A first-order B-format panner needs to implement the equations W = S * sqrt(1/2) X = S * cos(az) * cos(el) Y = S * sin(az) * cos(el) Z = S * sin(el)
where S is the signal being panned and az and el define the direction. The Calrec Soundfield MkIV controller box has analog circuitry for something like this in the "Soundfield Controls" section. Take a look at http://ambisonics.dreamhosters.com/schematic-4.pdf and http://ambisonics.dreamhosters.com/MkIV-Tech-Manual.pdf to see how Ken Farrar and Richard Lee did it. Aaron (hel...@ai.sri.com) Menlo Park, CA US On Thu, Sep 26, 2013 at 10:20 AM, Kan Kaban <kanka...@alivecinema.org>wrote: > Thanks for your reply Jörn. You´ll have to excuse my basic english > sentences, as it´s not my primary language. > > > "A-format" panning as you call it has nothing to do with ambisonics per > se, and the term frankly doesn't make much sense. > > the module you mention is a simple amplitude panner. > > > > so for your purposes, you might want to look into amplitude panning. > > but this has none of the characteristics of ambisonics. > > Yes, I know there´s no ambisonics until there is. The idea of amplitude > panning, during A format stage, is to simplify an analogue path before > b-format exists. Without plugins while possible. Soundfield B-format to 5.1 > / 7.1 converter (http://www.soundfield.com/products/sp451.php) is > actually hardware, so it seems interesting to make analogue panners > (anywhere, amplitude or B signals) to keep audio into an analogue path like > this: > > Quadraphonic (same to A-Format but without height?) keyboard or synth > signals /// then an amplitude panner /// then the A to B converter /// then > a B-format mixing stage /// the hole B-format mix to a Sounfield converter > for 5.1 - 7.1 or anything else. > > > now you _could_ implement an ambisonic with-height b-format panner in > analog. likewise, i could have faxed you my reply in 2's complement, and > you could have OCR'ed it back into your computer. it's needlessly > complicated, a waste of resources, and unless the equipment is constantly > being re-calibrated to perfect accuracy, the result will be so full of > errors that it's pretty much pointless. > > Well, if there is some kind of B-format analogue panner we would also like > to learn about it´s design, so we can actually see how pointless it is. The > idea of panning quadraphonic packs seems easier to implement BEFORE an A to > B converter. > Does that exist?. I suppose something had to exist before DSP´s > possibilities. > Thanks again. > Gino. > > El 26/09/2013, a las 7:01, Jörn Nettingsmeier < > netti...@stackingdwarves.net> escribió: > > > On 09/26/2013 09:21 AM, Kan Kaban wrote: > >> Greetings to all Sursound list. > >> > >> First of all, thanks for all this years supporting Ambisonics. We´re > >> a collective of audiovisual artists preparing for our next project. > >> We have been researching ambisonics for the last few moths, seeding > >> the possibility of it´s implementation. There are still some concerns > >> regarding workflow. Our initial idea is to keep signals / conversions > >> into the analogue domain. > > > > erm? > > > >> For example, analogue panners. I´ve stepped > >> with very few B-format ideas on the internet, so I was wondering if > >> there´s a case considering simple A-format panners, before AB > >> converters. This eurorack module seems right for the task, right?: > >> http://www.intellijel.com/eurorack-modules/planar/ > > > > "A-format" panning as you call it has nothing to do with ambisonics per > se, and the term frankly doesn't make much sense. > > the module you mention is a simple amplitude panner. > > > > so for your purposes, you might want to look into amplitude panning. > > but this has none of the characteristics of ambisonics. > > > >> But height > >> information?. Are B-format panners somehow better? We know of the > >> multiple ambisonics ITB plugins available, but again, we love ancient > >> analogue qualities. Any info will be very appreciated, we´re really > >> exited about this & will love to share the results somewhere in the > >> near future. Best regards. Gino. > > > > for height, you will need vbap, and it's totally insane to even consider > doing this in analog (just think of the operation to find the three nearest > speakers for a given direction). > > > > unless it's actually pain you love, in which case you've struck a gold > mine. > > > > now you _could_ implement an ambisonic with-height b-format panner in > analog. likewise, i could have faxed you my reply in 2's complement, and > you could have OCR'ed it back into your computer. it's needlessly > complicated, a waste of resources, and unless the equipment is constantly > being re-calibrated to perfect accuracy, the result will be so full of > errors that it's pretty much pointless. > > > > -- > > Jörn Nettingsmeier > > Lortzingstr. 11, 45128 Essen, Tel. +49 177 7937487 > > > > Meister für Veranstaltungstechnik (Bühne/Studio) > > Tonmeister VDT > > > > http://stackingdwarves.net > > > > _______________________________________________ > > Sursound mailing list > > Sursound@music.vt.edu > > https://mail.music.vt.edu/mailman/listinfo/sursound > > _______________________________________________ > Sursound mailing list > Sursound@music.vt.edu > https://mail.music.vt.edu/mailman/listinfo/sursound > -------------- next part -------------- An HTML attachment was scrubbed... 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