Welcome, Guest. Please Login or Register
Decware Audio Forums
10/20/14 at 13:57:42


Pages: 1
Send Topic Print
3-D sound, misc. ramblings (Read 544 times)
ski bum
Seasoned Member
****




Posts: 177
3-D sound, misc. ramblings
06/03/13 at 19:23:06
 
So, being an audio nut with a fascination with music and sound reproduction in general, I wanted to share an interesting link.  This is from Princeton University, and is research concerning the fundamental aspect of spatial hearing in humans.  For those who have read about ambisonics and other odd-ball approaches, this will ring a bell.  The research is not about creating an enveloping soundscape a la surround sound, but rather a realistically three dimentional sonic image.  Be sure to watch the video on this page, the bug circling your head effect really works.

http://www.princeton.edu/3D3A/index.html

This made me ponder my little se84 amps and their ability to pull off a rather compelling semblance of 3-D imaging.  If the Princeton guys can make a fly buzz around your head from two forward located speakers using cross-talk cancellation/manipulation, what do my se84 amps do in terms of crosstalk, and how may that be influencing the perceived image?

There are a couple aspects of the se84 amps relevant to cross-talk and how it may be doing some interesting things.  First, the "Carver effect", i.e. high output impedance mediated speaker microphonicity; your speakers pick up the sound of the room and play it back at you, which would involve considerable cross-talk and phase differences; and second, shared cathode resistors in the circuit.  What I wonder is if this mish-mash of real, measurable cross-talk effects have direct bearing on holographic trickery?  It sure is enjoyable, whatever the cause.

I think this may be why I prefer se84 amps in stereo over bridged se84 amps; the bridged amps obviously don't share cathode resistors between channels, and so that ingredient of the holographic pie is missing.  

Feel free to discuss, hopefully while enjoying the music.


Back to top
 
« Last Edit: 06/04/13 at 01:13:28 by ski bum »  
  IP Logged
Mark
Seasoned Member
****




Posts: 190
Re: 3-D sound, misc. ramblings
Reply #1 - 06/03/13 at 21:53:36
 
Oddly enough, I find that a closer speaker placement cancels out a lot of inter-aural crosstalk between speakers [and your head, of course]... And also not tilting the speakers inward...

Did some experimenting when I was younger with binaural recordings... Two mics with a dummy head in between... But when you play it back with loudspeakers, you always get some of the right channel in the left ear, etc. It works great with headphones, though...

Read the ambiosonics literature earlier on here... Interesting, but I don't know how practical all this is...

Anyway, for what it's worth, a performance [usually] takes place in front of you, as on a stage... The instruments are all point sources... With proper room treatment, you should be able to reap a more believable presentation without all the fancy electronic compensation...   (m.)

Back to top
 
 

If a rabbit defined intelligence the way man does, then the most intelligent animal would be a rabbit, followed by the animal most willing to obey the commands of a rabbit. -Robert Brault, writer (b. 1938)
  IP Logged
beowulf
Seasoned Member
****




Posts: 851
Re: 3-D sound, misc. ramblings
Reply #2 - 06/05/13 at 01:55:12
 
Very interesting, thanks for posting that link.  It looks as though the program is already available, but measurements need to be done in order for optimal setup so trained installers need to set it up.  There are a couple of vendors doing it though.

What's very cool about it is only 2 speakers are required for this to work ... so almost all 2 channel stereo systems are potential candidates and if you already have favorite playback system only the processor/filter is needed.  However, I believe the speakers should be point source though rather than Radial, so perhaps the Decware ERRs would not do as well as say the MG944s.

I found this leaflet online about the BACC 3D here.

The sort of nuts and bolts of it online here.

and FAQs online here.

p.s. I should mention that this is compatible with all existing stereo media that's already in production, so even MP3s, DSDs, Vinyl Records, Redbook CD's, etc. can be used ... no special formats such as Dolby, etc. needed ... although could you imagine how great it would sound using Vinyl Records and a Decware ZP3 or even DSD files using one of the newer DACs that can process DSD files?  I would imagine stunning!

p.p.s Besides 3D ... the filter also functions as room  corrections:

Not only does BACCH™ 3D Sound provide a shocking improvement to the spatial realism of sound reproduction, but the same digital filter used in BACCH™ 3D Sound also corrects, in both the frequency and time domains, most non-idealities in the playback chain (including loudspeaker coloration and resonances, listening room modes, spatial comb filtering, balance differences between channels, etc…) so that the frequency and impulse responses at the listener’s ears are as close to ideal as possible for a given listening room and hi-fi system. This corrective property of BACCH™ 3D Sound , which by itself is a highly desirable enhancement to the fidelity of any audio system, is only the secondary feature of BACCH™ 3D Sound – the primary feature being 3D sound.
Back to top
 
« Last Edit: 06/05/13 at 02:06:40 by beowulf »  
  IP Logged
Pages: 1
Send Topic Print