On Sat, Dec 05, 2015 at 01:28:11AM +0000, Stefan Schreiber wrote: > I don't believe a S/N ratio of 64dB will imply "30 dB self-noise > caused by crappy MEMS capsules", at least not here.
It does. S/N ratio for microphones is by convention the noise level referred to the output level for 1 Pa SPL or 94 dB SPL. 94 - 64 = 30. This figure is very typical for MEMS mics. Even cheap consumer grade electrets will be 10 dB better on noise. And 120 dB is a typical AOL (Acoustic Overload Point) for MEMS, the level at which you can expect 10% harmonic distortion. > I guess the noise is introduced because of interference between > the capsules, which means sound from any direction will reach > always more than 2/3/4 capsules. That does not add noise. > Anyway: This microphone is probably very able to record "location > sound", whereas the direct sound (and say voices) can be mixed into > this "background" at a later stage. > > (A pretty normal procedure in the area of film sound, by the way?) Exactly. Which is why the OZO's audio part can have these sort of specs - it's not meant to be used on its own. Remains the question of _how_ to actually use the available signals to produce anything surround. Linear beamforming is limited to LF (due to aliasing). The only way I see is some rather complicated non-linear 'logic' decoding. This kind of thing is still a research topic. 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 - unsubscribe here, edit account or options, view archives and so on.
