gedlee said:... Hence, I do disagree that two channels are "capable" of good spaciousness in the sense that I use the word.
Earl, I strongly disagree but I guess its semsantics.
What would you use – instead of " spaciouness " that seems to have a very specific meaning to you - for the holographic illusion a mere two channel headphones can provide?
Michael
Originally posted by mige0 What would you use – instead of " spaciouness " that seems to have a very specific meaning to you - for the holographic illusion a mere two channel headphones can provide?
Don't know what Earl would use but I use perception of room size and distance of sound source. It's formed by the initial time delay gap (ITDG) and length/level of reverberation on the recording.
Longer ITDG means near sound source. Shorter means sound source is far away.
Strong early reflections from the listening room can disturb that.
Best, Markus
mige0 said:
Earl, I strongly disagree but I guess its semsantics.
What would you use – instead of " spaciouness " that seems to have a very specific meaning to you - for the holographic illusion a mere two channel headphones can provide?
Michael
I think that I would just call it imaging. To me imaging is the "holographic illusion" created from the speakers, but spaciousness is a feeling that one gets from the local acoustics. People are always surprised by how much larger my room sounds than it actually is. Thats because it has a lot of spaciousness added by the room which is real, not an illusion. The ear is very hard to trick on this kind of thing and most, if not all, recordings that I have heard fail in this regard.
There is a tradeoff that one has to make here. Good imaging of the recording requires things that minimize the rooms spaciousness - things like narrow directivity will dramatically lower the spaciousness added by the room, it has too, There is far greater direct to reveberant ratio with narrow directivity. But without a narrow diirectivity a small room has a plethora of early reflections and these will ruin the image, albeit the spaciousness will increase.
Seems to me that the solution is obvious - a very live room with highly directional speakers. Seems to work according to all the reviewers that I've had.
tinitus said:
I can make my speaker sound spacious
And I can make the same speaker very precise and with 3D pinpointing
And I have succeded in combining both "worlds"
Wow, always interested in juicy recipes. Can you share your secrets or did you lay 'em down somewhere else?
Besides that until now I didn't distinguish between the two of it.
To me the core of spaciousness (if I got the translation of that word to some degree) is kind of entering a sonic room.
The room / space itself is well defined – even if it reaches out endlessly – and all events have shape (for missing a better term) position and relation.
Imagine the most beautiful viewpoint on earth you can think of to watch all kinds of exciting landscapes passing by. This is what I feel when entering a holographic sound illusion.
It can make you addicted – even to nonsense music.
The easier I can step through the door the higher I rate the parts of the audio chain with respect to spaciouness.
----------------------
markus76 said:
Don't know what Earl would use but I use perception of room size and distance of sound source. It's formed by the initial time delay gap (ITDG) and length/level of reverberation on the recording.
Longer ITDG means near sound source. Shorter means sound source is far away.
Strong early reflections from the listening room can disturb that.
Best, Markus
Thanks.
What exactly is this different to " spaciouness" now?
-------------
Thanks Cilla, for getting this up.
Originally posted by mige0 What exactly is this different to " spaciouness" now?
It's a completely different perception – I'll try to upload some examples so you can experience the difference.
Best, Markus
Marcus
Do you and I see this differentiation the same way? I come from the same technical reading that you do; Blauert and Kutruff (both Germans. Germans excell at acoustics ever since Helmholtz. One of my advisors did acoustics for U-boats. He was smuggled out of Germany at the end of the war along with Werner Von Braun. Right out under the Russians noses who didn't realize what they had.)
Do you and I see this differentiation the same way? I come from the same technical reading that you do; Blauert and Kutruff (both Germans. Germans excell at acoustics ever since Helmholtz. One of my advisors did acoustics for U-boats. He was smuggled out of Germany at the end of the war along with Werner Von Braun. Right out under the Russians noses who didn't realize what they had.)
Earl, Markus, thanks for your effort.
You both seem to restrict the term to what is added by a real room if I got you right.
Very much appreciated !
Michael
You both seem to restrict the term to what is added by a real room if I got you right.
markus76 said:
It's a completely different perception – I'll try to upload some examples so you can experience the difference.
Best, Markus
Very much appreciated !
Michael
mige0 said:
Wow, always interested in juicy recipes. Can you share your secrets or did you lay 'em down somewhere else?
Hi, I really wish I could, but I have no measurements, so its hard to exsplain in detail
What I can say is that apart from a sensible box design, drivers etc, its mostly a matter of the crossover
When you get really close the speaker gets exstremely sensitive to changes
General xo layout makes a difference, like where to connect the parts
Small changes in inductor orientation
Very very small fine tuning of inductors
I am not a parts freak, but use common sensible parts
One point I think is very important is to have only one component in its place to do the job needed...most people will laugh at this, I know, but several caps or resistors in paralel with each other doesnt please my ears...I would rather deal with a size that is a bit off
Im not an expert, but I have a suspicion that its about controlling directivity, and phase...but it may be like simplifying it just a bit
One point that may be of importance...I use a series resistor on ALL paralel components, which means not just the caps(RC), but also on inductors
Light cone tuning with coating is also used
The od thing is that when I am adjusting the xo, I am at the side of the speaker, but can still hear if its good or not...but most adjustments will change over time...its a very long process
Yeah, I wish I knew better what it really is I am doing...but I just like doing it
tinitus said:
Yeah, I wish I knew better what it really is I am doing...but I just like doing it
"So much of this is the recording and not the playback. Don;t blaim the playback for flaws in the recording."
Hello Earl
I am not trying to blame the speakers. You should be able to hear differences between recordings. It it all sounds the same or very close somethings not quite right. There is a great deal of variability in the source material and that should be clearly audible through the speaker.
Rob
Hello Earl
I am not trying to blame the speakers. You should be able to hear differences between recordings. It it all sounds the same or very close somethings not quite right. There is a great deal of variability in the source material and that should be clearly audible through the speaker.
Rob
gedlee said:There is a serious limit to which two speakers can reproduce the spatiousness of a live performance. Thats because good spaciouness - in the room acoustics sense - requires multiple lateral reflection from the non axial direction. This is precisely what the interaural cross correlation measures. Two speaker in the front cannot achieve this without the room adding in the non-coherent lateral reflections.
what are the "non-coherent lateral reflections"? what is the difference between them and "coherent lateral reflections"?
gedlee said:Markus
That early refections help audibility is well know, but not relavent to the music situation.
why? Isn't audibilty about retrieving information? What is the difference between musical information and speech information?
best regards!
graaf
Russell Dawkins said:Based on a few recent comments here and elsewhere, I am starting to wonder whether the answer to the question "what is the major factor contributing to good phantom imaging" is lower waveform distortion
what precisely is this waveform distortion You are speaking of? how to lower it? what makes a loudspeaker with low waveform distortion?
best regards!
graaf
Hello Markus,
While most stereophonic recordings are unable to keep the information about shape and dimensions of the instrument, you may experience it with a good 2 microphones recording in phase stereophony.
The radiation of sound from an instrument often possess a very complex pattern (see in attached file the example of a flute, left part of the attached graph).
When the instrumentist moves as it is often the case to impige some wanted effect to the music, the different radiating lobes turns in the space. With a system able of a 3D holographic image you perceive those movements.
Also fundamental and harmonics may be emitted from different parts of the instruments and if your system don't keep the phase coherence between the components of the notes (note: with some instruments such initial relation between the phase of the harmonics doesn't exist) you may have, by example, the fundamental delayed from the harmonics and a perceived stretching of the shape of the intruments.
It is easy to understand that because minor variations of phase are implied in the perception of the shape and dimension of the instrument (even for a blind person) it is very difficult to obtain a good reproduction of such characteristics with an audio system. Binaural diaphony which is helpful when listening to real instruments to interpret their shape and dimension is an inconvenient when listening to a record of the same instrument in phase stereophony.
André Charlin who did a lot of 2 microphone records (see http://charlin1.free.fr/ and http://www.svalander.se/charlin/ACbioengp.htm ) was well aware that the binaural diaphony induces a distortion of the perceived position (and shape) of the instruments of the orchestra (see attached graph on right). That's why he asked the instrumentist to place on another place than normal concert in order that during listening to the sterophonic records their position will be correctly perceived.
Best regards from Paris, France
Jean-Michel Le Cléac'h
While most stereophonic recordings are unable to keep the information about shape and dimensions of the instrument, you may experience it with a good 2 microphones recording in phase stereophony.
The radiation of sound from an instrument often possess a very complex pattern (see in attached file the example of a flute, left part of the attached graph).
When the instrumentist moves as it is often the case to impige some wanted effect to the music, the different radiating lobes turns in the space. With a system able of a 3D holographic image you perceive those movements.
Also fundamental and harmonics may be emitted from different parts of the instruments and if your system don't keep the phase coherence between the components of the notes (note: with some instruments such initial relation between the phase of the harmonics doesn't exist) you may have, by example, the fundamental delayed from the harmonics and a perceived stretching of the shape of the intruments.
It is easy to understand that because minor variations of phase are implied in the perception of the shape and dimension of the instrument (even for a blind person) it is very difficult to obtain a good reproduction of such characteristics with an audio system. Binaural diaphony which is helpful when listening to real instruments to interpret their shape and dimension is an inconvenient when listening to a record of the same instrument in phase stereophony.
André Charlin who did a lot of 2 microphone records (see http://charlin1.free.fr/ and http://www.svalander.se/charlin/ACbioengp.htm ) was well aware that the binaural diaphony induces a distortion of the perceived position (and shape) of the instruments of the orchestra (see attached graph on right). That's why he asked the instrumentist to place on another place than normal concert in order that during listening to the sterophonic records their position will be correctly perceived.
Best regards from Paris, France
Jean-Michel Le Cléac'h
markus76 said:Jean-Michel,
I don't think that there's something like "shape" or "dimensions" of an instrument in stereophony. This is something that we've learned and lives solely in our brains memory. Spaciouseness generated by room reflections or reflections in a recording (yes that's possible to some extend) will make a phantom image bigger just because we aren't able to pin point those phantom images any more.
But what's much more of interest for me is how much reflections at what time and angle are preferable in stereophony or multichannel? When do they start to become destructive? Do they help at all (Toole even claims that early first reflections can help with intelligibility of speech). The common practice of attenuating first reflections and creating a RFZ (Reflection Free Zone) isn't based on scientific facts.
Best, Markus
Attachments
Jean-Michel,
what you're talking about is only possible with wave field synthesis. Stereophony is not capable of providing "a 3D holographic image". That would require the soundfield at the ears to be exactly the same as it was at the original venue. Nevertheless there are some special situations in which such a perception can occur (e.g. crosstalk cancelling techniques like Griesinger promotes) but it can't be transported reliably to a broad range of listeners (they don't have the setup or the room – e.g. who uses QSound for loudspeaker playback any more?) or require special recording techniques that are not compatible with stereo or surround sound setups.
Build low distortion speakers with appropriate polar patterns, treat the room accordingly and enjoy what stereophony has to offer. Don't try to get something that stereophony can't deliver.
Best, Markus
what you're talking about is only possible with wave field synthesis. Stereophony is not capable of providing "a 3D holographic image". That would require the soundfield at the ears to be exactly the same as it was at the original venue. Nevertheless there are some special situations in which such a perception can occur (e.g. crosstalk cancelling techniques like Griesinger promotes) but it can't be transported reliably to a broad range of listeners (they don't have the setup or the room – e.g. who uses QSound for loudspeaker playback any more?) or require special recording techniques that are not compatible with stereo or surround sound setups.
Build low distortion speakers with appropriate polar patterns, treat the room accordingly and enjoy what stereophony has to offer. Don't try to get something that stereophony can't deliver.
Best, Markus
Hello Markus,
That is not the first time that someone tells me that what I describe cannot be heard. But IMHO you are wrong saying "Don't try to get something that stereophony can't deliver".
Very few complete loudspeakers system have sufficiently good pulse response and low phase distortion to allow 3D holographic perception, we are talking here about loudspeakers but one major source of phase distortion in a loudspeakers system is the crossover itself. Also most loudspeakers system has a too low directivity in order to reduce partly interaural diaphony.
For what I see since 1995, date since which I participate to many audio discussions on Internet, very few persons are trying to reach the goal of a good 3D holographic imaging. For what it seems Earl and Lynn are looking in that direction. Also few discussion groups like the french speaking [son-qc], of which I am moderator, has since 10 years a group work on that subject that includes, low phase distortion crossovers, low group delay variation of bass reflex, low phase distrortion horns,etc... Many people can give testimony that 3D holographic image can be heard using the proper records.
Best regards from Paris, France
Jean-Michel Le Cléac'h
That is not the first time that someone tells me that what I describe cannot be heard. But IMHO you are wrong saying "Don't try to get something that stereophony can't deliver".
Very few complete loudspeakers system have sufficiently good pulse response and low phase distortion to allow 3D holographic perception, we are talking here about loudspeakers but one major source of phase distortion in a loudspeakers system is the crossover itself. Also most loudspeakers system has a too low directivity in order to reduce partly interaural diaphony.
For what I see since 1995, date since which I participate to many audio discussions on Internet, very few persons are trying to reach the goal of a good 3D holographic imaging. For what it seems Earl and Lynn are looking in that direction. Also few discussion groups like the french speaking [son-qc], of which I am moderator, has since 10 years a group work on that subject that includes, low phase distortion crossovers, low group delay variation of bass reflex, low phase distrortion horns,etc... Many people can give testimony that 3D holographic image can be heard using the proper records.
Best regards from Paris, France
Jean-Michel Le Cléac'h
markus76 said:Jean-Michel,
what you're talking about is only possible with waveform synthesis. Stereophony is not capable of providing "a 3D holographic image". That would require the soundfield at the ears to be exactly the same as it was at the original venue. Nevertheless there are some special situations in which such a perception can occur (e.g. crosstalk cancelling techniques like Griesinger promotes) but it can't be transported reliably to a broad range of listeners (they don't have the setup or the room – e.g. who uses QSound for loudspeaker playback any more?) or require special recording techniques that are not compatible with stereo or surround sound setups.
Build low distortion speakers with appropriate polar patterns, treat the room accordingly and enjoy what stereophony has to offer. Don't try to get something that stereophony can't deliver.
Best, Markus
markus76 said:Stereophony is not capable of providing "a 3D holographic image". That would require the soundfield at the ears to be exactly the same as it was at the original venue.
well, non sequitur
"a 3D holographic image" is not the same as "a 3D holographic image (...) at the original venue"
it is like distinction between "they are here" and "You are there" experiences
You can have "they are here" without "You are there"
perhaps You can take a look at the Stereolith thread?
markus76 said:
Nevertheless there are some special situations in which such a perception can occur (e.g. crosstalk cancelling techniques like Griesinger promotes) but it can't be transported reliably to a broad range of listeners
first - why broad range of listeners? listening to HiFi is rather solitary activity, body on the sofa-head in the vice
second - there is more than Griesinger in various techniques of dealing with crosstalk
please take a look at the Stereolith thread
markus76 said:
Build low distortion speakers with appropriate polar patterns, treat the room accordingly and enjoy what stereophony has to offer. Don't try to get something that stereophony can't deliver.
are You sure?
would You be interested in trying?
"stereophony" as we know it today (would Blumlein call it stereophony?) is deeply unsatisfying
please take a look at the Stereolith thread
best regards!
graaf
Jean-Michel
I agree with Markus completely. There is a 3D holographic effect, but to extend this down to the level of saying that you can correctly perceive the actual "shape" of the instrument is IMO fooling yourself. I would stake my career on the fact that you could not do this in blind tests - but of course you can convince yourself that its real otherwise.
I particularly liked the right side of the plot you showed since it is completely consistant with my impresses of what is possible. The center image suffers the most in stereo because this is a purely phantom source. It is always too wide, whereas right and left sources come out pretty well.
There is a solution to the center problem (also a reason why it occurs, but thats too lengthy). Derive a center channel and use it. But you can't do this correctly with a simple sum. You have to remove that part of the signal that you send to the center from the left and right. This is not trivial, but these days of high speed DSP this could be done in real time without much trouble.
Jean-Michel there is so much of what you say and do that I agree with, but we part company when you get into things which the science seems to say are not real. For instance even though phase does disrupt the waveform shape all evidence points to the fact that phase changes are simply not audible at the higher frequencies. The ear is simply not synchronous with the signals above about 500 Hz, it is a frequency and envelope detector and the phase information is discarded because the nuerons can't track signals that fast. You'd have to show me where the science is wrong before I can buy into what you are saying.
I agree with Markus completely. There is a 3D holographic effect, but to extend this down to the level of saying that you can correctly perceive the actual "shape" of the instrument is IMO fooling yourself. I would stake my career on the fact that you could not do this in blind tests - but of course you can convince yourself that its real otherwise.
I particularly liked the right side of the plot you showed since it is completely consistant with my impresses of what is possible. The center image suffers the most in stereo because this is a purely phantom source. It is always too wide, whereas right and left sources come out pretty well.
There is a solution to the center problem (also a reason why it occurs, but thats too lengthy). Derive a center channel and use it. But you can't do this correctly with a simple sum. You have to remove that part of the signal that you send to the center from the left and right. This is not trivial, but these days of high speed DSP this could be done in real time without much trouble.
Jean-Michel there is so much of what you say and do that I agree with, but we part company when you get into things which the science seems to say are not real. For instance even though phase does disrupt the waveform shape all evidence points to the fact that phase changes are simply not audible at the higher frequencies. The ear is simply not synchronous with the signals above about 500 Hz, it is a frequency and envelope detector and the phase information is discarded because the nuerons can't track signals that fast. You'd have to show me where the science is wrong before I can buy into what you are saying.
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