SO ... HOW do we measure soundstage???

[Justdafactsmaam]

The issue is an old one. The idea we can re-create truly the original recorded sound space with two channels. You cannot get there from here so to say.

It is an old issue. But there is new technology. And I can say from first hand experience you can get there. I am sorry if I seem like a broken record and/or shill but IMO the BACCH SP has fully achieved this. The system actually allows you to make in room recordings using the microphones that are used to create the filters. You can record sound sources anywhere in the room and directly A/B the actual sound source with the playback of the recording of it. The spatial accuracy is pretty much 100% from any position in the room.

Of course we are not going to get that level of personal configuration with commercial recordings. But the system does have the capability of 100% spatial accuracy

With custom HRTF's and binaural you might get kind of close for headphones or if some advanced DSP can totally remove the room. You still have the issue of we regularly move our heads about a bit, and dummy/binaural doesn't do that. Maybe that can be finessed away with enough computing power and head tracking.

Yes it can. Head tracking is essential and we have it

 

[Blumlein 88]

It is an old issue. But there is new technology. And I can say from first hand experience you can get there. I am sorry if I seem like a broken record and/or shill but IMO the BACCH SP has fully achieved this. The system actually allows you to make in room recordings using the microphones that are used to create the filters. You can record sound sources anywhere in the room and directly A/B the actual sound source with the playback of the recording of it. The spatial accuracy is pretty much 100% from any position in the room.

Of course we are not going to get that level of personal configuration with commercial recordings. But the system does have the capability of 100% spatial accuracy



Yes it can. Head tracking is essential and we have it

I thought the head tracking currently in use with headphones was to create the sound of listening to speakers in your room. There is more than one version and I'm not up to speed on all of them.

As for BACCH, I have heard some demos and while interesting was not as impressed, but maybe it is improved.

So are you telling me we can completely remove the room (or completely enough) and completely hear only what was on the two channel stereo source? Two channel recordings still lack the information to fully recreate the original soundfield or is this not what you are saying is possible?

 

[Justdafactsmaam]

I thought the head tracking currently in use with headphones was to create the sound of listening to speakers in your room. There is more than one version and I'm not up to speed on all of them.

There is that. But there is also head tracking with speaker playback. That’s really a huge part of the BACCH SP and IMO essential

As for BACCH, I have heard some demos and while interesting was not as impressed, but maybe it is improved.

So are you telling me we can completely remove the room (or completely enough) and completely hear only what was on the two channel stereo source?

Yes. I have heard it for myself

Two channel recordings still lack the information to fully recreate the original soundfield or is this not what you are saying is possible?

We are stuck with the history of commercial recordings. None of them are perfect. There are binaural recordings that do a great job of demonstrating the capacity of a two channel recording creating an accurate and convincing illusion of spatial perception.

One of the demo tracks from David Chesky has him standing 30 feet way from the microphone off to the side. You can clearly hear his position in the playback. He walks toward the microphone and continues to talk until he is about 6 inches away 90 degrees to the side of the microphone. And that is exactly where you hear him. I had one person literally jump out of the chair with this demo and exclaimed “I felt him breathing on me!”

With other demo tracks you can hear imaging from a multitude of directions with depth/distances in excess of 100 feat. And yes, my listening room, being quite dead, disappears and the recorded environment takes over.

And there are many non binaural recordings that are every bit as astonishing. I have a record from Rhea, a Chinese audiophile-ish label of traditional Chinese music. The expansiveness of the sound stage and specificity of the imaging, both of the instruments and their reverb on the concert hall walls and ceiling is truly spectacular. It’s a remarkable illusion of transportation to another space.

Even with studio recordings the expansion of the sound stage and delineation of imaging in all three axis is astonishing and in almost all cases a huge subjective improvement.

I would not have believed it either had I not heard it for myself

Killing room reflections is really important, head tracking is essential and custom filters are significant

 

[goat76]

OK so you tried the entry level SP. you didn’t *like* the effect in some cases. There are two debates going on here.

1. Whether or not room reflections and cross talk are a necessary component for soundstage and imaging or are an inhibitor.

So when you auditioned the U BACCH did the soundstage expand or contract? Was the imaging more ore less convincing?

Oh, you think I must have heard it wrong? No, I had time to set it up right, it worked well for what it was supposed to do and it effectively canceled out the sound from the opposite ear. It just didn't sound very natural, it sounded wider but in an obvious phase-canceling way.

2. The other debate seems to be about artists’ and recording and mastering engineers’ intent.

I take the position that we can never know those things and even if we could we are not obligated by them

No, that's not at all what I have been saying. I just want to hear the sound of ordinary recordings in a natural way without obvious phase manipulation tricks going on.

When mixing music, a lot of thought goes into how things are panned in the mix, I’m sure most mixing engineers would have done the panning differently in the mix if the music were intended to be listened to with crosstalk cancellation.

 

[Justdafactsmaam]

Oh, you think I must have heard it wrong? No, I had time to set it up right, it worked well for what it was supposed to do and it effectively canceled out the sound from the opposite ear. It just didn't sound very natural, it sounded wider but in an obvious phase-canceling way.

If you used the U BACCH you didn’t hear it “wrong” you just didn’t hear it anywhere near it’s best.

Which is fine. You didn’t like what you heard you probably wouldn’t like it any better with a custom filter, head tracking and minimal room sound.

 

[AJM1981]

Yes, it's possible to fool with separation, (at least horizontally), electrically by changing the Left-Right mix. Years ago I had a Apt Holman preamp that had such a control; look at the picture (from the ASR review), it's the third knob from the right. Turning the knob clockwise a bit would tend to expand the soundstage by reducing the apparent center channel due to L+R blend ...

I suppose it would be possible for a maker to build in such a control in the component, (with or without talking about).

There are tube "effects" that affect the sense of apparent depth from a component. But in comparison of my tube preamp with s/s and passive preamp I had at the time, I concluded that it was an artifact, not anything on the recording.

Nice one, and probably either by coincidence or a bit of altering in components these little off-sets happen that audiophiles don't mind and even value.

Given that; the mindset kind of separates studio gear from hi-fi.

I imagine that when someone records a guitar part with a tube amp that (however it's special) the producer does not want a "double tube sauce" on what he or she hears in the output since it will sound more "clinical" when having the output on most used regular amps that dictate the reference. But to me a bit of "spice mix" in hi-fi, when being the listener is not that bad

 

[goat76]

That is comparable to arguing against the use of jet engines by demanding documentation of the inventors of the airplane advocated their use.

I never said that you are restricted to documents from the time of the birth of stereo, you are perfectly free to provide modern documents that describe what you claim. If it happens to be a general consensus that the sound from each speaker in stereo is meant to be heard in each ear, it shouldn't be that hard to find information about it no matter if it's old or new documents.

There is plenty of documentation on the ill effects of crosstalk on stereo perception. It’s actually a common measure in stereo components.

Yes, we can call it an “ill effect” if the crosstalk occurs in the electrical signal domain in the stereo components, but not when it happens acoustically as that is a completely natural way of hearing things.

Technology advances. Are you interested in adhering just to Bluemlein’s original studies on stereo or are you interested in the studies, development, and new technologies that have since followed?

I’m interested in natural-sounding reproduction of music and crosstalk cancellation is unfortunatly not the answer to that. It's simply not a development toward a more “accurate” sound.

An opinion you get to have. An opinion as someone who has actually lived with crosstalk cancelation SP and done 100s of A/B comparisons I don’t share. And I challenge your assertion that there even exists such a thing as a “normal 2 channel recording.” There is no such standardization that we can make that delineation between a “normal” stereo recording and non normal stereo recording

It's not about “normal 2-channel recordings” or not, it’s all about how our sense of hearing works and there are definitely never any crosstalk cancellations happening when we hear sounds in the real world either.Do you know of any documentation that specifically cites such a thing as a “normal stereo recording” and states the objective parameters of such a recording so we can objectively identify a stereo recording as normal or non normal?

Do you know of any documentation that specifically cites such a thing as a “normal stereo recording” and states the objective parameters of such a recording so we can objectively identify a stereo recording as normal or non normal?

I can’t cite anything explaining the nature and properties of an undetermined entity.

No, do you have any documentation that describes that crosstalk cancelation occurs in our sense of hearing when sound happens to come from other directions than straight in front of us?

 

[Blumlein 88]

I never said that you are restricted to documents from the time of the birth of stereo, you are perfectly free to provide modern documents that describe what you claim. If it happens to be a general consensus that the sound from each speaker in stereo is meant to be heard in each ear, it shouldn't be that hard to find information about it no matter if it's old or new documents.



Yes, we can call it an “ill effect” if the crosstalk occurs in the electrical signal domain in the stereo components, but not when it happens acoustically as that is a completely natural way of hearing things.



I’m interested in natural-sounding reproduction of music and crosstalk cancellation is unfortunatly not the answer to that. It's simply not a development toward a more “accurate” sound.



It's not about “normal 2-channel recordings” or not, it’s all about how our sense of hearing works and there are definitely never any crosstalk cancellations happening when we hear sounds in the real world either.Do you know of any documentation that specifically cites such a thing as a “normal stereo recording” and states the objective parameters of such a recording so we can objectively identify a stereo recording as normal or non normal?



No, do you have any documentation that describes that crosstalk cancelation occurs in our sense of hearing when sound happens to come from other directions than straight in front of us?

You can read the Alan Blumlein patents on stereo. Not only is crosstalk expected, it is integral to stereo to allow us to hear directions of sound.

 

[Justdafactsmaam]

Yes, we can call it an “ill effect” if the crosstalk occurs in the electrical signal domain in the stereo components, but not when it happens acoustically as that is a completely natural way of hearing things.

Why? Why is it an I’ll effect in one case and not the other?

I’m interested in natural-sounding reproduction of music and crosstalk cancellation is unfortunatly not the answer to that.

Please objectively define “natural sound”

It's simply not a development toward a more “accurate” sound.

Sure it is. That cross talk is not on the recording. Adding it in the listening room is less accurate to the recording

It's not about “normal 2-channel recordings” or not, it’s all about how our sense of hearing works and there are definitely never any crosstalk cancellations happening when we hear sounds in the real world either.

Yes it is about how our sense of hearing works. Very much about that. And when we hear sounds in the real world they come without speaker/listening room cross talk or reflections. That’s a fact. I listen to an orchestra in a concert hall I am NOT hearing added cross talk from speakers or listener room reflections from the room where I listen to stereo. That is added to the playback in home stereo and most definitely is neither accurate nor natural

you know of any documentation that specifically cites such a thing as a “normal stereo recording” and states the objective parameters of such a recording so we can objectively identify a stereo recording as normal or non normal?



No,

Then you can’t use it as a premise for your arguments

do you have any documentation that describes that crosstalk cancelation occurs in our sense of hearing when sound happens to come from other directions than straight in front of us?

There is no cross talk to cancel when we are talking about original sound sources.

Here are some basic facts.
1. Our spatial perception comes from decoding the differences in sound from our two ears.
2. The primary elements of those differences are arrival time, amplitude and head transfer function
3. Speaker cross talk and room reflections send each ear information that directly conflicts with all three and the cues on the recording that apply to all three. 1. Arrival time 2. Amplitude 3. Head transfer function.

Or to put it more directly. Speaker/room crosstalk and reflections contaminate and degrade the effect of spatial cues on a stereo recording.

 

[Cbdb2]

Here are some basic facts.
1 All 3 of those depend almost fully on the direct sound, your room reflections are mostly cancelled out by the brain.
2 No natural sound has crosstalk cancelation.
3 Nobody records, mixes or masters with crosstalk cancellation.

If you want to use an effect go for it, but don't tell me its better. Thats your opinion, not a fact, justthefacts.

 

[Thomas_A]

There are other ways to decode and I wish Bremen had their three- channel system for sale; only seen that has been on demo on shows. It is a decoder, center speaker + two sidewall mounted speakers (ie their current 3D8 model). The system is meant to take walls out or the equation and ”replace it with the venue”. It is also friendly for multiple listeners.

Bremen.se

 

[Justdafactsmaam]

Here are some basic facts.
1 All 3 of those depend almost fully on the direct sound, your room reflections are mostly cancelled out by the brain.

“Mostly” Room reflections definitely have an audible effect on playback.

2 No natural sound has crosstalk cancelation.

No natural sound has cross talk. So there’s nothing to cancel

3 Nobody records, mixes or masters with crosstalk cancellation.

Cross talk cancelation is done during playback. Not recording.

If you want to use an effect go for it, but don't tell me its better. Thats your opinion, not a fact, justthefacts.

It’s not an effect. It removes an effect. “Better” is always an opinion. And I have always expressed it as an opinion. But it is also more accurate. And that’s not an opinion. That’s a testable fact.

 

[audiofooled]

You can read the Alan Blumlein patents on stereo. Not only is crosstalk expected, it is integral to stereo to allow us to hear directions of sound.

Mine are even pointed to opposite ears and I have no problem with it. I have a head in between and nothing is made for it's transfer function anyway. We are fine at adapting.

 

[Duke]

The vinyl had horrific pre-echo

Yes, that is a very common phenomenon... Yes, that is a very common phenomenon...

 

[Sal1950]

Multichannel doesn’t cut it unless it’s a dedicated original multichannel recording.

Ah, but it will never equal what a fully discreet multichannel system can deliver.

 

[goat76]

Why? Why is it an I’ll effect in one case and not the other?

It's an obvious fault in the component chain if the channels leak into each other already in the electrical domain, opposite to the natural crosstalk that occurs in the acoustic domain, where both ears should hear the sound of both channels similarly as the ears would hear a real sound 30 degrees in front of them.

Please objectively define “natural sound”

A sound that is not canceled out in the opposite ear.

Sure it is. That cross talk is not on the recording. Adding it in the listening room is less accurate to the recording

No, it isn't. Even if the recording is mixed to a separate left and a right channel, and the playback consists of one left loudspeaker and one right loudspeaker, it doesn't mean that the sound of those two channels is exclusively meant to be heard just in the left or the right ear. For a stereo recording to sound natural, we must be able to hear everything in the mix with both our ears in the same way as we would hear the sounds live.

Yes it is about how our sense of hearing works. Very much about that. And when we hear sounds in the real world they come without speaker/listening room cross talk or reflections. That’s a fact. I listen to an orchestra in a concert hall I am NOT hearing added cross talk from speakers or listener room reflections from the room where I listen to stereo. That is added to the playback in home stereo and most definitely is neither accurate nor natural

Ask yourself this: If a real sound object was positioned 30 degrees to the left in front of you, wouldn't you hear that sound with both your ears and be able to know exactly from what direction that sound was coming? And take that experiment further, do you think you would be better able to pinpoint that sound position more accurately if you blocked your right ear with your finger?



In the example below you have the left channel only of a Norah Jones song.
https://www.dropbox.com/scl/fi/m12w...-sec.wav?rlkey=8ncp6ex7ah2fmhwbx7dllchnm&dl=0

1. When you listen to this track you will hear that the sound is coming from the exact position of the left loudspeaker, that is of course expected because that IS the exact position of the sound, and that's the correct direction this sound IS coming from.

2. Try now to keep your head looking straight forward between your speakers and now block your right ear with your finger. By doing that you will most likely notice that the sound seems to be coming from a position outside the left speaker, but do you find this to be more correct than when you heard the recording with both your ears? No, you shouldn't think that because you fully well know that is not a more accurate way of hearing it. But still, that's exactly your argument when you say that the sound would be more accurate if you use crosstalk cancellation.

There is no cross talk to cancel when we are talking about original sound sources.

There is no crosstalk to cancel in a normal 2-channel audio production either, that is if you like to hear the mix naturally in a similar way as our hearing normally works in real life. It's of course perfectly okay if you may subjectively prefer the recordings with crosstalk cancellation, but please don't say it's a more accurate way of hearing things.

Here are some basic facts.
1. Our spatial perception comes from decoding the differences in sound from our two ears.
2. The primary elements of those differences are arrival time, amplitude and head transfer function
3. Speaker cross talk and room reflections send each ear information that directly conflicts with all three and the cues on the recording that apply to all three. 1. Arrival time 2. Amplitude 3. Head transfer function.

Or to put it more directly. Speaker/room crosstalk and reflections contaminate and degrade the effect of spatial cues on a stereo recording.

Yes, yes, and yes. But crosstalk cancellation will not solve those problems, and unfortunately, it introduces new problems.

 

[Blumlein 88]

Do you realize that we only need 17 db channel separation for full right/left stereo effect? Do you know that the reason that is the case is due to our head sound shadow from one ear to the other that is about the greatest difference in level you'll get with a natural sound? And that this being the case our hearing doesn't make use of any additional channel separation. Further if you do a left-center-right mix, it will sound highly unnatural over headphones, but perfectly fine with speakers. This is because listening to speakers one channel leaks into the other. The fix for phones is crossfeed, or reduce the channel separation between each channel so it sounds okay over headphones.

 

[Justdafactsmaam]

Mine are even pointed to opposite ears and I have no problem with it. I have a head in between and nothing is made for it's transfer function anyway. We are fine at adapting.

I’ve read them and his system advocated a center channel. But it doesn’t matter. His work was innovative. But not scripture

 

[Justdafactsmaam]

Ah, but it will never equal what a fully discreet multichannel system can deliver.

I’d love to put it to the test. I would like to know how you beat 100% perceptual spatial accuracy? Does multichannel go to 11?

 

[olieb]

For a stereo recording to sound natural, we must be able to hear everything in the mix with both our ears in the same way as we would hear the sounds live.

Hm, somehow you got this backwards.
In stereo we do hear everything in the mix with both our ears, right, but that is not at all always the same way as we would hear the sounds live, certainly not for frontal sounds. And therefore a stereo recording rarely sounds "natural", it is quite tricky to get near a good sound. People study that a lot and still many fail.

Stereo is good at reproducing sounds from the speaker positions at the edge of the scene, you pointed this out.
But with frontal sounds there is a major problem in stereo as each ear hears these sounds twice with a delay of about 250µs in between. One of the effects (comb filter dip) was discussed above.
I would rather like to have good center sound at the expense of some problems at the edge, instead of the other way around.

As I understand crosstalk canceling tries to do something like that. I tried uBACCH in my rather inadequate room for a short time and was not impressed. Maybe other techniques are better but my guess is the amount of extra sound that is radiated into the room to cancel at the ear positions will always compromise the result (unless in super treated rooms). And the complexity is another problem. So I highly doubt the "100% perceptual spatial accuracy".

So we have to live with a compromise in either way. Because that is what stereo is in the first place. I am pretty sure Blumlein would have loved a way to just switch off crosstalk, but there isn't. Two speakers in a room produce crosstalk, not because it is the best thing but because you cannot (easily) change it. And if you do make the effort, you get new problems.