certainly not EVERY stereo recording sums into mono well
BUT it just "happens" sometimes - not as a rule
in such a case I prefer stereo headphones
I covered the foam with hard fiber boards to do an A-B comparison with or without absorption. Covering the horizontal absorber resulted in a strong reduction of hight, covering the vertical in a slight reduction of depth, just as expected. I hope I won't have to replace the foam due to cleaning issues.
Interestingly I came closer to something like an imaging with a crossed dipole, like a Blumlein microphone.
http://www.diyaudio.com/forums/multi-way/10962-stereolith-loudspeakers-question-13.html
I too have had VERY good luck with recording summing well to mono. I can't recall any that don't specifically. Maybe someone has an example of one that won't? I'd like to hear it--well actually probably not.
You can get some sense of spaciousness from mono. Just aim the speaker to where it's axis passes a few feet in front of you and fires into the wall opposite the speaker. If you sitting within a few feet of that wall, the reflection will be significant enough to provide your ear with some reverb. So if the speaker is on your left, it should fire into the wall on your right. You should sit a few ft from that wall on your right. I like this arrangement for mono.
Dan
interesting essay:
http://home.provide.net/~djcarlst/SLCBI.htm
very scientific "Auditory scene analysis" approach to the questions of spatial reproduction of sound, a lot of very insightful observations much in agreement with may own experience
some of them seem to indirectly confirm the validity of speaker/room arrangement approach for stereo I have proposed in this thread and also the validity of CFS mono
therefore in a typical listening room the more diffuse sound the more natural sound
yes, no "wavefield synthesis" is needed
quasi-omni CFS stereo that I have proposed meets the first and the fifth requirements perfectly
the second requirement is in fact a nonissue in a normal listening room of typical size (see below "simple dereverberation experiment")
the third and forth requirements are not questions of speaker/room but quality of hardware and software
as regards loudspeakers themselves I wonder though wheter we should consider transient and waveform distortions as harmful "reproduction chain artifacts"
I agree completely that the second - "extreme reverberant method" - fails in a "too large reverberant room" that "cannot cannot be dereverberated"
but I argue that very rarely a real listening room can be regarded as "too large" in that sense, typical living room RT60 is perfectly suitable for succesful sound reproduction
once again - in a typical listening room the more diffuse sound (more room reverb) the more natural sound
and quasi-omni "ceiling flooder" is clearly best at that because it "interacts with the acoustics of the listening room" more than any any other mono loudspeaker and that results in the most diffuse sound with the speaker itself (direct sound) being completely drowned in room reverb and as such acoustically "invisible"
http://home.provide.net/~djcarlst/SLCBI.htm
very scientific "Auditory scene analysis" approach to the questions of spatial reproduction of sound, a lot of very insightful observations much in agreement with may own experience
some of them seem to indirectly confirm the validity of speaker/room arrangement approach for stereo I have proposed in this thread and also the validity of CFS mono
therefore in a typical listening room the more diffuse sound the more natural sound
yes, no "wavefield synthesis" is needed
quasi-omni CFS stereo that I have proposed meets the first and the fifth requirements perfectly
the second requirement is in fact a nonissue in a normal listening room of typical size (see below "simple dereverberation experiment")
the third and forth requirements are not questions of speaker/room but quality of hardware and software
as regards loudspeakers themselves I wonder though wheter we should consider transient and waveform distortions as harmful "reproduction chain artifacts"
I agree completely that the second - "extreme reverberant method" - fails in a "too large reverberant room" that "cannot cannot be dereverberated"
but I argue that very rarely a real listening room can be regarded as "too large" in that sense, typical living room RT60 is perfectly suitable for succesful sound reproduction
once again - in a typical listening room the more diffuse sound (more room reverb) the more natural sound
and quasi-omni "ceiling flooder" is clearly best at that because it "interacts with the acoustics of the listening room" more than any any other mono loudspeaker and that results in the most diffuse sound with the speaker itself (direct sound) being completely drowned in room reverb and as such acoustically "invisible"
A lot of questionable conclusions. The sound field in acoustically small rooms is NOT diffuse (homogeneous and isotropic) and it will never be. There's more to the story. Psychoacoustics is currently stuck in two competing models (virtual source vs. phantom source, see p. 30 http://hauptmikrofon.de/HW/Wittek_thesis_201207.pdf). My hope is that neuroscience will reveal more about how our perception works.
Here's a link to Bregman's work: http://webpages.mcgill.ca/staff/Group2/abregm1/web/
Best, Markus
Here's a link to Bregman's work: http://webpages.mcgill.ca/staff/Group2/abregm1/web/
Best, Markus
Markus
I know Dave - the author well - and he is well intentioned. HE would readily admit the comments as being "his opinions", but admitedely his "group" tends far too much IMO towards the "opinions are facts - if they are mine". There were the ones to develop the ABX box, but then seemed to loose it somewhere along the line. Sound fields in small room certainly can be diffuse - above some frequency. Thats the problem with statements like yours and his that they are not sufficiently descriptive to define the differences, so they are both correct - in a limited scope - and incorrect as well.
Earl,
I have to disagree. The sound field in an acoustically small room is never diffuse (even a concert hall shows only an approximation). There are strong directional first reflections and a dimished quasi-diffuse sound field.
One can certainly make a sound field more diffuse but then we'll end up where we always do: how diffuse is diffuse enough and how to measure? Nobody knows because we don't have enough data on that.
I have to disagree. The sound field in an acoustically small room is never diffuse (even a concert hall shows only an approximation). There are strong directional first reflections and a dimished quasi-diffuse sound field.
One can certainly make a sound field more diffuse but then we'll end up where we always do: how diffuse is diffuse enough and how to measure? Nobody knows because we don't have enough data on that.
You are using the word "diffuse" in a manner inconsistant with standard usage. "Diffuse" only has a meaning in the steady state and so "strong directional first reflections" are beside the point. The steady state sound field in the seating location of my listening room is going to be "sufficiently difuse" by my standards. Not by yours, of course, because your deffinitions for terms always seem to be sufficient for you to be right. There is no "high precision" measurement of difusivity, it's really more of a theoretical concept, so you can be right once again by just taking your requirements for precision to whatever extreme is necessary.
Dancing around my point again. You started talking about "transient" examples, which I am sure you can now see are inappropriate. But there is NOTHING that prevents a small room from being difuse above the Schroeder frequency.
Lots of absorption will decrease it, but my rooms are very live. The reality is that divusivity is a continuum where no room is "perfectly diffuse", but small rooms can still be "highly diffuse", but granted, more commonly are low diffuse fields. That's one reason why I rebel against "common" rooms and treatments.
Earl,
I'm not "dancing around" anything. What I said is that the concept of diffusity (which was born out of the need to calculate reverberation time) doesn't help in describing the relevant properties of small room acoustics. But this is what David Carlstrom did. We need more insight into perception when talking about what the optimal reflection pattern as opposed to the optimal reverberation time might be.
You're all just expressing your believes and subjective impressions on that topic. I'm aiming for a more objective evaluation.
I'm not "dancing around" anything. What I said is that the concept of diffusity (which was born out of the need to calculate reverberation time) doesn't help in describing the relevant properties of small room acoustics. But this is what David Carlstrom did. We need more insight into perception when talking about what the optimal reflection pattern as opposed to the optimal reverberation time might be.
You're all just expressing your believes and subjective impressions on that topic. I'm aiming for a more objective evaluation.
BTW I have to say that after many experiments I grew tired of any kind of stereo and I am finally fed up with all those pseudo-real effects
I still have two spekaers suitable for CFS but I use only one
It all started by accident (when a kitten destroyed one of the speakers) but when after a while and fixing the problem I was able to go back to stereo I have discovered to my own suprise that I am unhappy with it, that I had enjoyed the music better earlier in mono (in the CFS configuration of course)
so I am definitely into mono now and I have to say that I am really happy listening exclusively to the MUSIC itself again
I know and in fact I experience that not every stereo recording sums into mono well but it bothers me less then distracting stereo pseudo-realistic effects
Have you thought about possible solutions for that problem? I wonder whether an upfire/downfire combination of the two channels causes less summation problems.
Do you know this company? They use such a configuration for conventional stereo.
Bolzano Villetri™ - High end home theater systems, home theater surround sound systems, home theater subwoofers
Last edited:
Markus
You misused the term, that's my main point and you never did admit to that fact (hence the "dancing arround" comment). And, as usual, the discussion got to a point where there can be no resolution because its a continuum and there isn't going to be a single X = .65349187862323 answer. Sometimes things can't be totally "objective" and one has to use what information is available and be content that some areas will always be gray. Its your inability to accept anything being gray that bothers me.
I too would "like" to have all the answers, I don't, no one does or ever will. And in the end the answers to ever more detailed questions become ever more unimportant. I am simply trying to get people to use what information there is out there since the vast majority of audiophiles don't use even a fraction of what we do know, but instead replace it with a huge amount of folklore. To me the issue isn't that "we don't know enough", but that we don't do enough with what we do know.
I didn't read Dave Carlstroms paper, I'm sure that its psuedo-scientific because thats the way those guys do things. But he certainly does use more of the known information than most and compared to many I would agree with his position much more. He is actually very well read on the subjects.
What makes you so sure that science can't advance past the point of what is known today?
When did I say that!!??
Surely it can, but it won't. The reason is obvious isn't it? There is no incentive to advance the science when nobody pays attention to what's out there now.
Lidia and I showed that THD was a meaningless number. Did it go away? No! Is there a need for further study, sure, but what's the point when nobody uses what's already been done.
Maybe you can afford to be idealistic, but the people who pay the bills for the research can't and they don't pay for what isn't wanted.
I don't share that pessimistic perspective and I do pay close attention to "what is out there". I just don't wait for the common audiophool to catch up with what is already available. There's no point in arguing with people that chose believe over knowledge (or lack of).
To me, you are the pessimistic one. I accept the situation and move on. You often comment about the complete lack of information, and I'm just agreeing with you, but saying that we need to just go ahead with what we have - not that its the ideal situation. I hardly "wait" for the audiophool to catch up, but I am willing to help anyone who wants to learn to do so. You know that I don't disagree with you, I just don't see the point in discounting everything that we know because of what we don't know.