On Thu, Jun 16, 2011 at 10:11:25PM +0200, Philipp wrote: > Hi there, > in a discussion today someone asked me where those 60 degrees necessary > for the production of phantom images come from and I couldn't deliver a > satisfactory answer. Someone tried to explain to me that it has > something to do with wavelengths or whatever but couldn't explain it in > a way that anyone would understand. > > My best guess is that with a larger angle the head gets in the way and > the ears have an easier time telling the signals apart. Also, I guess 60 > degrees is a rough estimate and chosen because this leads to a nice > Equilateral triangle. > > So, what's the real reason behind those 60 degrees? Just what you suggest: it leads to an equilateral triangle and that *suggests* there is something fundamental about it. But as far as I know there isn't. Another reason may be that +/- 30 degrees corresponds to the perspective of an average listener in a concert hall - probably more than say +/- 45 degrees. OTOH, a recording technique like e.g. Blumlein (two fig-8 mics at 90 degrees) would suggest a speaker angle of 90 degrees instead. A wider angle will make near-center sources less stable. The number that matters here is the magnitude of the velocity vector which is cos(1/2 the angle): 0.866 for 60 degrees, 0.707 for 90 degrees, while for a 'real' source it would be 1. Ciao, -- FA _______________________________________________ Linux-audio-user mailing list Linux-audio-user@xxxxxxxxxxxxxxxxxxxx http://lists.linuxaudio.org/listinfo/linux-audio-user
