21 Apr
2007
21 Apr
'07
6:34 a.m.
thankyou Xavier ...
I guess that one of the things that surprises me is that the old rule of
"first wave to impact determine the apparent direction" is not at play
here, at least not for sound images between speakers and perhaps not at
all.
I can create a mental picture where some 300 small waves travels across
my bathtub to finally join at the center, creating a splosh as if I just
dropped my soap just there ... and then travels back to only create a
small swell along the sides more ore less equivalent to the original set
of 300 waves ...
Hey, say we put that quiet conversation about illegal substances in the
center - at origo - wouldn't that mean that all speakers would have to
work together in phase as if it was a single one channel mono system?
Superimpose 300 distinct random noises on top of that to give the
impression that those guys indeed intended to keep their conversation
private ... I think their signal at origo should then be approx -30db
below average sound level? Lipreading not being allowed.
Then there wouldn't be a single point in the room where one could
accidentally overhear the conversation except for in a location near the
center of the room. Although the signal would be present all over the
place, it would fall below hearing treshold.
-
-
-
Am I closing in now to an explanation of how this works?
I also came to think about how one can have whispering conversations
across places build as huge perfect domes without bystanders having a
clue about what is going on. The sum of the reflections from the dome
would then be kind of equivalent to the sum of the 300 speakers. (To do
this experiment at home, it is of course an advantage if you happen to
be the Pope and have the Peter Church in your backyard.)
mvh // Jens M Andreasen
On Fri, 2007-04-20 at 22:00 -0700, Xavier Amatriain wrote:
Jens M Andreasen wrote:
--
Uhm ... But you said earlier that "you could
literally walk in
between ..."
Is it OK if I get confused now?
Where do you see the contradiction? Ok, here is more or less the situation:
Large room, 297 speakers spread over the four walls at ear-height.
Speakers are one-way
mid-hi and around 4 subs are in charge of lows (not directional anyway).
The demo starts. You clearly hear the sound of the band coming from one
side of the
room (and the song... is that actually Miles and John?). You walk in
that direction and
can clearly "hear the position" of each of the players. Uhm, now John is
moving from
left to right in the stage. You get next to the drums, you can feel the
band around you.
You walk away from the stage and get distracted from the music by the
sound of
clinging glass and melted conversations. To the right a group of girls
laugh way too
loud as you pass by them. You get close to one of the corners of the
room and can
clearly hear two boys discussing where to get the best shit in town...
And remember, all this with 300 speakers surrounding you on the four
walls ;)
As a matter of fact I know the people from Iosono (Brandenburg a.k.a.
father of
mp3) are trying to team up with construction companies so speakers are
actually
embedded in living-room walls. We'll see it sooner than we think, I am sure.
XA
_______________________________________________
Linux-audio-dev mailing list
Linux-audio-dev(a)lists.linuxaudio.org
http://lists.linuxaudio.org/mailman/listinfo.cgi/linux-audio-dev