Ah you must mean this:

http://en.wikipedia.org/wiki/Stereo_imaging

Your delay idea only covers one part of the psychoacoustics of the stereo image: the difference in time when a sound reaches each ear. Psychoacoustics are a bit more complicated than that I'm afraid. You might look up HRTF (head related transfer functions) to get a better idea of the time differences involved. But there are a lot of other factors. An intro book on psychoacoustic might be a good place to start.

Maybe some of the ambisonics experts around here will chip in some other things...

best, Derek

Derek Holzer wrote:

What is an imager supposed to do? I've never heard of this effect and Google isn't too helpful on the subject.

D.

Johannes wrote:

...

hello people,

i like to build an imager effect in pd but have some trouble with it. what i´ve acually tryed is very simple: sending one signalchannel of an stereo pair into delaywrite~ (while the other goes directy into dac~) after 6 - 26 ms later i read out of it with delread~ and is connected to the second input of dac~.

is this the right way to build an imager?

does anybody know the theoretic background of the imager?

some other ideas how i can do an imager in pd?

Dunno if this is relevant. The stereo imager on Logic Pro assigns frequency bands to be boosted and cut slightly in each channel (roughly describing a sine wave through the frequency spectrum) so that there'll be more of one band in the left, the same band is slightly cut in the right, thus creating the illusion of a wider stereo image. Although this is fully adjustable so I can't really tell you where to start emulating this. It's a very subtle effect, too, even at it's most severe there's very little difference. As a simple version of this you could use the hi-fi 'surround' method, simply boost the treble (from about 10kHz) in one or other chanel, in theory then that will cause more reflectivity in the room and stereo effects become 'surround' (sic) effects. It's not as good as it sounds, but it is one way to vary your stereo image.

Date: Wed, 11 Nov 2009 23:37:03 +0100 From: derek@umatic.nl To: THIS_IS_POP@web.de CC: pd-list@iem.at Subject: Re: [PD] imager

Ah you must mean this:

http://en.wikipedia.org/wiki/Stereo_imaging

Your delay idea only covers one part of the psychoacoustics of the stereo image: the difference in time when a sound reaches each ear. Psychoacoustics are a bit more complicated than that I'm afraid. You might look up HRTF (head related transfer functions) to get a better idea of the time differences involved. But there are a lot of other factors. An intro book on psychoacoustic might be a good place to start.

Maybe some of the ambisonics experts around here will chip in some other things...

best, Derek

Derek Holzer wrote:

...

What is an imager supposed to do? I've never heard of this effect and Google isn't too helpful on the subject.

D.

Johannes wrote:

...

hello people,

i like to build an imager effect in pd but have some trouble with it. what i´ve acually tryed is very simple: sending one signalchannel of an stereo pair into delaywrite~ (while the other goes directy into dac~) after 6 - 26 ms later i read out of it with delread~ and is connected to the second input of dac~.

is this the right way to build an imager?

does anybody know the theoretic background of the imager?

some other ideas how i can do an imager in pd?

-- ::: derek holzer ::: http://blog.myspace.com/macumbista ::: http://www.vimeo.com/macumbista ::: ---Oblique Strategy # 24: "Bridges -build -burn"

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Johannes wrote:

thanks guys,

andrew, nice that you wrote about the logic imager. i was inspired by it to think about how the imager effect workes. do you think there is no delay between the channels at all? is it just stereo filtering?

any other voices on how to build an imager in pd?

there was Georg Holzmann's spatialization workshop also explaining some of the underlying perception mechanisms.

the workshop media, containing several self explaining patches are on the net:

http://grh.mur.at/misc/PdSpatialization.tar.gz

cheers Martin

hi chris,

i read a bit about the rss stuff - that sounds nice. but i have no idea how to use the phase to get something like the results of the rss technoligy. can you please give me an exsample or an startingpoint on that?

thanks alot. j

chris clepper schrieb:

Look into the Haas effect and also changing phase along with delay time. Roland had a technology called RSS that could do pretty wild things with the stereo image based on phase and delay.

On Fri, Nov 13, 2009 at 5:20 AM, Johannes <THIS_IS_POP@web.de mailto:THIS_IS_POP@web.de> wrote:

thanks guys,

andrew, nice that you wrote about the logic imager. i was inspired
by it to think about how the imager effect workes.
do you think there is no delay between the channels at all? is it
just stereo filtering?

any other voices on how to build an imager in pd?

jo