From: milne_v@hotmail.com (milne_v) Newsgroups: alt.mindcontrol Subject: Sound projection tech Date: 10 Oct 2002 17:19:32 -0700 Organization: http://groups.google.com/ Lines: 30 Message-ID: NNTP-Posting-Host: 24.215.29.66 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 8bit X-Trace: posting.google.com 1034295573 5777 127.0.0.1 (11 Oct 2002 00:19:33 GMT) X-Complaints-To: groups-abuse@google.com NNTP-Posting-Date: 11 Oct 2002 00:19:33 GMT Path: rsl2.rslnet.net!cyclone.bc.net!newsfeed.stanford.edu!postnews1.google.com!not-for-mail Xref: rsl2.rslnet.net alt.mindcontrol:3340 The directivity (narrowness) of any wave producing source depends on the size of the source, compared to the wavelengths it generates. Audible sound has wavelengths ranging from a few inches to several feet, and because these wavelengths are comparable to the size of most loudspeakers, sound generally propagates omnidirectionally. Only by creating a sound source much larger than the wavelengths it's producing can a narrow beam be created. Clearly, having loudspeakers twenty metres wide is not very useful. therefore ... to make a narrow beam of sound from a small acoustic source, we instead generate only ultrasound. The ultrasound, whose wavelengths are only a few millimetres long, are much smaller than the source, and consequently travel in an extremely narrow beam. http://www.holosonics.com/ --- What is HSS? HyperSonic Sound Technology is simply the most revolutionary sound reproduction system of this century. Not since the development of the "cone" loudspeaker more than 75 years ago has any technology provided such significant departure from conventional loudspeakers and such a remarkable new approach to the reproduction of sound. http://www.atcsd.com/tl_hss.html