On Tue, Mar 18, 2014 at 01:40:25PM -0300, Iain Mott wrote: > What does one do though if one is metering a B-format or other ambisonic > signal? Unlike stereo or 5.1 etc. the relationship between a particular > channel on the meter and a given loudspeaker channel isn't so direct > because of the decoding. jkmeter offers a 4 channel "ambisonic" k-system > meter, so someone (Fons at least) must have thought about this problem > before!
For Ambisonics The W channel represents level, so that's the one you'd be watching while mixing. A stereo system calibrated as you describe will output 86 dB SPL if both channels are -20 dB on the K-meter. To calibrate the AMB system, send the pink noise through an AMB panner, set the level for -20 dB RMS in W, and pan the sound in a direction corresponding to a speaker. Adjust decoder/amp gain for 86 dB SPL. Check this remains more or less constant in all directions. Note that having a *fixed* monitor gain is more important than having any particular defined SPL level (unless you are moving between studios all the time (e.g. in broadcasting). For example when I'm working in the LABEL studio the Ambdec gain will always be at -10 dB, and there are no other (easily accessible) gain controls downstream. That gives me a fixed reference, even if I have no idea of the actual SPL. 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
