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Old 20th November 2012, 06:23 PM   #29621
gedlee is online now gedlee  United States
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Quote:
Originally Posted by SY View Post
Very well, but some quibbles: minimum phase can apply to nonlinear systems as well. The only requirement is that the phase be the derivative of the amplitude response wrt to frequency. And single valued functions indeed contain no loops, but if (for example) you have a 2d function unwinding in a 3d space, you can inadvertently have multiple values which are not loops in the 2d representation. Rooms have 3 dimensions (assuming the room size is time invariant!), the signal applied to them has one dimension plus time. So, no minimum phase (there's delays from reflections) and multiply valued (amplitude varies over space as well as time).
Since the concept of "Minimum phase" (MP) comes from "linear systems theory" it is dangerous to try and apply it to a nonlinear system. It may appear to be MP at one level and not at another one - so is it or is it not MP? It cannot be defined.

Also MP is a one dimensional concept and has no multidimensional meaning. A room can be MP from a source to one point and not be to a different point - again it cannot be defined.
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Old 20th November 2012, 06:42 PM   #29622
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Originally Posted by Wavebourn View Post
I thought you understand the difference between damping of ringing and equalizing the rest of response that can't be tamed mechanically?
I'm sorry Guru Wave. I'm just trying to add to my knowledge & experience from my own poor attempts at these techniques of which you are expert.

But I'm confused You say
  • You've tried the 0R1 resistor, PFB bla bla method
  • unlike other people, you find no distortion advantage
  • There is a need to make sure Impedance of speaker is flat
  • But no need to compensate for the bass resonance in a speaker which is surely the biggest feature in a speaker's impedance
  • That Audyssey solves everything
  • Audyssey DOESN'T solve everything
So can you explain what advantage your PFB, 0R1 resistor gives which Audyssey doesn't? Please use simple words suitable for dummies.

Do you see less ringing with the PFB? Is this acoustic or electrical? Is it at LF?

Messrs George & SY, I'll pontificate a little about Minimum Phase later cos I'm a pseudo guru on the subject .. especially as it pertains to speakers & rooms.
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Old 20th November 2012, 06:48 PM   #29623
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Originally Posted by kgrlee View Post
cos I'm a pseudo guru on the subject
You too ?
Did-you suffer slings and arrows ?

[edit] My English humor is pathetic.
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Last edited by Esperado; 20th November 2012 at 06:56 PM.
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Old 20th November 2012, 06:55 PM   #29624
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Originally Posted by Esperado View Post
You too ?
Did-you suffer slings and arrows ?
It is hard to tell what he suffered, but as the result he definitely acts as if he sees contests in any discussion.
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Old 20th November 2012, 07:13 PM   #29625
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Originally Posted by Wavebourn View Post
It is hard to tell what he suffered
Hard ? Mr kgrlee is the patient, not the disease.
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Old 20th November 2012, 07:18 PM   #29626
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Hard ? Mr kgrlee is the patient, not the disease.
Darn. I was hoping to use the phrase "your a disease, I'm the cure"

jn
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Old 20th November 2012, 07:28 PM   #29627
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Darn. I was hoping to use the phrase "your a disease, I'm the cure"
It is called Symbiosis
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Old 20th November 2012, 07:38 PM   #29628
PMA is offline PMA  Europe
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My favorite example. These signals differ only in phase of one of the spectral components. For absolutely identical amplitude spectra, we get totally different time domain signals. One of them will push the amp to clipping, the 2nd will not .....

One has to be careful when working with amplitude spectra only. It is only a half of the necessary information.
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Last edited by PMA; 20th November 2012 at 07:40 PM.
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Old 20th November 2012, 07:50 PM   #29629
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It is called Symbiosis
No. It's called Cobra, as in Cobretti.

jn
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Old 20th November 2012, 07:54 PM   #29630
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Quote removed from post that was removed.

I believe he was responding to your posting verbage with sarcasm. I must admit that what you wrote could be read several ways.

It would be nice if you both stood down. I enjoy tremendously the technical content you both provide, and wish it to remain above animosity.

thanks,

jn
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