Comments on: 3D is happening

By: Binaural Beats

Binaural Beats — Fri, 17 Dec 2010 11:45:17 +0000

I have seen 3D here in our place with the movie avatar. Amazing but I'm not really a fan of 3D. But I consider it good and still its amazing.

By: Janos

Janos — Thu, 27 May 2010 12:34:14 +0000

'Real' 3D is going to be achieved by holography – in my opinion – within the next 5-7 years. What I have seen so far is a gimicky quasi solution, not worth bothering about

By: Gary LaRock

Gary LaRock — Fri, 19 Mar 2010 05:35:49 +0000

Test comment from Facebook.

By: Chris Kyriakakis

Chris Kyriakakis — Fri, 22 Jan 2010 16:11:29 +0000

Hi Dave,
That would be nice, but it’s not really possible to measure HRTFs that way. The mic has to be inserted in the ear canal very carefully. Perhaps some combination of open air headphones and speakers can provide a more immersive experience. This has been tried in theme parks, but I don’t think it is all that practical for movie theaters and certainly not for the home.

By: Dave

Dave — Fri, 22 Jan 2010 11:02:23 +0000

It might be possible to adapt over-ear headphones with built-in microphones to dynamically measure the HRTF of the listener’s ears to provide a degree of custom calibration, but would you put the processing in the headphone or back at the amp? Also, to do individual calibration and processing for a whole theatre would seem prohibitively expensive.

By: Troy

Troy — Fri, 22 Jan 2010 09:44:53 +0000

3D wont be near as good as home than what it is at cinema. I mean honestly do you think my family is going to be immersed by a 50″ panel?

By: Chris

Chris — Wed, 20 Jan 2010 20:57:21 +0000

Hi Larry,

In order to create binaural content that works for everyone, the head-related transfer functions (HRTFs) must be customized for each person. This has always been the fundamental limitation of binaural recordings: they either use microphones in a “generic” head or they use HRTFs from a real person (but not you!). In either case, the mismatches between the HRTFs used and your own always result in one main problem: lack of externalization. It’s impossible to perceive sounds outside your head especially straight in front where the center channel should be.

Over the past 20 years several methods have been proposed to address these issues. Solutions involve some degree of room acoustical simulation that adds some artificial acoustics to the content and helps with making sources appear a little more distant. Also, the best demonstrations that I have heard include head tracking. One problem with headphones is that the world turns with you as your head moves and that is not what happens in real life. A head tracking device can monitor the rotation of your head and keep the world fixed. This greatly enhances realism, but makes such systems highly impractical for distribution by the hundreds in a movie theater.

By: Larry

Larry — Wed, 20 Jan 2010 20:08:31 +0000

Hi Chris,

Thanks for your insights.

Could you please elaborate on the pros and cons of headphones regarding a 3D presentation? Apparently headphones solve the issue of interaural crosstalk cancellation that you discussed. Don’t biaural recordings provide the necessary content for 3D audio? Are you saying that headphone approaches always result in an “in-your-head” presentation, and the sounds can not be externalized?

Assuming one had multiple wireless headphones available to an audience along with an option to select a biaural soundtrack, how would that approach compare with Audyssey DSX with speakers for realism?

Thanks.

Larry