Dear fernando
I forwarded your link to marc Lavallée when you first posted them. My intent is that we should have multiple compatible systems for calibrating A format mics Sent from my Windows 10 phone From: Fernando Lopez-Lezcano<mailto:na...@ccrma.stanford.edu> Sent: 05 January 2017 00:28 To: Surround Sound discussion group<mailto:sursound@music.vt.edu>; glard...@iol.ie<mailto:glard...@iol.ie> Subject: Re: [Sursound] [allowed] brahma On 01/02/2017 09:59 PM, Bo-Erik Sandholm wrote: > Good luck in your continued effekt. > > By the way, i have accuired one of your Tetra mic 3d shapeway for 14 mm > capsules. > I have not yet assembler it. > I Wonder is there any software package and description on How to create > calibration files for The mic? > I will probably have The possibility to get temporary access to a anechoic > room. Hi Bo-Erik, You could take a look at my project here (I posted about this a while back): https://cm-gitlab.stanford.edu/ambisonics/SpHEAR/ (there is mailing list with 0 posts so far, ha ha..) See paper here (been working on this for over a year): https://ccrma.stanford.edu/~nando/publications/sphear.pdf The project includes free software (open source, GPL) that runs in Matlab and derives a calibration matrix (4x4 matrix of FIR filters) that can be used directly with TetraProc (by Fons Adriansen) - or any other software that can run the filters. Just a few days ago I _finally_ managed to get the software into somewhat usable shape in that I think (and I'm pretty much wrong every time I say this, so...) it is working correctly. The calibration relies on having 16 measurements (could be 8) in the horizontal plane around the Ambisonics microphone plus one more of a calibration microphone in the same exact location. Aliki is used to capture the IRs and edit (trim and window) them. DRC (Digital Room Correction) is used to equalize the excitation speaker. Then the software I wrote processes those IRs and outputs a 4x4 matrix of filters. Many parameters can be tuned. I'll post a couple of pictures later... Documentation (surprise!) is mostly lacking. I hope to remedy that somewhat soon (at least a list of the sequence of octave function calls you need to get the job done). My latest prototype with 10mm capsules was hastily measured before I left for "vacation" and the plotted results of the calibration are looking good. A re-calibration with the latest software of my first prototype which captured a full concert also sounds fairly decent. Anyway, Good luck! -- Fernando > In worst case i Will use the generic calibration from sennheiser :-) > > The mechanical size of The tetraeder is about right. > Bo-Erik > > > > Den 2 jan. 2017 9:01 em skrev "Gerard Lardner" <glard...@iol.ie>: > >> Sorry to hear of the falling-out. I have had some issues with the >> build-quality of my Brahma, which was made by Embrace Video, but >> nevertheless it remains my 'go-to' mic for choral recording. >> >> With best wishes for 2017, and for your ongoing Ambisonic microphone >> projects, >> >> Gerard >> >> >> On 02/01/2017 06:57, umashankar manthravadi wrote: >> >>> This is just an announcement that Nakul Sood and Embrace video will no >>> longer be manufacturing or selling Brahma ambisonic microphones. Our very >>> informal arrangement has come to an end as Nakul Sood demanded 1)I hand >>> over complete technology and manufacturing protocols, 2) sign a >>> non-disclosure agreement and 3) sign a non-compete agreement. (there were >>> other demands) I have always worked on Brahma as a shared project, with >>> help from many people and I have no desire to sign a non-disclosure >>> agreement. >>> >>> I had made atleast 20 Brahma microphones before this project began, and I >>> will continue to make one off brahmas as demanded (I am currently making >>> five second order microphones for Angelo Farina) and I am setting up fairly >>> high tech processes in Bangalore where I now live (laser cut microphone >>> bodies!) >>> >>> Umashankar >>> >>> >> -------------- next part -------------- >> An HTML attachment was scrubbed... >> URL: <https://mail.music.vt.edu/mailman/private/sursound/attachme >> nts/20170102/572ce57e/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. >> > -------------- next part -------------- > An HTML attachment was scrubbed... > URL: > <https://mail.music.vt.edu/mailman/private/sursound/attachments/20170103/f956a4dd/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. > _______________________________________________ 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... 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