Re: [Sursound] Ambisonic hydrophone?
Oh, and a couple of other tips for anyone wanting to use condoms for protecting microphones - wipe as much of the lubricant off as you can before use (it's a b***er to remove from microphone) and use the featherlite variety for maximum acoustic transparence. Dave On 19 February 2013 21:46, Dave Malham wrote: > The trouble with the sort of materials used in condoms is that they > are inherently stretchy. Under any sort of pressure (more than a quite > small depth of water) the material presses through any holes and > either (a) rips or be (b) comes into contact with the diaphragm which > is potentially almost as big a disaster. That's why the first DIY > hydrophone I linked to uses an electret capsule immersed in oil in a > canister. I have uses both condoms and cling film to waterproof > microphones but only really for splash proofing. For those situations > you can measure the mic before wrapping and after so that compensation > can be made for the inevitable resonances. Probably not possible for > underwater systems without the the same problems of needing a > calibrated source and a lot of underwater space which, given the fact > that it probably won't be possible to use the assembly at any sort of > depth, is not going to be easy. > >Dave > > PS The wackiest thing I ever sealed a microphone for (with cling film) > was to listen to worms under the ground for a biologist who was trying > to find a way to assess the number of worms in a given volume of soil > without crushing them up with the soil and extracting the (now dead) > biological material. > > On 19 February 2013 17:48, Martin Leese > wrote: >> Fons Adriaensen wrote: >> >>> Don't know what Len will think of it, but putting a Tetramic >>> (or any such mic) in a plastic bag isn't likely to produce >>> anything usable. Basic problem is that the acoustic impedance >>> of water is around 3400 times higher than that of air, so the >>> water/air interface will reflect almost all energy. You need >>> a transducer that is more or less matched to the acoustic >>> impedance. >> >> I have read that the standard trick is to use a >> condom. However, I puzzle whether this would >> work with a Tetramic. >> >> Regards, >> Martin >> -- >> Martin J Leese >> E-mail: martin.leese stanfordalumni.org >> Web: http://members.tripod.com/martin_leese/ >> ___ >> 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, so this > disclaimer is redundant > > > These are my own views and may or may not be shared by my employer > > Dave Malham > Ex-Music Research Centre > Department of Music > The University of York > Heslington > York YO10 5DD > UK > > 'Ambisonics - Component Imaging for Audio' -- As of 1st October 2012, I have retired from the University, so this disclaimer is redundant These are my own views and may or may not be shared by my employer Dave Malham Ex-Music Research Centre Department of Music The University of York Heslington York YO10 5DD UK 'Ambisonics - Component Imaging for Audio' ___ Sursound mailing list Sursound@music.vt.edu https://mail.music.vt.edu/mailman/listinfo/sursound
Re: [Sursound] Ambisonic hydrophone?
the worm-mic reminds me of this installation in Brazil "Som da terra" (sound of the earth) at the garden/gallery "Inhotim" - it's by American artist Doug Aitken - where 5 mics are lowered 202m down into the earth. Here's a video showing the installation and an EV re20 protected in a plastic water bottle. Someone describes the sound as being violent and noisy sometimes and other times more peaceful. http://www.youtube.com/watch?v=ITr5NzDSqlw Em Ter, 2013-02-19 às 21:46 +, Dave Malham escreveu: > The trouble with the sort of materials used in condoms is that they > are inherently stretchy. Under any sort of pressure (more than a quite > small depth of water) the material presses through any holes and > either (a) rips or be (b) comes into contact with the diaphragm which > is potentially almost as big a disaster. That's why the first DIY > hydrophone I linked to uses an electret capsule immersed in oil in a > canister. I have uses both condoms and cling film to waterproof > microphones but only really for splash proofing. For those situations > you can measure the mic before wrapping and after so that compensation > can be made for the inevitable resonances. Probably not possible for > underwater systems without the the same problems of needing a > calibrated source and a lot of underwater space which, given the fact > that it probably won't be possible to use the assembly at any sort of > depth, is not going to be easy. > >Dave > > PS The wackiest thing I ever sealed a microphone for (with cling film) > was to listen to worms under the ground for a biologist who was trying > to find a way to assess the number of worms in a given volume of soil > without crushing them up with the soil and extracting the (now dead) > biological material. > > On 19 February 2013 17:48, Martin Leese > wrote: > > Fons Adriaensen wrote: > > > >> Don't know what Len will think of it, but putting a Tetramic > >> (or any such mic) in a plastic bag isn't likely to produce > >> anything usable. Basic problem is that the acoustic impedance > >> of water is around 3400 times higher than that of air, so the > >> water/air interface will reflect almost all energy. You need > >> a transducer that is more or less matched to the acoustic > >> impedance. > > > > I have read that the standard trick is to use a > > condom. However, I puzzle whether this would > > work with a Tetramic. > > > > Regards, > > Martin > > -- > > Martin J Leese > > E-mail: martin.leese stanfordalumni.org > > Web: http://members.tripod.com/martin_leese/ > > ___ > > 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] Ambisonic hydrophone?
The trouble with the sort of materials used in condoms is that they are inherently stretchy. Under any sort of pressure (more than a quite small depth of water) the material presses through any holes and either (a) rips or be (b) comes into contact with the diaphragm which is potentially almost as big a disaster. That's why the first DIY hydrophone I linked to uses an electret capsule immersed in oil in a canister. I have uses both condoms and cling film to waterproof microphones but only really for splash proofing. For those situations you can measure the mic before wrapping and after so that compensation can be made for the inevitable resonances. Probably not possible for underwater systems without the the same problems of needing a calibrated source and a lot of underwater space which, given the fact that it probably won't be possible to use the assembly at any sort of depth, is not going to be easy. Dave PS The wackiest thing I ever sealed a microphone for (with cling film) was to listen to worms under the ground for a biologist who was trying to find a way to assess the number of worms in a given volume of soil without crushing them up with the soil and extracting the (now dead) biological material. On 19 February 2013 17:48, Martin Leese wrote: > Fons Adriaensen wrote: > >> Don't know what Len will think of it, but putting a Tetramic >> (or any such mic) in a plastic bag isn't likely to produce >> anything usable. Basic problem is that the acoustic impedance >> of water is around 3400 times higher than that of air, so the >> water/air interface will reflect almost all energy. You need >> a transducer that is more or less matched to the acoustic >> impedance. > > I have read that the standard trick is to use a > condom. However, I puzzle whether this would > work with a Tetramic. > > Regards, > Martin > -- > Martin J Leese > E-mail: martin.leese stanfordalumni.org > Web: http://members.tripod.com/martin_leese/ > ___ > 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, so this disclaimer is redundant These are my own views and may or may not be shared by my employer Dave Malham Ex-Music Research Centre Department of Music The University of York Heslington York YO10 5DD UK 'Ambisonics - Component Imaging for Audio' ___ Sursound mailing list Sursound@music.vt.edu https://mail.music.vt.edu/mailman/listinfo/sursound
Re: [Sursound] Ambisonic hydrophone?
Absolutely! Dave On 19 February 2013 12:49, Fons Adriaensen wrote: > On Tue, Feb 19, 2013 at 09:54:25AM +, Dave Malham wrote: > >> The trouble with Angelo's kit is that it's not really "hi-fi". >> Works well for what it was designed for (noise pollution research) but >> not really good enough for serious audio. > > It was primarily designed to find the direction of arrival of sounds, > which is something entirely different from reproduction. > > 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 -- As of 1st October 2012, I have retired from the University, so this disclaimer is redundant These are my own views and may or may not be shared by my employer Dave Malham Ex-Music Research Centre Department of Music The University of York Heslington York YO10 5DD UK 'Ambisonics - Component Imaging for Audio' ___ Sursound mailing list Sursound@music.vt.edu https://mail.music.vt.edu/mailman/listinfo/sursound
Re: [Sursound] Gran Sasso - first impressions
Needless to say, it would be even more interesting if they actually posted the IRs somewhere! If they have, it is very well hidden. Richard Dobson On 19/02/2013 17:28, Martin Leese wrote: ... Also, it looks like the University of Salford have already measured IRs of the original Stonehenge plus a completed replica using some sort of soundfield mic, visit: http://www.acoustics.salford.ac.uk/res/fazenda/acoustics-of-stonehenge/ Regards, Martin ___ Sursound mailing list Sursound@music.vt.edu https://mail.music.vt.edu/mailman/listinfo/sursound
Re: [Sursound] Ambisonic hydrophone?
David Worrall wrote: > Subject: [Sursound] Ambisonic hydrophone? > Does anone know of such a beast? > (I thought of putting the TetraMic in a plastic bag, but I'm not sure Len > would approve :-) > > Or how one might go about building one... > Failing which, does anyone have a recommendation on a cost-effective > single-channel unit? About a year ago, the following real-time sound installation was mentioned on the list: http://www.dezeen.com/2011/09/14/sonic-seascape-terrace-by-decoster-taivalkoski-haaslahti-and-montes-de-oca/ Not many technical details are given, except that signals from hydrophones are processed into a four-channel Ambisonic soundscape. Perhaps you could contact the artists for more information. Regards, Martin -- Martin J Leese E-mail: martin.leese stanfordalumni.org Web: http://members.tripod.com/martin_leese/ ___ Sursound mailing list Sursound@music.vt.edu https://mail.music.vt.edu/mailman/listinfo/sursound
Re: [Sursound] Ambisonic hydrophone?
> Fons Adriaensen wrote: > >> Don't know what Len will think of it, but putting a Tetramic >> (or any such mic) in a plastic bag isn't likely to produce >> anything usable. Basic problem is that the acoustic impedance >> of water is around 3400 times higher than that of air, so the >> water/air interface will reflect almost all energy. You need >> a transducer that is more or less matched to the acoustic >> impedance. > > I have read that the standard trick is to use a > condom. However, I puzzle whether this would > work with a Tetramic. > Apparently there is a special size for precocious youth in Switzerland. Might be your solution ... ? Michael ___ Sursound mailing list Sursound@music.vt.edu https://mail.music.vt.edu/mailman/listinfo/sursound
Re: [Sursound] Ambisonic hydrophone?
Fons Adriaensen wrote: > Don't know what Len will think of it, but putting a Tetramic > (or any such mic) in a plastic bag isn't likely to produce > anything usable. Basic problem is that the acoustic impedance > of water is around 3400 times higher than that of air, so the > water/air interface will reflect almost all energy. You need > a transducer that is more or less matched to the acoustic > impedance. I have read that the standard trick is to use a condom. However, I puzzle whether this would work with a Tetramic. Regards, Martin -- Martin J Leese E-mail: martin.leese stanfordalumni.org Web: http://members.tripod.com/martin_leese/ ___ Sursound mailing list Sursound@music.vt.edu https://mail.music.vt.edu/mailman/listinfo/sursound
Re: [Sursound] Gran Sasso - first impressions
Gerard Lardner wrote: > Here's a suggestion: a place that is publicly-accessible, but is under > threat of being demolished. It's Achill Henge, a modern copy of much of > Stonehenge but built on Achill Island, off the west coast of Ireland. There are a number of Stonehenge replicas dotted around the world, both "ruined" and completed. Try sifting through: http://en.wikipedia.org/wiki/Stonehenge_replicas_and_derivatives Also, it looks like the University of Salford have already measured IRs of the original Stonehenge plus a completed replica using some sort of soundfield mic, visit: http://www.acoustics.salford.ac.uk/res/fazenda/acoustics-of-stonehenge/ Regards, Martin -- Martin J Leese E-mail: martin.leese stanfordalumni.org Web: http://members.tripod.com/martin_leese/ ___ Sursound mailing list Sursound@music.vt.edu https://mail.music.vt.edu/mailman/listinfo/sursound
Re: [Sursound] Ambisonic hydrophone?
On Tue, Feb 19, 2013 at 09:54:25AM +, Dave Malham wrote: > The trouble with Angelo's kit is that it's not really "hi-fi". > Works well for what it was designed for (noise pollution research) but > not really good enough for serious audio. It was primarily designed to find the direction of arrival of sounds, which is something entirely different from reproduction. 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
Re: [Sursound] Any experience with dome acoustics?
> > The University of Derby has a published policy regarding email and > > reserves the right to monitor email traffic. If you believe this email > was > > sent to you in error, please notify the sender and delete this email. > > Please direct any concerns to info...@derby.ac.uk. > > ___ > > Sursound mailing list > > Sursound@music.vt.edu > > https://mail.music.vt.edu/mailman/listinfo/sursound > > > > > > -- > 07580951119 > > augustine.leudar.com > -- next part -- > An HTML attachment was scrubbed... > URL: < > https://mail.music.vt.edu/mailman/private/sursound/attachments/20130219/d21ed42b/attachment.html > > > ___ > Sursound mailing list > Sursound@music.vt.edu > https://mail.music.vt.edu/mailman/listinfo/sursound > > _____ > The University of Derby has a published policy regarding email and > reserves the right to monitor email traffic. If you believe this email was > sent to you in error, please notify the sender and delete this email. > Please direct any concerns to info...@derby.ac.uk. > ___ > Sursound mailing list > Sursound@music.vt.edu > https://mail.music.vt.edu/mailman/listinfo/sursound > -- 07580951119 augustine.leudar.com -- next part -- An HTML attachment was scrubbed... URL: <https://mail.music.vt.edu/mailman/private/sursound/attachments/20130219/f9457773/attachment.html> ___ Sursound mailing list Sursound@music.vt.edu https://mail.music.vt.edu/mailman/listinfo/sursound
Re: [Sursound] Any experience with dome acoustics?
i think it will work - have heard enough phantom sources in archaeological sites - but ideally your dome should be a hemisphere - that is when you will get precise reflected points. umashankar i have published my poems. read (or buy) at http://stores.lulu.com/umashankar > Date: Tue, 19 Feb 2013 11:50:04 + > From: augustineleu...@gmail.com > To: sursound@music.vt.edu > Subject: Re: [Sursound] Any experience with dome acoustics? > > You need LOTS of very closely aligned speakers and the software will take a > while to install/learn, then rendering the channels also takes time if you > do it that way. The "holosonic" point source next to the ear is my holy > grail - I havent got it yet - but I am told IRcams system can do this. I > have heard stories of weird phase effects next to the ear in other systems, > and have got that working - but thats not quite the same. The truth is you > could probably get something more spectacular going with quarter the amount > of speakers and Vbap. > > On 19 February 2013 11:39, Peter Lennox wrote: > > > Just a quick one: > > > > It seems to me that a dome could be interesting used as a kind of > > wavefield synthesis device. > > > > Domes have the interesting property of focussing sound at a point that is > > opposite the source, as it were. So you can create a 'holosonic' point > > source right next to someone's ear > > > > Dr. Peter Lennox > > > > School of Technology, > > Faculty of Arts, Design and Technology > > University of Derby, UK > > e: p.len...@derby.ac.uk > > t: 01332 593155 > > > > > > -Original Message- > > From: sursound-boun...@music.vt.edu [mailto:sursound-boun...@music.vt.edu] > > On Behalf Of Neil Waterman > > Sent: 18 February 2013 16:47 > > To: Surround Sound discussion group > > Subject: [Sursound] Any experience with dome acoustics? > > > > Greetings, > > > > Does anyone on the list have prior experience installing ambi-based 3D > > sound into 'dome' shaped replay environments? > > > > Any tips, specifically on speaker placement, approaches, etc. > > > > The problems I am facing include a 12 foot 240 degree partial dome made of > > fabric, an 18 foot 240 degree partial dome using fiberglass and a much > > bigger 40 foot 360 degree full dome in fiberglass. > > > > All of the above will actually be 1/2 domes in the sense they are not full > > spheres, but 1/2 a sphere resting on the ground. > > > > My only prior experience was with a full sphere, fibre dome that was a > > nightmare to put sound into... > > > > One option for the 40 foot dome is to use a central cluster of directional > > speakers, hung in a "chandelier" that would use the dome surface as a > > virtual speaker through reflection, but I have never tried this. My concern > > with this is that the listeners (who will be roughly central in all these > > dome areas) will hear both the direct sound and reflected sound and end-up > > with a confused mess. > > > > For all of these domes there will be an 18" skirt area below the dome that > > could be used for loudspeakers around the periphery - is it better to try > > to beam the sound directly at the listeners position, or perhaps use a more > > diffuse speaker, facing up into the dome face? There will be space to get > > at least one speaker overhead for all configurations. > > > > Regards, Neil > > > > ___ > > Sursound mailing list > > Sursound@music.vt.edu > > https://mail.music.vt.edu/mailman/listinfo/sursound > > > > _ > > The University of Derby has a published policy regarding email and > > reserves the right to monitor email traffic. If you believe this email was > > sent to you in error, please notify the sender and delete this email. > > Please direct any concerns to info...@derby.ac.uk. > > ___ > > Sursound mailing list > > Sursound@music.vt.edu > > https://mail.music.vt.edu/mailman/listinfo/sursound > > > > > > -- > 07580951119 > > augustine.leudar.com > -- next part -- > An HTML attachment was scrubbed... > URL: > <https://mail.music.vt.edu/mailman/private/sursound/attachments/20130219/d21ed42b/attachment.html> > ___ > 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/20130219/417987be/attachment.html> ___ Sursound mailing list Sursound@music.vt.edu https://mail.music.vt.edu/mailman/listinfo/sursound
Re: [Sursound] Any experience with dome acoustics?
I was talking about a whole lot cruder approach - not actually rendering into WFS - let the dome physically do that. Position a sound at point A, get an image at point B. for more image-locations, use more speakers, to move the image, pan from one to t'other, and live with the slight imprecision during movement. Oh, the point was, especially at HF, - point the speaker at the dome, let the dome do the rest... ;) - cheap to try out Dr. Peter Lennox School of Technology, Faculty of Arts, Design and Technology University of Derby, UK e: p.len...@derby.ac.uk t: 01332 593155 -Original Message- From: sursound-boun...@music.vt.edu [mailto:sursound-boun...@music.vt.edu] On Behalf Of Augustine Leudar Sent: 19 February 2013 11:50 To: Surround Sound discussion group Subject: Re: [Sursound] Any experience with dome acoustics? You need LOTS of very closely aligned speakers and the software will take a while to install/learn, then rendering the channels also takes time if you do it that way. The "holosonic" point source next to the ear is my holy grail - I havent got it yet - but I am told IRcams system can do this. I have heard stories of weird phase effects next to the ear in other systems, and have got that working - but thats not quite the same. The truth is you could probably get something more spectacular going with quarter the amount of speakers and Vbap. On 19 February 2013 11:39, Peter Lennox wrote: > Just a quick one: > > It seems to me that a dome could be interesting used as a kind of > wavefield synthesis device. > > Domes have the interesting property of focussing sound at a point that > is opposite the source, as it were. So you can create a 'holosonic' > point source right next to someone's ear > > Dr. Peter Lennox > > School of Technology, > Faculty of Arts, Design and Technology University of Derby, UK > e: p.len...@derby.ac.uk > t: 01332 593155 > > > -Original Message- > From: sursound-boun...@music.vt.edu [mailto:sursound-boun...@music.vt.edu] > On Behalf Of Neil Waterman > Sent: 18 February 2013 16:47 > To: Surround Sound discussion group > Subject: [Sursound] Any experience with dome acoustics? > > Greetings, > > Does anyone on the list have prior experience installing ambi-based 3D > sound into 'dome' shaped replay environments? > > Any tips, specifically on speaker placement, approaches, etc. > > The problems I am facing include a 12 foot 240 degree partial dome made of > fabric, an 18 foot 240 degree partial dome using fiberglass and a much > bigger 40 foot 360 degree full dome in fiberglass. > > All of the above will actually be 1/2 domes in the sense they are not full > spheres, but 1/2 a sphere resting on the ground. > > My only prior experience was with a full sphere, fibre dome that was a > nightmare to put sound into... > > One option for the 40 foot dome is to use a central cluster of directional > speakers, hung in a "chandelier" that would use the dome surface as a > virtual speaker through reflection, but I have never tried this. My concern > with this is that the listeners (who will be roughly central in all these > dome areas) will hear both the direct sound and reflected sound and end-up > with a confused mess. > > For all of these domes there will be an 18" skirt area below the dome that > could be used for loudspeakers around the periphery - is it better to try > to beam the sound directly at the listeners position, or perhaps use a more > diffuse speaker, facing up into the dome face? There will be space to get > at least one speaker overhead for all configurations. > > Regards, Neil > > ___ > Sursound mailing list > Sursound@music.vt.edu > https://mail.music.vt.edu/mailman/listinfo/sursound > > _ > The University of Derby has a published policy regarding email and > reserves the right to monitor email traffic. If you believe this email was > sent to you in error, please notify the sender and delete this email. > Please direct any concerns to info...@derby.ac.uk. > ___ > Sursound mailing list > Sursound@music.vt.edu > https://mail.music.vt.edu/mailman/listinfo/sursound > -- 07580951119 augustine.leudar.com -- next part -- An HTML attachment was scrubbed... URL: <https://mail.music.vt.edu/mailman/private/sursound/attachments/20130219/d21ed42b/attachment.html> ___ Sursound mailing list Sursound@music.vt.edu https://mail.music.vt.edu/mailman/listinfo/sursound
Re: [Sursound] Any experience with dome acoustics?
You need LOTS of very closely aligned speakers and the software will take a while to install/learn, then rendering the channels also takes time if you do it that way. The "holosonic" point source next to the ear is my holy grail - I havent got it yet - but I am told IRcams system can do this. I have heard stories of weird phase effects next to the ear in other systems, and have got that working - but thats not quite the same. The truth is you could probably get something more spectacular going with quarter the amount of speakers and Vbap. On 19 February 2013 11:39, Peter Lennox wrote: > Just a quick one: > > It seems to me that a dome could be interesting used as a kind of > wavefield synthesis device. > > Domes have the interesting property of focussing sound at a point that is > opposite the source, as it were. So you can create a 'holosonic' point > source right next to someone's ear > > Dr. Peter Lennox > > School of Technology, > Faculty of Arts, Design and Technology > University of Derby, UK > e: p.len...@derby.ac.uk > t: 01332 593155 > > > -Original Message- > From: sursound-boun...@music.vt.edu [mailto:sursound-boun...@music.vt.edu] > On Behalf Of Neil Waterman > Sent: 18 February 2013 16:47 > To: Surround Sound discussion group > Subject: [Sursound] Any experience with dome acoustics? > > Greetings, > > Does anyone on the list have prior experience installing ambi-based 3D > sound into 'dome' shaped replay environments? > > Any tips, specifically on speaker placement, approaches, etc. > > The problems I am facing include a 12 foot 240 degree partial dome made of > fabric, an 18 foot 240 degree partial dome using fiberglass and a much > bigger 40 foot 360 degree full dome in fiberglass. > > All of the above will actually be 1/2 domes in the sense they are not full > spheres, but 1/2 a sphere resting on the ground. > > My only prior experience was with a full sphere, fibre dome that was a > nightmare to put sound into... > > One option for the 40 foot dome is to use a central cluster of directional > speakers, hung in a "chandelier" that would use the dome surface as a > virtual speaker through reflection, but I have never tried this. My concern > with this is that the listeners (who will be roughly central in all these > dome areas) will hear both the direct sound and reflected sound and end-up > with a confused mess. > > For all of these domes there will be an 18" skirt area below the dome that > could be used for loudspeakers around the periphery - is it better to try > to beam the sound directly at the listeners position, or perhaps use a more > diffuse speaker, facing up into the dome face? There will be space to get > at least one speaker overhead for all configurations. > > Regards, Neil > > ___ > Sursound mailing list > Sursound@music.vt.edu > https://mail.music.vt.edu/mailman/listinfo/sursound > > _ > The University of Derby has a published policy regarding email and > reserves the right to monitor email traffic. If you believe this email was > sent to you in error, please notify the sender and delete this email. > Please direct any concerns to info...@derby.ac.uk. > ___ > Sursound mailing list > Sursound@music.vt.edu > https://mail.music.vt.edu/mailman/listinfo/sursound > -- 07580951119 augustine.leudar.com -- next part -- An HTML attachment was scrubbed... URL: <https://mail.music.vt.edu/mailman/private/sursound/attachments/20130219/d21ed42b/attachment.html> ___ Sursound mailing list Sursound@music.vt.edu https://mail.music.vt.edu/mailman/listinfo/sursound
Re: [Sursound] Any experience with dome acoustics?
Just a quick one: It seems to me that a dome could be interesting used as a kind of wavefield synthesis device. Domes have the interesting property of focussing sound at a point that is opposite the source, as it were. So you can create a 'holosonic' point source right next to someone's ear Dr. Peter Lennox School of Technology, Faculty of Arts, Design and Technology University of Derby, UK e: p.len...@derby.ac.uk t: 01332 593155 -Original Message- From: sursound-boun...@music.vt.edu [mailto:sursound-boun...@music.vt.edu] On Behalf Of Neil Waterman Sent: 18 February 2013 16:47 To: Surround Sound discussion group Subject: [Sursound] Any experience with dome acoustics? Greetings, Does anyone on the list have prior experience installing ambi-based 3D sound into 'dome' shaped replay environments? Any tips, specifically on speaker placement, approaches, etc. The problems I am facing include a 12 foot 240 degree partial dome made of fabric, an 18 foot 240 degree partial dome using fiberglass and a much bigger 40 foot 360 degree full dome in fiberglass. All of the above will actually be 1/2 domes in the sense they are not full spheres, but 1/2 a sphere resting on the ground. My only prior experience was with a full sphere, fibre dome that was a nightmare to put sound into... One option for the 40 foot dome is to use a central cluster of directional speakers, hung in a "chandelier" that would use the dome surface as a virtual speaker through reflection, but I have never tried this. My concern with this is that the listeners (who will be roughly central in all these dome areas) will hear both the direct sound and reflected sound and end-up with a confused mess. For all of these domes there will be an 18" skirt area below the dome that could be used for loudspeakers around the periphery - is it better to try to beam the sound directly at the listeners position, or perhaps use a more diffuse speaker, facing up into the dome face? There will be space to get at least one speaker overhead for all configurations. Regards, Neil ___ Sursound mailing list Sursound@music.vt.edu https://mail.music.vt.edu/mailman/listinfo/sursound _ The University of Derby has a published policy regarding email and reserves the right to monitor email traffic. If you believe this email was sent to you in error, please notify the sender and delete this email. Please direct any concerns to info...@derby.ac.uk. ___ Sursound mailing list Sursound@music.vt.edu https://mail.music.vt.edu/mailman/listinfo/sursound
Re: [Sursound] Sound Field Microphone
On 02/18/2013 02:58 PM, Michael Chapman wrote: Good Morning Everyone, I'm interesting to buy a Sound Field Microphone but I don't have any experience in this field. Could you recommend me some models or brands according to your experience? There are many on here more expert than I. But to get the ball rolling, I think you are limited to: 1) Soundfield (tradename) 2) TeraMic (Coresound) 3) Home made. (1) is ??four times the price of (2). Jörn published a review on a (1) he was leant. (I think a direct comparison with a (2) he owns ... but time dims the memory.) Conclusion (IIRC) was he'd buy one ... if he had the money. The review should still be on the Web. The link in this lists archive. http://www.stackingdwarves.net/download/TetraMic_vs_ST450/ -- 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
Re: [Sursound] Ambisonic hydrophone?
Angelo's paper relating to this is at http://www.angelofarina.it/Public/UAM-2011/ Dave On 19 February 2013 04:03, Marc Lavallée wrote: > umashankar manthravadi a écrit : >> angelo farina has exactly the beast you are looking for. he had a >> power point presentation describing its use here is the link >> http://www.angelofarina.it/Public/Presentations/UAM2011_Underwater_Ambisonics_files/frame.htmumashankar > > Fons Adriaensen a écrit : >> Most hydrophones (and certainly any low-cost ones) will be >> omnis, so the A/B processing will be very different from >> what is required for a normal tetra mic using directional >> capsules. > > Hydrophones are omnidirectional, and the underwater probe for the > Brahma is tetrahedral... Are omnidirectional "sensors" appropriate to > build tetrahedral ambisonic microphones? > > -- > Marc > ___ > 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, so this disclaimer is redundant These are my own views and may or may not be shared by my employer Dave Malham Ex-Music Research Centre Department of Music The University of York Heslington York YO10 5DD UK 'Ambisonics - Component Imaging for Audio' ___ Sursound mailing list Sursound@music.vt.edu https://mail.music.vt.edu/mailman/listinfo/sursound
Re: [Sursound] Ambisonic hydrophone?
Hi, The trouble with Angelo's kit is that it's not really "hi-fi". Works well for what it was designed for (noise pollution research) but not really good enough for serious audio. Because it's based on differencing omni's to generate directional responses it has a relatively limited bandwidth and because of the difficulty of calibrating it it is not necessarily very accurate. As Fons says, the cost of a good, flat frequency response, underwater speaker is prohibitive (not to say humungous!) but, even worse, underwater anechoic chambers are not exactly common so you'd need to do the calibration in deep water, well away from the shore, sea bottom etc. Don't forget that the speed of sound in water is 5 times that in air so everything has to be 5 times bigger (hence the large size of his hydrophone). You CAN get figure 8 hydrophones but only if you have military sized budgets - they have been used in aoustic torpedoes and DIFAR buoys (google them) but it looks like using Blumlein differencing techniques, with two different separations to cover low and high frequencies separately might be the best approach for audio purposes. Good hydrophones are several hundred (or more) Euros each (for instance the Reson ones from http://www.ambient.de/en/products/ambient-recording/underwater.html), so this can get expensive and if you want to work in anything other than the top waters, the cost of connectors and cable is frightening. There are cheaper alternatives like the Dolphinear ones (http://www.dolphinear.com/) which are pretty good or the JrF ones (http://hydrophones.blogspot.co.uk/) or you can even make your own (http://www.dosits.org/resources/all/classroom/buildhydrophone/ or http://leafcutterjohn.com/?p=915). As you can tell, I have been looking at this a lot, in the context of the TBA-21 Academy project (http://tba21academy.org/), though since my retirement I am no longer directly connected to them (at present) Dave http://www.dezeen.com/2011/09/14/sonic-seascape-terrace-by-decoster-taivalkoski-haaslahti-and-montes-de-oca/ On 19 February 2013 04:03, Marc Lavallée wrote: > umashankar manthravadi a écrit : >> angelo farina has exactly the beast you are looking for. he had a >> power point presentation describing its use here is the link >> http://www.angelofarina.it/Public/Presentations/UAM2011_Underwater_Ambisonics_files/frame.htmumashankar > > Fons Adriaensen a écrit : >> Most hydrophones (and certainly any low-cost ones) will be >> omnis, so the A/B processing will be very different from >> what is required for a normal tetra mic using directional >> capsules. > > Hydrophones are omnidirectional, and the underwater probe for the > Brahma is tetrahedral... Are omnidirectional "sensors" appropriate to > build tetrahedral ambisonic microphones? > > -- > Marc > ___ > 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, so this disclaimer is redundant These are my own views and may or may not be shared by my employer Dave Malham Ex-Music Research Centre Department of Music The University of York Heslington York YO10 5DD UK 'Ambisonics - Component Imaging for Audio' ___ Sursound mailing list Sursound@music.vt.edu https://mail.music.vt.edu/mailman/listinfo/sursound
