On Wed, 2007-04-25 at 10:02 +0200, Fons Adriaensen wrote: > On Wed, Apr 25, 2007 at 09:15:35AM +0200, Jens M Andreasen wrote: > > > 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. > > ... > > Would that work? > > It probably would, *if* you can get all speakers to be exactly in phase > over the entire frequency band. This will be difficult at HF, and having > part of the range not focused will destroy the effect and identify the > radios as the source of the sound.
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. > > You don't even need a full circle or sphere. I'm currently involved in > a project using an array of 228 speakers / 64 channels suspended as a 3m > diameter 'chandelier' from the ceiling. It will create sound sources moving > above and around the listener's head. > 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 > > FA > > Follie! Follie! Delirio vano รจ questo ! > > > _______________________________________________ > Linux-audio-dev mailing list > [email protected] > http://lists.linuxaudio.org/mailman/listinfo.cgi/linux-audio-dev -- _______________________________________________ Linux-audio-dev mailing list [email protected] http://lists.linuxaudio.org/mailman/listinfo.cgi/linux-audio-dev
