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[Level]

the entire concept requires several stages of DSP to work properly with control needed but to make it simple...

Record a sax with microphones in a circular pattern (sphere) and assign the number of microphones to a number of channels and reproduce that in a spherical "exploding format" loudspeaker that contains the same number of drivers as mic channels. Instead of sound propagating through the medium of a loudspeaker system reproducing the instrument and all of its natural dispersion (including reflections, you have separate channels , drivers /amplifiers to model all of the audio from the instrument from various angles.

This is a small part of the dsp..how it works with multiple instruments is rather complex. Read more of the 'Micro Macro volume' paper.

Since I did not write the papers..(I am only working with certain sections of the dsp) I am not responsible for the wording nor the presentation...simply my part is demonstration/validation of certain sections of the platform.

The entire platform is very multifaceted. The system is realized, parts of it are in operation patents are approved and documented. Don't ask me to explain it all. The papers should pique enough interest for expounding purposes.

Now..lets talk about loudspeaker technology..I simply wanted to present some research that is ongoing for now.

(Also..more papers than published are needed to realize the full scope and need for such a system. That is a different department from what I am working in. I am certain I will get a "few papers" out if it, in due time)

[bblackwood]

That's an, err, interesting graph there, DC. That's the first one in the paper?

What is the x axis variable?

[dcollins]

bblackwood wrote on Tue, 25 October 2005 14:43

That's an, err, interesting graph there, DC. That's the first one in the paper? What is the x axis variable?

Brad, we are talking paradigm shifts here, I wouldn't expect you to understand it.

Especially when it comes to graphing "Subjective Sonic Improvement."

I think everyone should read that paper, it's a hoot!

DC

[Phillip Graham]

Jon Hodgson wrote on Mon, 24 October 2005 17:41

so maybe we can talk about them for a bit and I can learn something new? Let's start with something by John Watkinson http://www.celticaudio.co.uk/articles/science.pdf Has anyone used any other "unusual" speakers? Electrostatic, Flat Panel, Telepathy? How did they work, how did they sound? Does anyone know of things that are being done to improve speaker accuracy? Monitors, PA, HiFi, I'm interested in all of them.

Hey Jon,

Speakers is something that I can chime in on, as BBlackwood and some of the other mastering folks can attest to.

Please know that I am heavily bent towards the pro sound world, but all the basic principles still apply.

I read the celtic audio paper, and it is interesting.  The author draws from a lot of other disciplines in a reasonably correct way.  There are a few errors that I noticed, but the underlying design philosophy is solid.  The basic principles of minimizing time domain error, minimizing diffraction, and using low group delay LF alignments are all good engineering practice.  I am puzzled by the comments relating to the unsuitability of strontium ferrite magnets for drivers.

For some hard science on some of the issues alluded to in the above paper, I suggest reading the following two PDFs links.  They were written by Jay Mitchell, a fellow GT yellowjacket, and head loudspeaker designer at frazier loudspeakers, a professional loudspeaker manufacturer for the pro-sound consulting market.

http://www.frazierspeakers.com/download/cross.pdf--Covers practical limits of time domain accuracy for traditional analog crossovers.  Requires familiarity with the ideas of transfer functions.

http://www.frazierspeakers.com/download/bounds.pdf--discusses the diffraction of sound off of the boundaries of a loudspeaker cabinet.  Familiarity with the concept of boundary conditions in solutions of differential equations is a plus.

A relatively new movement development in the world of prosound speakers comes from EAW (Eastern Acoustics Works).  They have developed a new series of DSP corrected loudspeakers that use completely custom transfer functions, not based on existing filter topologies, to precisely compensate for the spatially consistent LTI components of the drivers and horns.

This is their dog and pony:
http://www.eaw.com/products/nt/brochure2/accuracy.html

Here is the spec sheet.  Pay particular attention to the !excellent! phase response, which nearly matches the theoretical phase response of a 2nd order high pass (i.e. from the sealed box loading):
http://www.eaw.com/products/nt/pdf/RD0300(A)NT26-29_SPEC.pdf

If you want the AES on this speaker, the title is "Improving Loudspeaker Transient Response with Digital Signal Processing" by D. Gunness, 119th AES Convention, Paper 6590

Two other very useful links are:
http://www.linkwitzlab.com
http://www.klippel.de

Is this the kind of stuff you were interested in, Jon?

[CCC]

dcollins wrote on Tue, 25 October 2005 06:49

That stuff is so full of gobbledygook, new made-up terms, I defy anyone to understand it, as presented.  But willing to be proved wrong.

I got a feeling that when the phrase 'talking out of your ass' was coined it was with this paper in mind. Then again, considering it was written by the marketing manager of a company that "manufactures obsolete parts for aircraft, military vehicles, and other miscellaneous government equipment requiring machine tooling and/or fabrication" it's pretty creative. About as credibly scientific as the grocery list I just made, but entertaining nonetheless.

I referred to this once before on this forum, but there is a classic intentional bullshit paper by a physics professor named Alan Sokal, called "Transgressing the Boundaries: Towards a Transformative Hermeneutics of Quantum Gravity" that all fans of total bullshit must read. Check it out here;

http://www.physics.nyu.edu/faculty/sokal/transgress_v2/trans gress_v2_singlefile.html

Remember - this is a spoof!

[Jon Hodgson]

Hi Phill,

Thanks, yes that is the kind of thing I'm looking for, the problems involved in making perfect speakers, and any "neat" or interesting attempts to solve these problems. Even failed architectures can be interesting, to me it's not just the technology, it's the history, what people tried and why, and the future, what people are thinking of trying.

[12345]

dcollins wrote on Mon, 24 October 2005 22:49

That stuff is so full of gobbledygook, new made-up terms, I defy anyone to understand it, as presented.  But willing to be proved wrong.

What's not to understand?  It introduces transfer functions as part of the coding of the performance...nice to see...and nothing to be "afraid of."  

MW

[12345]

John Sorensen wrote on Tue, 25 October 2005 16:13

Then again, considering it was written by the marketing manager of a company that "manufactures obsolete parts for aircraft, military vehicles, and other miscellaneous government equipment requiring machine tooling and/or fabrication" it's pretty creative. About as credibly scientific as the grocery list I just made, but entertaining nonetheless.

John,

Companies that manufacture aftermarket aircraft components are some of the most "advanced" technology companies in the world!!!  Not only do they have to prove to the FAA that their components can be directly substituted for the OEM, but they often have to go "farther" than the OEMs to prove this...while accepting the liability that goes along with it.  It is a multibillion dollar industry...and even some of the OEMs are partnering with such companies...  I have not researched which company Mr. Metcalf is from, or his scientific background, but the technological assets of the aftermarket aircraft (PMA) industry are formidable!!!

MW

[CCC]

My World wrote on Wed, 26 October 2005 02:35

[Companies that manufacture aftermarket aircraft components are some of the most "advanced" technology companies in the world!!!  Not only do they have to prove to the FAA that their components can be directly substituted for the OEM, but they often have to go "farther" than the OEMs to prove this...while accepting the liability that goes along with it.  It is a multibillion dollar industry...and even some of the OEMs are partnering with such companies...  I have not researched which company Mr. Metcalf is from, or his scientific background, but the technological assets of the aftermarket aircraft (PMA) industry are formidable!!! MW

Hey man, thanks for the feedback.

Now, for kicks, go  to this site and poke around a bit;
http://electroproducts.biz/

Then go here and read the papers;
http://www.integraltransference.com/

....and get back to me.....

[12345]

Hi John,

Thank you.  

I wish them the best of luck.  

MW

[dcollins]

My World wrote on Tue, 25 October 2005 18:30

What's not to understand?  It introduces transfer functions as part of the coding of the performance...nice to see...and nothing to be "afraid of."

I had to have my BS detector professionally repaired after that white paper.  Stuck right on the pin, it was...

Have you seen the graph?  Nothing?

Not even a weensie bit strange or nonsensical?

DC

[Level]

DC, WTF does this have to do with loudspeakers? Sounds like a witch hunt to me.

   

[minister]

even Thomas Kuhn abandoned using "paradigm" after a while....

that first graph is, um, how you say, um, err...yer telling me what now?

[dcollins]

Level wrote on Tue, 25 October 2005 20:24

DC, WTF does this have to do with loudspeakers? Sounds like a witch hunt to me.

Of course it does.

But since you did bring it up, I'll repeat my questions:

Describe the concept as simply as you can.

I think your first descrpition of how it works can't be the whole story, as it is like 50 years old.

His patent actually says ""Sonic Holy Grail" btw!

Or does the new paradigm need speakers at all?

Hmm.

DC

[dcollins]

minister wrote on Tue, 25 October 2005 21:07

that first graph is, um, how you say, um, err...yer telling me what now?

No matter how much you spend you can't get past 100-odd points of "Subjective Sonic Improvement"

"This one goes to 200."

DC