Wavebourn, if you look at the spectrum of the trumpet submitted by PMA, you will find the essence of Hirata distortion, which is something else that is difficult to understand. It is a spectrum that is uneven in + to - amplitude, BUT still DC stable.
john curl said:
There is no "Hirata distortion". In an AES article:
Study of Nonlinear Distortion in Audio Instruments
JAES Volume 29 Issue 9 pp. 607-610; September 1981
Public abstract:
Several types of nonlinear distortion in audio instruments are discussed using distortion models. An input pulse is characterized by an asymmetric waveform with zero dc component. Pulse responses corresponding to the s-type nonlinearity, clipping and crossover distortion of an amplifier, the transient distortion of a level compressor, and the s-type nonlinearity of a loudspeaker are illustrated with their spectra. One result shows that the nonlinearities of an amplifier and a loudspeaker are physically distinguishable.
all that Hirata did was to try to clasify the nonlinear distortions in:
- S-Type Nonlinearity
- Clipping
- Crossover
- Level compression
He defined a mathematical model for each and analyzed the impact on a pulse response. Funny enough, Hirata clearly states that:
In this paper several types of nonlinear distortions in audio instruments are discussed using an input pulse which is characterized by an asymmetric waveform with zero dc component
which is in total collision with what Pavel revealed in his FFTs 😀 😀 😀
His main result is:
It was shown that amplitude nonlinearities have an effect upon the spectrum at low frequency; in contrast, the displacement nonlinearity of a loudspeaker changes the spectrum at high frequency.
That's it!
In another AES article, Hirata developed a method of measuring distortions which was discussed here before. I've experimented with (I think Bob Cordell did as well) and found it being not sensitive enough to be useful in any modern, low THD IM TIM DIM PIM etc... audio amplifier:
http://www.diyaudio.com/forums/showthread.php?postid=1453596#post1453596
It was probably good enough in the 70's and 80's though.
Avoiding waiving "that flag" for brevity.
I have a Hirata box, and I have measured differences that make no impact with any other test.
I am pretty sure that I could 'improve' the CTC Blowtorch circuit to measure even lower distortion and have even greater 'Hirata' distortion. Why?
I am pleased that this Hirata distortion is being used to explain possible sound differences in electronics. I can't see it supporting cable directionality.
fredex said:
I can't see why we speak of Hirata... Thumps generated by acoustical sound sources lost in HPFs of recording consoles? Directivity of cables? Break-in of cables? Silver VS copper wires between meters of thin copper wire in pickup and high impedance input of JFET? Or what? Or there are other distortions more significantly playing the role except described by Hirata?
John, can you clarify, please?
Because the 2 types of distortion arejohn curl said:
mutually exclusive to some extent.
(at least instrumentationwise)
bear said:
there are those who either doubt or deny the reality
or possibility that this even exists as a real effect
🙂
Reality - what is?
The Reality defined as structure in material world, outside you
Something that can be defined in terms of atomic structures and molecules
or
The Reality as you perceive what is outside you
one 'reality' which is different to each and every one of us
....except for if we are one and same person
with the same genetics and have lived each day in identical envioronment
eating same food
to become identical Cloned Human Beings + Shaped by environment in 100 % same way
Does LOVE exsists?
even if it does,
does everybody feel LOVE
or know about it
what is real
in terms of 'sound'
what is sound
- it is fluctuations in pressure of air
in the room where your 2 air pressure sensors are located
like a fly have 2 antennas to sensor things
'sound' and 'light' sensors ('ears' & 'eyes')
is needed and were needed
in order to get information
in order to better the odds of survival
the most fit to environment
will live to be father & mothers
of next generation
the most fitted
have an apparatus
to interpret sensory information in most effective way
that is mainly in terms of matters for life & death
for survival or for nor survive
if sensors will trigger unfit behavior
the odds of survival will become worse
about 'hearing' it is same as with 'seeing'
if we really perceived correctly
our eyesight
what our eyes can sense
the world would be upside down
because this is what info your eyes will send
to your mind
we have to learn to interpret the world around us
no matter if the information is
sounds or visions
it has to be passed one mind
in order to be meaningful
and useful in any way
Lineup
in terms of 'sound'
what is sound
- it is fluctuations in pressure of air
in the room where your 2 air pressure sensors are located
like a fly have 2 antennas to sensor things
'sound' and 'light' sensors ('ears' & 'eyes')
is needed and were needed
in order to get information
in order to better the odds of survival
the most fit to environment
will live to be father & mothers
of next generation
the most fitted
have an apparatus
to interpret sensory information in most effective way
that is mainly in terms of matters for life & death
for survival or for nor survive
if sensors will trigger unfit behavior
the odds of survival will become worse
about 'hearing' it is same as with 'seeing'
if we really perceived correctly
our eyesight
what our eyes can sense
the world would be upside down
because this is what info your eyes will send
to your mind
we have to learn to interpret the world around us
no matter if the information is
sounds or visions
it has to be passed one mind
in order to be meaningful
and useful in any way
Lineup
bear said:
Bear, no offense meant, but there is lots and lots of well documented, scientifically tested and accepted stuff related to the difference between subjective perception and objective phenomena. Not just for audio but in many if not all fields of human activity. *You* may not be aware of it, and indeed most audiophiles seem not interested in how they hear what they hear.
But is it abjectly wrong to say that there isn't a well extablished theory, proven with documented tests, that explain it.
Jan Didden
C'mon, everyone can clearly see it's an artistic impression of the missing knob link :bs:
Mr Curl is saying he aims at balancing the levels of symmetrical and asymmetrical distortion ?
Mr Curl is saying he aims at balancing the levels of symmetrical and asymmetrical distortion ?
cable directionality
Here is another nice anecdote about cable directionality:
An acquaintance of mine (BS in electronics, pun intended) was unhappy with the sound of his system. When he connected the speaker cables the other way around, he observed a marked improvement.
That's not all. He also had a very plausible explanation: In the first case, the strands of the cable were twisted in the wrong direction, that is, counterclockwise when looking from amp to speaker. In the second case however, strand were twisted in the right direction, i.e. clockwise (again when looking from amp to speaker, of course)!
Then I really felt sorry for this poor fellow. What was wrong with his reasoning?
Here is another nice anecdote about cable directionality:
An acquaintance of mine (BS in electronics, pun intended) was unhappy with the sound of his system. When he connected the speaker cables the other way around, he observed a marked improvement.
That's not all. He also had a very plausible explanation: In the first case, the strands of the cable were twisted in the wrong direction, that is, counterclockwise when looking from amp to speaker. In the second case however, strand were twisted in the right direction, i.e. clockwise (again when looking from amp to speaker, of course)!
Then I really felt sorry for this poor fellow. What was wrong with his reasoning?
Re: cable directionality
I am quite sure most people realise that if you turn around any 'screw' like in this example where there is a spiral winding involved along an overall linear (but circular) path, it doesn't 'reverse' the direction of the 'screw'. It remains the same, either clockwise or anti-clockwise both ways around.
However, it is also valueless to quote one extreme example of an error or basic misunderstanding like this, and it proves absolutely nothing other than the fact that the person invoved was wrong if he believed this was the cause of 'directionality' in his cables.
It certainly does not indicate that there is no such thing as cable 'directionality', so I cannot understand why this is relevant to the discussion.
Regards,
Edmond Stuart said:
I am quite sure most people realise that if you turn around any 'screw' like in this example where there is a spiral winding involved along an overall linear (but circular) path, it doesn't 'reverse' the direction of the 'screw'. It remains the same, either clockwise or anti-clockwise both ways around.
However, it is also valueless to quote one extreme example of an error or basic misunderstanding like this, and it proves absolutely nothing other than the fact that the person invoved was wrong if he believed this was the cause of 'directionality' in his cables.
It certainly does not indicate that there is no such thing as cable 'directionality', so I cannot understand why this is relevant to the discussion.
Regards,
Re: Re: cable directionality
Bob,
Whether extreme or not, this is a perfect example of someone who thought he has heard an improvement, while it is crystal clear that in reality there was no difference at all.
As the majority of believers in directionality and comparable BS most likely suffers from the same kind of hallucinations and lack of common sens, I think aforementioned example is very relevant.
Bob,
Whether extreme or not, this is a perfect example of someone who thought he has heard an improvement, while it is crystal clear that in reality there was no difference at all.
As the majority of believers in directionality and comparable BS most likely suffers from the same kind of hallucinations and lack of common sens, I think aforementioned example is very relevant.
Re: Re: Re: cable directionality
Hi Edmund,
Assuming what you originally said is the entire story, what you now suggest isn't supported by the details of this anecdote of yours.
Your friend's mistake in assuming that the (imaginary) change of rotation of the 'field' (or whatever) when he reversed his cables only suggests that he was deluded with his explanatory 'hypothesis'.
With respect, it certainly does not indicate that he didn't experience any sonic changes when he did the cable reversal, which was why I originally commented.
I don't see how anyone can reach the conclusion after what you have said that "it is crystal clear that in reality there was no difference at all", nor that there are any "hallucinations" involved over whether or not he actually heard some differences.
Regards,
Edmond Stuart said:
Hi Edmund,
Assuming what you originally said is the entire story, what you now suggest isn't supported by the details of this anecdote of yours.
Your friend's mistake in assuming that the (imaginary) change of rotation of the 'field' (or whatever) when he reversed his cables only suggests that he was deluded with his explanatory 'hypothesis'.
With respect, it certainly does not indicate that he didn't experience any sonic changes when he did the cable reversal, which was why I originally commented.
I don't see how anyone can reach the conclusion after what you have said that "it is crystal clear that in reality there was no difference at all", nor that there are any "hallucinations" involved over whether or not he actually heard some differences.
Regards,
Re: Re: Re: Re: cable directionality
Why would you think that me or anybody else should attempt to prove the statement "cables are directional"?
Why would you think that me or anybody else should take JC's, PMA's, yours, or anybody else "cable directionality" word as gospel truth, without a shred of proof beyond a blank statement?
Have you ever heard of "cable directionality" effects in any other fields but audio? If not, why would you think cables are directional for the use of audio only, and not in video, radioastronomy or your beer cooler?
Bobken said:
Why would you think that me or anybody else should attempt to prove the statement "cables are directional"?
Why would you think that me or anybody else should take JC's, PMA's, yours, or anybody else "cable directionality" word as gospel truth, without a shred of proof beyond a blank statement?
Have you ever heard of "cable directionality" effects in any other fields but audio? If not, why would you think cables are directional for the use of audio only, and not in video, radioastronomy or your beer cooler?
PMA said:
With all due respect mathematical artifacts due to the way one choses to take your sample are not proof of anything. I could turn on a 60Hz sine wave wait 10 minutes and take a short sample. If I catch an odd portion of a cycle there is a DC component in the FFT. In general you can't sychronously sample music so a random grab will almost always have something in bin zero.
Directionality in a uniform media would violate superposition.
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