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syntheticwave
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The end of the transmitting chain....

...until today regarding the loudspeakers. But the most of the errors arise, if those have done its work.

By the principle of wave field synthesis become possible, to include the rendition room into the transmitting chain for aimed corrections of his properties. Not only for the frequency response. Much more important the correct spatial distribution of the mirror sources, which determinate the spatial soundfield in the recording room.
By the website http://www.syntheticwave.de become described a patented procedure, able to restore that spatial distibution of the early strong reflection sources to a large extend. In that manner becomes possible resizing the rendition room virtually.
The procedure is not easy to understand, I admit. But the wave field synthesis principle is applying in action successfully today.

bobedaone
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Re: The end of the transmitting chain....

Ich kann Ihnen nicht gut verstehen.

Aber die Website sieht sehr interessant aus.

syntheticwave
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Re: The end of the transmitting chain....

...Eric rapped my bad english in good German. Sorry, we old east Germans has only education in russian and that would possibly increase the problems.
I have tried to edit the text a little, hope is understandable now.

bobedaone
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Re: The end of the transmitting chain....

Yes, that's a bit better.

If I understand correctly, you're saying this:

Until today, loudspeakers have been regarded as the end of the transmitting chain, but most errors arise after they have done their work. The principle of wave field synthesis has made it possible to include the rendition room in the transmission chain with targeted corrections of its properties, including more than just frequency response. Specifically, it allows for the correct spatial distribution of the mirror sources, which determine the spatial soundfield in the recording.
The website http://www.syntheticwave.de describes a patented procedure, able to restore that spatial distribution of the early strong reflection sources to a large extent. In that manner, it becomes possible to resize the rendition room virtually.

You do write well enough that I think people will get the gist of what you're saying.

syntheticwave
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Re: The end of the transmitting chain....

Thanks for the proper translation!

KBK
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Re: The end of the transmitting chain....

Very interesting.

rvance
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Re: The end of the transmitting chain....


Quote:
Very interesting.

Thank you, Colonel Klink!

syntheticwave
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Re: The end of the transmitting chain....

...thank you all for the positive resonance.
If anybody see rough mistakes in the translation inside the website, please give a advice.

cyclebrain
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Re: The end of the transmitting chain....

Though guilty of not reading the link yet, at first read the post sounds like marketing double talk.

syntheticwave
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Re: The end of the transmitting chain....

Hi cyclebrain,
today it is intelligent to be sceptical.
But your brain should not go in the cycle. Without reading text you can see the principle by that animation:
http://www.syntheticwave.de/sound%20field%20transformation.htm

KBK
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Re: The end of the transmitting chain....


Quote:

Quote:
Very interesting.

Thank you, Colonel Klink!

You should see the post I went back and deleted..and then put 'very interesting'-instead of it.

I'm a manufacturer again, damn it. I'm not allowed to have an opinion on other folks stuff.

But I am bald and (partially) German. And I do scrunch my face up at times. Score one for Rvance.

syntheticwave
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Re: The end of the transmitting chain....

...sorry, I cannot really understand whats going up here, because i don

trevort
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Re: The end of the transmitting chain....

I didn't get the reference myself when I first scanned this thread.

I think buddy (KBK) said "Very Interesting", aparently in earnest, which is a phrase that a character on a TV show -- was it Hogan's Heroes? -- always stated in a very affected manner. So much so that it is well possible that, decades later, someone who listened to that show might be prompted to recall that character from seeing the words "Very Interesting".

Given it was RVance who seemed to slip into that little time warp, you can consider it humour. And given that your article was in German, as is Colonel Klink (If I've got my pop culture reference straight), RVance is being pretty freakin' funny!

syntheticwave
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Re: The end of the transmitting chain....

Hi ttt,
thank you for the explanation, I am very happy, because are no communism in America still.
I believe that the idea would need a discussion in that matter, whether the goal of reproduction a genuine like sound field? And what should be the effect of such a procedure, when exist no original, most of the productions are studio productions ?

trevort
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Re: The end of the transmitting chain....

Your proposed solution seems very elegant, certainly in theory, but my concern is that it is also very complicated to put into practice.

It may well be that your system could work, say, in a special venue, similar to an IMAX theatre, but given the price of hi-fi components, I'm not too eager to switch from 2 channel to current surround sound, never mind a whole bunch of speakers.

Each of those speakers might not need to be full range, but still, it represents a pretty involved system.

There's something to be said about simplicity -- those with experience in both quality surround sound and 2 channel sound might be able to pipe up that actually 2 channel is better, overall. If so, then although your solution does address some issues of sound reproduction, the practical implementation may not meet the ideal because its so complicated.

2 cents worth from the peanut gallery

PS -- I am NOT an american, so I won't speak for the communism there. I do admire the Dixie Chicks!

syntheticwave
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Re: The end of the transmitting chain....

Hi ttt,

good start for a discussion.
I am sure, each normally LCD TV is much more complicated. You must deliver signals for millions of single points. The technique of the signal processors very sophisticated and we should not overvaluing the effort. The production of such repeating structures as in the speaker field is very effective today. But you need early adapters of course.

In some cinemas are work wfs applications as horizontal rows around the listener still. The technical implementation remains no problem today. We have in Germany such Cinemas in Ilmenau and Munich, currently also in Hollywood become building up such wfs speaker rows as far as I know. But the rendition room must be hushed widely by that solution, because his reflections are disturbing signals. Such rows around the listener seem me not applicable for home use.

This also was the opinion of the most participants of the international wfs workshop in Ilmenau in September. I wondered by that way, because no peer was from America except the AES- President. All technicians in Iraq still?

Like you currently I am prefer stereo rendition in the most cases, the utterly overacting effects in most of the surround productions awfully. But those are not a problem of the procedure, but of the people are working with. To build a proper surround production you need very high knowledge of physics and psychoacoustic issues. Pick up a dry record by a tight spaced micro for each source seems more easily.

PS.: I love more the chicken wings

rabpaul
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Re: The end of the transmitting chain....

H,
I came across your site sometime back but did not quite understand what it was about but after reading this thread I think I have a better picture.
It looks to me that what you are doing is similar in concept to line array vertical tower speakers only these arrays are horizontal. Some line arrays designs don't send the same signal to all speakers but progressively reduce the signals to some of the speakers e.g below the center to floor.
I can see from the examples that the application in a cinema not just the front array but all around makes a lot of sense and I would expect such an implementation to be spectacular. Any plans for people with purpose built home theatres just like a cinema but on a smaller scale?
Do you have any plans for the home stereo user? I believe it will be possible to create a horizontal front wall array. I am not sure if you would split that array into left and right or even feed both left and right signals into the same array. I am guessing that the electronics needs to know the room dimensions and location of the arrays to be able to calculate the correct amplitude to send to a particular speaker in order to create the correct wave.

syntheticwave
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Re: The end of the transmitting chain....

Hello RebPaul,
possibly you have searched Colonel Kilnk, as you have found my site ?

The horizontal loudspeaker rows around the listener you mentioned are not my approach, such facilities build up by various scientific institutes in Europe, based by an invention of Prof. Berkhout in 1988 by the University of Delft. It is not very similar the Beamforming procedure for sound projectors, fits a constant amount of wavelengths into the radiation. Isn

rabpaul
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Re: The end of the transmitting chain....

H,
Actually I think I came across your site when I was looking up wavelengths. Someone had asked about the ability to hear bass in a small room which would not be actually able to accomodate even a full 30Hz wavelength.

So its actually a few rows of speakers on the front wall which are timed to release a proper wave into the room.

Would you handle longer wavelengths differently from shorter wavelengh e.g 40Hz comapared to 1000Hz?
Would you use a different set of speakers for lower frequencies i.e the wall of speakers are actually not identical i.e some handle higher while some handle lower frequencies?

Rgds, R

syntheticwave
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Re: The end of the transmitting chain....

Hello RabPaul,

I am pleased because the site now appears by looking up wavelengths.

Different wavelengths must be handling differentiated by the System. You need very small membrane elevations because of the excellent air- resistance adaptation of such a large speaker field. In principle would possible a good bass reproduction by poor speakers. But such small elevations also would be ideally for electrostatic, diverted in small single regions and working as picture screen. I would see 160 Hz as a tolerable lower end limit by such an approach. Such relatively high frequency becomes possible, if the sub included in the time domain regarding the system.

On the other hand the system must work by the upper end only up to 3,6kHz, in future possibly up to 8 kHz. The effort is strongly dependent from this limit because of the spatial aliasing effects, arising by too large spacing of the single Speakers. The range between 160Hz and 3, 6 kHz is the most important for the source position detection. Above that limit two tweeters may doing its work.

rabpaul
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Re: The end of the transmitting chain....

H,
I see it is now becoming more complicated with the addition of different drives to cater for different frequencies. As long the system can handle at least 20-20Khz it would be fine as most people would know something is missing if it did not.

syntheticwave
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Re: The end of the transmitting chain....

Hello RabPaul,

I would agree the system becomes very complicated. But unfortunately all easy tasks were solved today.

In principle it would be possible to handle the whole frequency range by the speaker matrix. But then you would need more as 10.000 single speakers because aliasing problems arise otherwise. ( http://en.wikipedia.org/wiki/Aliasing ) Each of those speakers needs to radiate the whole frequency range. The membrane elevation for 20 Hz, 100 dB would remain below 1 mm because of the huge cumulative expanse still, but for sale of such equipment you would need very rich early adapters.

On the other hand we work in a widely determinate system. Thereby it becomes possible to adapt time, phase and level for a crossover system much more accurate then in a system, which handling some indeterminate factors.

Of course you need a subwoofer not identifiably by its overtones. And it would be better to radiate by the speaker screen up to 8 , possibly 10kHz as only 3,6 kHz , because then it becomes possible to evaluate the correct interaural level differences not only by two single speakers, based by phantom source detection, as we do it by stereo equipment. You must miss yet not more as thereby. But the most important cues for spatial determination are the interaural level differences, working only upon approximate 3, 6 kHz. Above that the evaluation becomes ambivalent, because more as one wavelength fit into the ear distance.

Such a system would need app 800, by some tricks I cannot talk about yet app. 200 payable speakers.

In future I would see such digital speakers as possible solution:

http://www.ece.cmu.edu/research/publications/2002/CMU-ECE-2002-001.pdf

That would perform the Raleigh 2 integral conditions regarding wave field synthesis for the whole range.

syntheticwave
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Re: The end of the transmitting chain....

...i want to add a good link for a literature reviev regarding the wave field synthesis principle:

http://www.hauptmikrofon.de/wfs.htm

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Re: The end of the transmitting chain....

Hi,
today i have reworked the wave field synthesis for Home-use site. Its possibly more easy to understand now:
http://www.syntheticwave.de/wave-field-synthesis.htm
If somebody detecting hard mistakes in language send a P.M., please.

Regards Helmut

syntheticwave
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Re: The end of the transmitting chain....

Besides the wfs topic,
the initial time delay gap is one of the most important cues regarding intimacy of loudspeaker reproduction. But the topic hardly described in the net and when, the description sometimes is wrong.
I have build up a easily understandable antimation in that matter:

http://www.syntheticwave.de/ITDG.htm

syntheticwave
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Re: The end of the transmitting chain....

Little story seems more easily to grasp for the wave field synthesis topic:

Imagine you are situated in an opera house, best place, great tenor sings. Suddenly unexpected some bricklayers come in, build up a little housing around you. You are angrily, 56$ for the ticket and now you can hear nothing!

But help is coming. One of the masons made holes into all walls, 10 cm in diameter, each on the other. Super, you hear Caruso as good as without the house. But now the electricians coming, sticking each hole by a loudspeaker. The sound is blocked again, but then, suddenly you hear likely the holes would be open. The electricians have supplied each speaker by a small amplifier and a microphone just on the outside of each hole. Nothing is changed, speakers and microphones working well today.

The problem is only; you need one discrete channel for each micro, if you want to build the speakers into your living room walls. The second, mostly bigger problem is your wife, if you want to load all walls around in your living room by loudspeakers.

Wave field synthesis does nothing else as describing a solution for those problems. It describes a way for build up all different signals for the direct wave from a dry recorded mono track for each singer. The same signal is able for generate the first strong reflections in the recording room, which hit the listener from all different directions. Its temporally and spatial behavior is the core of each acoustic, but by conventionally loudspeaker reproduction we are far away from the goal, to be able for reproducing this spatial distribution roughly correct. The reverberation tail then becomes created from the impulse response, that's common practice in all studios today. The impulse response becomes suppressed for the early reflection time, so that the first reflections don't produce again. The reverberation is coming from all directions by such approach, likely in the opera house.

By including of the reflecting playback room walls, as it is known from the directed radiation used in the sound projectors, you can resign the loudspeakers all around, only those behind the picture screen remain. Your wife shouldn't' be able for discover that, the signal of each single speaker (holes) are hardly louder as the sound by the listener place.

But the speaker field isn't producing virtually loudspeakers, as doing in the sound projectors. The speaker field simulates the source itself.

vladoslav
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Re: The end of .... A BIT OUT OF TOPIC

I am sure, each normally LCD TV is much more complicated. You must deliver signals for millions of single points. The technique of the signal processors very sophisticated and we should not overvaluing the effort. The production of such repeating structures as in the speaker field is very effective today. But you need early adapters of course.

If LCD TV is such complex, why the speaker manufacturers are asking such unbelievably prices??? Recently I read a report from Canadian HIFI show and I was petrified by the prices of speakers from newcomer "companies". Eight thousand of whatevercurrency is asking a young guy whose name is unknown even for his next door neighbor, another one twentytwo thousand, somebody else a Kbuck?.... Who can stop the madness??? I fully understand and accept AD frustration. Any GOOD recommendation for speaker circa 3.000 EUR / 4.500 USD ??

syntheticwave
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Re: The end of .... A BIT OUT OF TOPIC

Hello Dr.S,

4.500 USD in future possibly the loudspeakers for the poore people. If you want to build an widely aliasing free reproduction by the described loudspeaker field would be need 1296 single loudspeakers, each guided by own microprocessor, D/A and an amplifier. The speaker field has 2,80 meter in diagonale. The calculated cost would be above 80.000 $.
But if I see your picture, that should not become a problem for you.

Regards Helmut
www.syntheticwave.de

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