my $.02 ... But the unanswered question is, can we really detect the originating > direction of low frequency sound if you do not > have assistance of the over 80-120Hz overtones ? >
conventional thought says no. This matches my experience. This description from wikipedia http://en.wikipedia.org/wiki/Sound_localization#Evaluation_for_low_frequenciesseems pretty good to me. "For frequencies below 800 Hz, the dimensions of the head (ear distance 21.5 cm, corresponding to an interaural time delay of 625 µs), are smaller than the half wavelength of the sound waves. So the auditory system can determine phase delays between both ears without confusion. Interaural level differences are very low in this frequency range, especially below about 200 Hz, so a precise evaluation of the input direction is nearly impossible on the basis of level differences alone. As the frequency drops below 80 Hz it becomes difficult or impossible to use either time difference or level difference to determine a sound's lateral source, because the phase difference between the ears becomes too small for a directional evaluation. " > Or is the directional hint the the sensation of the impact on you body of > the sound preassure wave ( high volume needed)? There are research results indicating that it is not so important, that the > highfrequency pshychocoustic impressions overrides and creates the > directional impression. > > this relates to the impact of transients in the bass. and alignment of the subs with the mains can matter. not really a stereo/multichannel localization concern. > Do any one have the definitive answer to this? Or do we really have to > care, as far as "normal" use of mono channel for < 80Hz sounds. > > as far as localization i don't think one needs to worry about sounds below around 80Hz (and even below 120Hz perhaps). But frequency response is effected by the placement and number of subwoofers. jim > For the 5.1 specification satellite speakers are to be able to go down to > the cutover between 80 to 100 Hz, that some manufacturers of lowcost 5.1 > appliances have a much higher cutover frequency is the normal corner cutting > in low cost products. > > - Bo-Erik > > -----Original Message----- > From: [email protected] [mailto:[email protected]] > On Behalf Of Martin Leese > Sent: den 8 juni 2011 18:35 > To: [email protected] > Subject: Re: [Sursound] Fwd: Bass Problem in crosstalk cancellation > > Marc Lavall?e <[email protected]> wrote: > ... > > Ambisonics can supposedly reproduce > > bass from all directions; is it true? > > Yes, assuming: > > 1. The source contains bass from all > directions > 2. The standing waves in the room don't > screw up localisation of bass frequencies. > > But this is also true for 5.1 (assuming some idiot doesn't stuff all of the > bass into the LFE channel). > > Regards, > Martin > -- > Martin J Leese > E-mail: martin.leese stanfordalumni.org > Web: http://members.tripod.com/martin_leese/ > _______________________________________________ > Sursound mailing list > [email protected] > https://mail.music.vt.edu/mailman/listinfo/sursound > _______________________________________________ > Sursound mailing list > [email protected] > https://mail.music.vt.edu/mailman/listinfo/sursound > -- Jim Moses Technical Director/Lecturer Brown University Music Department and M.E.M.E. (Multimedia and Electronic Music Experiments) -------------- next part -------------- An HTML attachment was scrubbed... URL: <https://mail.music.vt.edu/mailman/private/sursound/attachments/20110609/8110c153/attachment.html> _______________________________________________ Sursound mailing list [email protected] https://mail.music.vt.edu/mailman/listinfo/sursound
