On Fri, 2007-04-20 at 18:08 -0700, Xavier Amatriain wrote: Now this is the kind of experience ... Could you walk back and forth to deceptelively pick up up the best place to buy crack in town ... or would the whole audience hear the same as you (and show up later in the same flat) Sweet spot is OK, but we would like to widen it. Uhm ... But you said earlier that "you could literally walk in between ..." Is it OK if I get confused now? --

Jens M Andreasen wrote: 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

Jens M Andreasen wrote: Incidentally, my main project right now is the design of such a dome (actually it is a complete sphere, which will have 500+ speakers): http://www.mat.ucsb.edu/allosphere Cheers, XA

On Sat, 2007-04-21 at 12:05 +0200, Jens M Andreasen wrote: Well, the "Pope" IS also on our side: http://www.create.ucsb.edu/~stp :-)

After looking closer to Xaviers 'Allosphere' I doubt that it would be possible to do the "acoustic experiment with a dome to demonstrate positioned sound coming out of thin air" that I suggested. You'd need a dome made out of marble or concrete to do that. It all depends on the sum of reflections, so any acoustic dampening or slip thru would lessen the effect. What I think would be possible as an experiment though (without involving a budget the size of the Pope or TU-Berlin), is to place a large amount of uniform speakers in a circle and then feed them with the same monophonic signal. If everything works as expected, it should then appear like the sound emerges from the center of the circular array of speakers. * The speakers could be a collection of ghettoblasters and kitchen radioes with fresh batteries. * The signal could be a local radiostation (hey, this is /wireless/ :-). * The location could be a park or a stadium in your city. Would that work? I am convinced that it would really surprise everybody involved - in a positive way - if it did. But if it doesn't ... Then one would have 200 buddies carrying ghettoblasters in hand staring suspiciously at the initiator ... /jens On Sat, 2007-04-21 at 13:24 -0400, Eric Dantan Rzewnicki wrote: --

Uhmm ... You say that one should antiphase the signal from the speakers in the opposite direction? Since this is a signal supposed to emerge from the center and the speakers are arranged in a circle, then either there are no speakers in the opposite direction or all speakers can be considered to be opposite. Is origo a special case that doesn't work? I would have thought it to be the simple base-case, even simpler than the "dropping the soap in a bathtub, but reversed" wawe propagation I suggested earlier. I understand that standing outside the ring of more or less omni-directonal speakers will sound in unpredictional ways, but this is not the subject. Only a few of those (say 200) involved would be allowed at any one time to enter the ring to experience the effect, otherwise the mass of the crowd would get in the way. /jens On Wed, 2007-04-25 at 09:51 +0200, Joern Nettingsmeier wrote: --

On Wed, 2007-04-25 at 11:33 +0200, Joern Nettingsmeier wrote: [getting back to you later, but for now:] I guess you never had to deal with a real horse on stage? :-D --

On Wed, 2007-04-25 at 11:33 +0200, Joern Nettingsmeier wrote: Origo is the name of the center of a cartesian space where we have x = 0 and y = 0. The word "original" may ring a bell? This is where it all originates or is derived from. I am assuming a four quadrant system with negative as well as positive values to map our floor-space. Well, I am certainly no expert either but I know that we can sometimes be easily lured, not being able to tell the difference between a pre-delay and a post-delay. What is at play her is that there is a stronger signal present that we prefere to believe in. So it is acceptable with a weak pre-delay signal from certain speakers close to you, as long as you will immidiately after be overwhelmed by a stronger signal showing "the true origin" of the signal. /jens

Xavier Amatriain wrote: granted. but a bass drum does have hi-frequency cues as well. the interesting thing about that drum was that there was an insane amount of sound energy in a very small space, with very few and quite soft phantom images. yes you can, but my point was it does not work very well when you are between the speakers and the virtual source, which does happen in a large auditorium. from my listening experience in the wfs room at tu berlin i can say that sources outside the speaker array are far more stable and convincing than those inside. that said, it's still amazing what you can do inside. best, jörn (who is still fiddling to get decent 1st order ambisonics at home and hasn't come very far yet...) -- jörn nettingsmeier home://germany/45128 essen/lortzingstr. 11/ http://spunk.dnsalias.org phone://+49/201/491621 Kurt is up in Heaven now.

On Wed, 2007-04-25 at 09:40 -0700, Xavier Amatriain wrote: Jörn, did you feel the impact of the low frquecies in your belly? /jens --

On Tue, 2007-05-08 at 14:40 +0200, torbenh(a)gmx.de wrote: I think Roger Waters could be interrested in joining one of those demo sessions, judging from this review of his latest tour: -8<------------------- ... I will only comment on a few individual aspects of the performance. First of all, the accompanying screen projections and 3D affects were incredible and added significantly to the overall experience. The quadraphonic sound system employed on this tour made for the ultimate listening experience as music and sound affects seemed to surround and envelope you. http://blogcritics.org/archives/2006/09/29/105808.php

On Wed, 2007-04-25 at 10:02 +0200, Fons Adriaensen wrote: First problem would be that there is no guarantee that all devices would agree on that a positive signal indicates pressure and the speaker should move outwards. There is a good probability though that it will be that way. Second problem, as you say, to control the entire frequency band: That is not possible with random equipment, therefore I suggest to carefully choose a bandwith limited signal. For instance; we have here, at certain times, a female voice on the radio giving us detailed information of wind and pressure all along the coast. It lasts for a while ... Those devices that have a treble or tone control could be set to a minimum to focus on frequency band around 1K. Right, I was getting in that direction as well. Still thinking about swayed arrays of standard signals (as in CD:s or FM-stereo.) for unusual sound experinces in otherwise bland environments. I also came to think of closing "the gap in the middle" by having two swayed arrays of left respectively right creating a virtual center channel slightly in front of both.Then the focus would be on the lead singer rather than the little mandolins left and right. Perhaps a variation on a Phillips array(sp?) could be useful here: L-R, L, L+R, R, R-L /jens --

A defence for 5.1 The 3D-system discussed in the other thread (Cathedral in your backyard) is not really fit for cinematography. Huh? - you might say - You just admitteded that you figured out the basic principles of how it works? Yes, but it is still not fit for cinematography and here is why. Allow me to invite you in to my virtual theatre; It is early morning as I walk across sct Marcus Square, the pidgins gets annoyed and flies away out over the audience (that would be you.) I lift my hand and follow them with my eyes ... Now we could imagine two scenarios, either this is me performing live or you are looking at a photographic image at a screen in the cinema. Suppose we are at the cinema then, in which direction are the pidgins flying? Through the center of the cinema or across your head? At the cinema you would all have a visual experince of what happened as if you were sitting at the point of the camera position. The pidgins did not really fly over you, but over the camera and it doesn't matter if you are sitting left or right, you'd still experience the visuals from the camera position and most likely expect the sound to follow suit. For arguments sake, lets suppose there exist a sound of pidgins flying out of screen to .. Ehrmm, somewhere. A completely different scenario would be if I was live on stage, and agin for the sake of argument say in the cinema closest to you. Now when I lift my hand and follow those virtual pidgins, those of you to the right will see the left side of my arm and expect the pidgins to flutter out on your right side, those to the right will expect the opposite to happen. Really, none of you would buy it. It worked in the movie, but having me standing there live is disturbing and erronius (or the sound is all wrong?) For a final display, let me introduce Joe Labero!! (applause, applause) [me] Joe, how does it feel to be at TU-Berlin tonight? [joe] Oh, just like any other place where I've performed. It's a lovely audience tonight though ... Joe slings an arm towards the audience, and 200 pidgins appears to circle around the room before returning back to stage. Joe now have some five or seven white pidgins crawling around his suit and in his hair. [me] Joe!? How did you do that!? [joe] I didn't, it's just an illusion >;-> mvh // Jens M Andreasen On Sat, 2007-04-21 at 13:24 -0400, Eric Dantan Rzewnicki wrote: --

On Sat, Apr 21, 2007 at 02:41:14AM +0200, Jens M Andreasen wrote: There were numerous times thoughout the days leading up to the conference and during the conference that I physically, suddenly and involuntarily jumped due to some unexpected sound directly behind my shoulder, or, for instance, the sound of sirens that made me check to be sure I hadn't just been run over. Marije has said that some effect can be achieved with as few as 8 speakers, iirc. The TU system is the largest installed to date, afaik. -Eric Rz.