http://www.williamsonic.com/DipoleMic/ as often I am too fast to post :-) I found the article again on a practical differential microphone for DIY.
Regards Bo-Erik 2015-12-04 20:46 GMT+01:00 Bo-Erik Sandholm <bosses...@gmail.com>: > > I came to think about a software written by Angelo Farina a long time ago > > http://pcfarina.eng.unipr.it/Public/B-format/Software/Crux7toBform.exe > this is for 7 omni mics, one in the center on a cross created by x y z > direction placed omni mic pairs placed the same distance from the center > element. > > > I once saw a working design to create a figure 8 mic by using 2 omni > electret elements side by side in the end of 2 , > the priciple of Differential Microphone Arrays is described for example > here here https://www.spsc.tugraz.at/sites/default/files/Main.pdf > > It should be workable to create a figure 8 mic signal by taking the > differential signal from 2 omni mics, the optimal operation frequency range > for this ofcource depends on the distance between the microphones. > the central omni mic can possibly be replaced by the sum of all the > mirophones? > > I once speculated that it should be possible to modify this mic setup to > work withouth the 7th microphone in the center as this is a central omni - > maybe this signal can be created from the sum of all the others? > > For a horizontal array we could use just 4 microphones :-) > > I also had the idea that one could create a better working mic by using > several omni mics with different distances from the center to optimize the > responce for a number of frequenzy bands. > > I do not know how relewant or workable this is but I think it might be a > workable solution if we can produce a software for this. > > Any reflection on this? apperently it has alredy been done,,, > > > http://lcav.epfl.ch/research/topics/gradient_based_sndfield_acquisition.html > > > https://www.google.se/search?q=differential+microphone+array&biw=1192&bih=463&tbm=isch&tbo=u&source=univ&sa=X&ved=0ahUKEwj-ipr_-MLJAhVDJHIKHeJGA6kQsAQIUg#imgrc=LCpYmEPkSqx8-M%3A > > Best Regards Bo-Erik > > > 2015-12-04 19:03 GMT+01:00 Stefan Schreiber <st...@mail.telepac.pt>: > >> (Ok, I try to improve the look of my posting for the last time. I sent in >> plain text format before, even so the sursound list kept on to "reformat" >> the text I was seeing on my mail client... Anyway, I hope things work out >> this time. Otherwise, I give up... :-D ) >> >> >> Marc Lavallée wrote: >> >> The upcoming Ozo spherical camera by Nokia with have 8 lens and 8 >>> microphones capsules. That's all the specs I found. Will it use >>> Ambisonics? >>> -- >>> Marc >>> >>> >>> >>> >> >> >> Well, the specifications of Nokia's VR camera are finally out. >> >> See for example: >> >> >> http://www.biztekmojo.com/001681/vr-nokia-introduces-ozo-virtual-reality-camera-60000-starts-shipping-q1-2016 >> >> >> Audio: >> >> ------------------------------------- >> >> Audio Sensor Type: Omnidirectional, solid state >> Audio Area Coverage: Full-spherical, 360 x 360 degrees >> Audio Dynamic Range: 64dB S/N, 120dB max SPL >> >> -------------------------------------- >> >> These specifications can be seen on Nokia's page, obviously. >> >> >Will it use >> >Ambisonics? >> >> No. But nevertheless, a camera with full-sphere audio capture.... >> >> The specs are really very interesting, for several reasons. >> >> In a private e-mail conversation with a major microphone (and of course >> surround) expert, we (or at least I...) came to the conclusion that the >> principle on which the Ozo microphone is based could be a supercardioid >> 8-channel hedgehog configuration, where 8 capsules (w. supercardioid >> response) are positioned at the corners of a cube. (See Ozo pictures, >> including openings for the microphone capsules.) >> >> Similar if not identical: (Schoeps') ORTF-3D microphone. >> >> >> However, Nokia states in the official specifications that the capsules >> are "omnidirectional"... >> >> It could still be that the Ozo case would shield sound "from behind" >> (referring to the capsules, of course). >> If so (?), you would obtain a "de facto" cardioid 8-channel hedgehog >> microphone. >> >> Or does Ozo introduce a new form of full-spherical microphone?! >> >> I will keep looking into this. I also believe that Nokia could be a lot >> clearer about how the audio part of this < professional > VR camera >> actually works. (They righteously insist that immersive audio is a very >> important part of any VR experience.) >> >> >> >> Best regards, >> >> Stefan >> >> P.S.: >> >> https://www.youtube.com/watch?v=3ZxC2_Lb41k >> >> >> >> _______________________________________________ >> 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. >> > > -------------- next part -------------- An HTML attachment was scrubbed... URL: <https://mail.music.vt.edu/mailman/private/sursound/attachments/20151204/b4422fcb/attachment.html> _______________________________________________ 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.
