On Wed, Mar 19, 2014 at 07:50:43PM +0000, Dave Hunt wrote: > Surely the best approach is to feed the noise signal (post decoder) > into each speaker channel in turn and adjust the amplification on > each channel until the level measured at the centre listening point > is the same for each speaker.
That would be a prerequisite for the method I explained. But it still leaves you with an uncalibrated system, as the decoder gain (no matter how you define it) isn't included. > The panning approach won't work, as all speakers would be excited at > various different levels. It would be useful after the above > calibration to see if the sound of the noise of the noise was > consistent everywhere everywhere it was panned. On the contrary, it's the only one that will give the correct result. *** Calibration means to have a defined relation between *** the level of the W channel and the measured SPL. This can be done only with the decoder in the path. Another approach would be to sent W only (at reference level) to the decoder, and then measure each individual speaker (by soloing it, ambdec provides the function) and adjusting for reference SPL - 10 * log(number_of speakers). This would be less accurate as it doesn't allow for the partial correlation between speaker signals (which will depend on frequency if you use dual band decoding). 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
