Excerpts from Fons Adriaensen's message of 2011-06-16 22:35:10 +0200: > 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, Thanks Fons, this might be the stuff this guy was talking about. Sadly I don't know how to understand the magnitude of the velocity vector. What does it represent? Why does the magnitude decrease with the angle? Best regards, Philipp _______________________________________________ Linux-audio-user mailing list Linux-audio-user@xxxxxxxxxxxxxxxxxxxx http://lists.linuxaudio.org/listinfo/linux-audio-user
