It’s not just us folks, it’s science that demands it. You are oversimplifying to (and beyond) the point of contradicting the facts/science. The actual fact is that the reality is much harder and more complex.
I didn't know science demands anything. It is just that if you oversimplify too much, science stops working the way it is supposed to work. If I want to describe how an apple falls from a tree, I can oversimplify gravity. I don't need to worry about how the mass of Earth bends 4-dimensional space-time. So, Newton's simplyfied theory of gravity works just fine, but if I want to describe the movement of Merkurius around the Sun, I need Einstein's theory of gravity, because Sun is so massive that the way it bends space-time is
significant at the distance of Merkurius.
Similarly depending on what I am doing with spatiality matters in how precise models I need to use. Crossfeed is a very coarse manipulation of spatiality and therefore looking at ILD only works fine. When you use HRTF to create very realistic soundstage you obviously need much more detailed models and ILD alone is not enough!
Yes, you ignored a great deal and some of what you stated was not even correct to start with! Crossfeed does not lower ITD a little bit, it just crossfeeds the signal below the crossfeed freq threshold, the ITD above that threshold is unaffected and,
Of course. Cross-feed level goes down with frequency. Similar thing happens acoustically with speakers, because with frequency the listeners head starts to shadow the sound more and more blocking crossfeed. this is part of the principles of spatial hearing and leads to natural spatiality.
by crossfeeding the signal you now have the timing differences between the two channels superimposed on the opposite channel.
Same happens with speakers. Spatial hearing is "used" to this, even expecting such cross-correlation between the ears and it means natural spatiality. Headphone sound can be avoid of such cross-correlation leading to unnatural spatiality.
So now you’ve got an arbitrary timing difference between the same sound source between freq bands and potential phase issues.
Similar thing happens with speakers. It is called mono colourization. Typically crossfeed happens up to 800 Hz (wavelength 43 cm) and crossfeed timing difference is typically 250 µs (8-9 cm). This means that the original and the crossfed signals add up close to in phase. At 800 Hz the delay is actually only 71 % of the 250 µs (180 µs to be generous whch is 54° phase difference) and even the crossfeed level has dropped by 3 dB making "phase issues" milder. The phase issues would be serious, if the phase difference was about 180° (canceling), but it isn't even close to that.
Also, crossfeeding happen from left to right and from right to left meaning things are mirrored on both "sides" and spatial hearing is able to figure out what is going on.
There are related issues with ISD and the spectral differences in the recording. Reverberation ratio to direct sound is unaffected because crossfeed does not separate reverb from direct sound, it crossfeed the entire signal (below a threshold) and reverb typically has less separation than the direct sound because it is diffuse.
Make a test signal of in phase (mono) noise and out of phase noise summed. Crossfeed it. You'll hear how the mono noise is not affect almost at all, but the out of phase noise gets attenuated. So, crossfeed indeed CAN separate signal components of differing channel difference. Since reverberation (diffuse sound field characteristics) tend to have much higher channel separation than direct sound (free field charasteristics), crossfeed can to some extend separate them and modify them differently.
There are various other things you’re ignoring and/or misrepresenting but the above is enough to be going on with!
You are just craping the bottom of the barrel to find reasons to discredit me. Nobody is talking about "various other things" in the context of crossfeed and for a good reason: They are irrelevant! If you think otherwise then please give me a mathematical calculation of why these things shouldn't be ignored. I am a math guy. Give me the math and I believe you!
Nonsense, spatiality does NOT happen in our brains! Early reflections, reverb and spectral, level and timing of both the direct and reflected sound occurs in reality.
Reality generates spatial
cues our brain interprets in a way that more or less aligns with the reality, but not always! If you play mono sound on both stereo speakers, the reality is sound is radiated from the speakers, but your brain interprets the situation as sound coming from the middle point between the speakes. Simple proof of spatiality happening in brain. Spatial
cues normally happen in reality but can be generated other ways too such as HRIR convolution.
These factors are what define spatiality, they are all objective and objectively measurable. All these factors then get modified again by HRTFs which again occurs in reality and is objective and objectively measurable. What happens in the brain is the determination of how and what we perceive in response to all this actual/objective spatial information and our personal preferences of it.
They are objectively measurable properties of the reality, but how we hear them is a separate thing, although very highly correlated.
But if there wasn’t objective spatiality stereo would not exist.
Human spatial hearing has developed in reality so that's why what we hear and what the reality is are VERY close to each other. Our spatiality is subjective, but almost identical to identical with objective reality. That's why it seems our spatiality is objective, but there are differencies and the illusion of stereo sound is based on them.
No, spatiality is a reality. The perception of spatiality when listening to stereo is partly an illusion.
Yes, stereo is illusion.
No, you can have reasonable spatiality with just one speaker without illusion, you can have distance/depth using the previously mentioned objective factors. Of course, this is just the spatial dimension of distance (and potentially height) that doesn’t include width, so we could argue it’s “reasonableness”.
Yes, but I have limited this to stereo, because the topic of crossfeed "requires" stereo to make sense.
No, (stereo) speaker spatiality is just two point sources (speakers). We perceive a line (under certain conditions) thanks to the illusion. Typically we perceive more than just a line (also depth) due to objective factors and how our brains interpret them.
Yes, no disagreements here.
As reverb is very diffuse it will have lower ILD, ISD and ITD values than direct sound, not larger. Except in the case of a direct sound in the phantom centre, in which case it will have roughly the same or marginally more.
You are right if we talk about reality, but we don't crossfeed "reality." We crossfeed stereo recordings made in reality. Those recordings can have wild values depending on how they were produced. Also, when I said direct sound, I meant direct sound from centre of near centre. Sorry about that. Direct sound from the side has larger values than reverb as you say, but how often are instrumets recorded that way? You know this better than I.
ERs are not diffuse, the ILD and ITD values will depend on the relative position of the sound source relative to the initial reflection points and therefore can be greater or less than the ILD and ITD of the direct sound. The spectrum of the ERs will depend on the distance and reflective properties of the boundaries.
Of course not "100 % diffuse", but the combination of all ER is more diffuse than direct sound. Otherwise I completely agree.
Crossfeed does not reduce “especially ILD”, it reduces/changes everything equally below the freq threshold. It also does not separate direct sound from the reverb/reflections and therefore does not reduce reverb relative to direct sound.
Yeah, it reduces my blood pressure equally... ...depending on how the recording is mixed direct sound can have differing effect to reverb as I have explained above. If mono remains almost the same mono, but out of phase sound attennuates, there is separation. Now, it is up to the recording how mono or out of phase things are...
It is probably the exact same issue or sometimes worse, because studio recordings are often close mic’ed and therefore have relatively little acoustic room information and often the rooms used in studio recording are not of a similar size and/or have significantly different acoustic properties.
Yes, but don't those productions use room mics to add room acoustics?
You’ve changed your rhetoric in regards to effectively stating that what you perceive is definitely right and anyone who perceives something different is an ignorant idiot. Obviously that was both factually false and exceptionally offensive but thankfully you don’t do that anymore, you seem to accept that perception varies and isn’t correlated to ignorance or idiocy. However, your rhetoric regarding spatiality, what crossfeed does to it and why it works so well for you, has not changed. I don’t correct you as much because your posts are generally not so offensively false, not as incorrect (except when you go off on your hobby horse of ILD at the expense of everything else) and sometimes I just can’t be bothered because it’s all been stated before and you either just ignore it or acknowledge and then dismiss it on the basis of circular arguments about your perception/preferences of ILD!
G
I was VERY offensive back then, because the way my first posts here were received stunned me. Since then I have learned that this planet is VERY hostile toward crossfeeders and I better accept being a second-class citizen. So I am more humble, but also more depressed and I don't believe myself at all. I have always failed so I am a loser. At least 2012-17 gave me an illusion of knowing something relevant.
If I am wrong about why crossfeed works for me then can you tell me why it works for me? I have not seen your alternative theory. That's why I have no need to abandon my own theories. For me my theories make perfect sense. I don't understand why they don't make sense to you. You haven't been able to explain that. I need math. Your posts don't have much math. Sorry.