Re: [Sursound] Converting 16 mic array recording to B format
Oh, dear...I wonder if I can persuade my wife that a trip to Austria in our Motorhome (say, sometime in September) would be a rather nice idea Dave On 20 May 2015 at 06:15, Matthias Kronlachner m.kronlach...@gmail.com wrote: On 20/05/15 14:28, Richard Lee wrote: Mathias, can you please post these recordings on ambisonia.com The Furse-Malham *.AMB format allows up to 3rd order These would be the first publically available live HOA recordings of music from a HOA mike and may re-surrect the discussion of HOA decoders By the way, the ICSA 2015 ( http://www.tonmeister.de/index.php?p=veranstaltungen/icsa2015 ) might be a good place to be if you want to hear a lot of HOA material. Matthias ___ 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. -- 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/20150520/2d5c853d/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.
Re: [Sursound] Converting 16 mic array recording to B format
On 05/20/2015 09:53 AM, Dave Malham wrote: Oh, dear...I wonder if I can persuade my wife that a trip to Austria in our Motorhome (say, sometime in September) would be a rather nice idea Dave It will be. The Styrian countryside is right around the corner, and it is gorgeous. As is Graz. As is the wine :-D -- 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 - unsubscribe here, edit account or options, view archives and so on.
Re: [Sursound] Converting 16 mic array recording to B format
Dear Richard, I can't make the material available publicly as you might expect. But mhacoustics has some raw EM demo recordings on their website: http://mhacoustics.com/download For some recordings we compared the EM with the ST450 and for some with the SPS200. I used several different playback rigs, varying from 15-30 loudspeakers (mostly hemispherical, once in a full sphere) and I was happy with the result in each case. I exclusively used the AllRAD decoder. In the IEM Cube (24 spk) we compared AllRAD with the ones included in Spat (Energy-preserving, Mode-matching). Each of the decoders sounded slightly different for the EM recordings. Interestingly the capsule noise was audible at a different level for each of the decoders. The radial filters are not part of the decoder, they are part of the encoding process to get from 32 microphone signals to the HOA signals. Here you can get some information on this part, but the filter coefficients itself are not public domain. http://iaem.at/Members/zotter/2015_loeslerzotter_sphmicradialfiltdesgn_daga.pdf Best, Matthias On 20/05/15 14:28, Richard Lee wrote: Mathias, can you please post these recordings on ambisonia.com The Furse-Malham *.AMB format allows up to 3rd order These would be the first publically available live HOA recordings of music from a HOA mike and may re-surrect the discussion of HOA decoders Which Soundfield did you use? What was the Playback Speaker Rig? How many, how many levels? What was the Decoder? Is the L?sler/Zotter decoder in the Public Domain? Or even a description? From: Matthias Kronlachner m.kronlach...@gmail.com To: sursound@music.vt.edu Subject: Re: [Sursound] Converting 16 mic array recording to B format FWIW, I have Eigenmike recordings from the Essen Philharmonic (a contemporary piece performed by musikFabrik K?ln) - they have been sitting on my hard drive for more than a year because I couldn't get studio time anywhere to do anything with it. Matthias Kronlachner was part of that project, he might have done something with them. I did not do any mixing of the material, but the IEM Graz played excerpts of the Eigenmike recording on several occasions eg. at the Ambisonics Symposium in Berlin and people did like it very much. The 360? video recording is not so useful from this recording as it was very dark in the hall and the resolution is not that great. But who needs video if the sound is great ;-) I did quite a number of recordings since then with the EM. Compared to a first order recording you can use a larger number of loudspeakers for playback and achieve a bigger sweet spot. The immersiveness is really nice! At the IEM we did several informal comparisons with switching between EM, a Soundfield (decoded 1st order and 3rd order with Harpex) and a Schoeps Omni as reference. All of these configurations have their use cases, but the representation of the space was always best with the EM. The problem of limited bandwith for each order though makes it difficult to achieve the same tonal balance when changing the decoder/loudspeaker configuration. But using good radial filters eg. by Mr. L?sler/Zotter (which is the only thing needed to process EM recordings that are currently not available to the public as far as I know) gives you something to start with and only little EQ is needed to get a convincing playback. ___ 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.
Re: [Sursound] Converting 16 mic array recording to B format
On 20/05/15 14:28, Richard Lee wrote: Mathias, can you please post these recordings on ambisonia.com The Furse-Malham *.AMB format allows up to 3rd order These would be the first publically available live HOA recordings of music from a HOA mike and may re-surrect the discussion of HOA decoders By the way, the ICSA 2015 ( http://www.tonmeister.de/index.php?p=veranstaltungen/icsa2015 ) might be a good place to be if you want to hear a lot of HOA material. Matthias ___ 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.
Re: [Sursound] Converting 16 mic array recording to B format
Mathias, can you please post these recordings on ambisonia.com The Furse-Malham *.AMB format allows up to 3rd order These would be the first publically available live HOA recordings of music from a HOA mike and may re-surrect the discussion of HOA decoders Which Soundfield did you use? What was the Playback Speaker Rig? How many, how many levels? What was the Decoder? Is the L?sler/Zotter decoder in the Public Domain? Or even a description? From: Matthias Kronlachner m.kronlach...@gmail.com To: sursound@music.vt.edu Subject: Re: [Sursound] Converting 16 mic array recording to B format FWIW, I have Eigenmike recordings from the Essen Philharmonic (a contemporary piece performed by musikFabrik K?ln) - they have been sitting on my hard drive for more than a year because I couldn't get studio time anywhere to do anything with it. Matthias Kronlachner was part of that project, he might have done something with them. I did not do any mixing of the material, but the IEM Graz played excerpts of the Eigenmike recording on several occasions eg. at the Ambisonics Symposium in Berlin and people did like it very much. The 360? video recording is not so useful from this recording as it was very dark in the hall and the resolution is not that great. But who needs video if the sound is great ;-) I did quite a number of recordings since then with the EM. Compared to a first order recording you can use a larger number of loudspeakers for playback and achieve a bigger sweet spot. The immersiveness is really nice! At the IEM we did several informal comparisons with switching between EM, a Soundfield (decoded 1st order and 3rd order with Harpex) and a Schoeps Omni as reference. All of these configurations have their use cases, but the representation of the space was always best with the EM. The problem of limited bandwith for each order though makes it difficult to achieve the same tonal balance when changing the decoder/loudspeaker configuration. But using good radial filters eg. by Mr. L?sler/Zotter (which is the only thing needed to process EM recordings that are currently not available to the public as far as I know) gives you something to start with and only little EQ is needed to get a convincing playback. ___ 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.
Re: [Sursound] Converting 16 mic array recording to B format
On 05/17/2015 09:34 PM, Richard Lee wrote: Fons, have you heard any music recordings with EigenMike? No one seems to have tried. FWIW, I have Eigenmike recordings from the Essen Philharmonic (a contemporary piece performed by musikFabrik Köln) - they have been sitting on my hard drive for more than a year because I couldn't get studio time anywhere to do anything with it. Matthias Kronlachner was part of that project, he might have done something with them. It's really a pity that I've been unable to get anyone interested in that material, we have a soundfield st450 main mike, an eigenmike pretty close to that, and about 30 spot mikes in total. Plus Matthias brought a 360-degree cam which we used to record the whole thing. But this thing has so far cost me 1k out of my own pocket already, and unless someone's going to throw at least a week of studio time my way, it's going to keep sitting on my harddrive. -- 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 - unsubscribe here, edit account or options, view archives and so on.
Re: [Sursound] Converting 16 mic array recording to B format
On 18/05/15 10:26, Jörn Nettingsmeier wrote: On 05/17/2015 09:34 PM, Richard Lee wrote: Fons, have you heard any music recordings with EigenMike? No one seems to have tried. FWIW, I have Eigenmike recordings from the Essen Philharmonic (a contemporary piece performed by musikFabrik Köln) - they have been sitting on my hard drive for more than a year because I couldn't get studio time anywhere to do anything with it. Matthias Kronlachner was part of that project, he might have done something with them. It's really a pity that I've been unable to get anyone interested in that material, we have a soundfield st450 main mike, an eigenmike pretty close to that, and about 30 spot mikes in total. Plus Matthias brought a 360-degree cam which we used to record the whole thing. But this thing has so far cost me 1k out of my own pocket already, and unless someone's going to throw at least a week of studio time my way, it's going to keep sitting on my harddrive. Hi, I did not do any mixing of the material, but the IEM Graz played excerpts of the Eigenmike recording on several occasions eg. at the Ambisonics Symposium in Berlin and people did like it very much. The 360° video recording is not so useful from this recording as it was very dark in the hall and the resolution is not that great. But who needs video if the sound is great ;-) I did quite a number of recordings since then with the EM. Compared to a first order recording you can use a larger number of loudspeakers for playback and achieve a bigger sweet spot. The immersiveness is really nice! At the IEM we did several informal comparisons with switching between EM, a Soundfield (decoded 1st order and 3rd order with Harpex) and a Schoeps Omni as reference. All of these configurations have their use cases, but the representation of the space was always best with the EM. The problem of limited bandwith for each order though makes it difficult to achieve the same tonal balance when changing the decoder/loudspeaker configuration. But using good radial filters eg. by Mr. Lösler/Zotter (which is the only thing needed to process EM recordings that are currently not available to the public as far as I know) gives you something to start with and only little EQ is needed to get a convincing playback. Best, Matthias ___ 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.
Re: [Sursound] Converting 16 mic array recording to B format
By all means. We'd like to hear them. Why not put them on Ambisonia? http://www.ambisonia.com -- On Sun, May 17, 2015 10:47 PM PDT Bo-Erik Sandholm wrote: I have a number of recordings using a tetramic and Tascam DR-680, the recordings are mostly: church choirs among other recordings a full church with only singers making a 700+ choir singing Händel, Jazz recordings ( Benny Goodman style) in a club with audience eating and talking, One Gospel recording with all of the public joining in, A few short recordings of rainy afternoons with a bit of thunderstorms from the Swedish archipelago. A long recording of Early morning birdsong at sunrise 03:30, with absolutely no wind or man made background sounds, from a wooden glade in the archipelago. Most of them can be distributed within this group and the ambisonic community if someone is interested and wants to listen. Best Regards Bo-Erik Sandholm -Original Message- From: Sursound [mailto:sursound-boun...@music.vt.edu] On Behalf Of Curtis Alcock Sent: den 14 maj 2015 12:33 To: Surround Sound discussion group Subject: Re: [Sursound] Converting 16 mic array recording to B format Thank you everyone who contributed to answering my question. I am now fully convinced that using the DEMAND library would be next to useless and not worth the work involved in trying to make it (partially) usable. Pity really, as a database of everyday noise would be a useful resource - but only if it's done properly in the first place. I am in the process of doing my own field recordings using a Brahma mic (been impressed with results so far: birdsong; a very noisy, reverberant restaurant; organ playing in a church) but as it will take some time to build up a complete library I was looking for some other material I could use, particularly every day environments. Thanks, Richard, for your suggestion of ambisonia.com. I started there but was having trouble downloading the torrent files. (The internet access I have here (in a shared building) blocks torrent files so I need to download somewhere else then transfer.) Will continue to pursue this route. Thanks again, everyone. On 14 May 2015, at 19:11, Richard Lee rica...@justnet.com.au wrote: Duu.uuh!! http://parole.loria.fr/DEMAND/DEMAND.pdf states the microphones of the array ... are not calibrated with respect to each other, and so gain variations are to be expected: we found that the energy in some channels is consistently higher than in other channels. Algorithms working on this data should compensate for this variation ie they haven't a clue what each capsule is doing. This precludes any attempt at conversion to B-format and also of beamforming. I was hoping this might lead to a discussion about EigenMike and how it might be made good enough to record music but this is certainly NOT the vehicle. I can't help feeling they should beg borrow or steal a TetraMic and repeat their recordings. Presently, about all you can say is they have a close bunch of unspecified mikes in some sort of horizontal pattern. Curtiss, if you are after some 'realistic' atmospheric background (and this is something TetraMic and properly aligned Soundfields do better than an ything else), try ambisonia.com and recordings by John Leonard (soundmanjohn), Paul Doombusch, JH Roy others. John Leonard's specialty is WW2 aircraft flyovers but he includes a lot of airfield noise too :) He's also got some very realistic street scenes, audience noise, applause etc too. Aaron, you are right about SVD not being much use here as we have multiple solutions but I was hoping to dream up something to help S/N at LF. ___ 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. ___ 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.
Re: [Sursound] Converting 16 mic array recording to B format
Hi Jörn I would be very interested in getting involved. It would be great to get a higher order mix embedded with the visual, which we could make available. I have a 31 speaker 4 sub purpose built studio, which I use for post production, and composition. I would gladly do a mix for you. Or if you can get to London, you are welcome to use my studio. All the best. Steve On 18 May 2015 09:26, Jörn Nettingsmeier netti...@stackingdwarves.net wrote: On 05/17/2015 09:34 PM, Richard Lee wrote: Fons, have you heard any music recordings with EigenMike? No one seems to have tried. FWIW, I have Eigenmike recordings from the Essen Philharmonic (a contemporary piece performed by musikFabrik Köln) - they have been sitting on my hard drive for more than a year because I couldn't get studio time anywhere to do anything with it. Matthias Kronlachner was part of that project, he might have done something with them. It's really a pity that I've been unable to get anyone interested in that material, we have a soundfield st450 main mike, an eigenmike pretty close to that, and about 30 spot mikes in total. Plus Matthias brought a 360-degree cam which we used to record the whole thing. But this thing has so far cost me 1k out of my own pocket already, and unless someone's going to throw at least a week of studio time my way, it's going to keep sitting on my harddrive. -- 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 - 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/20150518/970130df/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.
Re: [Sursound] Converting 16 mic array recording to B format
Fons, have you heard any music recordings with EigenMike? No one seems to have tried. Elko has a standing invitation to bring EM to any venue that Aaron Eric are recording world class orchestras in good halls ... I mean obscure Mid West bands in non-descript halls :) They can reliably record a zillion channels. I've been trying to follow Angelo and his Merry Mens' efforts with EM but IIRC ... the best result so far, shows 1st order Ambi with an absolute (nearly brick wall) top limit of 10kHz which sorta ties in with your observations. This was with Angelo's beloved funky Kirkeby FIRs :D It's so nearly there but not quite. Date: Thu, 14 May 2015 09:52:59 + From: Fons Adriaensen f...@linuxaudio.org To: sursound@music.vt.edu Subject: Re: [Sursound] Converting 16 mic array recording to B format ... The limits pointed out above are something that Gary Elko has clearly understood very well (and some others apparently have not). The beamforming sofware that comes with the Eigenmike will in general not let you do things that depend on unrealistic accuracy of the mic gain calibration. On the upper end the limit for the EM is around 8 kHz. Above that, the SW will just give you the signal of the single capsule that is closest to the intended direction of the beam. The polar pattern above the upper limit will be the one resulting from diffraction caused by the solid spherical body (this becomes quite directional in the frequency range considered). This at least produces a clean signal in the upper octave which is better than the chaotic pattern a beamformer would produce. On the lower end, the limits that can be achieved assuming +/- 0.5 dB gain errors are roughly 1st order: 50 Hz 2nd order: 630 Hz 3rd order: 1.6 kHz 4th order 2.5 kHz The latter has such a limited frequency range that it's probably better to forget about it. The EM software wisely doesn't claim anything above third order. The result of this, in particular of the lower frequency limits, is that any higher order directional pattern will have to be a compromise between on-axis and diffuse-field frequency response. The requirements for this will depend on the application: a spot mic or a set of beams intended for surround reproduction. The tradeoff can be made partly by EQ. So when using the EM for e.g. orchestral recording using a number of beams pointed at the various sections of the orchestra, you will need some rather unconventional EQ for the best results. This will probably surprise most sound engineers used to the more traditional way of using a set of normal mics to cover the sections. It may also put them off. But it is certainly possible to make very good recordings with the EM. ___ 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.
Re: [Sursound] Converting 16 mic array recording to B format
I have a number of recordings using a tetramic and Tascam DR-680, the recordings are mostly: church choirs among other recordings a full church with only singers making a 700+ choir singing Händel, Jazz recordings ( Benny Goodman style) in a club with audience eating and talking, One Gospel recording with all of the public joining in, A few short recordings of rainy afternoons with a bit of thunderstorms from the Swedish archipelago. A long recording of Early morning birdsong at sunrise 03:30, with absolutely no wind or man made background sounds, from a wooden glade in the archipelago. Most of them can be distributed within this group and the ambisonic community if someone is interested and wants to listen. Best Regards Bo-Erik Sandholm -Original Message- From: Sursound [mailto:sursound-boun...@music.vt.edu] On Behalf Of Curtis Alcock Sent: den 14 maj 2015 12:33 To: Surround Sound discussion group Subject: Re: [Sursound] Converting 16 mic array recording to B format Thank you everyone who contributed to answering my question. I am now fully convinced that using the DEMAND library would be next to useless and not worth the work involved in trying to make it (partially) usable. Pity really, as a database of everyday noise would be a useful resource - but only if it's done properly in the first place. I am in the process of doing my own field recordings using a Brahma mic (been impressed with results so far: birdsong; a very noisy, reverberant restaurant; organ playing in a church) but as it will take some time to build up a complete library I was looking for some other material I could use, particularly every day environments. Thanks, Richard, for your suggestion of ambisonia.com. I started there but was having trouble downloading the torrent files. (The internet access I have here (in a shared building) blocks torrent files so I need to download somewhere else then transfer.) Will continue to pursue this route. Thanks again, everyone. On 14 May 2015, at 19:11, Richard Lee rica...@justnet.com.au wrote: Duu.uuh!! http://parole.loria.fr/DEMAND/DEMAND.pdf states the microphones of the array ... are not calibrated with respect to each other, and so gain variations are to be expected: we found that the energy in some channels is consistently higher than in other channels. Algorithms working on this data should compensate for this variation ie they haven't a clue what each capsule is doing. This precludes any attempt at conversion to B-format and also of beamforming. I was hoping this might lead to a discussion about EigenMike and how it might be made good enough to record music but this is certainly NOT the vehicle. I can't help feeling they should beg borrow or steal a TetraMic and repeat their recordings. Presently, about all you can say is they have a close bunch of unspecified mikes in some sort of horizontal pattern. Curtiss, if you are after some 'realistic' atmospheric background (and this is something TetraMic and properly aligned Soundfields do better than an ything else), try ambisonia.com and recordings by John Leonard (soundmanjohn), Paul Doombusch, JH Roy others. John Leonard's specialty is WW2 aircraft flyovers but he includes a lot of airfield noise too :) He's also got some very realistic street scenes, audience noise, applause etc too. Aaron, you are right about SVD not being much use here as we have multiple solutions but I was hoping to dream up something to help S/N at LF. ___ 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. ___ 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.
Re: [Sursound] Converting 16 mic array recording to B format
dear Curtis I am happy you like the brahma microphone. can you please post some samples on ambisonia.com. particularly bird song, as it will be some time before I can go out and record (might be able to get some good monsoon recordings in south india though, when I shift there) There are many queries about how Brahma works for nature recordings, and I am hoping to build a 25 mm capsule version just for such use. umashankar From: curtis.alc...@tiscali.co.uk Date: Thu, 14 May 2015 11:33:02 +0100 To: sursound@music.vt.edu Subject: Re: [Sursound] Converting 16 mic array recording to B format Thank you everyone who contributed to answering my question. I am now fully convinced that using the DEMAND library would be next to useless and not worth the work involved in trying to make it (partially) usable. Pity really, as a database of everyday noise would be a useful resource – but only if it's done properly in the first place. I am in the process of doing my own field recordings using a Brahma mic (been impressed with results so far: birdsong; a very noisy, reverberant restaurant; organ playing in a church) but as it will take some time to build up a complete library I was looking for some other material I could use, particularly every day environments. Thanks, Richard, for your suggestion of ambisonia.com. I started there but was having trouble downloading the torrent files. (The internet access I have here (in a shared building) blocks torrent files so I need to download somewhere else then transfer.) Will continue to pursue this route. Thanks again, everyone. On 14 May 2015, at 19:11, Richard Lee rica...@justnet.com.au wrote: Duu.uuh!! http://parole.loria.fr/DEMAND/DEMAND.pdf states the microphones of the array ... are not calibrated with respect to each other, and so gain variations are to be expected: we found that the energy in some channels is consistently higher than in other channels. Algorithms working on this data should compensate for this variation ie they haven't a clue what each capsule is doing. This precludes any attempt at conversion to B-format and also of beamforming. I was hoping this might lead to a discussion about EigenMike and how it might be made good enough to record music but this is certainly NOT the vehicle. I can't help feeling they should beg borrow or steal a TetraMic and repeat their recordings. Presently, about all you can say is they have a close bunch of unspecified mikes in some sort of horizontal pattern. Curtiss, if you are after some 'realistic' atmospheric background (and this is something TetraMic and properly aligned Soundfields do better than an ything else), try ambisonia.com and recordings by John Leonard (soundmanjohn), Paul Doombusch, JH Roy others. John Leonard's specialty is WW2 aircraft flyovers but he includes a lot of airfield noise too :) He's also got some very realistic street scenes, audience noise, applause etc too. Aaron, you are right about SVD not being much use here as we have multiple solutions but I was hoping to dream up something to help S/N at LF. ___ 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... URL: https://mail.music.vt.edu/mailman/private/sursound/attachments/20150514/6a5ed8f2/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.
Re: [Sursound] Converting 16 mic array recording to B format
You can always come direct to me for other stuff as well. I have some music recordings made with a TetraMic and an increasing bunch of stuff using the ST450. (I know this is heresy, but I've also just acquired Mike Skeet's DPA 5100. By the way, Mike's not at all well, apparently, and has sold off most of his microphone collection, including his Soundfields.) Regards, John Please note new email address direct line phone number email: j...@johnleonard.uk phone +44 (0)20 3286 5942 On May 14, 2015, at 19:11, Richard Lee rica...@justnet.com.au wrote: John Leonard's specialty is WW2 aircraft flyovers but he includes a lot of airfield noise too :) He's also got some very realistic street scenes, audience noise, applause etc too. ___ 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.
Re: [Sursound] Converting 16 mic array recording to B format
Duu.uuh!! http://parole.loria.fr/DEMAND/DEMAND.pdf states the microphones of the array ... are not calibrated with respect to each other, and so gain variations are to be expected: we found that the energy in some channels is consistently higher than in other channels. Algorithms working on this data should compensate for this variation ie they haven't a clue what each capsule is doing. This precludes any attempt at conversion to B-format and also of beamforming. I was hoping this might lead to a discussion about EigenMike and how it might be made good enough to record music but this is certainly NOT the vehicle. I can't help feeling they should beg borrow or steal a TetraMic and repeat their recordings. Presently, about all you can say is they have a close bunch of unspecified mikes in some sort of horizontal pattern. Curtiss, if you are after some 'realistic' atmospheric background (and this is something TetraMic and properly aligned Soundfields do better than an ything else), try ambisonia.com and recordings by John Leonard (soundmanjohn), Paul Doombusch, JH Roy others. John Leonard's specialty is WW2 aircraft flyovers but he includes a lot of airfield noise too :) He's also got some very realistic street scenes, audience noise, applause etc too. Aaron, you are right about SVD not being much use here as we have multiple solutions but I was hoping to dream up something to help S/N at LF. ___ 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.
Re: [Sursound] Converting 16 mic array recording to B format
Thank you everyone who contributed to answering my question. I am now fully convinced that using the DEMAND library would be next to useless and not worth the work involved in trying to make it (partially) usable. Pity really, as a database of everyday noise would be a useful resource – but only if it's done properly in the first place. I am in the process of doing my own field recordings using a Brahma mic (been impressed with results so far: birdsong; a very noisy, reverberant restaurant; organ playing in a church) but as it will take some time to build up a complete library I was looking for some other material I could use, particularly every day environments. Thanks, Richard, for your suggestion of ambisonia.com. I started there but was having trouble downloading the torrent files. (The internet access I have here (in a shared building) blocks torrent files so I need to download somewhere else then transfer.) Will continue to pursue this route. Thanks again, everyone. On 14 May 2015, at 19:11, Richard Lee rica...@justnet.com.au wrote: Duu.uuh!! http://parole.loria.fr/DEMAND/DEMAND.pdf states the microphones of the array ... are not calibrated with respect to each other, and so gain variations are to be expected: we found that the energy in some channels is consistently higher than in other channels. Algorithms working on this data should compensate for this variation ie they haven't a clue what each capsule is doing. This precludes any attempt at conversion to B-format and also of beamforming. I was hoping this might lead to a discussion about EigenMike and how it might be made good enough to record music but this is certainly NOT the vehicle. I can't help feeling they should beg borrow or steal a TetraMic and repeat their recordings. Presently, about all you can say is they have a close bunch of unspecified mikes in some sort of horizontal pattern. Curtiss, if you are after some 'realistic' atmospheric background (and this is something TetraMic and properly aligned Soundfields do better than an ything else), try ambisonia.com and recordings by John Leonard (soundmanjohn), Paul Doombusch, JH Roy others. John Leonard's specialty is WW2 aircraft flyovers but he includes a lot of airfield noise too :) He's also got some very realistic street scenes, audience noise, applause etc too. Aaron, you are right about SVD not being much use here as we have multiple solutions but I was hoping to dream up something to help S/N at LF. ___ 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.
Re: [Sursound] Converting 16 mic array recording to B format
--On 14 May 2015 11:33 +0100 Curtis Alcock curtis.alc...@tiscali.co.uk wrote: Thanks, Richard, for your suggestion of ambisonia.com. I started there but was having trouble downloading the torrent files. (The internet access I have here (in a shared building) blocks torrent files so I need to download somewhere else then transfer.) Will continue to pursue this route. Note that my files from Ambisonia, and John Leonard's, can be downloaded directly from http://ambisonic.info/audio.html. Paul -- Paul Hodges ___ 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.
Re: [Sursound] Converting 16 mic array recording to B format
Thanks, Richard, for your suggestion of ambisonia.com. I started there but was having trouble downloading the torrent files. (The internet access I have here (in a shared building) blocks torrent files so I need to download somewhere else then transfer.) Will continue to pursue this route. There has been talk, on and off, of 'mirroring' ambisonia.com in a non-torrent format (the files ar hardly large by 2015 standards ...). It would certainly be a _big_ plus for some of us. . . (?). Michael ___ 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.
Re: [Sursound] Converting 16 mic array recording to B format
On Thu, May 14, 2015 at 06:11:49PM -, Richard Lee wrote: Duu.uuh!! http://parole.loria.fr/DEMAND/DEMAND.pdf states the microphones of the array ... are not calibrated with respect to each other, and so gain variations are to be expected: we found that the energy in some channels is consistently higher than in other channels. Algorithms working on this data should compensate for this variation ie they haven't a clue what each capsule is doing. This precludes any attempt at conversion to B-format and also of beamforming. Indeed. Unless maybe in a very limited frequency range. Once the phase differences between the capsule signals exceed 180 degrees any synthesized polar pattern will break down and be reduced to chaos. This determines the upper limit. On the other side, when wavelenght is much larger than the distance between the mics, creating anything non-omni requires amplification of the small differences between mic signals, and the required gain increases by 6 db times order for each octave down. If the mic gains are not perfectly matched amplified errors will dominate the result. This in practice determines the lower limit of the frequency range. I was hoping this might lead to a discussion about EigenMike and how it might be made good enough to record music but this is certainly NOT the vehicle. The limits pointed out above are something that Gary Elko has clearly understood very well (and some others apparently have not). The beamforming sofware that comes with the Eigenmike will in general not let you do things that depend on unrealistic accuracy of the mic gain calibration. On the upper end the limit for the EM is around 8 kHz. Above that, the SW will just give you the signal of the single capsule that is closest to the intended direction of the beam. The polar pattern above the upper limit will be the one resulting from diffraction caused by the solid spherical body (this becomes quite directional in the frequency range considered). This at least produces a clean signal in the upper octave which is better than the chaotic pattern a beamformer would produce. On the lower end, the limits that can be achieved assuming +/- 0.5 dB gain errors are roughly 1st order: 50 Hz 2nd order: 630 Hz 3rd order: 1.6 kHz 4th order 2.5 kHz The latter has such a limited frequency range that it's probably better to forget about it. The EM software wisely doesn't claim anything above third order. The result of this, in particular of the lower frequency limits, is that any higher order directional pattern will have to be a compromise between on-axis and diffuse-field frequency response. The requirements for this will depend on the application: a spot mic or a set of beams intended for surround reproduction. The tradeoff can be made partly by EQ. So when using the EM for e.g. orchestral recording using a number of beams pointed at the various sections of the orchestra, you will need some rather unconventional EQ for the best results. This will probably surprise most sound engineers used to the more traditional way of using a set of normal mics to cover the sections. It may also put them off. But it is certainly possible to make very good recordings with the EM. Ciao, -- FA A world of exhaustive, reliable metadata would be an utopia. It's also a pipe-dream, founded on self-delusion, nerd hubris and hysterically inflated market opportunities. (Cory Doctorow) ___ 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] Converting 16 mic array recording to B format
Hi All I am wondering how I go about converting a recording made with a 16 microphone array into B format? I have downloaded the 16 channel recordings of noise from the DEMAND: Diverse Environment Multichannel Acoustic Noise Database and would like to play them back through an ambisonics rig. The recordings were made using a microphone array of 16 microphones arranged in 4 staggered rows, spaced such there is a 5 cm distance form each microphone to its immediate neighbors. The array is in a plane which in all recordings is parallel to the ground. The authors include a MATLAB script which creates a 16 x 2 MATLAB array with the xy coordinates (in meters) of each channel microphone relative to the microphone of channel 1. I don't have MATLAB, but I'm assuming that somehow I can still use the positional information from the array, but I confess I don't know what the process is or what software is required. Any guidance would be most appreciated. The website for DEMAND is: http://parole.loria.fr/DEMAND/ With kind regards Curtis Alcock ___ 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.
Re: [Sursound] Converting 16 mic array recording to B format
I think you probably do have a good chance of being able to do this using conventional beamforming techniques but with the following provisos: - Given the mic spacing, the beams will only be accurate at frequencies below about 2kHz - You will need to assume that the mics are omnidirectional and do not shadow each other - Some height information could be derived but not very accurately and there will be an upwards-downwards ambiguity For an idea of the processing required, you may find this paper useful: https://www.researchgate.net/publication/44035458_Sound_Field_Recording_by_Measuring_Gradients Best wishes Tim -Original Message- Hi All I am wondering how I go about converting a recording made with a 16 microphone array into B format? I have downloaded the 16 channel recordings of noise from the DEMAND: Diverse Environment Multichannel Acoustic Noise Database and would like to play them back through an ambisonics rig. The recordings were made using a microphone array of 16 microphones arranged in 4 staggered rows, spaced such there is a 5 cm distance form each microphone to its immediate neighbors. The array is in a plane which in all recordings is parallel to the ground. The authors include a MATLAB script which creates a 16 x 2 MATLAB array with the xy coordinates (in meters) of each channel microphone relative to the microphone of channel 1. Weird ... ... must admit to _not_ having followed the link ... so perhaps mea culpa, ... but A MATLAB script might be a courtesy to those that use MATLAB, but we are only talking about 30 numbers ... akin to see the attached Word(TM) file for my postal address ;-) All the mics are in a horizontal plane(?) and the sounds presumably(??) mostly off to the sides. So you can only (at best) extract pantophony (2-D ambisonics). To record that you would only have needed 3 (or 4) mics _as_close_together_as_possible_. To extract something from (some of) the sixteen: -I'm not optimistic -you'd need to know about polar patterns, directions, whether they shield each other, ... If you don't get a better reply I'm happy to visit the link and be more serious ... but on this list there is usually someone who's already (with success, or not) 'been down that route'. Michael I don't have MATLAB, but I'm assuming that somehow I can still use the positional information from the array, but I confess I don't know what the process is or what software is required. Any guidance would be most appreciated. The website for DEMAND is: http://parole.loria.fr/DEMAND/ With kind regards Curtis Alcock ___ 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.
