Re: [Sursound] the recent 2-channel 3D sound formats andtheir viability for actual 360 degree sound
60 degrees seems excessive head movement for someone seated listening to speakers.. Why ? It's a natural thing to do if there is any significant sound from that direction. Why should being listening to speakers make any difference ? I like to forget I'm listening to speakers. And *if* I turn my head, for whatever reason, and the illusion collapses, I'm not impressed... [Fons] I'd take that a stage further - the ideal arrangement would allow you to move around within the sound field with complete freedom. You should indeed be unaware of where any speakers are - and sweet spots, and need to face rigidly in one direction, are anathema to the anyone but a dedicated (and perhaps blinkered?) enthusiast. I've only ever had the chance to observe two demos (one Ambisonic, one WFS) which have been sufficiently impressive (with the programme material available) that the NON-cognoscenti recognised that they were in a space that wasn't the same as the physical room. Chris Woolf ___ Sursound mailing list Sursound@music.vt.edu https://mail.music.vt.edu/mailman/listinfo/sursound
Re: [Sursound] the recent 2-channel 3D sound formats andtheir viability for actual 360 degree sound
On 09/07/2011 10:03, ch...@chriswoolf.co.uk wrote: 60 degrees seems excessive head movement for someone seated listening to speakers.. Why ? It's a natural thing to do if there is any significant sound from that direction. Why should being listening to speakers make any difference ? I like to forget I'm listening to speakers. And *if* I turn my head, for whatever reason, and the illusion collapses, I'm not impressed... [Fons] I'd take that a stage further - the ideal arrangement would allow you to move around within the sound field with complete freedom. You should indeed be unaware of where any speakers are - and sweet spots, and need to face rigidly in one direction, are anathema to the anyone but a dedicated (and perhaps blinkered?) enthusiast. Listen you! I am at home not Glastonbury. I know when a play a recording, or watch TV, that there is nothing actually there! If I hear a sound behind am I supposed to get up and walk around, or use a mirror, just to look at the bloody walls. And don't confuse me with an audiophool. I've only ever had the chance to observe two demos (one Ambisonic, one WFS) which have been sufficiently impressive (with the programme material available) that the NON-cognoscenti recognised that they were in a space that wasn't the same as the physical room. Chris Woolf ___ Sursound mailing list Sursound@music.vt.edu https://mail.music.vt.edu/mailman/listinfo/sursound ___ Sursound mailing list Sursound@music.vt.edu https://mail.music.vt.edu/mailman/listinfo/sursound
Re: [Sursound] the recent 2-channel 3D sound formats and their viability for actual 360 degree sound
[Hello to all - It was good 2 C some of you at ICAD Budapest - and +ve 2 C a deal of activity in ambisonics for auditory design.] On 09/07/2011, at 6:40 AM, Fons Adriaensen wrote: On Fri, Jul 08, 2011 at 02:06:37PM -0600, Bearcat M. Sandor wrote: The ear canal is just a tube, so there's no directionality once the waves are in there. Two words act as special alarms to me. In finance: secret and in phenomenology: just. The ear canal is no less than just a tube than is a didgeridoo at the lips of an experienced player. One can certainly say the ear canal is tubular but it is not just a tube because, for eg, a) tube cannot be assumed to be regular, but arbitrarily complex, is arbitrarily flanged at both ends b) it has a transverse piece of sound-sensitive skin (the 'drum'), to which is attached other 'stuff' c) it is part of a head which has a brain in it that is also connected other sense receptors, including the vestibular labyrinth etc etc and that it has extensive experience using it/them to perceive events in external and internal environs, etc etc etc. as well as efference copy-being aware that a movement is one's own and not the world's. Related to (c), does anyone have any reports of empirical experiments on the brain's ability to learn/adapt to HRTF encoded signals encoded for 'foreign' ears? David Once they are in there. Which is why you can make things work with headphones plus head motion tracking. When using speakers, the sound has to get 'in there' first. And you are allowed to turn and otherwise move your head, so even when e.g. seated you can (and will) explore the sound field around it, and your brain will correlate your movements with the changes of the sound entering your ears. So getting the right sound 'in there' is not just a matter of recreating the sound field at the two points where your ear canals would be if your head were clamped into a vise. You have to create something matching the field of a real source at least in the near vicinity. And it turns out you can't do that without energy arriving from more or less the right direction. Ciao, -- FA ___ Sursound mailing list Sursound@music.vt.edu https://mail.music.vt.edu/mailman/listinfo/sursound _ Dr David Worrall Adjunct Research Fellow, Australian National University david.worr...@anu.edu.au Board Member, International Community for Auditory Display Regional Editor, Organised Sound (CUP) IT Projects, Music Council of Australia worrall.avatar.com.au sonification.com.au mca.org.au musicforum.org.au -- next part -- An HTML attachment was scrubbed... URL: https://mail.music.vt.edu/mailman/private/sursound/attachments/20110710/a1727017/attachment.html ___ Sursound mailing list Sursound@music.vt.edu https://mail.music.vt.edu/mailman/listinfo/sursound
Re: [Sursound] the recent 2-channel 3D sound formats and their viability for actual 360 degree sound
ML: Maybe it can; is there a way to up convert non-ambisonics recordings to horizontal ambisonics? If you down sample a 48kHz recording to 16kHz what happens? All the audio information above 8kHz is lost right? If you up convert back to 48kHz can you recover the bandwidth lost? No. You just have a large file. Everything from 8kHz up is still missing... (where would it come from? It's GONE!). The concept is the same for directionality. Once you have selected the dimensional format (stereo, ambi, 5.1, etc) any format with a lesser directional 'bandwidth' will be rendered 'stuck'. The concept of up-converting dimensionally can only be a smoke and mirrors illusion at best. - Neil On 7/9/2011 1:07 PM, Marc Lavallée wrote: Fons Adriaensenf...@linuxaudio.org a écrit : And *if* I turn my head, for whatever reason, and the illusion collapses, I'm not impressed... I just tried turning my head while listening to XTC. I can turn it more than 45 degrees in both directions without destroying the stereo image. So if turning the head is part of the localization process, it does also work with XTC (to some extent). XTC brings out a better and larger stereo image from conventional stereo recordings, just by inserting a filter in the reproduction path and by using two small frontal speakers (not four or more speakers all around me as required by ambisonics). That's already impressive. I still don't know from experience if ambisonics is better than XTC for other than practical and ideological reasons. I hope to have a second epiphany with ambisonics, because it requires more investments and efforts to install a working system at home. I only heard a few minutes of ambisonics (rendered with the Harpex filter on a horizontal/hexagonal speakers setup), and it was interesting... I would be impressed if ambisonics could provide a better listening experience from stereo and/or 5.1 recordings. Maybe it can; is there a way to up convert non-ambisonics recordings to horizontal ambisonics? -- Marc ___ Sursound mailing list Sursound@music.vt.edu https://mail.music.vt.edu/mailman/listinfo/sursound ___ Sursound mailing list Sursound@music.vt.edu https://mail.music.vt.edu/mailman/listinfo/sursound
Re: [Sursound] the recent 2-channel 3D sound formats and their viability for actual 360 degree sound
Neil, I used the wrong words. Please excuse my up-converting nonsense, and let me ask again. The perceived directional bandwidth of stereo recordings is better than what conventional stereo (with cross-talk) can reproduce. So, is it possible to adapt a stereo recording to play on a horizontal ambisonics system, in order to get a better stereo image than with conventional stereo? A kind of restored stereo experience that ambisonics can provide because of its directional capabilities? Another example: there are ways to listen to ambisonics on 5.1 systems, but is it possible to listen to 5.1 recordings on a horizontal ambisonics system? Neil Waterman neil.water...@asti-usa.com a écrit : ML: Maybe it can; is there a way to up convert non-ambisonics recordings to horizontal ambisonics? If you down sample a 48kHz recording to 16kHz what happens? All the audio information above 8kHz is lost right? If you up convert back to 48kHz can you recover the bandwidth lost? No. You just have a large file. Everything from 8kHz up is still missing... (where would it come from? It's GONE!). The concept is the same for directionality. Once you have selected the dimensional format (stereo, ambi, 5.1, etc) any format with a lesser directional 'bandwidth' will be rendered 'stuck'. The concept of up-converting dimensionally can only be a smoke and mirrors illusion at best. - Neil On 7/9/2011 1:07 PM, Marc Lavallée wrote: Fons Adriaensenf...@linuxaudio.org a écrit : And *if* I turn my head, for whatever reason, and the illusion collapses, I'm not impressed... I just tried turning my head while listening to XTC. I can turn it more than 45 degrees in both directions without destroying the stereo image. So if turning the head is part of the localization process, it does also work with XTC (to some extent). XTC brings out a better and larger stereo image from conventional stereo recordings, just by inserting a filter in the reproduction path and by using two small frontal speakers (not four or more speakers all around me as required by ambisonics). That's already impressive. I still don't know from experience if ambisonics is better than XTC for other than practical and ideological reasons. I hope to have a second epiphany with ambisonics, because it requires more investments and efforts to install a working system at home. I only heard a few minutes of ambisonics (rendered with the Harpex filter on a horizontal/hexagonal speakers setup), and it was interesting... I would be impressed if ambisonics could provide a better listening experience from stereo and/or 5.1 recordings. Maybe it can; is there a way to up convert non-ambisonics recordings to horizontal ambisonics? -- Marc ___ Sursound mailing list Sursound@music.vt.edu https://mail.music.vt.edu/mailman/listinfo/sursound ___ Sursound mailing list Sursound@music.vt.edu https://mail.music.vt.edu/mailman/listinfo/sursound ___ Sursound mailing list Sursound@music.vt.edu https://mail.music.vt.edu/mailman/listinfo/sursound
Re: [Sursound] the recent 2-channel 3D sound formats and their viability for actual 360 degree sound
--On 09 July 2011 14:04 -0400 Marc Lavallée m...@hacklava.net wrote: So, is it possible to adapt a stereo recording to play on a horizontal ambisonics system, in order to get a better stereo image than with conventional stereo? A kind of restored stereo experience that ambisonics can provide because of its directional capabilities? Two approaches that Michael Gerzon took are exemplified by the Super Stereo mode of the early ambisonic decoders, and the later Trifield system using three speakers; but neither of these is about attempting to generate a full circle from the stereo signal. A problem that arises, in any case, is that the result does depend strongly on the way the stereo recording was made - coincident mics (e.g. Blumlein), spaced mics (e.g. Decca Tree), or a reliance on mixing from spot-mics. As these record very different directional cues, a single process can't be expected to handle them all equally effectively. As for 5.1 - there are a number of useful decoders available which can be used to reproduce ambisonic signals using speakers set up for 5.1; but the irregular spacing means inevitably that the results are not as good in some directions as they could be with the same speakers more uniformly spaced. Playing 5.1 signals through an ambisonic system is a matter of steering those signals as virtual sources at the required angles in a B-format signal; as with stereo, nothing is added to the experience because there is nothing extra to be found - but the reproduction will be less good to the extent that the sources expected when the 5.1 mix was done are being less precisely reproduced. Paul -- Paul Hodges ___ Sursound mailing list Sursound@music.vt.edu https://mail.music.vt.edu/mailman/listinfo/sursound
Re: [Sursound] the recent 2-channel 3D sound formats and their viability for actual 360 degree sound
On Sat, Jul 09, 2011 at 02:04:21PM -0400, Marc Lavallée wrote: The perceived directional bandwidth of stereo recordings is better than what conventional stereo (with cross-talk) can reproduce. This is again a game of words. Most stereo recordings are made to be reproduced by two speakers, seen by the listener at an angle of 60 to 90 degrees, and such that the signals from either speaker reach both ears. That is the way it is supposed to work. There is a solid theory behind this. Calling this 'crosstalk (a term which has a negative connotation as a defect of audio equipment), and the cure 'crosstalk cancellation' amounts to gross intellectual dishonesty. The signals you find on the vast majority of stereo records are _not_ meant to be delivered one-to-one to the ears. XTC will work (within some limits) on binaural recordings, and it produces a sort of spatial effect on some of those that are badly engineered for speaker reproduction, e.g. using widely spaced omni mics as the main source. It also can provide some 'spatiality' on TV sound, helped by the fact that when watching a screen in front you are unlikely to face other directions than the one to the screen. So, is it possible to adapt a stereo recording to play on a horizontal ambisonics system, in order to get a better stereo image than with conventional stereo? A kind of restored stereo experience that ambisonics can provide because of its directional capabilities? Starting from stereo there is little Ambisonics can do. One some (mostly classical music) recordings, you can add either algorithmic or convolution reverb to mimic the acoustics of a real concert hall, and this can be quite effective. An AMB reproduction rig can also do better room correction than would be possible with just two speakers. Ciao, -- FA ___ Sursound mailing list Sursound@music.vt.edu https://mail.music.vt.edu/mailman/listinfo/sursound
Re: [Sursound] the recent 2-channel 3D sound formats and their viability for actual 360 degree sound
On Sat, Jul 09, 2011 at 09:19:07PM +0100, Stefan Schreiber wrote: Fons Adriaensen wrote: On Sat, Jul 09, 2011 at 02:04:21PM -0400, Marc Lavallée wrote: The perceived directional bandwidth of stereo recordings is better than what conventional stereo (with cross-talk) can reproduce. This is again a game of words. Most stereo recordings are made to be reproduced by two speakers, seen by the listener at an angle of 60 to 90 degrees, and such that the signals from either speaker reach both ears. That is the way it is supposed to work. There is a solid theory behind this. Calling this 'crosstalk (a term which has a negative connotation as a defect of audio equipment), and the cure 'crosstalk cancellation' amounts to gross intellectual dishonesty. The signals you find on the vast majority of stereo records are _not_ meant to be delivered one-to-one to the ears. And people listen to the same stuff via headphones? The fact that many recordings intended for speaker reproduction (in particular those using panned mono sources) work also on headphones is remarkable, and an illustration of how adaptive our hearing can be. But almost always you can improve the results on headphones by introducing the sort of 'crosstalk' that a speaker system would produce. Either using HRTF, or in the simplest case a highpass filter on the difference signal (which is a crude approximation). The exceptions are binaural recordings of course, which should be left as they are. The simple fact is that there is *fundamental* difference between signals supposed to be correct when delivered 1-to-1 to the ears, and those intended to be reproduced using two speakers. The vast majority of available records are of the second kind. Ciao, -- FA ___ Sursound mailing list Sursound@music.vt.edu https://mail.music.vt.edu/mailman/listinfo/sursound
Re: [Sursound] the recent 2-channel 3D sound formats and their viability for actual 360 degree sound
Totally agree 100%. Personally I would state that I have a totally different experience when listening to the same recordings via loudspeakers versus headphones. Headphones rarely give me a the orchestra/band is in front of me presentation (and no it is not a function of cheap or crappy headphones... I have some nice Sennheiser HD600's amongst others), but tend to spread the sound across my head (hard to describe), whereas the same recordings presented via speakers has a nice soundstage in *front* of me. - Neil On 7/9/2011 4:38 PM, Fons Adriaensen wrote: On Sat, Jul 09, 2011 at 09:19:07PM +0100, Stefan Schreiber wrote: Fons Adriaensen wrote: On Sat, Jul 09, 2011 at 02:04:21PM -0400, Marc Lavallée wrote: The perceived directional bandwidth of stereo recordings is better than what conventional stereo (with cross-talk) can reproduce. This is again a game of words. Most stereo recordings are made to be reproduced by two speakers, seen by the listener at an angle of 60 to 90 degrees, and such that the signals from either speaker reach both ears. That is the way it is supposed to work. There is a solid theory behind this. Calling this 'crosstalk (a term which has a negative connotation as a defect of audio equipment), and the cure 'crosstalk cancellation' amounts to gross intellectual dishonesty. The signals you find on the vast majority of stereo records are _not_ meant to be delivered one-to-one to the ears. And people listen to the same stuff via headphones? The fact that many recordings intended for speaker reproduction (in particular those using panned mono sources) work also on headphones is remarkable, and an illustration of how adaptive our hearing can be. But almost always you can improve the results on headphones by introducing the sort of 'crosstalk' that a speaker system would produce. Either using HRTF, or in the simplest case a highpass filter on the difference signal (which is a crude approximation). The exceptions are binaural recordings of course, which should be left as they are. The simple fact is that there is *fundamental* difference between signals supposed to be correct when delivered 1-to-1 to the ears, and those intended to be reproduced using two speakers. The vast majority of available records are of the second kind. Ciao, ___ Sursound mailing list Sursound@music.vt.edu https://mail.music.vt.edu/mailman/listinfo/sursound
Re: [Sursound] the recent 2-channel 3D sound formats and their viability for actual 360 degree sound
On 09/07/2011 21:38, Fons Adriaensen wrote: On Sat, Jul 09, 2011 at 09:19:07PM +0100, Stefan Schreiber wrote: Fons Adriaensen wrote: On Sat, Jul 09, 2011 at 02:04:21PM -0400, Marc Lavallée wrote: The perceived directional bandwidth of stereo recordings is better than what conventional stereo (with cross-talk) can reproduce. This is again a game of words. Most stereo recordings are made to be reproduced by two speakers, seen by the listener at an angle of 60 to 90 degrees, and such that the signals from either speaker reach both ears. That is the way it is supposed to work. There is a solid theory behind this. Calling this 'crosstalk (a term which has a negative connotation as a defect of audio equipment), and the cure 'crosstalk cancellation' amounts to gross intellectual dishonesty. The signals you find on the vast majority of stereo records are _not_ meant to be delivered one-to-one to the ears. And people listen to the same stuff via headphones? The fact that many recordings intended for speaker reproduction (in particular those using panned mono sources) work also on headphones is remarkable, and an illustration of how adaptive our hearing can be. But almost always you can improve the results on headphones by introducing the sort of 'crosstalk' that a speaker system would produce. Either using HRTF, or in the simplest case a highpass filter on the difference signal (which is a crude approximation). The exceptions are binaural recordings of course, which should be left as they are. The simple fact is that there is *fundamental* difference between signals supposed to be correct when delivered 1-to-1 to the ears, and those intended to be reproduced using two speakers. The vast majority of available records are of the second kind. Ciao, Care to send a clip of an impossible-to-sound-as-good-as-with-stereo recording for me to play with. ps. You misunderstand the nature of my A-HYBRID filter, I think. I certainly hope so. pps. I am sure M Gerzon knew that ambisonics (low order) has theoretical sweet spot the size of a pea, but it still sounds good to some people, His fans are still as self-righteous as ever. ppps How are higher-order microphones coming aloing these days, or are we still happy truncating the infinite series at one order above an omni? ___ Sursound mailing list Sursound@music.vt.edu https://mail.music.vt.edu/mailman/listinfo/sursound
Re: [Sursound] the recent 2-channel 3D sound formats and their viability for actual 360 degree sound
On 07/09/2011 11:13 PM, dw wrote: Care to send a clip of an impossible-to-sound-as-good-as-with-stereo recording for me to play with. well, this kind of stand-off isn't likely to lead anywhere. sounds good is very hard to define or even test. i'm not terribly interested in applying xtc to standard stereo, because i know that perfect xtc is achived with headphones, and i don't like the imaging of stereo over headphones. and before you ask: i don't like the imaging of headphones bent outwards so as to benefit from my pinna filters, either. speaker xtc can only be worse than headphones. ps. You misunderstand the nature of my A-HYBRID filter, I think. I certainly hope so. i've browsed the readme on your site - is there some more in-depth information about this filter somewhere? pps. I am sure M Gerzon knew that ambisonics (low order) has theoretical sweet spot the size of a pea, but it still sounds good to some people, His fans are still as self-righteous as ever. i could imagine way worse things than being called a MAG fanboy. there has been very constructive discussion in the past about why first-order works way better than it obviously should, and what its limits are. this exchange however doesn't quite cut it in the constructive department. ppps How are higher-order microphones coming aloing these days, or are we still happy truncating the infinite series at one order above an omni? higher order microphones work in principle, but are nowhere near as pleasant as simpler stereo microphones. in addition to coloration problems, they suffer from noise problems due to the high gains required. -- Jörn Nettingsmeier Lortzingstr. 11, 45128 Essen, Tel. +49 177 7937487 Meister für Veranstaltungstechnik (Bühne/Studio) Tonmeister VDT http://stackingdwarves.net ___ Sursound mailing list Sursound@music.vt.edu https://mail.music.vt.edu/mailman/listinfo/sursound
Re: [Sursound] the recent 2-channel 3D sound formats and their viability for actual 360 degree sound
On 09/07/2011 22:28, Jörn Nettingsmeier wrote: On 07/09/2011 11:13 PM, dw wrote: Care to send a clip of an impossible-to-sound-as-good-as-with-stereo recording for me to play with. well, this kind of stand-off isn't likely to lead anywhere. sounds good is very hard to define or even test. i'm not terribly interested in applying xtc to standard stereo, because i know that perfect xtc is achived with headphones, and i don't like the imaging of stereo over headphones. and before you ask: i don't like the imaging of headphones bent outwards so as to benefit from my pinna filters, either. speaker xtc can only be worse than headphones. ps. You misunderstand the nature of my A-HYBRID filter, I think. I certainly hope so. i've browsed the readme on your site - is there some more in-depth information about this filter somewhere? I certainly hope not, apart from what I explained to Fons here, about the one I gave away , which was 'HYBRID'. I think I may 'disappear from the face of the earth' again, shortly. I've had enough already. ps. I am sure M Gerzon knew that ambisonics (low order) has theoretical sweet spot the size of a pea, but it still sounds good to some people, His fans are still as self-righteous as ever. i could imagine way worse things than being called a MAG fanboy. there has been very constructive discussion in the past about why first-order works way better than it obviously should, and what its limits are. this exchange however doesn't quite cut it in the constructive department. So how does this 'human energy-vector-detector work then? It is not the being a fan that I object to. I am a bit of a fan myself. You never objected to the non-constructive and rude comments of others.. ppps How are higher-order microphones coming aloing these days, or are we still happy truncating the infinite series at one order above an omni? higher order microphones work in principle, but are nowhere near as pleasant as simpler stereo microphones. in addition to coloration problems, they suffer from noise problems due to the high gains required. What you need is a 'virtual' high-order microphone. ___ Sursound mailing list Sursound@music.vt.edu https://mail.music.vt.edu/mailman/listinfo/sursound
Re: [Sursound] the recent 2-channel 3D sound formats and their viability for actual 360 degree sound
On 07/09/2011 11:49 PM, dw wrote: On 09/07/2011 22:28, Jörn Nettingsmeier wrote: ps. I am sure M Gerzon knew that ambisonics (low order) has theoretical sweet spot the size of a pea, but it still sounds good to some people, His fans are still as self-righteous as ever. i could imagine way worse things than being called a MAG fanboy. there has been very constructive discussion in the past about why first-order works way better than it obviously should, and what its limits are. this exchange however doesn't quite cut it in the constructive department. So how does this 'human energy-vector-detector work then? ok'ish. ppps How are higher-order microphones coming aloing these days, or are we still happy truncating the infinite series at one order above an omni? higher order microphones work in principle, but are nowhere near as pleasant as simpler stereo microphones. in addition to coloration problems, they suffer from noise problems due to the high gains required. What you need is a 'virtual' high-order microphone. the approach i'm exploring is this: http://stackingdwarves.net/public_stuff/linux_audio/tmt10/TMT2010_J%c3%b6rn_Nettingsmeier-Higher_order_Ambisonics.pdf skip the intro and jump to section 5. i used to think that this kind of hack is not really conceptually elegant (it isn't - nothing beats the simple beauty of a sound field microphone). but then i learned about all the unholy hacks that are routinely being employed by respected record labels to produce their (very nice sounding) surround recordings. i have been very relaxed about conceptual purity ever since. but for my work, i still want to have a plausible theory first and then see what can be done in practice. i dislike stuff that sounds nice whose proponents can't really explain why :) but that's a personal spleen of mine, not a snide remark at xtc in general. best, jörn -- Jörn Nettingsmeier Lortzingstr. 11, 45128 Essen, Tel. +49 177 7937487 Meister für Veranstaltungstechnik (Bühne/Studio) Tonmeister VDT http://stackingdwarves.net ___ Sursound mailing list Sursound@music.vt.edu https://mail.music.vt.edu/mailman/listinfo/sursound
Re: [Sursound] the recent 2-channel 3D sound formats and their viability for actual 360 degree sound
On Sat, Jul 09, 2011 at 10:13:13PM +0100, dw wrote: Care to send a clip of an impossible-to-sound-as-good-as-with-stereo recording for me to play with. If it's anything I produced myself you'd just say I engineered it to fail with XTC :-) Which indeed I could easily do... I've been listening to XTC using all processors I know of, in at least four very different rooms, and using all sorts of source material. Some things sound rather well: e.g. binaural recordings made using a dummy head, or using similar techniques such as closely spaced omnis with some baffle or disk between them. But those sound terrible on speakers if not processed, so that is not the kind of material most people would encounter. As to material produced for conventional speaker playback, some of it produces a 'nice' sound, with a clear spatial effect, as long as you are not trying to focus your attention on individual sources or instruments. Which is something I can't avoid doing being a trained sound engineer, but also something any musician or critical listener will do at some time. What almost certainly *fails in major ways* will be e.g. - opera (or other forms of stage drama) recordings meant for stereo listening (i.e. not the DVD productions which have all the singers at the center to match the video), - anything that has off-center bass (from ancient music with double bass flutes to reggea), - many organ recordings, which when XTC-ed produce an organ that seems to be wandering all around, making me seasick. ps. You misunderstand the nature of my A-HYBRID filter, I think. I certainly hope so. Then I hope you will explain it. pps. I am sure M Gerzon knew that ambisonics (low order) has theoretical sweet spot the size of a pea, but it still sounds good to some people, In fact first order AMB has some perception merits that are worse than for conventional stereo. Its great advantage is that it is surround *wihout any preferred directions*. Which makes for a very natural effect, even if the 'sweet spot' can be small. But it's never as restricted as it is for XTC. His fans are still as self-righteous as ever. Some of his fans hate me because I (and some others) have pointed out the limits of first order and moved on to higher order AMB, which is where things really start to work even in real-life and even in really adverse conditions. ppps How are higher-order microphones coming aloing these days, or are we still happy truncating the infinite series at one order above an omni? There are none ATM that can produce full frequency range higher order, and I doubt there will ever be. But we don't really need them either. Ciao, -- ___ Sursound mailing list Sursound@music.vt.edu https://mail.music.vt.edu/mailman/listinfo/sursound
Re: [Sursound] the recent 2-channel 3D sound formats and their viability for actual 360 degree sound
Fons Adriaensen f...@linuxaudio.org a écrit : Most stereo recordings are made to be reproduced by two speakers, seen by the listener at an angle of 60 to 90 degrees, and such that the signals from either speaker reach both ears. That is the way it is supposed to work. There is a solid theory behind this. Calling this 'crosstalk (a term which has a negative connotation as a defect of audio equipment), and the cure 'crosstalk cancellation' amounts to gross intellectual dishonesty. The signals you find on the vast majority of stereo records are _not_ meant to be delivered one-to-one to the ears. I understand your clinical point of view, but I don't consider the act of listening to reproduced music as a scientific activity. Each time a playback occurs, it can be a new creation, not always a perfect repetition of past events. I admire the virtues of hi-fidelity, but I don't have the required budget (and mindset) to play this game. Most honest people are listening to stereo in any possible ways, including some twisted people who enjoy stereo with XTC. :-) XTC will work (within some limits) on binaural recordings, and it produces a sort of spatial effect on some of those that are badly engineered for speaker reproduction, e.g. using widely spaced omni mics as the main source. I never experienced convincing 3D with binaural recordings, either with headphones or XTC. Many stereo recordings are better than binaural recordings. It also can provide some 'spatiality' on TV sound, helped by the fact that when watching a screen in front you are unlikely to face other directions than the one to the screen. True: XTC is not ideal for dancing. Starting from stereo there is little Ambisonics can do. One some (mostly classical music) recordings, you can add either algorithmic or convolution reverb to mimic the acoustics of a real concert hall, and this can be quite effective. An AMB reproduction rig can also do better room correction than would be possible with just two speakers. Interesting. The same trick is used with ambiophonics. What I'd like to avoid is to install those distinct setups: - conventional 60 degrees stereo - stereo with XTC - 5.1 and 7.1 - ambiophonics (with 4 speakers) - ambisonics Ambisonics is often described as THE grand unified theory of audio, but it's just one more. I accept it as one of the best, even if I don't understand its strange maths. I'd really like to understand that spherical harmonics business, but I'd have to go back to school... -- Marc ___ Sursound mailing list Sursound@music.vt.edu https://mail.music.vt.edu/mailman/listinfo/sursound
Re: [Sursound] the recent 2-channel 3D sound formats and their viability for actual 360 degree sound
On Sat, Jul 09, 2011 at 06:58:29PM -0400, Marc Lavallée wrote: I understand your clinical point of view, but I don't consider the act of listening to reproduced music as a scientific activity. Agreed 100%. But the act of analysing and discussing the merits of technical systems to reproduce sound or music surely is a scientific activity, or at least something that should be done using a scientific mindset and avoiding marketing language and suggestive terminology. Such as presenting the way stereo works (by delivering both speaker signals to both ears) as a 'defect' which has to be 'cancelled'. Ciao, -- FA ___ Sursound mailing list Sursound@music.vt.edu https://mail.music.vt.edu/mailman/listinfo/sursound
Re: [Sursound] the recent 2-channel 3D sound formats and their viability for actual 360 degree sound
Jörn Nettingsmeier wrote: On 07/09/2011 11:13 PM, dw wrote: Care to send a clip of an impossible-to-sound-as-good-as-with-stereo recording for me to play with. well, this kind of stand-off isn't likely to lead anywhere. sounds good is very hard to define or even test. i'm not terribly interested in applying xtc to standard stereo, because i know that perfect xtc is achived with headphones, and i don't like the imaging of stereo over headphones. But the main reason for in-head effects etc. is probably not related to XTC at all! I don't like listening via headphones, but this is IMO not related to the stereo image. ( There are certain other problems which are not related to stereo, binaural or 5.1 via headphones, so it is not just an imaging problem.) Listening to XTC stereo over speakers is actually quite different from listening via headphones, as you can move your head at least to a cetain degree. A serious listening experience via headphones might require head tracking, unless we clamp the head once more. Best, Stefan P.S.: IF tonemasters would arduously work to deliver the best-possible 60º stereo mix WITH deliberate cosstalk, I don't think we would see all the folks run around with earphones. Maybe I am wrong, but...:-P -- next part -- An HTML attachment was scrubbed... URL: https://mail.music.vt.edu/mailman/private/sursound/attachments/20110710/fade7e3e/attachment.html ___ Sursound mailing list Sursound@music.vt.edu https://mail.music.vt.edu/mailman/listinfo/sursound
Re: [Sursound] the recent 2-channel 3D sound formats and their viability for actual 360 degree sound
Jörn Nettingsmeier wrote: On 07/09/2011 10:19 PM, Stefan Schreiber wrote: Fons Adriaensen wrote: On Sat, Jul 09, 2011 at 02:04:21PM -0400, Marc Lavallée wrote: The perceived directional bandwidth of stereo recordings is better than what conventional stereo (with cross-talk) can reproduce. This is again a game of words. Most stereo recordings are made to be reproduced by two speakers, seen by the listener at an angle of 60 to 90 degrees, and such that the signals from either speaker reach both ears. That is the way it is supposed to work. There is a solid theory behind this. Calling this 'crosstalk (a term which has a negative connotation as a defect of audio equipment), and the cure 'crosstalk cancellation' amounts to gross intellectual dishonesty. The signals you find on the vast majority of stereo records are _not_ meant to be delivered one-to-one to the ears. And people listen to the same stuff via headphones? yes, and that is a problem :) you will find that a bit of artificial crosstalk greatly improves the spatial impression of traditional stereo recordings when delivered over headphones. I am actually aware of this, but as you say, it is a bit of X-talk. My theory is that most commercial recordings are exctly something between 60º and separated channels. As this seems to work, XTC can't be SO wrong. whatever floats your boat. xtc has a certain effect on most material which most xtc users like, and that's fine. Don't forget that RG would (righteously) argue that most stereo recordings are recordings which stereo users like, and that's fine. :-) the localisation of xtc'ed traditional stereo is similar to spaced omni miking, in the sense that it's kind of nice and spacey, but the result has nothing to do with reality, at all. and you have to keep in mind that what you are hearing with xtc is not what the producer intends you to hear. Now I am getting really impatient: A producer would probably mix something that works on 60º spaced speakers AND headphones. O how do most people listen to music, nowadays? (Answer: On computers and on mobile devices. Safe bet.) strictly speaking, xtc is only correct for binaural material (which, otoh, will be absolutely wrong when played back over stereo speakers). Yes, I knew. I am unaware if every stereo recording is meant for 60º speakers, in fact a Blumlein recording is not, and many microphones have a barrier. Just speaking as a layman... :-D and to comment on a previous remark about the turning of the head: with ambisonics, the point is not that the image doesn't collapse when you turn (that's really the most basic requirement), but rather that you gain additional information, because the soundfield is reproduced somewhat correctly in _all_ directions and you can benefit from your keener localisation sense in the frontal quadrant, turn your head and tune in to lateral sources. they will be reproduced just as convincingly as the frontal sound stage. that's a minor benefit as long as you're listening to the usual stage in front kind of music, but if you're a room acoustics nerd or you're into contemporary music with a somewhat wider sound stage, the advantage is quite palpable. with xtc, head turning doesn't ever give you extra information. you just perceive the binaural (or not) signal in a different (and strictly speaking incorrect) way, which may have a pleasant effect. then again, it may not. It is an advantage of surround speaker configurations (including 5.1) that you can turn your head, at least to some degree. In fact, you expect this from a surround speaker array. You should be able to move your head, and you should be able to move around in the room. (Well, depending on the sweet spot.) Best, Stefan -- next part -- An HTML attachment was scrubbed... URL: https://mail.music.vt.edu/mailman/private/sursound/attachments/20110710/b50ed4c0/attachment.html ___ Sursound mailing list Sursound@music.vt.edu https://mail.music.vt.edu/mailman/listinfo/sursound
Re: [Sursound] the recent 2-channel 3D sound formats and their viability for actual 360 degree sound
Fons Adriaensen f...@linuxaudio.org a écrit : As to material produced for conventional speaker playback, some of it produces a 'nice' sound, with a clear spatial effect, as long as you are not trying to focus your attention on individual sources or instruments. Which is something I can't avoid doing being a trained sound engineer, but also something any musician or critical listener will do at some time. I find it easier to focus on details with XTC. But it depends a lot on the recordings. Some are horrible, others are wonderful. With conventional stereo, I find that everything is equally smeared, like a kind of glorified mono with a larger stage. I'm waiting for a pair of very directional speakers that should (hopefully) help me enjoy conventional stereo. What almost certainly *fails in major ways* will be e.g. - opera (or other forms of stage drama) recordings meant for stereo listening (i.e. not the DVD productions which have all the singers at the center to match the video), I have one recording of a Scarlatti opera that sounds very nice (and detailed) with XTC. But usually I prefer mono for operas (listening on the radio). - anything that has off-center bass (from ancient music with double bass flutes to reggea), Why? I have no problem with off-center bass; I use 2 small speakers with XTC and 2 subs with normal stereo. - many organ recordings, which when XTC-ed produce an organ that seems to be wandering all around, making me seasick. True! I prefer mono or stereo for organ, or the real thing (in my city there's a lot of good organs and a yearly festival) XTC can do very strange things to bad stereo recordings, and there's a fair amount of those in circulation. The worst I heard are recent piano and harpsichord recordings that are considered masterworks by critics. They were made to sound glorious. XTC can reveal a lot of bad tricks, and can destroy many mediocre recordings. Pop and jazz gigs are a lot of fun with XTC. Anything with artificial reverb from the 80's is a catastrophe (what a terrible decade). Conventional stereo and mono, on the other hand, are very forgiving. I understand your clinical point of view, but I don't consider the act of listening to reproduced music as a scientific activity. Agreed 100%. But the act of analysing and discussing the merits of technical systems to reproduce sound or music surely is a scientific activity, or at least something that should be done using a scientific mindset and avoiding marketing language and suggestive terminology. Such as presenting the way stereo works (by delivering both speaker signals to both ears) as a 'defect' which has to be 'cancelled'. Ambisonics enthusiasts are also using strong words; to them, anything not ambisonics (or blumleinish) is flawed, and simple questions are often received as direct attacks. I use XTC to improve some of my listening skills, not to replace all other listening methods. I have nothing to sell, and I sometimes use a home-made physical barrier because it's still the best XTC method. Presenting ambisonics as a scientific tool, a sound engineering secret, or a surround system for museums or stadiums, are not very good ways to promote it to home listeners, especially considering the quasi-absence of ambisonics material in circulation. If you could help me understand spherical harmonics, I'd be a MAG fanboy in no time. The best didactic resource I found is a very strange article titled Notes on Basic Ideas of Spherical Harmonics. It's so good that I barely understand 10% of it. -- Marc ___ Sursound mailing list Sursound@music.vt.edu https://mail.music.vt.edu/mailman/listinfo/sursound
Re: [Sursound] the recent 2-channel 3D sound formats and their viability for actual 360 degree sound
There was a method developed by Finsterle that worked very well indeed, much better than Trifield(which has always seemed to me to have a serious center detent. Finsterle's method had sound in the rear psychoacoustically encoded not to sound in the rear but to solidify the front images. This worked very well in my experience Robert On Sat, 9 Jul 2011, Paul Hodges wrote: --On 09 July 2011 14:04 -0400 Marc Lavall?e m...@hacklava.net wrote: So, is it possible to adapt a stereo recording to play on a horizontal ambisonics system, in order to get a better stereo image than with conventional stereo? A kind of restored stereo experience that ambisonics can provide because of its directional capabilities? Two approaches that Michael Gerzon took are exemplified by the Super Stereo mode of the early ambisonic decoders, and the later Trifield system using three speakers; but neither of these is about attempting to generate a full circle from the stereo signal. A problem that arises, in any case, is that the result does depend strongly on the way the stereo recording was made - coincident mics (e.g. Blumlein), spaced mics (e.g. Decca Tree), or a reliance on mixing from spot-mics. As these record very different directional cues, a single process can't be expected to handle them all equally effectively. As for 5.1 - there are a number of useful decoders available which can be used to reproduce ambisonic signals using speakers set up for 5.1; but the irregular spacing means inevitably that the results are not as good in some directions as they could be with the same speakers more uniformly spaced. Playing 5.1 signals through an ambisonic system is a matter of steering those signals as virtual sources at the required angles in a B-format signal; as with stereo, nothing is added to the experience because there is nothing extra to be found - but the reproduction will be less good to the extent that the sources expected when the 5.1 mix was done are being less precisely reproduced. Paul -- Paul Hodges ___ Sursound mailing list Sursound@music.vt.edu https://mail.music.vt.edu/mailman/listinfo/sursound ___ Sursound mailing list Sursound@music.vt.edu https://mail.music.vt.edu/mailman/listinfo/sursound
