Available at http://www.waisman.wisc.edu/bhl/about_publications/1997LitovskyRakerdYinHartmannJNeurophsiol.pdf
Tons of other interesting studies from Litovsky:
Binaural Hearing & Speech Lab: About - Publications: Studies on the Precedence Effect
thank You Markus!
now all of us can see that the study is rather irrelevant to the question discussed here because:
very extreme cases of ...uhm ...localisation
and certainly far from elevation perception discussed hereAnd the alleged precedence effect working in the vertical localisation - elevation perception of sound sources in front of the listener has not been researched in the study.
News from Denmark
ALTO Højttaler
(Google translate)
Raw cabinet in beech. Inner damping included. Intended for 8 "unit. Example our 8" Audio Nirvana, or 8 "Monacor full tone. This construction sends the sound up toward the ceiling, the sound spreads more in the way. You do not need to sit exactly in the middle of the speakers to listen optimal. We have tried with a round ball over the device, but the sound is not better, it works really well without.
An externally hosted image should be here but it was not working when we last tested it.
ALTO Højttaler
(Google translate)
Raw cabinet in beech. Inner damping included. Intended for 8 "unit. Example our 8" Audio Nirvana, or 8 "Monacor full tone. This construction sends the sound up toward the ceiling, the sound spreads more in the way. You do not need to sit exactly in the middle of the speakers to listen optimal. We have tried with a round ball over the device, but the sound is not better, it works really well without.
here's a more relevant study:
Localization dominance in the median-sagittal plane
conclusions:
ps. it was an anechoic test and the test signal used was a broadband noise burst
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I posted some reference several hundreds of posts ago (???) indicating some individuals cannot localise sounds in median plane.
Simply put: Flooders may work for those individuals whose localisation ability in vertical domain is poor.
- Elias
or - as those reports of sound coming from the floor phenomenon are actually in minority - it can be alternatively simply put this way: FCUFS may not work for those individuals whose localisation ability in vertical domain is particularly acute
BUT we should also bear in mind that - as the quoted study suggested - the phenomenon in each case may be rather caused by the positional dependence factor as well
I'd suspect that's the minority as the top priority of our hearing is to identify the location of a source as quickly and exactly as possible. Studies by Litovsky show that there are considerable differences between individuals. All in all not a good idea to base a speaker concept on such shaky ground.
A conventional setup with surround speakers is probably more reliable as the amount of spatial "effect" can be freely varied. Furthermore real ambience can be extracted and used. All concepts utilizing the room as a "generator" of ASW use the direct signal on top of recorded ambience and not just the ambience signal.
the bottom line is that everyone should test it before publicly dismissing, and test it seriously - in stereo, in the listening room, not mono in the kitchen etc., in recommended configuration, preferably with recommended speakers (a coaxial of some type) not some junk speakers from the basement etc., trying all speaker and listening positions available in the room
ps.
and while reading some authoritatively put opinions here one must remember that for some users with most acute hearing virtually nothing works, even plain ordinary stereo phantom imaging
ps.
and while reading some authoritatively put opinions here one must remember that for some users with most acute hearing virtually nothing works, even plain ordinary stereo phantom imaging
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Graaf,
Since I did my testing previously with a mono source in the (cue shocked looks of disgust
) kitchen, thought I'd give it another go in stereo with better speakers in the listening room.This required moving the couch, coffee table and treadmill to one side of the room, a less symmetrical arrangement than normal, but equal for both speaker ends of the room.
The usual listening arrangement has the two-way L/R speakers located in the corners of the room on the north 11 foot (3.38 meter) wall, the length of the room is 21 feet (6.46 m) , height 8 feet (2.46 m) on the east wall, 7.6 feet ( 2.31 m) on the west wall.
The 5 inch full range floor coupled upward firing speakers were located near the corners of the south wall.
Temperature was 77 F, humidity 21 %.
Music consisted primarily from selections from two albums:
Aaron Copeland-Louis Lane/Atlanta Symphony Orchestra- Appalachian Spring-Rodeo
Susan McKeown & The Chanting House-Prophecy
First stage of the three part listening test (pictures of each set up below) was to equalize the speaker systems to sound similar and store presets so a quick change could be made when shifting from one to the other.
As a live sound engineer rapidly equalizing as many as a fourteen separate (and individually different) speaker systems in hundreds of concert halls and stages varying on a daily basis over the course of the last 38 years, this is fairly routine operation for me.
The presets and A/B speaker switch made rapid comparisons easy.
Rapid switches between the same portions of songs are important to actually retain a vivid acoustical memory to compare.
Listening position was from a seated position midway in the room, also with eyes closed and rotating around from time to time.
Observations of the usual L/R toed in triangular listening arrangement:
The usual stereo speakers presented a soundstage consistent with the recordings, with left, right and points between being easily discernible, and with some sense of upstage and downstage location.
For those not familiar with theatrical stage positions, upstage is towards the back wall, downstage is towards the audience.
Reverberation sounded similar to what I'd expect from the recording of a symphony orchestra, sounding like a large, live concert hall with a large, widely spaced orchestra.
The Susan McKeown songs generally had a nice (not too artificial sounding) studio/hall ambience, lead vocals center, background vocals spread L/R, instruments located in various "panned" positions.
Overall soundstage position had a location above ear height, consistent with the location of the speakers. The speakers midpoint is 60" off the floor, ear height 46" off the floor, about an 11 degrees up angle.
Observations of the floor coupled upward firing speakers:
Various positions were compared moving the speakers in and out, little overall change was noticed, though a position with the center of the speaker about 9 inches from the side wall seemed to give the most neutral sound, perhaps because that distance matched the depth of the speakers. The very shallow (1.5") speakers previously tested in a FCUF configuration did not seem as sensitive to side wall positioning.
The most obvious and immediate observation was the sound of the speakers coming from the floor. When I closed my eyes, the sense of listening from a relatively low balcony was palpable, consistent with the down angle of approximately 22 degrees.
Soundstage was consistent with the recordings, with left, right and points between generally locatable, but much more difficult to specifically "point to" than the usual L/R toed in triangular listening arrangement .
Sense of upstage and downstage location was ambiguous.
Of interest, turning the listening chair around so my back was to the operating speakers gave an inverted presentation, the general soundstage appeared to be elevated to near the ceiling, though instruments with little high frequency still sounded like they were behind and below. Quite "enveloping", but a bit disconcerting.
To determine whether the difference between the two types of speakers being tested was responsible for the reduced soundstage definition the FCUFS exhibited, a third test was conducted, the same speakers used as FCUFS were placed on a pair of stools which placed them at ear level, then again equalized for their new room position.
This resulted in a sound stage just as defined as my "usual" speakers, but one that was ear level, preferable as a position to the usual up angle I have been accustomed to in the listening position.
Having now compared FCUFS in the same listening room to the usual arrangement, I found no sonic advantage to the additional room reflections the position creates, and the down angle imaging simply reminded me of sitting in a balcony, often referred to in my business as the "nosebleeds" or "cheap seats".
If I were to desire additional "phantom imaging" over that afforded by the usual stereo triangle, my preference (over FCUFS) to achieve that would be to add additional side or rear speakers connected in series between the L/R positive (+) outputs, which presents only the stereo difference information as ambience in those speakers, while still leaving the main speakers definition unaffected by additional reflected sound.
That said, I soon became disenchanted with that "phantom speaker" approach too (other than for certain compromised listening environments) my preference for front and center listening is strong.
Art (gave FCUFS a chance four times) Welter
Attachments
You would be wrong here. I think stereo works, but it has its profound limitations. From the very beginning, stereo was not the first choice in sound reproduction, three channels were. However no medium could carry three channels at the time, vinyl certainly could not do it. Then comes tape, and only magnetic tape could carry three channels - and it was not affordable or practical for most people outside the studio. Then comes CD, and any more than two channels shortened playback time. Stereo has only be evaluated on the basis of convenience, not performance. The limitations of the carrier system has always been why it has been chosen in the first place.
Plain ordinary stereo phantom imaging works very effectively when one sits exactly in between the two speakers. Once you move from the centered position, the whole effect falls apart. Flooders can widen the soundstage, but it also smears detail, causes imaging to become fuzzy, and some can identify its location in the room(on or near the floor). So you are trading one benefit(spaciousness) for several others. You can raise the bit and sample rate, but you still have a presentation with very limited spatial abilities.
__
Graaf,
Since I did my testing previously with a mono source in the (cue shocked looks of disgust
This required moving the couch, coffee table and treadmill to one side of the room, a less symmetrical arrangement than normal, but equal for both speaker ends of the room.
The usual listening arrangement has the two-way L/R speakers located in the corners of the room on the north 11 foot (3.38 meter) wall, the length of the room is 21 feet (6.46 m) , height 8 feet (2.46 m) on the east wall, 7.6 feet ( 2.31 m) on the west wall.
The 5 inch full range floor coupled upward firing speakers were located near the corners of the south wall.
Temperature was 77 F, humidity 21 %.
Music consisted primarily from selections from two albums:
Aaron Copeland-Louis Lane/Atlanta Symphony Orchestra- Appalachian Spring-Rodeo
Susan McKeown & The Chanting House-Prophecy
First stage of the three part listening test (pictures of each set up below) was to equalize the speaker systems to sound similar and store presets so a quick change could be made when shifting from one to the other.
As a live sound engineer rapidly equalizing as many as a fourteen separate (and individually different) speaker systems in hundreds of concert halls and stages varying on a daily basis over the course of the last 38 years, this is fairly routine operation for me.
The presets and A/B speaker switch made rapid comparisons easy.
Rapid switches between the same portions of songs are important to actually retain a vivid acoustical memory to compare.
Listening position was from a seated position midway in the room, also with eyes closed and rotating around from time to time.
Observations of the usual L/R toed in triangular listening arrangement:
The usual stereo speakers presented a soundstage consistent with the recordings, with left, right and points between being easily discernible, and with some sense of upstage and downstage location.
For those not familiar with theatrical stage positions, upstage is towards the back wall, downstage is towards the audience.
Reverberation sounded similar to what I'd expect from the recording of a symphony orchestra, sounding like a large, live concert hall with a large, widely spaced orchestra.
The Susan McKeown songs generally had a nice (not too artificial sounding) studio/hall ambience, lead vocals center, background vocals spread L/R, instruments located in various "panned" positions.
Overall soundstage position had a location above ear height, consistent with the location of the speakers. The speakers midpoint is 60" off the floor, ear height 46" off the floor, about an 11 degrees up angle.
Observations of the floor coupled upward firing speakers:
Various positions were compared moving the speakers in and out, little overall change was noticed, though a position with the center of the speaker about 9 inches from the side wall seemed to give the most neutral sound, perhaps because that distance matched the depth of the speakers. The very shallow (1.5") speakers previously tested in a FCUF configuration did not seem as sensitive to side wall positioning.
The most obvious and immediate observation was the sound of the speakers coming from the floor. When I closed my eyes, the sense of listening from a relatively low balcony was palpable, consistent with the down angle of approximately 22 degrees.
Soundstage was consistent with the recordings, with left, right and points between generally locatable, but much more difficult to specifically "point to" than the usual L/R toed in triangular listening arrangement .
Sense of upstage and downstage location was ambiguous.
Of interest, turning the listening chair around so my back was to the operating speakers gave an inverted presentation, the general soundstage appeared to be elevated to near the ceiling, though instruments with little high frequency still sounded like they were behind and below. Quite "enveloping", but a bit disconcerting.
To determine whether the difference between the two types of speakers being tested was responsible for the reduced soundstage definition the FCUFS exhibited, a third test was conducted, the same speakers used as FCUFS were placed on a pair of stools which placed them at ear level, then again equalized for their new room position.
This resulted in a sound stage just as defined as my "usual" speakers, but one that was ear level, preferable as a position to the usual up angle I have been accustomed to in the listening position.
Having now compared FCUFS in the same listening room to the usual arrangement, I found no sonic advantage to the additional room reflections the position creates, and the down angle imaging simply reminded me of sitting in a balcony, often referred to in my business as the "nosebleeds" or "cheap seats".
If I were to desire additional "phantom imaging" over that afforded by the usual stereo triangle, my preference (over FCUFS) to achieve that would be to add additional side or rear speakers connected in series between the L/R positive (+) outputs, which presents only the stereo difference information as ambience in those speakers, while still leaving the main speakers definition unaffected by additional reflected sound.
That said, I soon became disenchanted with that "phantom speaker" approach too (other than for certain compromised listening environments) my preference for front and center listening is strong.
Art (gave FCUFS a chance four times) Welter
Art, thanks very much for this. Once again this mirrors my impressions on the FCUFS I heard. I prefer a listening experience that has a reference versus other within the listening comparison. No reference means I am listening without a perspective.
For me, I would prefer a discrete 7.1 set up over a matrixed "phantom speaker" surround set up. Having two or four independent channels offers a better chance of "mapping" the concert or performance hall than a monophonic surround experience does.
This demonstrates that you haven't listened to reproduction of sufficiently high enough quality. When the replay is of that necessary level then the effect doesn't "fall apart", it's rock solid ... in fact, it's essentially impossible to make it fail by moving to a 'bad' spot.
Yet again, I have to agree with Frank. Sure, typical speakers don't stereo image very well - but some speakers do a great job. So it can't be the limitations of 2 channel.
That takes nothing away from a good 5.1 or 7.1 system, it's just that 2 channel stereo does not have to be as bad as is often claimed.
That takes nothing away from a good 5.1 or 7.1 system, it's just that 2 channel stereo does not have to be as bad as is often claimed.
So inter-aural time differences mean nothing to you? Are you saying you can sit closer to the right speaker and still hear a centered image? Are you saying if I move off center line towards the back of the room that the stereo effect remains the same? Are you saying that no matter where in the room you stand you will still hear a stereo effect with a center mono image?
I call BS on this.
'Fraid it ain't ...So inter-aural time differences mean nothing to you? Are you saying you can sit closer to the right speaker and still hear a centered image? Are you saying if I move off center line towards the back of the room that the stereo effect remains the same? Are you saying that no matter where in the room you stand you will still hear a stereo effect with a center mono image?
I call BS on this.
It's quite remarkable to hear this happen, and it is rare - that I'll certainly concede! - but it most certainly 'works'. As an 'extreme' version of this, I've had on a true mono recording, stood well to the right of the perpendicular to the right hand speaker, moved back and forth along this line, and the image remains in front of me, that is, at a distance beyond the right of the right hand speaker.
Why this apparently happens is that if no distortion calls attention to the speaker drivers producing the sound, then the clarity of the sound, the high standard of reproduction of the low level detail in the recording, aided by reverbation in the listening room perhaps, is sufficient for the ear/brain to accept the illusion presented by the audio system. Precisely why the human hearing system manages to be this capable I can't say, but enough other people have definitely experienced it for me to say that it would relatively common for people to "get it" ...
Call whatever you like. That does not change the fact that the effect exists. No hand waving will change that.I call BS on this.
And what does that have to do with up-firing speakers, anyway?
Of course it remained in front of you, that is where all of the output is coming from. It is easy for a "mono" recording to "remain in front of you" as that is where the output is coming from in the first place. What is difficult to quantify is that the imaging remains stable no matter where you position yourself. What is equally difficult is to take the position that hard left and right instrument positions will remain hard left and right(and centered) when you move off axis. It does not happen based on inter-aural time difference at the ears. No matter how much your diffuse the images, this will always dominate off axis listening.
Can you please prove this hypothesis? We can throw words and assumptions like a monkey throws doo doo, but can we convince other listeners this hypothesis is actually accurate? You have perhaps-es, is sufficient's, can't say's, and you make claims, but where is the proof of these claims, can't say's and hypothesis? What is enough people, and how big is the sample rate you are judging this enough people by?
thank You so much!Still it wasn't that sound sources were all over the place (as one user described his FCUFS experiments) and I am very glad to hear that.
Yes, well, as I said above it can be explained either by imbalance between the HRTF freqs coming from below and from above (ie. too much from below) or by te factor of positional dependence (variance in performance across position combinations) or just by the factor of considerable inter-subject variability.
I would say that most probable is perhaps the third explanation because of Your professional background. It could be not as much a matter of an individual high sensitivity to vertical localisation cues as of a professional (over)sensitization described by Toole in His book.
After all You are
and because of this sensitization You can hear things in a way others cannot
as Dr Toole put it: "Audio professionals may have their own preferences - it’s all right, they are just different"
very strange!
thanks for reporting this, perhaps it can be somehow explained and perhaps when explained this strange phenomenon can itself explain some important aspects of FCUFSLooking on the bright side it was neither a very garbled wash of sound (as one user described His FCUFS experiments)
thanks again for taking Your time!
