"Sorry, this doesn't make any sense... A decoder doesn't give 'spherical coordinates', it outputs signals. What makes you think that ORTF captures 'a small 8th of a sphere' ??"
Ummm - because it has 8 super cardioid microphones pointing in eight different directions each of which corresponds to one speaker in an octaphonic cube array and requires no decoding ? And because I've read this paper : https://schoeps.de/fileadmin/user_upload/user_upload/Wittek_AES_3D_24.05.2018_web.pdf and because I phoned to Scheops to confirm my understanding of their system was correct and they confirmed it was . Plus I've spent years discussing the development of this kind of thing with people whos research has contributed to the development of this and other similar systems ? This short video explains it quite well too : https://www.youtube.com/watch?v=K-ktLM0dQeA&list=PLRqzOEeUQ2l91Gt-d7a2-wDpp6JTwWD4W&index=2&ab_channel=SCHOEPSMikrofone When I say sphere - Im talking about a cube really but when you consider phantom sources this cube obviously could be considered as a 360 degree solution - aka a sphere . I hope we are not getting crossed wires here- I am talking about this system : https://schoeps.de/en/products/surround-3d/ortf-3d/ortf-3d-outdoor-set.html Yes I know A format puts out signals (seeing as I did actually bother to make one) - by spherical coordinates I mean the A format converted to B perhaps my phrasing is incorrect - but Im pretty sure the summing I used was correct.. Also I didnt say I got bad results - the ambisonic mic I made was callibrated, each capsule painstakingly , and was actually OK, no soundfield but OK for a DIY project- I quite liked the results as did others - I'm just saying other techniques have given me better results than ambisonics. My opinion of ambisonics is not based on my DIY microphone - You have to bear in mind that during my time at the Sonic Arts Research Centre (7 years) I heard literally hundreds of ambisonics compositions, installations and recordings made by many different researchers and composers using all sorts of different hi end Ambisonics mics and on some of the best speakers in the world, and since then I have been working exclusively in the field of spatial audio - so my view is not uninformed nor am I alone in my opinions in the industry. I (and many others I might add) found the imaging to be quite poor with Ambisonics, even at high orders, in many situations. This led many of us to look for different solutions and is the reason Shchoeps have adopted this approach. . A lot of composers and researchers have reached similar conclusions but often felt they couldnt really voice this openly as it would offend the Ambisonics researchers. whislt I can understand if youve dedicated your life to ambisonics this would be an irritating view, but let me be clear - I use ambisonics and find it useful especially at the moment and the way you can send one file round the world and decode it to different arrays etc and see it as a useful tool and I have many colleagues and friends who have worked on it - but I have found far better ways of creating 3D soundscape for installations . I actually wrote a paper on a related approach to this years ago and although looking back on it I can see some errors - some of the ideas in this paper are now being developed by others, and Im sure people have been doing this for years but I never found much on it : http://divergencepress.net/2014/12/01/2016-11-20-an-alternative-approach-to-3d-audio-recording-and-reproduction/ On Thursday, 22 October 2020, Fons Adriaensen <f...@linuxaudio.org> wrote: > On Wed, Oct 21, 2020 at 02:37:39PM +0100, Augustine Leudar wrote: > > > So if you > > had say, 8 ambisonics mics pointed in 8 different directions ,in order to > > record that small 8th of a sphere (or in this case cube) in the > direction > > they are pointed in (which is what the ORTF does) - how would this work > if > > the decoder if a format gives spherical coordinates rather than an 8th > of a > > sphere/cube (hope this makes sense), and with the capsules pointing in > all > > directions... ? > > Sorry, this doesn't make any sense... A decoder doesn't give 'spherical > coordinates', it outputs signals. What makes you think that ORTF captures > 'a small 8th of a sphere' ?? > > Each Ambisonic mic, by suitable combination of its capsule signals [1], > can provide the same signals as any number of conventional capsules > (omni, cardioid, fig-of-eight,...) placed at the same point in space > and in any direction. > > So you can always replace every group of (nearly) coincident conventional > capsules (e.g. an M/S pair) by an Ambisonic one and get exactly the same > signals. > > If you use a higher order AMB mic (e.g. an OctoMic) you can even get > polar patterns for which no conventional capsule equivalent exists, and > which certainly provide an advantage for surround. > > That's all there is to it. > > > [1] This involves some filtering as well as just summing/subtracting > signals, and for good reults it requires calibration of the AMB mic's > capsules. If you experimented with Ambisonics in the way you pointed > out, it's no surprise you got bad results. > > As I've stated a number of times before, there is *a lot* of completely > bogus information on Ambisonics technology floating around. Some of this > stuff is at the same level of intellectual integrity as e.g. flat-earth > theories. Most of it is just the results of failing to understand basic > things, or of simplifying things to the point that whatever remains is > 'not even wrong'. Combine that with some people having their own agenda. > > Ciao, > > -- > FA > > _______________________________________________ > 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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