Re: [Sursound] New Ambisonic VST Plugins
Another possible approach is to use a standard 1st order microphone set in the far field and add panned in (at third order) signals from close mics from each of the instruments. These will need to be delayed to match the distance to the main POA mic. It might also be necessary to some second/third order components corresponding to early reflections but this would have to be experimented with. It won't be perfect but it will be closer to the output from a true third order mic than using Harpex - and without the processing artefacts. Dave On 22 November 2013 22:23, Michael Chapman s...@mchapman.com wrote: �David Pickett d...@fugato.com�wrote: How does one record in third order (or indeed any order above first order)?�� What kind of microphone array does one need, for instance, for 3rd order with no height information (WXYUVPQ)?� Is there a native format method for HOA or is it all extended A format, with conversion through matrices? I don't dispute Eric's very short, but very full summary but I think we may be at cross purposes. Richard Furse's software obviously works with a higher order microphone (if anyone has one) but I would suggest his primary motivation was for synthesised higher order soundfields. You can obviously create a synthetic soundfield of any order you want. Michael All excellent questions. �It is not quite as obvious how to record any order of Ambisonics above first order. �It will require some sort of microphone array and post-processing. �One of my favorites is the array described by Craven, Lawe and Travis in: Microphone arrays using tangential velocity sensors P.G. Craven, C. Travis, M.J. Law We introduce a new class of 3D microphone arrays that use symmetrical arrangements of tangential velocity sensors.� Use of velocity sensors allows these arrays to recover spherical harmonics of a given degree with less low-frequency boost than when using pressure sensors only.� As an example we present a symmetrical array of twelve velocity sensors that resolves the eight harmonics of degrees 1 and 2.� A second-order spherical microphone can now be constructed by combining this array with one or more pressure sensors that provide the missing harmonic of degree 0. http://ambisonics.iem.at/symposium2009/proceedings/ambisym09-craventravis-tangentialsphmic.pdf/at_download/file The other practical method for constructing an array that produces higher order spherical harmonic outputs is to use a group of omnidirectional microphones on a sphere, such as the commercially available Eigenmike: http://www.mhacoustics.com/products There are other methods. �It's still early days for this technology. Eric Benjamin -- next part -- An HTML attachment was scrubbed... URL: https://mail.music.vt.edu/mailman/private/sursound/attachments/20131122/1436acf9/attachment.html ___ 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 -- As of 1st October 2012, I have retired from the University. These are my own views and may or may not be shared by the University Dave Malham Honorary Fellow, Department of Music The University of York York YO10 5DD UK 'Ambisonics - Component Imaging for Audio' -- next part -- An HTML attachment was scrubbed... URL: https://mail.music.vt.edu/mailman/private/sursound/attachments/20131123/f50985b7/attachment.html ___ Sursound mailing list Sursound@music.vt.edu https://mail.music.vt.edu/mailman/listinfo/sursound
Re: [Sursound] New Ambisonic VST Plugins
-- As of 1st October 2012, I have retired from the University. These are my own views and may or may not be shared by the University Dave Malham Honorary Fellow, Department of Music The University of York York YO10 5DD UK 'Ambisonics - Component Imaging for Audio' -- next part -- An HTML attachment was scrubbed... URL: https://mail.music.vt.edu/mailman/private/sursound/attachments/201311 22/d895072c/attachment.html ___ 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 -- As of 1st October 2012, I have retired from the University. These are my own views and may or may not be shared by the University Dave Malham Honorary Fellow, Department of Music The University of York York YO10 5DD UK 'Ambisonics - Component Imaging for Audio' -- next part -- An HTML attachment was scrubbed... URL: https://mail.music.vt.edu/mailman/private/sursound/attachments/20131123/28bd4965/attachment.html ___ Sursound mailing list Sursound@music.vt.edu https://mail.music.vt.edu/mailman/listinfo/sursound
Re: [Sursound] New Ambisonic VST Plugins
I basically agree with all of this - I just don't think it's that big of an issue in practice. We don't generally ask engineers to provide their stereo mixes twice for -3dB and -6dB pan laws, though arguably we should. [Okay, tenuous parallel.] HOWEVER, we want these plugin libraries to do what folk need! We actually already have first order decoders computed for all these layouts, reasonably aligned with the third order ones - they are already used in Rapture3D. Putting them into a separate VST plugin library would be tedious but easy. Should we do this? Would this address everything raised on this thread? IMHO the biggest argument against it is that these minor worries might sow FUD among potential ambisonic novices (I can imagine a naïve engineer observing that 5.1 doesn't have these issues). Quick vote maybe? If folk email me *OFF-LIST* with I would use a first order decoding plugin library like that and we can get to a count of five from folk on this list, I'll schedule the work. I'll subtract one for each email saying No! Too much FUD! How's that? ;-) Best wishes, --Richard -Original Message- From: Sursound [mailto:sursound-boun...@music.vt.edu] On Behalf Of Dave Malham Sent: 23 November 2013 10:39 To: Surround Sound discussion group Subject: Re: [Sursound] New Ambisonic VST Plugins Hi Richard, The only problem I see is that straight first order decoding generally has a different ratio of W to XYZ components that that used for third order, which ideally should be corrected before feeding first order material to a third order decoder, otherwise the first order material in the mix won't be decoded optimally. Unfortunately, of course, correcting this on the first order material in the mix (so that it is right on TOA decoders) means that if it is then decoded at first order (say, with an older decoder) the decode will be wrong - and unfixable, as we've discussed before on this forum. The only full solution is to keep first order only material completely separate from third order so that it can be handled separately at the decoder - or, alternatively, say it has to be 3rd order always, though I am not sure how this would work out with decoders to small numbers of speakers. Dave [...] ___ Sursound mailing list Sursound@music.vt.edu https://mail.music.vt.edu/mailman/listinfo/sursound
Re: [Sursound] Ambisonic first approach
Before I retired, I intended to remove the ppu's for our Tetramic from their individual tubes and mount them all into a single 25mm (or there abouts) tube, with a ST450 standard connector at one end and a mini-xlr recessed into the other. The mic would then plug directly into this with a degree of support thanks to the recessing, with rubber vibration isolation. The larger diameter tube could then be mounted into one of the lovely Rycote mounts that the ST450 uses. This system would get rid of most of fragility problems of the existing system and help with any problems of rf pickup due to having sections of unbalanced cable runs. Dave On 17 November 2013 12:18, Michael Chapman s...@mchapman.com wrote: On 11/15/2013 07:23 PM, Len Moskowitz wrote: J?rn Nettingsmeier netti...@stackingdwarves.net wrote: the tetra sounds great, but the connectors are very flimsy. The connectors are all from Switchcraft's Tini-Q (mini-XLR) series, used in many professional products and contexts. In the six years since TetraMic was introduced, we've had exactly one cable returned to us due to connector or cable failure. you are right, i should have phrased that more precisely, the connectors are actually fine, or at least not the biggest problem. the _cables_ are frightfully flimsy (which is a consequence of the small size of the 6-pin miniXLR), and they are very inconvenient to re-solder in-the-field, which i've been forced to do several times, despite handling them with the utmost care. most of these issues were a consequence of the comparably heavy PPUs which cause a great strain on the split when handled or transported. since i've taken to tying the the PPUs to a bundle, i've had no further problems, but i'm still muttering prayers before every important recording. I tend to put the four (Mk. I) PPUs directly into a snake box (4xXLR--CAT5). At least then the mass is so great one takes care, whereas one PPU can be optimistically/mistakenly be left in a line ... Mmmm, what is the new project ... this gets worse than an Apple launch ;-) Michael ___ Sursound mailing list Sursound@music.vt.edu https://mail.music.vt.edu/mailman/listinfo/sursound -- As of 1st October 2012, I have retired from the University. These are my own views and may or may not be shared by the University Dave Malham Honorary Fellow, Department of Music The University of York York YO10 5DD UK 'Ambisonics - Component Imaging for Audio' -- next part -- An HTML attachment was scrubbed... URL: https://mail.music.vt.edu/mailman/private/sursound/attachments/20131123/e3f57add/attachment.html ___ Sursound mailing list Sursound@music.vt.edu https://mail.music.vt.edu/mailman/listinfo/sursound
Re: [Sursound] New Ambisonic VST Plugins
Le 2013-11-22 12:12, Richard Furse a écrit : you should also be able to upsample to third order using Svein's excellent HARPEX-B plugin, although the public version of that currently generates only horizontal components at third order (for compatibility with channel count limits in other hosts). Is there a non-public, beta, version that outputs the full 3rd order 16 channels? - Daniel ___ Sursound mailing list Sursound@music.vt.edu https://mail.music.vt.edu/mailman/listinfo/sursound
Re: [Sursound] New Ambisonic VST Plugins
Le 2013-11-22 12:12, Richard Furse a �crit : you should also be able to upsample to third order using Svein's excellent HARPEX-B plugin, although the public version of that currently generates only horizontal components at third order (for compatibility with channel count limits in other hosts). Is there a non-public, beta, version that outputs the full 3rd order 16 channels? Non, (or so I am informed). Michael - Daniel ___ 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
Re: [Sursound] Hector bird recording - SoundCloud
Hello! Yes, I gave those recordings to Umashankar before I got the microphone calibrated. I just uploaded a B-format version converted using Tetraproc and the preset file that Fons made for me after I gave him my IR measurements. It's not exactly the same fragment but comes from the same group of recordings. Those birds make indeed very strange sounds, they are called Urracas in Mexico, were the recording was done. This is obviously not a pure nature recording since it was done in the backyard of a house in the city. I placed the mic right under the tree where the birds were perching. http://www.hcenteno.net/extras/Urracas_WXYZ.wav.zip I'll try to get the music recording processed too by tomorrow. Cheers! Hector On Fri, Nov 22, 2013 at 2:41 PM, Eric Benjamin eb...@pacbell.net wrote: Is the W level correct? I am finding myself turning up my W knob 3-6dB I'm tempted to agree. Of course it's difficult to be certain. From: dw d...@dwareing.plus.com To: sursound@music.vt.edu Sent: Friday, November 22, 2013 6:21 AM Subject: Re: [Sursound] Hector bird recording - SoundCloud On 21/11/2013 19:08, Aaron Heller wrote: I took the liberty of merging them into 4-channel files and putting them on my server, which might be easier to access than the skydive (the UI was in Japanese for me, fortunately I recognized the character for 'down') http://ambisonics.dreamhosters.com/01-Birds_WXYZ-110425_0119.wav http://ambisonics.dreamhosters.com/05-Music_WXYZ-110425_0127.wav They sound quite nice. In Harpex, you can clearly see the locations of the singers, percussion, and birds. Impressive! Thanks... Aaron (hel...@ai.sri.com) Menlo Park, CA US Is the W level correct? I am finding myself turning up my W knob 3-6dB relative to other recordings before it sounds good.. ___ Sursound mailing list Sursound@music.vt.edu https://mail.music.vt.edu/mailman/listinfo/sursound -- next part -- An HTML attachment was scrubbed... URL: https://mail.music.vt.edu/mailman/private/sursound/attachments/20131122/fb208b96/attachment.html ___ 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
