Re: [Sursound] Subject: Re: Why do you need to decode ambisonic/b format signals ?

[Dave Malham]

Trying again - one of these days I'll get it right! It's the self powered version, the MM-4XP we're 
using. Data for that is at


http://www.meyersound.com/products/industrialseries/mm-4xp/


On 27/01/2011 12:48, Dave Malham wrote:

Yep, well spotted - twitchy fingers on the keyboard :-[

Info at http://www.meyersound.com/products/industrialseries/mm-4/

On 27/01/2011 00:12, John Leonard wrote:
I think you mean the MM4, don't you? Just specified a whole bunch of the directional versions 
(MM4-XPD) for a job in New York. List price is ridiculously high, but they can be beaten down!


Regards,

John

On 26 Jan 2011, at 22:34, dave.mal...@york.ac.uk wrote:


Have you looked at the Meyer M44's

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Re: [Sursound] Subject: Re: Why do you need to decode ambisonic/b format signals ?

[Dave Malham]

Yep, well spotted - twitchy fingers on the keyboard :-[

Info at http://www.meyersound.com/products/industrialseries/mm-4/

On 27/01/2011 00:12, John Leonard wrote:

I think you mean the MM4, don't you? Just specified a whole bunch of the 
directional versions (MM4-XPD) for a job in New York. List price is 
ridiculously high, but they can be beaten down!

Regards,

John

On 26 Jan 2011, at 22:34, dave.mal...@york.ac.uk wrote:


Have you looked at the Meyer M44's

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--
 These are my own views and may or may not be shared by my employer
/*/
/* Dave Malham   http://music.york.ac.uk/staff/research/dave-malham/ */
/* Music Research Centre */
/* Department of Music"http://music.york.ac.uk/";   */
/* The University of York  Phone 01904 432448*/
/* Heslington  Fax   01904 432450*/
/* York YO10 5DD */
/* UK   'Ambisonics - Component Imaging for Audio'   */
/*"http://www.york.ac.uk/inst/mustech/3d_audio/"; */
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Re: [Sursound] Subject: Re: Why do you need to decode ambisonic/b format signals ?

[John Leonard]

I think you mean the MM4, don't you? Just specified a whole bunch of the 
directional versions (MM4-XPD) for a job in New York. List price is 
ridiculously high, but they can be beaten down!

Regards,

John

On 26 Jan 2011, at 22:34, dave.mal...@york.ac.uk wrote:

> Have you looked at the Meyer M44's

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Re: [Sursound] Subject: Re: Why do you need to decode ambisonic/b format signals ?

[dave . malham]

On Jan 26 2011, Jörn Nettingsmeier wrote:


On 01/26/2011 06:33 AM, Augustine Leudar wrote:


There
is no way a physical decoder could be in the biome - we generally have to
throw speakers away or sell them on ebay after a few uses because of the
ants and humidity (wav players are in sealed plastic boxes).


i don't understand this. are you perhaps using paper membranes? it 
should be possible to obtain outdoor speakers that withstand these 
conditions for years. of course they will cost a lot more, but that 
should be negligible if you have to replace your current speakers that 
often...

what do the ants do to the speakers, btw?

Have you looked at the Meyer M44's (plus their matching sub) - The Morning 
Line uses these and they have already lived outside in Seville for a year 
then were moved to Istanbul for another 7 months and are now in Budapest 
waiting to be installed for a further run (after that? not sure but maybe 
Vienna, or New York or...). Very low failure rate and pretty good 
performance. Connected by a single four-way cable with balanced line level 
audio and 48 volt power, the only thing that's difficult about using them 
is that the connector is a bit of a so-and-so to wire up.


 Dave

(and, no, I don't get a commision!)

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Re: [Sursound] Subject: Re: Why do you need to decode ambisonic/b format signals ?

[Richard Dobson]

On 26/01/2011 17:49, Augustine Leudar wrote:

Hello all, and thankyou for your wonderful and informative replies. There is
a lot to learn it seems and I will no doubt pose other questions after Ive
read more and digested what has already been said.
David - 56 channels ! I would have been drowning in a spaghetti of cables
and tape I think. I dont know the speakers you speak of but please let me
know if you remember what they are called.
In regards to the speakers - yes we are looking into buying some tropical
proof weather speakers. I believe Eden had some type of  all weather
speakers before but even they didnt last long. Put it this way - even
keeping a  mains supply is difficult in the biome - ants chew though
everything (literally) and the humidity is fercocious - Ive heard there are
some self draining military grade speakers around and any suggestions are
appreciated. The thing is even speakers designed for subtropical conditions
may not hack it - they really have to be specially designed for really
really humid conditions (we can treat them with antiant stuff )




There are underwater speakers (used in swimming pools among other 
things); might they be any use? Not hifi but it sounds like hifi + water 
don't mix well anyway.


Richard Dobson

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Re: [Sursound] Subject: Re: Why do you need to decode ambisonic/b format signals ?

[Augustine Leudar]

ay MAG handled a virtual 'test signal' in the
> > paper; other recording techniques work ok too, but with varying
> > results, much as they do over two speakers:-).
> >
> > The main difference between 'Trifield' and 'Super-stereo' is that
> > the former works over a number of speakers >2 across the front
> > sector and the latter seeks to use an ambisonic array of speakers
> > all around the listener to lock the front in place. There were a
> > number of different alignments of 'Super-stereo' in various decoder
> > implementations, but in essence they all sought to bend the 'washing
> > line' of the in-phase stereo image around the front arc with
> > variable width, and anything substantially out of phase generally
> > somewhere else, again rather dependent on the source material.
> >
> > Geoffrey
> >
> >
> >
> >
> >
> >
> > -- next part --
> > An HTML attachment was scrubbed...
> > URL: <
> https://mail.music.vt.edu/mailman/private/sursound/attachments/20110125/52e2d5cc/attachment.html
> > >
> > ___
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>
>
>
> --
>
> Message: 3
> Date: Wed, 26 Jan 2011 05:33:05 +
> From: Augustine Leudar 
> Subject: [Sursound] Subject: Re: Why do you need to decode ambisonic/b
>format signals ?
> To: sursound@music.vt.edu
> Message-ID:
>
> Content-Type: text/plain; charset="iso-8859-1"
>
> Message: 6
> Date: Sat, 22 Jan 2011 23:56:42 +0100
> From: f...@kokkinizita.net
> Subject: Re: [Sursound] Why do you need to decode ambisonic/b format
>
>
> First, don't try and send HTML to this list, as you can see it will
> be removed.
>
> Sorry - I  dont know what you mean - as far as  Iknow  I haven't sent any
> html to this list (at least not intentionally) - I assume you don't mean
> links as there was no link in my original message and
>  there are also many links in the messages on this list.
>
>
> Your question reveals that you have not even started to study and
> > understand Ambisonics theory - the answer would be quite evident
> > in the other case
> >
>
> Obviously - or I wouldnt be asking how it works.  I do however have a
> lot of experience creating 3d soundscapes (in fact its my job) and have
> spent a reasonable amount of time studying a wide range of psychoacoustic
> topics and other areas pertaining to sound art. Now Ive read a bit more it
> is certainly something I will be persuing.
>
>
> . You could as well ask a engineer why he needs
> > complex numbers while you can do your bookkeeping without.
> >
>
> Engineers ? bookeeping ?  I think I know what you mean.
>
> Hoping you will eventually have a go at it,
> >
>
> I will absolutely be having a go at it - the  replies I received here  has
> led me to a flurry of reading - the result is  I am now utterly intrigued
> by
> ambisonics and cant wait to try it out the more I read the more I get
> sucked
> in - I even found myself trying to unravel the maths last night - that
> might
> take a while...)  . I only got so far but as I understand it it uses sound
> pressure levels and phase differences to plot x,y,z spherical coordinates
> which are then reconstituted in the decoding - out of curiosity Why the
> need
> for the w coordinate - cant the sound pressure level be gleaned from the
> x,y
> and z ? At the moment the soundscapes I am working on are large jungle
> soundscapes in a large indoor tropical conservatory  ( covering several
> acres)  - perhaps with twenty metres between speakers. Because of the
> problems of amplitude panning and the sheer size of the installations often
> sounds are localised by using real world object analogues (ie if a monkey
> is
> meant to sound like it comes from behind a certain tree there is a speaker
> with a monkey noise behind that tree)a thunderstorm is represented by a
> stereo pair high on a hillside - we even had neighbours thinking there was
> real thunderstorm happening and it does sound well, realistic (don't take
> my
> word for it you can read the public response here :
> http://augustineleudar.110mb.com/Hd/Hod.html ) . This type of localisation
> has proved extremely effective and don't think that any system no matter
> how
> clever at fooling the human ear can improve upon a sound actually coming
> from the direction its meant to (though recording ambisonically probably
> would)  .  

Re: [Sursound] Subject: Re: Why do you need to decode ambisonic/b format signals ?

[Eero Aro]

Jörn Nettingsmeier wrote:
 > recording insects with a soundfield will probably yield even better

results.


Been there, done that. As many insect and nature sounds, such as cicadas,
mosquitos, rain, wind etc. are "noise type" sounds, they don't include
point sources that localize sharply to any direction.

A Soundfield recording of mosquitos sounds good, but in fact you get almost
the same impression by using for example two stereo recordings of
the same type of material. I have noticed that if you spread a stereo signal
into the Ambisonic soundfield by panning L and R directly to West
and East, you lose all directivity. A better solution is to pan one stereo
pair for example into 40 and 320 degrees and another to 150 and 210.
This is what you do in 5.1 mixing, eh? But with B-format you have the
possibility to tweak that soundfield even more.

You often hear the cicadas "sing" in "waves". The insects in certain
directions are louder at one moment, then fade and others in other
directions fade up at the same time. That is something that might be
good to record with the Soundfield.


it
should be possible to obtain outdoor speakers that withstand these
conditions for years. of course they will cost a lot more


I have good experiences of the JBL Control 1 AW model, "All Weather".
Is it too small for your use, Gus? Control 1 makes a mighty loud noise,
even though it is small in size. We once had eight of them in a periphonic
cube outdoors in the Finnish climate in December (rain, snow, slash, zero
degrees, -28 C degrees, then plus degrees and over again from the start)
playing continously for four weeks 12 hours every day. All worked
fine all the time. When we took the installation down, I had to hit two 
of the

speakers hard with my fist so that I could break the ice that had formed
around the speaker. Anyway, the speaker was playing back fine.

Another type of speakers I have used in outdoor installation, are speakers
that have been designed for boats. They are full plastic and tolerate even
sea water. A set of 16 ran a month in an installation in a park in the
summer of 2009. I think they were LTC speakers.

Eero
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Re: [Sursound] Subject: Re: Why do you need to decode ambisonic/b format signals ?

[Jörn Nettingsmeier]

On 01/26/2011 06:33 AM, Augustine Leudar wrote:

out of curiosity Why the need
for the w coordinate - cant the sound pressure level be gleaned from the x,y
and z ?


you can't deduce w from figures-of-eight, because they simply don't move 
when the pressure rises uniformly (and if they do, that's an artefact of 
capsule diameter vs. wavelength and not something we could use).
if the fig8s you've worked with are the double-diaphragm, switchable 
pattern type: of course you could take both diaphragms and add them 
in-phase, and that would work, because you fake a velocity transducer 
with two at least partly pressure-sensitive ones. but that's cheating 
and doesn't change the fact that xyz and w are totally independent.


w is important as a phase reference: without w, you couldn't say from 
where the signal in x, y, or z was coming, because your ears can't 
detect absolute polarity...
try taking away the centre mic from an m/s pair, and just listen to L=s 
and R=-s. no localisation at all.



This type of localisation
has proved extremely effective and don't think that any system no matter how
clever at fooling the human ear can improve upon a sound actually coming
from the direction its meant to


absolutely. this approach is perfect if your sound event is a point 
source, and all you want is the direct sound. if you have wider sources, 
or you need to convey ambience, reverb, reflections, it doesn't work so 
well, but that's not an objective here iiuc.



Where ambisonics could help in the installation is the insect
noises - at the moment there are large 4 speaker areas with 4mic recorded
insect noises . Gaps in the image are plugged with other speakers with say
cicadas on them - despite the doubts expressed here it also has been
effective perhaps because insect noises are high  frequency and the leaves
on the bushes and trees disperse the sound filling out the sound field.
Generally the effect is pretty similar to being in the rain forest- except
you don't get bitten.


recording insects with a soundfield will probably yield even better results.

you could also use "cheat wave field synthesis" if you can place 
speakers every meter or so. i heard iosono present such a system at 
TMT2010, and they did focused sources (!) :-o
at this speaker distance, spatial aliasing will be terrible, but their 
sound example was, brace yourselves: rain. presto. virtual sources all 
over the place. should work with insects beautifully, although calling 
it wfs might be slightly questionable.


for fairness, i should say that ambi is just as bad in reproducing 
insect or rain noises, but the artefacts (ambiguity, jumpy localisation, 
coloration, phasiness) are generally beneficial, as they increase the 
"density" and "buzz" of the rain, insect swarm, whatever.
so unless you want your listeners to be able to track the queen bee in 
the swarm, you should be fine.



There
is no way a physical decoder could be in the biome - we generally have to
throw speakers away or sell them on ebay after a few uses because of the
ants and humidity (wav players are in sealed plastic boxes).


i don't understand this. are you perhaps using paper membranes? it 
should be possible to obtain outdoor speakers that withstand these 
conditions for years. of course they will cost a lot more, but that 
should be negligible if you have to replace your current speakers that 
often...

what do the ants do to the speakers, btw?

for purely technical reasons you should probably go for 70 or 100v 
versions, as i expect your speaker lines to be lng. the problem is 
that  70/100 amplifiers are meant to drive many speakers in parallel, 
not many channels discretely, so the price per amp channel might be 
prohibitive. but it does give you the option to run the amps and players 
outside of the habitat, in conditions appropriate to semiconductors.




--
Jörn Nettingsmeier
Lortzingstr. 11, 45128 Essen, Tel. +49 177 7937487

Meister für Veranstaltungstechnik (Bühne/Studio), Elektrofachkraft
Audio and event engineer - Ambisonic surround recordings

http://stackingdwarves.net

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Re: [Sursound] Subject: Re: Why do you need to decode ambisonic/b format signals ?

[fons]

On Wed, Jan 26, 2011 at 05:33:05AM +, Augustine Leudar wrote:

> First, don't try and send HTML to this list, as you can see it will
> be removed.
> 
> Sorry - I  dont know what you mean - as far as  Iknow  I haven't sent any
> html to this list (at least not intentionally) - I assume you don't mean
> links as there was no link in my original message and
>  there are also many links in the messages on this list.

No, links are perfectly OK. But your messages (as they arrive
to readers of the list) end like this:

An HTML attachment was scrubbed...
URL: 


which means your mail program is sending an HTML copy of your
text as well. Most mailing lists have a 'no HTML' policy, and
some, like this one, will actually remove it.
 
> I only got so far but as I understand it it uses sound
> pressure levels and phase differences to plot x,y,z spherical coordinates
> which are then reconstituted in the decoding - out of curiosity Why the need
> for the w coordinate - cant the sound pressure level be gleaned from the x,y
> and z ?

If they were just coordinates then you could find w from x,y,z.
But they are something different. 

Image the sound field created by some source, e.g. a sine wave
reproduced by a speaker. At each point in space there two physical
quantities involved:

* The pressure is going up and down at the frequency of the signal.
  This the W signal, which will be produced by an omnidirectional
  microphone.
* To make the pressure variations possible at all, some air must move. 
  Image a tiny volume of air around some point. It will be moving 
  back and forth. The velocity of this movement is a sine wave, and it
  will (in normal cases) be in phase with the pressure signal. But it
  also has a *direction* - it is a vector in 3-D space. So it can be
  split as the sum of three components along some chosen x,y,z axes.
  These components are the X,Y,Z signals. A figure-of-8 microphone
  produces a signal equal to the projection of the velocity vector
  on its (the microphone's) axis. Three of them are required to have
  the full vector.
  
For a single source at sufficient distance, the magnitude of the 
velocity is proportional to the pressure, they are in phase, and
the direction of the velocity points towards the source. Pressure
and velocity are closely related in that case, but even then you
can't find W from X,Y,Z alone. The reason is that if you put the
source in the exactly opposite direction, and invert its phase,
then it will produce exactly the same X,Y,Z - the inversion of
the signal and the direction cancel each other. So you need W
(which will be inverted) as a phase reference.

In the more general case, pressure and velocity are independent.
If you have the same signal reproduced by different sources
(or just a single source and a reflection on a wall) you get
standing waves, and there will be points were the pressures
cancel but velocity does not and vice versa.

Now pressure and velocity are the only two physical quantities
that define a sound field. The basic idea of Ambisonics is that
if you can somehow reconstruct them at the listener's position,
the the listener must hear the same thing as for the real source.

First order Ambisonics (the version using only W,X,Y,Z) can do
this in a small area, where 'small' is expressed in wavelengths.
So this area is large for low frequencies and gets smaller as
frequency goes up. Above a few hundred Hz it has become so small
that it is even too small for single listener. So for mid and
high frequencies, Ambisonics will use a different strategy which
is based on psychoacoustics. For installations where the listening
area has to be much larger, the 'psychoacoustic' strategy is 
normally used at all frequencies. 

Higher order Ambisonics (using more signals) can reconstruct the
sound field in a larger area. It still needs the psychoacoustic
approach for all but the LF range, but this improves as well as
order goes up. At third order and above it becomes very close to
VBAP in fact, with only the speakers nearest to a source direction
contributing in any significant way. The difference with VBAP is
that Ambisonics will not treat the directions corresponding to
the speakers as 'special'. This helps to conceal the speakers
being the source of the reproduced sound.

Ciao,

-- 
FA

There are three of them, and Alleline.

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Re: [Sursound] Subject: Re: Why do you need to decode ambisonic/b format signals ?

[Dave Malham]

On 26/01/2011 05:33, Augustine Leudar wrote:


  Because of the
problems of amplitude panning and the sheer size of the installations often
sounds are localised by using real world object analogues (ie if a monkey is
meant to sound like it comes from behind a certain tree there is a speaker
with a monkey noise behind that tree)a thunderstorm is represented by a
stereo pair high on a hillside - we even had neighbours thinking there was
real thunderstorm happening and it does sound well, realistic (don't take my
word for it you can read the public response here :
http://augustineleudar.110mb.com/Hd/Hod.html ) . This type of localisation
has proved extremely effective and don't think that any system no matter how
clever at fooling the human ear can improve upon a sound actually coming
from the direction its meant to (though recording ambisonically probably
would)
Absolutely true - Ambisonics is not the answer to life, the universe and everything! (but it comes 
close in some areas). It was for exactly the reasons you give above that when we did the original 
soundscapes for the Yorvik Viking Centre (http://www.jorvik-viking-centre.co.uk/) way back in the 
early 80's we chose to go with 56 tracks of audio (on McKenzie 4 track 1/4" continuous loop analogue 
tape!) going through even more speakers, rather than using Ambisonics - and Yorvik is a much smaller 
area! BTW, have you seen those tiny speakers that fir into a standard electrical socket back box 
(and hence are almost invisible)? I was most impressed with them when I visited an exhibition of 
South African sculpture in Madeira this summer...trouble is, I can't remember who made them :-(



  .   Where ambisonics could help in the installation is the insect
noises - at the moment there are large 4 speaker areas with 4mic recorded
insect noises . Gaps in the image are plugged with other speakers with say
cicadas on them - despite the doubts expressed here it also has been
effective perhaps because insect noises are high  frequency and the leaves
on the bushes and trees disperse the sound filling out the sound field.
Generally the effect is pretty similar to being in the rain forest- except
you don't get bitten. However if what I have read about ambisonics is true
it would make it sound even better and there is always room for improvement
.

Certainly worth trying


  I am currently trying to translate some of these sound installations to a
format that can be listened to at home - I have to admit 5.1 is a bit
frustrating so ambisonics might hold the key.  What I would like to know is
can the decoding be done with software and then burnt to wav files ?  There
is no way a physical decoder could be in the biome - we generally have to
throw speakers away or sell them on ebay after a few uses because of the
ants and humidity (wav players are in sealed plastic boxes) .   Are there
any ambisonic panners that are VST compatible (I mainly use Nuendo and MAx
MSP) ? Could I design a horizontal surround sound DVD using ambisonic
software for panning and localisation - and then burn 6 wav files and
release it on a 5.1 DVD which could be played on a normal home system ?
best,
Gus

This is definitely where Ambisonics would shine, I feel , though the use of G format, as others have 
said - or even UHJ



  Dave

--
 These are my own views and may or may not be shared by my employer
/*/
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/* Music Research Centre */
/* Department of Music"http://music.york.ac.uk/";   */
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/* Heslington  Fax   01904 322450*/
/* York YO10 5DD */
/* UK   'Ambisonics - Component Imaging for Audio'   */
/*"http://www.york.ac.uk/inst/mustech/3d_audio/"; */
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Re: [Sursound] Subject: Re: Why do you need to decode ambisonic/b format signals ?

[Dave Malham]

Oops - I'll check the versions! I certainly run the current ones we use here on 10.6 and I thought 
the ones on the web were able to, too. Sorry folks.


  Dave

On 26/01/2011 08:06, Andrew Levine wrote:

On 26.01.2011, at 08:56, Eero Aro wrote:

Dave Malham:
http://www.dmalham.freeserve.co.uk/vst_ambisonics.html
http://www.york.ac.uk/inst/mustech/3d_audio/vst/welcome.html

these have not worked for me on a Mac runnig OSX 10.6.

Cheers,

Andrew
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 These are my own views and may or may not be shared by my employer
/*/
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/* Music Research Centre */
/* Department of Music"http://music.york.ac.uk/";   */
/* The University of York  Phone 01904 432448*/
/* Heslington  Fax   01904 432450*/
/* York YO10 5DD */
/* UK   'Ambisonics - Component Imaging for Audio'   */
/*"http://www.york.ac.uk/inst/mustech/3d_audio/"; */
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Re: [Sursound] Subject: Re: Why do you need to decode ambisonic/b format signals ?

[Andrew Levine]

On 26.01.2011, at 08:56, Eero Aro wrote:
> Dave Malham:
> http://www.dmalham.freeserve.co.uk/vst_ambisonics.html
> http://www.york.ac.uk/inst/mustech/3d_audio/vst/welcome.html

these have not worked for me on a Mac runnig OSX 10.6.

Cheers,

Andrew
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Re: [Sursound] Subject: Re: Why do you need to decode ambisonic/b format signals ?

[Eero Aro]

Augustine Leudar wrote:

Why the need for the w coordinate


I am not a mathematician or a scientist. A sound designer's reply:
The W is a "reference" signal. For example, at decoding:
+ W + X is the "front" direction (W and X at equal phase)
+ W - X is the "rear" direction (X phase reversed in relation to W)

Try to look at 1st order B-Format (WXYZ) as a "three dimensional
MS-stereo signal". That helped me in the beginning.


the soundscapes I am working on are large jungle
soundscapes in a large indoor tropical conservatory


You must have looked at Timax?
http://www.outboard.co.uk/pages/timax.htm


Where ambisonics could help in the installation is the insect
noises


Yep. A single mono sound is best localized to all listeners when you
play it back through one speaker only. It is a good idea to route that
kind of signals directly into the appropriate speaker. A combination of
different techniques is possibly the best way to do it. Soundfields with
moving phantom images and ambiences and spatial images are easy
to control with B-Format Ambisonics. As somebody already said, it is
possible to rotate, tilt and tumble a full 3D soundfield, and much more.
You can for example "zoom in" into a certain direction.


can the decoding be done with software and then burnt to wav files ?


Andrew gave you good pointers. Bruce Wiggins has described workflows
in his page. Possibly you'd like to check also these sites:

Dave Malham:
http://www.dmalham.freeserve.co.uk/vst_ambisonics.html
http://www.york.ac.uk/inst/mustech/3d_audio/vst/welcome.html

Visual Virtual Mic:
http://mcgriffy.com/audio/ambisonic/vvmic/

Aristotel Digenis:
http://www.digenis.co.uk/

Acousmodules. No Ambisonics in there, but you might find other useful tools:
http://acousmodules.free.fr/acousmodules_en.htm

Eero
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Re: [Sursound] Subject: Re: Why do you need to decode ambisonic/b format signals ?

[Andrew Levine]

Hi Augustine,

On 26.01.2011, at 06:33, Augustine Leudar wrote:
> I am now utterly intrigued by
> ambisonics and cant wait to try it out the more I read the more I get sucked
> in

I know what you're talking about :-)

> Gaps in the image are plugged with other speakers with say
> cicadas on them - despite the doubts expressed here it also has been
> effective perhaps because insect noises are high  frequency and the leaves
> on the bushes and trees disperse the sound filling out the sound field.
> Generally the effect is pretty similar to being in the rain forest- except
> you don't get bitten.

I didn't know cicadas bit ;-)

> What I would like to know is
> can the decoding be done with software and then burnt to wav files ?  

Sure. This is what some call G-format.

> Are there
> any ambisonic panners that are VST compatible (I mainly use Nuendo and MAx
> MSP) ? Could I design a horizontal surround sound DVD using ambisonic
> software for panning and localisation - and then burn 6 wav files and
> release it on a 5.1 DVD which could be played on a normal home system ?

So far I haved worked with plugins by Bruce Wiggins 
(http://www.brucewiggins.co.uk/?page_id=78) and Daniel Courville 
(http://www.radio.uqam.ca/ambisonic/b2x.html).

Regards,

Andrew
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Re: [Sursound] Subject: Re: Why do you need to decode ambisonic/b format signals ?

[Danny McCarty]

Nice response Gus and certainly more gracious than I would have been.
Danny



On Jan 25, 2011, at 9:33 PM, Augustine Leudar wrote:

> Message: 6
> Date: Sat, 22 Jan 2011 23:56:42 +0100
> From: f...@kokkinizita.net
> Subject: Re: [Sursound] Why do you need to decode ambisonic/b format
> 
> 
> First, don't try and send HTML to this list, as you can see it will
> be removed.
> 
> Sorry - I  dont know what you mean - as far as  Iknow  I haven't sent any
> html to this list (at least not intentionally) - I assume you don't mean
> links as there was no link in my original message and
> there are also many links in the messages on this list.
> 
> 
> Your question reveals that you have not even started to study and
>> understand Ambisonics theory - the answer would be quite evident
>> in the other case
>> 
> 
> Obviously - or I wouldnt be asking how it works.  I do however have a
> lot of experience creating 3d soundscapes (in fact its my job) and have
> spent a reasonable amount of time studying a wide range of psychoacoustic
> topics and other areas pertaining to sound art. Now Ive read a bit more it
> is certainly something I will be persuing.
> 
> 
> . You could as well ask a engineer why he needs
>> complex numbers while you can do your bookkeeping without.
>> 
> 
> Engineers ? bookeeping ?  I think I know what you mean.
> 
> Hoping you will eventually have a go at it,
>> 
> 
> I will absolutely be having a go at it - the  replies I received here  has
> led me to a flurry of reading - the result is  I am now utterly intrigued by
> ambisonics and cant wait to try it out the more I read the more I get sucked
> in - I even found myself trying to unravel the maths last night - that might
> take a while...)  . I only got so far but as I understand it it uses sound
> pressure levels and phase differences to plot x,y,z spherical coordinates
> which are then reconstituted in the decoding - out of curiosity Why the need
> for the w coordinate - cant the sound pressure level be gleaned from the x,y
> and z ? At the moment the soundscapes I am working on are large jungle
> soundscapes in a large indoor tropical conservatory  ( covering several
> acres)  - perhaps with twenty metres between speakers. Because of the
> problems of amplitude panning and the sheer size of the installations often
> sounds are localised by using real world object analogues (ie if a monkey is
> meant to sound like it comes from behind a certain tree there is a speaker
> with a monkey noise behind that tree)a thunderstorm is represented by a
> stereo pair high on a hillside - we even had neighbours thinking there was
> real thunderstorm happening and it does sound well, realistic (don't take my
> word for it you can read the public response here :
> http://augustineleudar.110mb.com/Hd/Hod.html ) . This type of localisation
> has proved extremely effective and don't think that any system no matter how
> clever at fooling the human ear can improve upon a sound actually coming
> from the direction its meant to (though recording ambisonically probably
> would)  .   Where ambisonics could help in the installation is the insect
> noises - at the moment there are large 4 speaker areas with 4mic recorded
> insect noises . Gaps in the image are plugged with other speakers with say
> cicadas on them - despite the doubts expressed here it also has been
> effective perhaps because insect noises are high  frequency and the leaves
> on the bushes and trees disperse the sound filling out the sound field.
> Generally the effect is pretty similar to being in the rain forest- except
> you don't get bitten. However if what I have read about ambisonics is true
> it would make it sound even better and there is always room for improvement
> .  I am currently trying to translate some of these sound installations to a
> format that can be listened to at home - I have to admit 5.1 is a bit
> frustrating so ambisonics might hold the key.  What I would like to know is
> can the decoding be done with software and then burnt to wav files ?  There
> is no way a physical decoder could be in the biome - we generally have to
> throw speakers away or sell them on ebay after a few uses because of the
> ants and humidity (wav players are in sealed plastic boxes) .   Are there
> any ambisonic panners that are VST compatible (I mainly use Nuendo and MAx
> MSP) ? Could I design a horizontal surround sound DVD using ambisonic
> software for panning and localisation - and then burn 6 wav files and
> release it on a 5.1 DVD which could be played on a normal home system ?
> best,
> Gus
> 
> 
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> 
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Danny McCarty
Monolith Media, Inc.
4183 Summi

[Sursound] Subject: Re: Why do you need to decode ambisonic/b format signals ?

[Augustine Leudar]

Message: 6
Date: Sat, 22 Jan 2011 23:56:42 +0100
From: f...@kokkinizita.net
Subject: Re: [Sursound] Why do you need to decode ambisonic/b format


First, don't try and send HTML to this list, as you can see it will
be removed.

Sorry - I  dont know what you mean - as far as  Iknow  I haven't sent any
html to this list (at least not intentionally) - I assume you don't mean
links as there was no link in my original message and
 there are also many links in the messages on this list.


Your question reveals that you have not even started to study and
> understand Ambisonics theory - the answer would be quite evident
> in the other case
>

Obviously - or I wouldnt be asking how it works.  I do however have a
lot of experience creating 3d soundscapes (in fact its my job) and have
spent a reasonable amount of time studying a wide range of psychoacoustic
topics and other areas pertaining to sound art. Now Ive read a bit more it
is certainly something I will be persuing.


. You could as well ask a engineer why he needs
> complex numbers while you can do your bookkeeping without.
>

Engineers ? bookeeping ?  I think I know what you mean.

Hoping you will eventually have a go at it,
>

I will absolutely be having a go at it - the  replies I received here  has
led me to a flurry of reading - the result is  I am now utterly intrigued by
ambisonics and cant wait to try it out the more I read the more I get sucked
in - I even found myself trying to unravel the maths last night - that might
take a while...)  . I only got so far but as I understand it it uses sound
pressure levels and phase differences to plot x,y,z spherical coordinates
which are then reconstituted in the decoding - out of curiosity Why the need
for the w coordinate - cant the sound pressure level be gleaned from the x,y
and z ? At the moment the soundscapes I am working on are large jungle
soundscapes in a large indoor tropical conservatory  ( covering several
acres)  - perhaps with twenty metres between speakers. Because of the
problems of amplitude panning and the sheer size of the installations often
sounds are localised by using real world object analogues (ie if a monkey is
meant to sound like it comes from behind a certain tree there is a speaker
with a monkey noise behind that tree)a thunderstorm is represented by a
stereo pair high on a hillside - we even had neighbours thinking there was
real thunderstorm happening and it does sound well, realistic (don't take my
word for it you can read the public response here :
http://augustineleudar.110mb.com/Hd/Hod.html ) . This type of localisation
has proved extremely effective and don't think that any system no matter how
clever at fooling the human ear can improve upon a sound actually coming
from the direction its meant to (though recording ambisonically probably
would)  .   Where ambisonics could help in the installation is the insect
noises - at the moment there are large 4 speaker areas with 4mic recorded
insect noises . Gaps in the image are plugged with other speakers with say
cicadas on them - despite the doubts expressed here it also has been
effective perhaps because insect noises are high  frequency and the leaves
on the bushes and trees disperse the sound filling out the sound field.
Generally the effect is pretty similar to being in the rain forest- except
you don't get bitten. However if what I have read about ambisonics is true
it would make it sound even better and there is always room for improvement
.  I am currently trying to translate some of these sound installations to a
format that can be listened to at home - I have to admit 5.1 is a bit
frustrating so ambisonics might hold the key.  What I would like to know is
can the decoding be done with software and then burnt to wav files ?  There
is no way a physical decoder could be in the biome - we generally have to
throw speakers away or sell them on ebay after a few uses because of the
ants and humidity (wav players are in sealed plastic boxes) .   Are there
any ambisonic panners that are VST compatible (I mainly use Nuendo and MAx
MSP) ? Could I design a horizontal surround sound DVD using ambisonic
software for panning and localisation - and then burn 6 wav files and
release it on a 5.1 DVD which could be played on a normal home system ?
best,
Gus


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