Hi Dave, >> This magnification effect has been reported many times. >> I wonder how much it has to do with playing back at too high >> levels. We do associate LF energy and size. Too much of it >> and the source 'must be' big. > > That's certainly important - kind of the other end of the scale of quite > but distorted sounds can be interpreted as very loud sounds but with a > distant source. For sound sources with perceivable angular extensions > which are perceived as single objects (pianos, geese and steam loco's > have been mentioned in the past), there is an even stronger cue in that > for the angles to be right the perceived size of the object is set by the > perceived distance which can in turn be modified if the reproduction > space reverberation is dominant over the recorded reverberation.
That is certainly the case for the new 3rd order AMB (horizontal only) system installed recently in la Casa del Suono (which is a small church, so quite reverberant). It works great for concerts, which is what is was designed to do, but for most recorded material indeed any sense of distance is lost. I did a small experiment a few weeks ago, and was quite surprised by the result. In a concert we did at the CdS there were three pieces for solo flute and 'tape'. We got the 'tapes' as CDs of course. The artistic director of the festival asked me if I could somehow 'spatialize' the tapes instead of just playing them via two speakers. There wasn't much time to do anything fancy, so I created six filters, one for each of X,Y,U,V,P,Q which would distribute a mono source in function of frequency, with one full cycle in azimuth for each octave. In fact I made two sets, one going clockwise and the second in the opposite sense. The tapes were all electronic noises, nothing you could recognise as a natural sound, and it worked quite well. Afterwards I took the filter set to the studio at the CdM which also has 3rd order monitoring, and used it on some non-electronic music recordings. Of course this produces quite unnatural effects, sounds which you know as from a single source are split in direction (but 2nd and 4th harmonic would coincide with the fundamental). Each of the speaker signals separately is extremely coloured, and when you solo them in the right order you get the 'infinitely ascending pitch' effect. What surprised me is that nobody could associate pitch and speakers. I somehow expected it would be obvious that e.g. all 'C' notes would come from the same direction, and that one would be able to identify the pitch of each speaker when listening to the complete signal. But that was not the case, and you had to go quite close to any speaker in order to notice there was something strange with the sound it produced. > PS - I gather you guys in Parma might be getting pretty shaken up by the > earthquakes in Northern Italy - hope all is well there. Here in Parma there's no major damage so far, but in the region just NE of Modena (60..70 km from here) it's dire misery. 16 people died on monday, mostly employees who were just resuming work a week after the first shock. And very probably it's not finished, there are lots of small tremors all day and night, and some more big ones can be expected. Ciao, -- FA A world of exhaustive, reliable metadata would be an utopia. It's also a pipe-dream, founded on self-delusion, nerd hubris and hysterically inflated market opportunities. (Cory Doctorow) _______________________________________________ Sursound mailing list Sursound@music.vt.edu https://mail.music.vt.edu/mailman/listinfo/sursound
