[GeekGirl]

After taking a look at the (lack of) display calibration standards for 3-D TV, I came across an IEEE paper that's investigating loudspeaker placement. How Does My 3D Video Sound Like? - Impact of Loudspeaker Set-Ups on Audiovisual Quality on Mid-Sized Autostereoscopic Display


Here's the abstract:

Quote:
In this paper, we examine an optimum loudspeaker set-up for audiovisual environments using a 15" autostereoscopic display to present video. By varying the number of loudspeakers and their distance from the listening point, we performed subjective assessment tests on four different setups with 32 participants. We measured simulator sickness to examine possible influencing side effects of visual presentation. As a test environment, we chose the MPEG-4 based audiovisual IAVAS player and content creation was done using virtual rooms. Our results show that four loudspeakers in a distance of one meter from the listener offer the most pleasant experience of audiovisual quality and the result is not significantly impacted by visual discomfort.

This reminds me when Consumer Reports used to base their audio quality on loudspeakers hung from the ceiling. That was a l-o-n-g time ago (I remember reading about it in The Absolute Sound mag...).


Are we going to have to adjust speaker placement for 3-D, or, is Dolby Digital (pick a flavor) OK as is?

 

[GregLee]



Quote:
Originally Posted by GeekGirl /forum/post/18237841


Are we going to have to adjust speaker placement for 3-D, ...

No. We already try to make the locations of sounds as listeners hear them correspond to their intended locations in the recording, as best we can. The proposal in that abstract to place 4 speakers 1 meter away from the listener(s) seems silly, to me. (I didn't read the paper itself.) Maybe the authors had only an old quadraphonic sound system to work with?

 

[GeekGirl]

OK, thanks. That helps. I didn't know if everyone was focusing on video and forgot about the audio. Real information is hard to come by. Some details from the paper:


The paper attempts to answer a general question of perceived overall quality when two stimuli (audio and video) are integrated as a single metric. IOW, perceived quality of one may affect perceived quality of the other. It doesn't address anything about accuracy of reproduction.


One of the criteria was concern that displays creating three-dimensional impressions might introduce sickness symptoms (nausea, oculomotor, disorientation) that reduce the presence and feeling of depth. The others were Acceptable Quality, Overall Quality Satisfaction, and Quality of Localization.


I'm not sure what material they were using to run the experiments, which used 4 then 5 speakers between 0.5 m and 2 m from the 15" display.


- A Sharp AL3DU autostereoscopic display was used, but no speaker brand was mentioned.


- Moving multimedia may be strongly impacted by different audio and visual presentation modes and devices. More research is needed to understand the impact of different setups.


- The paper suggested that when conducting quality evaluations "especially with naive participants for consumer-oriented assessment purposes", it might be enough to give an overall quality rating instead of judging the "certain quality attributes".


My non-professional opinion (I'm not a certified calibrator):

For low-end consumers, a "Good", "Better", "Best" ranking is all you need. It matters how you bundle the stereo / speaker package with the TV.


For AVS forum members (high end educated consumer), it might be useful for the physiology of 3-D, but otherwise has no added value.

 

[Lee Stewart]



I go to a theater (not IMAX) to see either a 2D or 3D film - the speaker placement is the same. Uses the the 5.1 setup:


Left Channel, Center Channel, Right Channel, Subwoofer - in front of me


Left Surround Channel, Right Surround Channel - to the side/back of me


Same setup I have in my home for 2D


Why do you think it will be any different for 3D?

 

[GeekGirl]

Simply because I thought that since 3-D changed the perceived optical distance from the display (the objects jump out at you), that the audio might follow. The IEEE paper threw me a curve down the wrong path. I just didn't know, so I asked. In hindsight, I see that I wasn't thinking this through correctly and now have the correct answer. Thanks.