph towards the later years ( that’s about 40 years of crosstalk research and implementation) preferred full range cancellation.

Theory is one thing but in reality music doesn’t not contain just a specific frequency and therefore both ITD and ILD used for direction finding especially with stereo speakers and XTC. You can literally find a source in an exact space with variable combinations of ILD and ITD that is not befitting your real HRTF.

I am also at loss of the claim of space. Perhaps, I do not know in what context the term space is used here. Perhaps, it is a new jargon just like wet and dry used by Stereophiles glossary by BACCH users.

If you make a re stereo recording of five or six players spread out at various distance in an anechoic chamber then the exact distance of the source is a guess work since space or reverbs would be lacking. If you are blindfolded you would typical judge the distance with difference in level. playing this recording with BACCH or XTC cannot bring out space information that is not there to begin with. So how could now BACCH reveal more space with XTC? I don’t sense additional space. Perhaps, the bigger width and space ( distance between instruments) and spread out reverbs info being misdescribed here as more space?

Just like moving from mono to stereo, spread soundstage will be judged as lacking intensity and often compensated with loudness. But the more I read about things that weren’t meant to be there as a result of XTC I am now beginning to wonder if we are talking just about XTC or additional effects to sweetened the XTC sound?

 

[LIΟN]

So how could now BACCH reveal more space with XTC? I don’t sense additional space. Perhaps, the bigger width and space ( distance between instruments) and spread out reverbs info being misdescribed here as more space?

Correct!
I've been listening to it comparatively. I've applied the XTC to impulses at various distances, both in a true anechoic chamber and in near-anechoic conditions, and to impulses in a typical home. (I don't know how the space I wrote in the post translated, maybe I chose the wrong word, maybe the translator translated it wrong.)
When I removed (or reduced) the crosstalk, I didn't notice much difference, other than the nature of the initial reflection that made me aware of the characteristics of the space.

we ( I mean RACE developers) never recommended to do cancellation below 100Hz but that was for another reason not because crosstalk doesn’t exist. Bass is Omni directional and ILD comes into play for frequencies below 700 Hz. But since the ILD difference is so small at lower level localization becomes impossible so that was the original reason for not effecting cancellation at lower frequencies and usually not above 7000Hz also since it is extremely difficult to suppress pinna natural direction finding with XTC. Having said that Ralph towards the later years ( that’s about 40 years of crosstalk research and implementation) preferred full range cancellation.

So I also apply a low high cut to the gated response with LR/24db at roughly 100hz,8000hz and repeat the XTC.
I was previously following Race's channel mapping, and now I'm using Bacch's algorithm, which I've adapted to work with.
I haven't tried anything below 100hz, so I don't know, but I haven't noticed much of a difference when applying XTC to anything above 8000hz.

But the more I read about things that weren’t meant to be there as a result of XTC I am now beginning to wonder if we are talking just about XTC or additional effects to sweetened the XTC sound?

I agree with this as well. I've described it as like a hidden sense being unlocked when speaking to other Korean users.
It's like we can hear or feel things that we normally can't hear because of Crosstalk. (Just My own personal expression. Don't get me wrong.)

@STC And as I've said before in other threads, I say fan because your blog was one of the first things I read and perused when I was learning about XTC. Please don't misunderstand the intent of my post. I think my translator is weird and something is getting lost in translation.
I enjoy XTC as well, I just have a question: what is it really that we are hearing and trying to accomplish?

So when I applied XTC to both the sound in near-anechoic conditions, as I wrote above, and in a typical room, I noticed that the boundaries that we often perceive as soundstage disappeared, leaving only the characteristic of early reflections that embedded the space, I thought, what more could I do?
And what does the positioning and spacing of the speakers mean anymore? And what does the position and spacing of the speakers mean anymore?
So I approached it with the idea of applying XTC to all of the different angles and heights and then playing them back simultaneously to add more information about those parts.

And while I was thinking about it, I also wondered why the sound didn't reach my ears.
For example, binaural ASMR videos.
When I listen to ASMR with cotton swabs in my ears, I want the sound to reach the inside of my ears in the XTC state, but it doesn't.
And the reason for this has to do with the fact that the speaker, the sound, is not a piece of information, as we realized when integrating the various multichannels above.
In order for the sound to penetrate the inside of my ear really clearly, I need the information that the speakers are placed very close to my ear. But since I didn't have that information, I wondered if the sound couldn't get inside my ear.
So I was thinking, what would ideally be the sound that would get inside my ear, should I re-record the speaker myself, and then I got some responses that were already personalized to me with the IEM.

So I thought that if I equalized the personalized IEM response to my ear canal and shot it into my ear, it would be a kind of Pure Pulse, and I aligned it with my other XTC responses to play simultaneously.
The sound became clearer, and I felt like I was listening to ASMR that was penetrating my brain.
It was very different from simply watching binaural videos with IEMs.

So the bottom line of why I'm telling this story is this.
we have to think what is "wide?" when we hear...
It seems to mean different things to different people.. maybe it is the mixing of the music, the characteristics of the early reflections, the distance from the speakers (which is actually part of the early reflections), the spacing between the speakers...
I think it's ambiguous. But obviously, the sound is already there without me trying to hear it, so it's a very natural experience, which is a positive thing.

So, as I wrote earlier, I don't think it's an extension of the sense of sense of space or soundstage, although it can feel that way.
However, it is clear that the act of listening leads to the question: what am I listening to? What (area? feeling? boundary?) have I not heard before? Am I actually listening?

 

[STC]

The website contains contact info. I asked Edgar directly about listening tests but that doesn’t really help you.

I have been following Choueiri since he was at Ambiophonics Institute. I also followed all his research at Princeton. The Therotica website doesn’t have any new info. If you look at the footnote 17 of the FAQ the explanation of why the sound doesn’t heard at 50 degrees is confusing. As far as I know Hass effect only takes place after 1 or 2 ms. Technically when speakers are placed at 60 degrees and a recordings only contain ITD of less then 220 μs is as pretty good 3D projection if not for the delayed 220 μs of crosstalk and in any event of the explanation in reference to footnote 17 then all sound sound be stuck to left and right speakers using the same logic which we all know that’s not the case.

 

[STC]

Please don't misunderstand the intent of my post. I think my translator is weird and something is getting lost in translation.

I am guilty of the same too that my posts often come as critical and confrontational as I too rely on translator. English is not my first language ( and not even my second ) .

I will post my detailed reply because you raised an interesting point. The same point was also raised by email by another uBACCH lover yesterday and I am not sure how to address it without causing further confusion. Will get back soon.

 

[LIΟN]

I will post my detailed reply because you raised an interesting point. The same point was also raised by email by another uBACCH lover yesterday and I am not sure how to address it without causing further confusion. Will get back soon.

Yes, I'll be waiting !
Oh, and I thought of one more thing.
Most of the reviews of Race or bach or manual xtc users seemed to have a lot of stories like "expanding," "expanding."
But what I just wrote is that the more important feeling than that is that the expression of distance becomes more detailed, doesn't it?
This is a similar story to how ASMR-XTC longed to feel in the ears and the eardrum.
One of the things that I felt when I applied XTC was that it allowed me to hear close things closely, it allowed me to hear far things far away, and it allowed me to hear certain sources at ambiguous distances in between.

 

[goat76]

XTC is fixing a known problem of crosstalk. hard panned is isolating the sound to the speaker so if you put the speaker 180 degree apart then you going to get sound from 3 and 9 o’clock; it is not what the mastering engineer intended. Most engineer work with a 60 degree angle so the width fixed by the position of speaker because you cannot extend beyond the position of the speaker due to crosstalk unless you use effects.

I think you mean the mixing engineers and not the mastering engineer, there are limitation of what a mastering engineer can do to the width of a recording.

It’s not because of crosstalk that a hard-panned sound can not extend beyond the position of the speaker, a hard-panned sound can simply not come from any other position as it is a true mono sound played by only one single sound source. A minimum of two sound sources is needed to move the sound from that position, but then it's no longer a hard-panned sound, it's instead a manipulated sound thanks to the use of another sound source.

The crosstalk cancellation institute already cited several papers why the speakers should be in Ambiodipole position due to psychoacoustics reasonings. The hard panned sound when XTC is implemented by such configuration will extend outwards from the speaker’s position. The exact position will depend on your speakers position and your own HRTF. If you have the right speakers and you know of a recordings where the hard panned sound supposed to emit from 30 degrees from the side based on conventional stereo setup then the speakers width can be determined so that you get the exact placement as the mastering engineer intended. This is where the circle of confusion comes in. Whether it is conventional stereo or XTC the exact width is not known.

If I understand you correctly, are you saying that people should move their speakers closer to each other than the typical audio standard of 30 degrees if the user have crosstalk cancelation in their system (granted that the listener is concerned about hearing the mixing engineer's intended pannings in the mix?

Proper crosstalk (not like BACCH) focuses on your HRTF and determines the position based on the shift you get due to pinna direction finding. often this will extend beyond 60 degrees width and depending on the frequencies. You can limit the XTC so that hard panned sound to come where you believe it should be but that would compromise on the crosstalk cancellation effect and this compromises the 3D experience. 3D is not about wide soundstage. It is about realism of the performance like real players Infront of you. It is difficult concept to comprehend unless you listen to a proper setup of XTc and compare best stereo setup side by side. most of the time it like explaining 3D TV to someone who has not seen one.

Funny that you mentioned it, 3D TV is also a filter effect and I find BACCH to have a somewhat similar effect but aimed at sound, but I don't find any of them to be fully convincing even though they can both be cool sometimes.

 

[Justdafactsmaam]

I think you mean the mixing engineers and not the mastering engineer, there are limitation of what a mastering engineer can do to the width of a recording.

It’s not because of crosstalk that a hard-panned sound can not extend beyond the position of the speaker, a hard-panned sound can simply not come from any other position as it is a true mono sound played by only one single sound source.

Simply not universally true. The reason any hard panned sound can not extend beyond, behind or in front of the speaker is exactly because the crosstalk from that speaker masks the spatial cues that would allow it to extend beyond or in front of or behind the speaker. This is exactly why with the BACCH the object will come from any number of positions beyond, in front of, behind or even at the speaker position. It is allowing the listener to get the full effect of the spatial cues on the recording.

A minimum of two sound sources is needed to move the sound from that position, but then it's no longer a hard-panned sound, it's instead a manipulated sound thanks to the use of another sound source.

Nope. The BACCH will in most cases move the sound away from the speaker with a hard panned sound. But it does NOT add a second or more sound. It simply cancels the crosstalk from the one speaker that is causing the opposite ear to identify the speaker as the location of the sound source

 

[STC]

, I just have a question: what is it really that we are hearing and trying to accomplish?

Something that would get μs closer to the real performance. With two speakers we strive to “they are here” realism and with multi channel and DCH concept we want “we are there”.

So I approached it with the idea of applying XTC to all of the different angles and heights and then playing them back simultaneously to add more information about those parts.

I did try this by using several speakers but due impracticality I just stopped at 2 front and 2 rear 45 degree top angle.

When I listen to ASMR with cotton swabs in my ears, I want the sound to reach the inside of my ears in the XTC state, but it doesn't.

I have to admit most AMSR or binaural 3D do not work for me. Even my own binaural recorded by me and played back with almost identical in ear phones hardly not really 3D. So it is possible they won’t work perfectly for some. Even Sony or Samsung came with note of similar warning that their 3D IRM may not work for all.

So I thought that if I equalized the personalized IEM response to my ear canal and shot it into my ear, it would be a kind of Pure Pulse, and I aligned it with my other XTC responses to play simultaneously.
The sound became clearer, and I felt like I was listening to ASMR that was penetrating my brain.
It was very different from simply watching binaural videos with IEMs.

I am not really a headphones listeners and simply do not strive Ambiophonics to do more than what to expect in a real live musical performance. extreme XTC requires measurements. I am not even close to that so I have no opinion there.

So the bottom line of why I'm telling this story is this.
we have to think what is "wide?" when we hear...
It seems to mean different things to different people.. maybe it is the mixing of the music, the characteristics of the early reflections, the distance from the speakers (which is actually part of the early reflections), the spacing between the speakers...
I think it's ambiguous. But obviously, the sound is already there without me trying to hear it, so

I always thought wide is to indicate the width of the performance from left and right.

It’s not because of crosstalk that a hard-panned sound can not extend beyond the position of the speaker, a hard-panned sound can simply not come from any other position as it is a true mono sound played by only one single sound source.

I thought I said the same thing but probably it got translated differently to mean something different.

If I understand you correctly, are you saying that people should move their speakers closer to each other than the typical audio standard of 30 degrees if the user have crosstalk cancelation in their system (granted that the listener is concerned about hearing the mixing engineer's intended pannings in the mix?

I think I have addressed this to before anyway the relevant papers are there if not you can just Google up for literatures on human localization accuracy.

Funny that you mentioned it, 3D TV is also a filter effect and I find BACCH to have a somewhat similar effect but aimed at sound, but I don't find any of them to be fully convincing even though they can both be cool sometimes

Same problem here. I refused to believe a speaker can somehow produce all the sound of a 120 member orchestra! Who they are trying to fool! pure marketing strategy!

So slowly I am trying to get closer and I am waiting if something else could do the job better.

 

[LIΟN]

Something that would get μs closer to the real performance. With two speakers we strive to “they are here” realism and with multi channel and DCH concept we want “we are there”.

Very good expression! Expressions like "they are here" , "we are there" certainly feel different than simply saying you hear a sound and that's close to how I feel too.

I always thought wide is to indicate the width of the performance from left and right.

This definitely seems to depend on the purpose or content.
When watching a 5ch or 7ch movie (with different channels behaving differently), the normal surround angles were fine.
However, when I approached it as a kind of upmix XTC concept for stereo only, I don't think the regular surround placement gave me a very positive feeling.
I don't know the exact point either (because this will vary by distance).
But what I definitely noticed while setting up was that below a certain angle (30 degrees or less), the closer the spacing between the speakers, the more it affected (affected? effect? changed? any word?) the feeling of what I was looking at in front of me, behind me, and to the rear when the XTC was applied // and the wider the spacing between the speakers, the more the less stimulating angles were filled in with information and became more natural. (40~60degree).
The presence or absence of a height channel also had a significant positive effect.
So, I end up using a combination of 8 degree angle XTCs // 45-70 degree angle XTCs // 100-120 degree angle XTCs // height channel angle XTCs.
To add to this, I sometimes run a reverb recorded further away to enhance the early reflections (30-80ms).
However, in most cases, a 2ch to 4ch setup should be sufficient.

I have to admit most AMSR or binaural 3D do not work for me. Even my own binaural recorded by me and played back with almost identical in ear phones hardly not really 3D. So it is possible they won’t work perfectly for some. Even Sony or Samsung came with note of similar warning that their 3D IRM may not work for all.

Thank you for sharing your experience. In fact, binaural ASMR may not have been the best example to use. Thanks for understanding.
The fundamental starting point for that question (which I was grappling with) was this: "Why should we always be chasing sound wider and further away?
"Am I even really listening to the sound if it's close?"
"Isn't it possible to get the sound in front of my eardrums in centimeters instead of 2 meters, 1 meter, or 50 centimeters?"
That's where the story began.

I always thought wide is to indicate the width of the performance from left and right.

That's what I've been thinking too.
Then when I listened to music using XTC and various digital (actually recorded) synthesis methods, I wondered: does it really sound as spacious as a concert hall when you compare applying a VST that seems to widen the left and right widths, such as Stereo Imager, with our own speakers in a small room, with the speakers in a large room, with XTC applied to each gap?
When we go to a concert hall and actually hear it live, and when you hear it in a big movie theater, there's a huge image.
So I thought, what's the point of that big image, and that's why I attached the graph in the first post.

And a distance of approximately 7 meters or more loses much crosstalk meaning. (But having such a listening distance in a typical home is very difficult. To adjust the direct/reflective ratio that suits your taste and purpose, as well as your listening distance.)

The most natural approach would be to increase the actual physical distance so that there is naturally little difference between the crosstalk and the main channel (so that there is little difference between the left ear and the right ear when the left sound comes out), but it's also the most ridiculous... =(

I use XTC to reduce some of the crosstalk, and then I run XTC to another speaker that I've placed a little bit further away from the main speaker, and I apply some sort of reverb to that speaker so that it starts at the same time.(To get a little more initial reflection from the physical distance.)
Decay reverbs of 100ms-200ms or more are not necessary, and the initial reflection of 100ms or less was the cue to get a big feel.
Of course, it's not really room acoustic at all in a very small room, and in a very uncontrolled environment, it's going to sound rather muddled...

 

[STC]

Very good expression! Expressions like "they are here" , "we are there" certainly feel different than simply saying you hear a sound and that's close to how I feel too.

More here https://ambiophonics.wordpress.com/...sis-of-concert-hall-sound-fields-in-the-home/

However, when I approached it as a kind of upmix XTC concept for stereo only, I don't think the regular surround placement gave me a very positive feeling.

I am lost here. Regular stereo do not have surround. At best you can have limited effect like QSound creating sound coming from back or even above. What we want is is envelopment because real reverbs comes from all direction and for that you use DCH or multichannel to achieve such envelopment. This is the opposite of HT surround concept for actual sound object coming from different direction. In any event surround is not the objective of XTC unless you have 4.0 format capturing vertical 360 sound even then for true envelopment you still need real hall IR and multiple speakers.

The fundamental starting point for that question (which I was grappling with) was this: "Why should we always be chasing sound wider and further away?

That’s not the purpose of XTC. it was to address the errors in stereo playback due to crosstalk as it contradict information of real sound direction. The inherent delay 220 μs due to the placement will always remind the brain that something is wrong with the perfect stereo playback causing us to constantly try to find upgrades. Perfectionist often try to achieve this wrongly by believing cable, amps and etc etc changes can make them better.

Isn't it possible to get the sound in front of my eardrums in centimeters instead of 2 meters, 1 meter, or 50 centimeters?"

50cm is possible with XTC and BACCH probably could do better but I don’t know. It doesn’t matter to me as most music are where the performance are locked to frontal stage unless I want to achieve true binaural sound which I think headphones already doing that better.

Then when I listened to music using XTC and various digital (actually recorded) synthesis methods, I wondered: does it really sound as spacious as a concert hall when you compare applying a VST that seems to widen the left and right widths, such as Stereo Imager, with our own speakers in a small room, with the speakers in a large room, with XTC applied to each gap?

We are there is only achievable with concept like DCH and it got nothing to do with XTC. I do demo of orchestra music

The most natural approach would be to increase the actual physical distance so that there is naturally little difference between the crosstalk and the main channel (so that there is little difference between the left ear and the right ear when the left sound comes out), but it's also the most ridiculous... =(

I use XTC to reduce some of the crosstalk, and then I run XTC to another speaker that I've placed a little bit further away from the main speaker, and I apply some sort of reverb to that speaker so that it starts at the same time.(To get a little more initial reflection from the physical distance.)
Decay reverbs of 100ms-200ms or more are not necessary, and the initial reflection of 100ms or less was the cue to get a big feel.
Of course, it's not really room acoustic at all in a very small room, and in a very uncontrolled environment, it's going to sound rather muddled...

with ordinary stereo without XTC with DCH which is pretty realistic compared to stereo or multichannel.

The most natural approach would be to increase the actual physical distance so that there is naturally little difference between the crosstalk and the main channel (so that there is little difference between the left ear and the right ear when the left sound comes out), but it's also the most ridiculous... =(

I use XTC to reduce some of the crosstalk, and then I run XTC to another speaker that I've placed a little bit further away from the main speaker, and I apply some sort of reverb to that speaker so that it starts at the same time.(To get a little more initial reflection from the physical distance.)
Decay reverbs of 100ms-200ms or more are not necessary, and the initial reflection of 100ms or less was the cue to get a big feel.
Of course, it's not really room acoustic at all in a very small room, and in a very uncontrolled environment, it's going to sound rather muddled...

As I said above, this is what DCH supposed to do. You need real hall or space IRs. You need IRs from every possible directions. That need a true stereo IR and if possible two speakers for each IR. It is CPU intensive. I think I am only using less than 1/3 of all the available IRs at my disposal because my i9-9000K already at it max.

 

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At best you can have limited effect like QSound creating sound coming from back or even above. What we want is is envelopment because real reverbs comes from all direction and for that you use DCH or multichannel to achieve such envelopment. This is the opposite of HT surround concept for actual sound object coming from different direction. In any event surround is not the objective of XTC unless you have 4.0 format capturing vertical 360 sound even then for true envelopment you still need real hall IR and multiple speakers.

Yes. We're talking about the same thing.
Only a few angles worked in terms of enhancing the sense of envelopment (or in other words, adding information that was lacking).

That’s not the purpose of XTC

Yes, I know. It wasn't a goal of XTC, it was a question about myself and a goal at the same time.
As I wrote before, I perceive the position of each speaker and where I am listening as a piece of information in a particular space. I thought that because I have less information about the sound coming close to my eardrums (due to the distance of the speakers, which are relatively far away from the sound in my ears), I don't get as much stimulation as I would like from binaural ASMR videos... and I thought that I was not getting as much stimulation as I would like. I realized that I had achieved what I was trying to achieve when I played it back simultaneously with the actual recorded speaker and the hypothetical speaker in my ear, as described above.

The inherent delay 220 μs due to the placement will always remind the brain that something is wrong with the perfect stereo playback causing us to constantly try to find upgrades.

I have a variety of distances and angles from 62.5us short to 512us long.
Most of them are in the 200-290us range when placed for stereo listening in a typical home. (30~40degree)

50cm is possible with XTC and BACCH probably could do better but I don’t know. It doesn’t matter to me as most music are where the performance are locked to frontal stage unless I want to achieve true binaural sound which I think headphones already doing that better.

Same story as above: the purpose was to enhance the sound in all directions, adding information about each angle, position, etc. And I already succeeded in my own way (from the length of the ear canal to more than 10 meters, all at the same time).

We are there is only achievable with concept like DCH and it got nothing to do with XTC. I do demo of orchestra music

The reason I mentioned XTC is to clear the speaker.
As I mentioned before, the gap between an anechoic chamber-like condition and a normal room, except for the characteristics of the initial reflections and the spatial perception, was very small.
Of course, the residual early reflections are affected by the question: is this a small room? Is it a large room? but it's much more ambiguous than before.
And the reason why XTC should be applied separately from IR is as shown in the graph I attached.
To simulate naturally XTCed conditions (concerts, orchestras, general performances, etc. that are heard at a distance of 10-20 meters or more), I believe that XTC must be preceded by XTC in our room so that we can at least try to achieve similar conditions.
As I said before, even after XTC, there is still a very slight sense of what kind of space this is due to the initial reflections, but it's vague, so after that, you can overlay different angles of true stereo IR or personalized binaural IR or real BRIR (which is what I do) at different distances and different angles and play them back simultaneously.

I think I am only using less than 1/3 of all the available IRs at my disposal because my i9-9000K already at it max.

I think your way of doing things is different from mine, and it can be hard on the CPU. (I respect your way of doing things, don't get me wrong!)
I create, as I said before, a virtual environment or condition, and then I put it together with REW and Audacity and Impulcifer, assuming that's when all of that sound is actually going to come out.
Same thing with the different angles of the files. I don't think of each IR as a single impulse, but rather as as much information as I want, like I said above, and then I add them together to give my brain more detailed cues.
So when I do Align, the file is not as big as I thought it would be, and there's very little lag. In addition, Reverb for nuance after 100ms can be convolved separately or loaded into an optimized VST, further reducing the length of the main file IR and the load on the computer.

And because I'm using headphones or IEMs to play XTC, you might think it's a slightly different kind of thing, but it's really just BacchHP and C_Bacch's workflow.
It's fun to talk to you because I don't think there are as many people to talk to about XTC as I thought there would be, regardless of how or why.
So I hope you don't have any prejudice against me applying XTC with IEMs or headphones, as I respect you.