Audibility of height in a stereo system?

[Marvin55]

Many times over the years I have heard reviewers and listeners assert that a stereo can reproduce height information. I have never heard it myself, nor can I think of a mechanism for it. Please note that I am speaking of a pair of stereo speakers only. Please correct me if I am wrong. A concrete example would help.

 

[Chrispy]

Wider/better vertical dispersion perhaps? Width and height can be reproduced somewhat depending on room/speaker setup. I'd hope you had the example, tho (of what might have "more" height than you currently experience, that is)

 

[GXAlan]

Dolby Atmos Virtual Height shows you how HRTFs can provide height cues from stereo speakers.

When it comes to speakers, non linearities can alter the perspective you have. There is a lecture from Amar Bose where he takes some keys and jingles them in the lecture hall while people close their eyes, and I think people end up pointing higher than you think when it is a keychain you are unfamiliar with. There was some sort of determination that people imagine sound coming from different heights due to frequency response and this is how Bose’s original automotive innovations came about.

A lot of it is sighted bias, of course, but it’s really about the recording and the cues in the room.

I have said that my Meyer Sound Amie’s make my room sound bigger than they really are in comparison to the JBL 708P. They have been measured here and the only finding I see is the altered vertical reflections.

(Edit: so maybe the volume of the reflections are cues to how big the room is)

 

[solderdude]

Many times over the years I have heard reviewers and listeners assert that a stereo can reproduce height information.

Speakers can't but the brain in combination with the ears and speakers in a room can certainly give the impression of differences in height.
So whenever you read this in a review just know it is a personal observation in his room, circumstances and the way this individual's brain is wired to process directional cues.

 

[Bugal1998]

As @GXAlan and @solderdude have said, there can be a perception of height but generally not a reproduction of height. HRTF processing of the signal could maybe be argued as an exception.

Here are some anecdotes that you can take or leave. If I decrease the downward tilt of the frequency response in my system (i.e. high frequencies become louder) many recordings seem to originate from a higher location in the room, but that's not reproduction. 70+ people have listened in my room, and while there is general overlap in perception for a given room tuning, people still have differeing perceptions of height. And then there are the outliers that percieve the music as coming from the ceiling (two people), and one person who heard it as coming from very low near the floor, and one person who said it sounded like the speakers were up high and behind them. As I have inched closer to a more neutral tuning the perceptions of height have converged more among listeners and trended towards a lower perception more in line with the height of the HF driver. In my experience it is also room dependent, which is another argument that it is not reproduction.

 

[boxerfan88]

Not sure if this relates to the question at hand, currently I get a taller soundstage height by placing my speakers higher.

The speakers acoustic center is approximately 40cm higher than ear level, and the speaker is tilted/angled down such that the vertical "on-axis" line is pointing at the ear level.

I like it this way as it creates for me the acoustic soundstage typically created by those big & tall speakers.

 

[sigbergaudio]

Perception of height can change due to room, speaker frequency response, physical height of speakers (typically location of midrange/tweeter), dispersion characteristics, tricks during mixing/production of the record you listen to.. So yes this is definitely an actual thing in stereo reproduction.

 

[MaxwellsEq]

For a simple, crossed pair recording in a lively acoustic space, where the floor, walls and ceiling are not equidistant from the instruments, there will be some capture of height differences because reverb from the boundaries will all be different. For example an array of identically tuned small bells arranged evenly on a tall pole should have different reverb depending on their height. Such information would not be available if the space was anechoic!

However, I'm not sure how reliably this would be reproduced in the home. I've mostly assumed that height information is an artefact of the speakers and listening room responding differently to different frequencies.

 

[Sokel]

This is intended to work with headphones but works with speakers too:

Virtual Acoustic Space | Auditory Neuroscience

auditoryneuroscience.com

Most stererophonic recordings are based only on differences in level between the two ears and the resulting sounds are therefore lateralized toward one ear or the other. By contrast, virtual acoustic space stimuli incorporate the full complement of localization cues and, in principle, replicate real free-field sounds. Consequently, as you move the mouse, you should hear the sounds move up or down as well as left or right and even seem as though they are either in front of or behind you. Of course, how well this will work depends to some extent on how closely your head and ears match those of the subject from whom the acoustical measurements were made to generate these stimuli.

 

[Pareto Pragmatic]

Vertical dispersion yes, but I think it is more generally a function of reflections from ceiling and floor. Dispersion is a factor, but so is distance from speaker to listener. More floor reflections will pull the image lower, more ceiling higher. Just like more right wall reflections pull the sound stage right.

You can try this out yourself. Pile a BUNCH of blankets on the floor half way between your speakers and seating location. See what happens. Move the speakers and seat further from each other (for more ceiling/floor reflections), reposition the blanket pile, try again.

I do have an example, but it's pretty absurd, because my room is absurd. I have a big, cupped, old floor that starts to bounce at a certain volume. A lot, and it gets worse pretty quickly after that point. It starts to fire sound up in the room towards the center of the ceiling at a slight angle.

The difference between when it starts to bounce and +2.5db past that point gives me around a 2' increase in sound stage height (stand mount speakers, no sub). This is certainly due to the floor starting to fire sound up at the ceiling more and more. A bit more volume, more ceiling reflections, more height.

I can get a huge sound stage by playing with reflections, wider than the sidewalls and not quite floor all the way to the 9' ceiling. The band is in the room kind of feel. But the downside is more distortion. So there is a trade off.

I do have speakers with less vertical dispersion for AV, which are 4' further back than my music speakers in the same room, which have more vertical dispersion. It pretty much equals out in terms of ceiling reflections at my listening position.

 

[DanielT]

Line array speakers known for good vertical dispersion. Some examples of such:

One moment, please...

And:

Ppataki's line arrays below. Challenges with line arrays, for example that EQ is needed, are addressed in that thread. Of course, the advantages of line arrays are also ventilated, for example reduced floor and ceiling reflections (if they are long enough).

Wesayso from Vandermill -Audio also participates in the discussions:

Murphy's Corner Line Array project

Another update: the 'sandwich' panels are done! As you can see in the below pictures, Green Glue has been applied between the panels (2x12mm birch plywood) There are some panels missing, they will be done a bit later The next phase will be to put together the back of the speaker, paint it (with...

audiosciencereview.com

Having said that, line array is not for everyone. Ppataki later did a 180 degree. Nowadays, he only builds speakers with broadband drivers:

Sphere shaped speakers with CHN110 drivers

I got inspired by an earlier thread here and decided to build my own sphere shaped speakers too The idea is the same, I will be using the largest Ikea Blanda Matt bamboo salad bowls (having an outer diameter of 28cm) The drivers will be Markaudio CHN110 full range models (I have used these...

audiosciencereview.com

 

[Mschn]

Back in 2005 I attended a demo/tutorial/whatever in which, among other things, we were subjected to a synthetically generated example in which a clicking noise moved from left to right speaker -- not horizontally but following an arc above the speakers. The explanation, as far as I remember it, was that interference with ground/floor creates a subtle but audible difference depending on the height to the sound source. We learn to judge this height 'by ear' by correlating to visual input from childhood and onward. Hence, blind people are really poor at judging the height of a sound source.

Two, two-way speakers were used for this demo. The room was fairly carefully treated and had a thick carpet on the floor.

/Martin

 

[Bugal1998]

Back in 2005 I attended a demo/tutorial/whatever in which, among other things, we were subjected to a synthetically generated example in which a clicking noise moved from left to right speaker -- not horizontally but following an arc above the speakers. The explanation, as far as I remember it, was that interference with ground/floor creates a subtle but audible difference depending on the height to the sound source. We learn to judge this height 'by ear' by correlating to visual input from childhood and onward. Hence, blind people are really poor at judging the height of a sound source.

Two, two-way speakers were used for this demo. The room was fairly carefully treated and had a thick carpet on the floor.

/Martin

I suspect the track you’re referring to is called the LEDR test. Stereophile has that track on some of their setup and test CD’s. I believe they manipulate the frequency spectrum of the click to simulate the spectrum shift of a typical HRTF…

Edit: You can hear the spectral shift if you rub the fingers of one hand together and slowly raise your hand above your head. It’s driven more by the pinna than height above the floor, though the cancellation frequency of the floor bounce (SBIR) also shifts with height above the floor and may provide a height cue as well.

 

[ripvw]

Online LEDR™ Sound Test | Listening Environment Diagnostic Recording Test

Audio Test Tones : check your stereo system for correct imaging

www.audiocheck.net

 

[GXAlan]

Found the lecture. It’s #25 in this series.

InfiniteMIT | Amar Bose: 6.312 Lecture 25

The InfiniteMIT site is a collection of videos that create a vivid portrait of an institution that is continually changing the way we live and work. Interviews with legendary change-makers, historic footage from the MIT Museum collection, unforgettable lectures, commencement speeches, and symposia.

infinite.mit.edu

Watch this about localization and this helps you understand height cues from stereo music.

 

[Shiva]

When I would go evaluate floor standing speakers, I would always take a copy of this song by Diana Krall,- My Love is- with me. It is short and I can quickly get a feel for a pair of speakers. It starts with yrj snapping of fingers, which should seem like it is coming high up on the right in the sound field and is quite dynamic as well. Then the big stand up bass begins and if the speakers cant convey that, it only takes 30 seconds to not be interested in that speaker, the bass also has some height info. Then Krall begins, and you should be able to hear her voice bounce offthe ceiling in the space she is singing in and is also very dynamic.

 

[Newman]

As @GXAlan and @solderdude have said, there can be a perception of height but generally not a reproduction of height. HRTF processing of the signal could maybe be argued as an exception.

Here are some anecdotes that you can take or leave. If I decrease the downward tilt of the frequency response in my system (i.e. high frequencies become louder) many recordings seem to originate from a higher location in the room, but that's not reproduction. 70+ people have listened in my room, and while there is general overlap in perception for a given room tuning, people still have differeing perceptions of height. And then there are the outliers that percieve the music as coming from the ceiling (two people), and one person who heard it as coming from very low near the floor, and one person who said it sounded like the speakers were up high and behind them. As I have inched closer to a more neutral tuning the perceptions of height have converged more among listeners and trended towards a lower perception more in line with the height of the HF driver. In my experience it is also room dependent, which is another argument that it is not reproduction.

I like that you are drawing the distinction between reproduction of height information that was deliberately intended by the recording engineer to be heard as such, and creation of a height illusion during home playback.

I wonder which interpretation was the OP's intent when opening this thread? @Marvin55

 

[Robin L]

I remember hearing a pair of Spica TC-50 speakers playing the Proprius release of the original Cantate Domino LP. That had a definite sense of height. Of course, the little Spicas had a deserved reputation for good imaging.

 

[DSJR]

I remember hearing a pair of Spica TC-50 speakers playing the Proprius release of the original Cantate Domino LP. That had a definite sense of height. Of course, the little Spicas had a deserved reputation for good imaging.

View attachment 391045

There were some huge pyramid-ish shaped French speakers with spherical mid/tweet pods (not sure if it was Cabasse and I'm stunned I can't remember the maker's name). Anyway, they were a mess on commercial music but Cantate Domino sounded incredible, especially on 'that' song..

 

[Pareto Pragmatic]

I like that you are drawing the distinction between reproduction of height information that was deliberately intended by the recording engineer to be heard as such, and creation of a height illusion during home playback.

I wonder which interpretation was the OP's intent when opening this thread?

... reproduction... never heard.... so maybe both?

From what little I understand... mics at different heights, and the timing difference between them is where the height in the recording is located. How that is mixed I have no idea.

That's the extent of my understanding, which I will not call knowledge.