Post # 48
I made statements about impedance of RF transmitters and RF transmission lines.
I stated that very few amplifiers are actually 8 Ohms output impedance, and very few speaker cables are actually 8 Ohms impedance; when measured from 20Hz to 20kHz.
I stated that all speaker cables of all length were reactive at some frequency.
I suggested that [some?] readers read up on transmission line theory [or reality if you look at it that way].
I mentioned that 1/4 wavelength of a speaker cable occurs at one, and only one frequency (if it actually is longe enough to be 1/4 wavelength at any audio frequency).
I mentioned that even fractional wavelengths (0.025 wavelength) of 20kHz was longer than many speaker cables. And that some systems and ears do not work well above 20kHz.
I stated that the “simple article”, 32 pages, mentioned by another poster, is not all that simple for some people.
I did not state that speaker cables do, or do not, make a difference in the sound you hear.
“Nuf Said about my Post # 48.
I made statements about impedance of RF transmitters and RF transmission lines.
I stated that very few amplifiers are actually 8 Ohms output impedance, and very few speaker cables are actually 8 Ohms impedance; when measured from 20Hz to 20kHz.
I stated that all speaker cables of all length were reactive at some frequency.
I suggested that [some?] readers read up on transmission line theory [or reality if you look at it that way].
I mentioned that 1/4 wavelength of a speaker cable occurs at one, and only one frequency (if it actually is longe enough to be 1/4 wavelength at any audio frequency).
I mentioned that even fractional wavelengths (0.025 wavelength) of 20kHz was longer than many speaker cables. And that some systems and ears do not work well above 20kHz.
I stated that the “simple article”, 32 pages, mentioned by another poster, is not all that simple for some people.
I did not state that speaker cables do, or do not, make a difference in the sound you hear.
“Nuf Said about my Post # 48.
My double blindfold tests were for testing 2 different characteristics,
First DBT. Three test days, etc. Successful.
1. The effects of [properly, and improperly] paralleling tubes.
These tests did not have a flaw.
For the 3 venues, 3 different sets of listeners, 3 different times of day, 3 different pairs of speakers, etc. the results were clear. One clear result in all 3 cases.
But run that test again . . . on a different day, different listeners, different time of day, different power mains, a fourth set of different speakers, etc. There might be a different outcome. It is up to you to repeat the test.
Second DBT. One test only. Not really successful, but cleared the way to the possibility of a successful test with another set-up, and different time.
2. The different sound of two amplifiers that had the same small signal input/driver tubes, a pair of 300B output tubes, and the same quiescent conditions of tube voltages, current, and load impedances presented to the output tube plates. The amplifiers were a mono block push pull, and a mono block parallel single ended.
This test had a big flaw, discovered when the test was conducted.
At no time did I do a double blindfold test of speaker cables.
I did not "attack" the idea that speaker cables do, or do not, make a difference in the sound you hear.
Some people have said that I am not normal, that other audiophiles are not normal, etc.
You pick your own normal listeners; I will not pick them for you.
First DBT. Three test days, etc. Successful.
1. The effects of [properly, and improperly] paralleling tubes.
These tests did not have a flaw.
For the 3 venues, 3 different sets of listeners, 3 different times of day, 3 different pairs of speakers, etc. the results were clear. One clear result in all 3 cases.
But run that test again . . . on a different day, different listeners, different time of day, different power mains, a fourth set of different speakers, etc. There might be a different outcome. It is up to you to repeat the test.
Second DBT. One test only. Not really successful, but cleared the way to the possibility of a successful test with another set-up, and different time.
2. The different sound of two amplifiers that had the same small signal input/driver tubes, a pair of 300B output tubes, and the same quiescent conditions of tube voltages, current, and load impedances presented to the output tube plates. The amplifiers were a mono block push pull, and a mono block parallel single ended.
This test had a big flaw, discovered when the test was conducted.
At no time did I do a double blindfold test of speaker cables.
I did not "attack" the idea that speaker cables do, or do not, make a difference in the sound you hear.
Some people have said that I am not normal, that other audiophiles are not normal, etc.
You pick your own normal listeners; I will not pick them for you.
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My Post # 56, copied in its entirety:
"Reverse Transfer Impedance of Coax.
Common Mode Rejection of Common Mode EMI
Differential Mode Rejection of Differential Mode EMI
And one of the worst Oxymorons ever, EMC, Electro Magnetic Compatibility.
In many situations, there is No Compatibility.
Passing EMI regulations hardly ever insures Compatibility.
I love reading Marketing's statement that their super low distortion amplifier is "Perfectly Stable Under All Conditions".
I have this bridge in Brooklyn I want to sell you."
Can you see any statement, or anything that I said: that speaker cables do, or do not, make a difference in the sound that you hear.
"Reverse Transfer Impedance of Coax.
Common Mode Rejection of Common Mode EMI
Differential Mode Rejection of Differential Mode EMI
And one of the worst Oxymorons ever, EMC, Electro Magnetic Compatibility.
In many situations, there is No Compatibility.
Passing EMI regulations hardly ever insures Compatibility.
I love reading Marketing's statement that their super low distortion amplifier is "Perfectly Stable Under All Conditions".
I have this bridge in Brooklyn I want to sell you."
Can you see any statement, or anything that I said: that speaker cables do, or do not, make a difference in the sound that you hear.
My Post # 60, repeated in its entirety:
"DSP_Geek,
You said:
"Shoot, almost any op-amp would be stable driving that load."
Thanks for reminding me of the LM301 Op Amp.
In order to drive a capacitive load . . .
The Op Amp output pin was connected to a 100 Ohm resistor, and through the 100 Ohm resistor to the capacitive load.
There were 2 negative feedback loops:
The AC feedback loop came from the Op Amp output pin (the near end of the 100 Ohm resistor).
The DC feedback loop came from the far end of the 100 Ohm resistor.
If a similar thing were done with tube amplifiers, it might be something like this . . .
Connect the output transformer secondary to a 1 Ohm resistor, and the other end of the 1 Ohm resistor to the output terminals on the back of the amplifier.
The global feedback would come from the output transformer secondary.
There would be no DC feedback loop (output transformers do not pass DC to the output).
And, the damping factor would be reduced because of the 1 Ohm series resistor (or from a lower series resistor value, such as 0.25 Ohm)."
Find the statement that speaker cables do, or do not sound different. It is Not in there.
"DSP_Geek,
You said:
"Shoot, almost any op-amp would be stable driving that load."
Thanks for reminding me of the LM301 Op Amp.
In order to drive a capacitive load . . .
The Op Amp output pin was connected to a 100 Ohm resistor, and through the 100 Ohm resistor to the capacitive load.
There were 2 negative feedback loops:
The AC feedback loop came from the Op Amp output pin (the near end of the 100 Ohm resistor).
The DC feedback loop came from the far end of the 100 Ohm resistor.
If a similar thing were done with tube amplifiers, it might be something like this . . .
Connect the output transformer secondary to a 1 Ohm resistor, and the other end of the 1 Ohm resistor to the output terminals on the back of the amplifier.
The global feedback would come from the output transformer secondary.
There would be no DC feedback loop (output transformers do not pass DC to the output).
And, the damping factor would be reduced because of the 1 Ohm series resistor (or from a lower series resistor value, such as 0.25 Ohm)."
Find the statement that speaker cables do, or do not sound different. It is Not in there.
My Post # 63 in its entirety,
"SMERSH,
A solid state amplifier with no output transformer, semiconductor junction capacitances that change versus signal voltage, and global negative feedback
Versus
A tube amplifier with output transformer and global negative feedback
When they both drive a capacitive load . . .
The two can respond completely differently, or very similar.
According to the amplifier models you pick . . .
Your Mileage Will Vary!
And if you make the circuitry respond to 10MHz, like your graphs, you may get AM stations, and HF Shortwave stations to listen to.
No tuner needed."
There is no statement that says speaker cables do, or do not, sound different.
Please bear with my, I am still trying to find my bad post.
"SMERSH,
A solid state amplifier with no output transformer, semiconductor junction capacitances that change versus signal voltage, and global negative feedback
Versus
A tube amplifier with output transformer and global negative feedback
When they both drive a capacitive load . . .
The two can respond completely differently, or very similar.
According to the amplifier models you pick . . .
Your Mileage Will Vary!
And if you make the circuitry respond to 10MHz, like your graphs, you may get AM stations, and HF Shortwave stations to listen to.
No tuner needed."
There is no statement that says speaker cables do, or do not, sound different.
Please bear with my, I am still trying to find my bad post.
My Post # 67 in its entirety:
"SMERSH,
You said:
"In the SSIF test of 19+29 kHz"
I believe that was a typo error.
Did you mean: "In the SSIF test of 19+20 kHz"
That works well for what you said next:
"an intermodulation level of approximately -144 dB was achieved for the difference component of 1 kHz."
(yes, 20kHz - 19kHz = 1kHz).
But I never had to use any signal sources that put full power out of the amplifier for a two tone test at 19kHz and 20kHz.
Other than Walter Carlos (Wendy Carlos), I am not aware of music that requires amplifier full power output at those frequencies.
Caution:
The use of a series inductor from the amplifier output, in order to fix a capacitive load problem . . . please remember that is a Resonant Series LC circuit.
A high Q inductor, and capacitance that is low dissipation factor will essentially present the amplifier output with dead short.
Test to see at what is the frequency of resonance (short, or extremely low impedance load).
The 33 Ohm resistor across the inductor that you show in your schematic may help to increase the series resonant impedance.
Calculate, build, test.
Then listen.
RFI?
Do not move to any of the US Navy's Megawatt transmitters that have Carrier Frequencies that are in the Audio Frequency range."
No statements were made by me to "attack" others who hear, or do not hear, differences in speaker cables.
"SMERSH,
You said:
"In the SSIF test of 19+29 kHz"
I believe that was a typo error.
Did you mean: "In the SSIF test of 19+20 kHz"
That works well for what you said next:
"an intermodulation level of approximately -144 dB was achieved for the difference component of 1 kHz."
(yes, 20kHz - 19kHz = 1kHz).
But I never had to use any signal sources that put full power out of the amplifier for a two tone test at 19kHz and 20kHz.
Other than Walter Carlos (Wendy Carlos), I am not aware of music that requires amplifier full power output at those frequencies.
Caution:
The use of a series inductor from the amplifier output, in order to fix a capacitive load problem . . . please remember that is a Resonant Series LC circuit.
A high Q inductor, and capacitance that is low dissipation factor will essentially present the amplifier output with dead short.
Test to see at what is the frequency of resonance (short, or extremely low impedance load).
The 33 Ohm resistor across the inductor that you show in your schematic may help to increase the series resonant impedance.
Calculate, build, test.
Then listen.
RFI?
Do not move to any of the US Navy's Megawatt transmitters that have Carrier Frequencies that are in the Audio Frequency range."
No statements were made by me to "attack" others who hear, or do not hear, differences in speaker cables.
My Post # 69, in its entirety:
"SMERSH,
My favorite: Rodrigues cartoon drawing was in Stereo Review:
Two men are attending a Classical concert with a full Orchestra.
One man faces the other and says: "My God, they are Clipping!"
My second favorite: Jack Elliano cartoon drawing was in Sound Practices or Vacuum Tube Valley, I can not remember which:
Scene: A detective and a reporter are looking at a dead man who is slumped over on a card table, with a Vacuum Tube stuck in his back.
Caption: He was shot with a 45.
Distortion?
What do you do when a recording has a very long, multiple measures, sustained 32 foot organ pipe note . . . if your walls are vibrating (resonating) at the 2nd Harmonic of the organ pipe Fundamental note?
Think Music Playback "System" (All components starting with the air pump and organ pipe, everything else along the way, and ending with the listening room walls."
I did not state that speaker cables do, or do not sound different.
"SMERSH,
My favorite: Rodrigues cartoon drawing was in Stereo Review:
Two men are attending a Classical concert with a full Orchestra.
One man faces the other and says: "My God, they are Clipping!"
My second favorite: Jack Elliano cartoon drawing was in Sound Practices or Vacuum Tube Valley, I can not remember which:
Scene: A detective and a reporter are looking at a dead man who is slumped over on a card table, with a Vacuum Tube stuck in his back.
Caption: He was shot with a 45.
Distortion?
What do you do when a recording has a very long, multiple measures, sustained 32 foot organ pipe note . . . if your walls are vibrating (resonating) at the 2nd Harmonic of the organ pipe Fundamental note?
Think Music Playback "System" (All components starting with the air pump and organ pipe, everything else along the way, and ending with the listening room walls."
I did not state that speaker cables do, or do not sound different.
My Post # 72 in its entirety:
"I am so sorry, rather than put that much time, effort, and money into my amplifiers, and into my listening room I am considering . . .
Going back to spending my time and effort to design and properly conduct double blindfold listening tests.
Man with one watch knows the time; man with two watches is never sure.
Without properly designed and properly conducted double blindfolded listening tests - - - we can only look at measurement results:
And . . . how many of you have ever conducted realistic measurements of an amplifier While it is connected to a real world loudspeaker?
(Not connected to a load resistor). Yes, easier said than done. You need some very expen$ive test and measurement equipment.
Gated Real Time Measurements, anybody?
Back to the drawing boards . . ."
No statement that different speaker cables do, or do not, sound different.
"I am so sorry, rather than put that much time, effort, and money into my amplifiers, and into my listening room I am considering . . .
Going back to spending my time and effort to design and properly conduct double blindfold listening tests.
Man with one watch knows the time; man with two watches is never sure.
Without properly designed and properly conducted double blindfolded listening tests - - - we can only look at measurement results:
And . . . how many of you have ever conducted realistic measurements of an amplifier While it is connected to a real world loudspeaker?
(Not connected to a load resistor). Yes, easier said than done. You need some very expen$ive test and measurement equipment.
Gated Real Time Measurements, anybody?
Back to the drawing boards . . ."
No statement that different speaker cables do, or do not, sound different.
I do not need to repeat any later posts than my Post # 72 on this thread.
Positron first posted on this thread at Post # 71.
In Post # 73 he responded to my earlier post # 72 with a question about DBT.
In all my later Posts up to Post # 75, he has copied my posts.
Now I responded by asking where I stated that different speaker cables do, or do not, sound difference.
Over and Out?
Positron first posted on this thread at Post # 71.
In Post # 73 he responded to my earlier post # 72 with a question about DBT.
In all my later Posts up to Post # 75, he has copied my posts.
Now I responded by asking where I stated that different speaker cables do, or do not, sound difference.
Over and Out?
Let’s analyze his responses on this page (5) and see what we come up with. He is claiming to place his posts in order number.
The # posts do appear in order except his post #90. Notice:
Let’s check his post #97.
“I do not need to repeat any later posts than my Post # 72 on this thread.
Positron first posted on this thread at Post # 71.
In Post # 73 he responded to my earlier post # 72 with a question about DBT.
What authorities can you present to support your opinion that dbts are scientific and accurate?
Would you please name all the variables involved in audio double blind testing?
Please explain how you perform your own dbt tests? Please be specific
I will be gone most of the weekend.”
In all my later Posts up to Post # 75, he has copied my posts.
Now I responded by asking where I stated that different speaker cables do, or do not, sound difference.
Over and Out? “
I already answered his question earlier concerning all the previous posts as well as mince since my post contained pertinent information
on how to make one's system more transparent.
He also stated that without properly conducted dbt tests we have to rely on measurements.
However, 6A3 has failed to produce:
A. Approximately how many subjects were in each of your three tests?
B. Please post any photos of the venues?
C. Approximately how many times did you A/B the subjects in your tests?
D. The time intervals between A/Bs?
E. How variably long in each position?
One would think 6A3 would at least have a copy of his article, magazine or data from when he performed the test, to provide information.
How can I or anyone else expect to believe you when you cannot be honest and forth coming.
pos
The # posts do appear in order except his post #90. Notice:
- he does not quote a post #, but it is a quote from somewhere. Where and why? First, pt 2.
- He posts #97 saying he does not need to quote after post #72.
- Now check post #89 and he quotes from post #48.
- Check post #91, and he quotes post #56.
- However, in post #90, he quotes from his post # 75, not between posts #48 or #56. He never posted anything about dbt tests between posts #48 and #56.
- He is changing the time frame of #75, attempting to place his quote Before my initial post #71. What happens.
- He can now distance his criticism of my post in particular since he falsely claims he posted it before my post
- If he wants to, he can falsely claim I started the attack against his dbt tests. Isn't that interesting.
Let’s check his post #97.
“I do not need to repeat any later posts than my Post # 72 on this thread.
Positron first posted on this thread at Post # 71.
In Post # 73 he responded to my earlier post # 72 with a question about DBT.
Do you have proof that a double blind test equates to normal listening?
What authorities can you present to support your opinion that dbts are scientific and accurate?
Would you please name all the variables involved in audio double blind testing?
Please explain how you perform your own dbt tests? Please be specific
I will be gone most of the weekend.”
In all my later Posts up to Post # 75, he has copied my posts.
Now I responded by asking where I stated that different speaker cables do, or do not, sound difference.
Over and Out? “
I already answered his question earlier concerning all the previous posts as well as mince since my post contained pertinent information
on how to make one's system more transparent.
He also stated that without properly conducted dbt tests we have to rely on measurements.
However, 6A3 has failed to produce:
- He refuses to present proof, 4th time now, that dbts equate to normal listening comparisons. Not surprising since not one time, over decades, has any dbt proponent presented any proof. None. Not surprising since not one proponent of dbt tests, over decades, has provided any proof that dbt testing equates to normal listening.
- Being an expert, 6A3 refuses to present even one variable besides sight. He developed his own dbt test but doesn’t know of another variable.Not even one.
A. Approximately how many subjects were in each of your three tests?
B. Please post any photos of the venues?
C. Approximately how many times did you A/B the subjects in your tests?
D. The time intervals between A/Bs?
E. How variably long in each position?
One would think 6A3 would at least have a copy of his article, magazine or data from when he performed the test, to provide information.
How can I or anyone else expect to believe you when you cannot be honest and forth coming.
pos
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Positron,
Your questions are good ones.
Let's discuss the Successful dbt test.
For now, I will Not further discuss the Flawed dbt listening test (proving the validity of a flawed dbt test is a fools errand).
1. There is no "validation proof" of the tests I ran, except what a knowledgeable reader can discern, by reading the article "Paralleling Tubes Effects" in Glass Audio Volume 12, Number 5, 2000. Let the reader decide.
Actually, the listeners, if you could get in touch with some of them, might remember and might have something to say.
Unfortunate for "late readers" I will not copy something that is copyrighted by the owner of that magazine buisiness, nor will I spend time and effort contacting him. Perhaps he is not even alive, 24 years later, the same may be true of some of the listeners.
I am Not a professor, but as some professors say, the research is up to you (Sell your possessions to get a copy of the magazine).
2. In one listening session, there were about 8 or 10 listeners. In another venue, there were 3 listeners, and the third venue, 2 listeners.
In one venue, the operator of the switches that activated the relays, became frustrated and mad when he could not hear any difference, so he threw the switches and umbelical cord across the room.
3. There were no photos of the listening sessions of the 3 venues.
4. The AB position and timing was up to the person that operated the switches, after initial listening tests were completed, others were allowed to run the switches.
Nobody knew what the switches were supposed to do during all the listening tests. They were told to try and hear any differences in the sound.
Telling someone what to listen for is a No No . . . I consider that to cause Bias; and to skew the results of the listening tests.
Likewise, the listeners were not told anything about the circuits, what circuit changes the switches did, etc., not before, and not during the tests.
But of course, anybody who operated the switches knew what position he put them in . . . but nothing of what the switches did.
With 2 switches, it was: both up; both down; 'one up and the other down; one down and the other up'.
Gee, thanks for making me think, I need to add a 3rd switch next time (like a placebo pill).
Would that make the test more valid, or would it make it less valid?
Again, that is up to you to decide, when you design your own dbt test.
5. Sometimes switching from any of the 4 modes to any other of the modes, was done with short intervals between mode changes, sometimes with long times between mode changes, sometimes a mix of the two.
It should be noted, that there were no discernible transients, volume changes, etc. when the switch positions were changed.
6. These were not 15 minute fly by night tests. The listening sessions were relaxed, different types of music were listened to.
Could this test be run for 4 hours straight . . . Hey, if you are listening for differences, you might get tired of listening, others might want to go well into the night.
You can please some of the people all of the time; you can please some of the people some of the time; but you can not please some people at all.
Ooops, those 3 types of people, disagrees with "Barth's Distinction", which states there are 2 types of people.
7. I am not a Moderator of diyAudio, so I can not answer your question of whether or not, dbt and abx is allowed to be discussed on this Forum.
8. For those of you who are willing to try, see if you can design a reasonably fair dbt listening test, and conduct the testing.
Then all who participated can discuss and analyze the listening results, and the validity or flaws of the test.
Have Fun!
I hope that satisfies some readers of this thread.
Your questions are good ones.
Let's discuss the Successful dbt test.
For now, I will Not further discuss the Flawed dbt listening test (proving the validity of a flawed dbt test is a fools errand).
1. There is no "validation proof" of the tests I ran, except what a knowledgeable reader can discern, by reading the article "Paralleling Tubes Effects" in Glass Audio Volume 12, Number 5, 2000. Let the reader decide.
Actually, the listeners, if you could get in touch with some of them, might remember and might have something to say.
Unfortunate for "late readers" I will not copy something that is copyrighted by the owner of that magazine buisiness, nor will I spend time and effort contacting him. Perhaps he is not even alive, 24 years later, the same may be true of some of the listeners.
I am Not a professor, but as some professors say, the research is up to you (Sell your possessions to get a copy of the magazine).
2. In one listening session, there were about 8 or 10 listeners. In another venue, there were 3 listeners, and the third venue, 2 listeners.
In one venue, the operator of the switches that activated the relays, became frustrated and mad when he could not hear any difference, so he threw the switches and umbelical cord across the room.
3. There were no photos of the listening sessions of the 3 venues.
4. The AB position and timing was up to the person that operated the switches, after initial listening tests were completed, others were allowed to run the switches.
Nobody knew what the switches were supposed to do during all the listening tests. They were told to try and hear any differences in the sound.
Telling someone what to listen for is a No No . . . I consider that to cause Bias; and to skew the results of the listening tests.
Likewise, the listeners were not told anything about the circuits, what circuit changes the switches did, etc., not before, and not during the tests.
But of course, anybody who operated the switches knew what position he put them in . . . but nothing of what the switches did.
With 2 switches, it was: both up; both down; 'one up and the other down; one down and the other up'.
Gee, thanks for making me think, I need to add a 3rd switch next time (like a placebo pill).
Would that make the test more valid, or would it make it less valid?
Again, that is up to you to decide, when you design your own dbt test.
5. Sometimes switching from any of the 4 modes to any other of the modes, was done with short intervals between mode changes, sometimes with long times between mode changes, sometimes a mix of the two.
It should be noted, that there were no discernible transients, volume changes, etc. when the switch positions were changed.
6. These were not 15 minute fly by night tests. The listening sessions were relaxed, different types of music were listened to.
Could this test be run for 4 hours straight . . . Hey, if you are listening for differences, you might get tired of listening, others might want to go well into the night.
You can please some of the people all of the time; you can please some of the people some of the time; but you can not please some people at all.
Ooops, those 3 types of people, disagrees with "Barth's Distinction", which states there are 2 types of people.
7. I am not a Moderator of diyAudio, so I can not answer your question of whether or not, dbt and abx is allowed to be discussed on this Forum.
8. For those of you who are willing to try, see if you can design a reasonably fair dbt listening test, and conduct the testing.
Then all who participated can discuss and analyze the listening results, and the validity or flaws of the test.
Have Fun!
I hope that satisfies some readers of this thread.
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Positron,
Your questions are good ones.
Let's discuss the Successful dbt test.
For now, I will Not further discuss the Flawed dbt listening test (proving the validity of a flawed dbt test is a fools errand).
1. There is no "validation proof" of the tests I ran, except what a knowledgeable reader can discern, by reading the article "Paralleling Tubes Effects" in Glass Audio Volume 12, Number 5, 2000. Let the reader decide.
Actually, the listeners, if you could get in touch with some of them, might remember and might have something to say.
Unfortunate for "late readers" I will not copy something that is copyrighted by the owner of that magazine buisiness, nor will I spend time and effort contacting him. Perhaps he is not even alive, 24 years later, the same may be true of some of the listeners.
I am Not a professor, but as some professors say, the research is up to you (Sell your possessions to get a copy of the magazine).
2. In one listening session, there were about 8 or 10 listeners. In another venue, there were 3 listeners, and the third venue, 2 listeners.
In one venue, the operator of the switches that activated the relays, became frustrated and mad when he could not hear any difference, so he threw the switches and umbelical cord across the room.
3. There were no photos of the listening sessions of the 3 venues.
4. The AB position and timing was up to the person that operated the switches, after initial listening tests were completed, others were allowed to run the switches.
Nobody knew what the switches were supposed to do during all the listening tests. They were told to try and hear any differences in the sound.
Telling someone what to listen for is a No No . . . I consider that to cause Bias; and to skew the results of the listening tests.
Likewise, the listeners were not told anything about the circuits, what circuit changes the switches did, etc., not before, and not during the tests.
But of course, anybody who operated the switches knew what position he put them in . . . but nothing of what the switches did.
With 2 switches, it was: both up; both down; 'one up and the other down; one down and the other up'.
Gee, thanks for making me think, I need to add a 3rd switch next time (like a placebo pill).
Would that make the test more valid, or would it make it less valid?
Again, that is up to you to decide, when you design your own dbt test.
5. Sometimes switching from any of the 4 modes to any other of the modes, was done with short intervals between mode changes, sometimes with long times between mode changes, sometimes a mix of the two.
It should be noted, that there were no discernible transients, volume changes, etc. when the switch positions were changed.
6. These were not 15 minute fly by night tests. The listening sessions were relaxed, different types of music were listened to.
Could this test be run for 4 hours straight . . . Hey, if you are listening for differences, you might get tired of listening, others might want to go well into the night.
You can please some of the people all of the time; you can please some of the people some of the time; but you can not please some people at all.
Ooops, those 3 types of people, disagrees with "Barth's Distinction", which states there are 2 types of people.
7. I am not a Moderator of diyAudio, so I can not answer your question of whether or not, dbt and abx is allowed to be discussed on this Forum.
8. For those of you who are willing to try, see if you can design a reasonably fair dbt listening test, and conduct the testing.
Then all who participated can discuss and analyze the listening results, and the validity or flaws of the test.
Have Fun!
I hope that satisfies some readers of this thread.
--------------------
I only asked for pertinent information of your dbts so I can continue to analyze your audio dbt. I have yet to see an audio dbt that is not
similar, only mentioning sight as a variable.
I wish to thank you for posting your additional dbt information, as your information supports that you know even the basics of how to perform a scientific audio dbt test. As indicated earlier, your test misleads consumers/members of the audio community with a false claim of accuracy. Your audio dbt test is skewed toward no sonic difference 100% of the time. The article will add nothing to help your case.
Thank you Smersh as well for revealing to us all that you also support such an anti scientific, skewed, inaccurate approach.
Let’s go through a few points.
Could this test be run for 4 hours straight."
Cochlea fatigue. 6A3 never accounted for cochlea fatigue! How many ABs? That is one of the very first basic variables to performing an accurate audio dbt test. The switcher nor subjects had any idea they were sabotaging the dbt test toward no sonic difference. And 6A3 glories over such, thought it was a great idea.
No wonder 6A3 refused to list any variables in his test besides sight. I hope he responds to this point.
No wonder he could not show any proof that dbt testing even equated to normal listening.
That reminds me of an individual, for years, who bet subjects they could not pass a dbt test at his venue. The subjects could run the test anyway they wanted just as 6A3 allowed (his Pt #4). Unfortunately, not one passed, but the individual made ~$150,000 off the subjects. Interestingly, the losers had no idea they sabotaged themselves, and they paid for it.
pos
Your questions are good ones.
Let's discuss the Successful dbt test.
For now, I will Not further discuss the Flawed dbt listening test (proving the validity of a flawed dbt test is a fools errand).
1. There is no "validation proof" of the tests I ran, except what a knowledgeable reader can discern, by reading the article "Paralleling Tubes Effects" in Glass Audio Volume 12, Number 5, 2000. Let the reader decide.
Actually, the listeners, if you could get in touch with some of them, might remember and might have something to say.
Unfortunate for "late readers" I will not copy something that is copyrighted by the owner of that magazine buisiness, nor will I spend time and effort contacting him. Perhaps he is not even alive, 24 years later, the same may be true of some of the listeners.
I am Not a professor, but as some professors say, the research is up to you (Sell your possessions to get a copy of the magazine).
2. In one listening session, there were about 8 or 10 listeners. In another venue, there were 3 listeners, and the third venue, 2 listeners.
In one venue, the operator of the switches that activated the relays, became frustrated and mad when he could not hear any difference, so he threw the switches and umbelical cord across the room.
3. There were no photos of the listening sessions of the 3 venues.
4. The AB position and timing was up to the person that operated the switches, after initial listening tests were completed, others were allowed to run the switches.
Nobody knew what the switches were supposed to do during all the listening tests. They were told to try and hear any differences in the sound.
Telling someone what to listen for is a No No . . . I consider that to cause Bias; and to skew the results of the listening tests.
Likewise, the listeners were not told anything about the circuits, what circuit changes the switches did, etc., not before, and not during the tests.
But of course, anybody who operated the switches knew what position he put them in . . . but nothing of what the switches did.
With 2 switches, it was: both up; both down; 'one up and the other down; one down and the other up'.
Gee, thanks for making me think, I need to add a 3rd switch next time (like a placebo pill).
Would that make the test more valid, or would it make it less valid?
Again, that is up to you to decide, when you design your own dbt test.
5. Sometimes switching from any of the 4 modes to any other of the modes, was done with short intervals between mode changes, sometimes with long times between mode changes, sometimes a mix of the two.
It should be noted, that there were no discernible transients, volume changes, etc. when the switch positions were changed.
6. These were not 15 minute fly by night tests. The listening sessions were relaxed, different types of music were listened to.
Could this test be run for 4 hours straight . . . Hey, if you are listening for differences, you might get tired of listening, others might want to go well into the night.
You can please some of the people all of the time; you can please some of the people some of the time; but you can not please some people at all.
Ooops, those 3 types of people, disagrees with "Barth's Distinction", which states there are 2 types of people.
7. I am not a Moderator of diyAudio, so I can not answer your question of whether or not, dbt and abx is allowed to be discussed on this Forum.
8. For those of you who are willing to try, see if you can design a reasonably fair dbt listening test, and conduct the testing.
Then all who participated can discuss and analyze the listening results, and the validity or flaws of the test.
Have Fun!
I hope that satisfies some readers of this thread.
--------------------
I only asked for pertinent information of your dbts so I can continue to analyze your audio dbt. I have yet to see an audio dbt that is not
similar, only mentioning sight as a variable.
I wish to thank you for posting your additional dbt information, as your information supports that you know even the basics of how to perform a scientific audio dbt test. As indicated earlier, your test misleads consumers/members of the audio community with a false claim of accuracy. Your audio dbt test is skewed toward no sonic difference 100% of the time. The article will add nothing to help your case.
Thank you Smersh as well for revealing to us all that you also support such an anti scientific, skewed, inaccurate approach.
Let’s go through a few points.
- The reader cannot intelligently decide if an audio dbt test is accurate because the only information provided is by 6A3, who cannot
- mention let alone address a single variable besides sight. (The variables he does not know are called “confounding variables”.)
- You continue to refuse to prove that dbt testing equates to normal listening. But then, so far no one has presented such proof over the decades, which tells us the lack of education the dbters have.
- You added switches, wire, connections, and associated parts, resistance, capacitance to the existing audio system/component under test, thus altering the test of the component. Just because you say it does not, does not make it so.
- This contains extra solder, which contains lead, tin and maybe more vs its natural connections in the audio system.
- What is the quality of the switch contacts?
- No timing done. That is really scientific.
- What other associated parts were used?
- How does 6A3 know the mental listening state of all the subjects. Magic. By the way, he only needs a very few “incorrect” A/Bs answers
- to fall below 95% confidence, thus claiming No sonic difference.
- 6A3s pt. #2, the switcher flung the jig across the room. Not surprising since 6A3 accounted for no variables, the test was skewed 100% towards no sonic difference. In other words the test was in “rigged”, unknowingly or knowingly, to no sonic difference.
- Back to point 4, 6A3 tells us, very generally, how the switcher and others flipped the switches, different intervals, lengths of music, beginning with music reference. And it was not 15 minutes, but let's quote:
Could this test be run for 4 hours straight."
Cochlea fatigue. 6A3 never accounted for cochlea fatigue! How many ABs? That is one of the very first basic variables to performing an accurate audio dbt test. The switcher nor subjects had any idea they were sabotaging the dbt test toward no sonic difference. And 6A3 glories over such, thought it was a great idea.
No wonder 6A3 refused to list any variables in his test besides sight. I hope he responds to this point.
No wonder he could not show any proof that dbt testing even equated to normal listening.
That reminds me of an individual, for years, who bet subjects they could not pass a dbt test at his venue. The subjects could run the test anyway they wanted just as 6A3 allowed (his Pt #4). Unfortunately, not one passed, but the individual made ~$150,000 off the subjects. Interestingly, the losers had no idea they sabotaged themselves, and they paid for it.
- Point 8. You can perform a dbt test, just like 6A3. However, you will sabotage your own dbt test toward no sonic difference. It is much much more involved than 6A3s amateurish attempt.
- I would like to thank 6A3 for providing information, that unfortunately demonstrates how unscientific, amateurish, skewed his (and typical) audio dbt testing is. That includes individuals attempting to perform their own audio dbt testing (with second individual).
pos
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wrenchchome,
The DCR, inductance, and capacitance of speaker cables do matter.
How much do they matter?
The amounts of those 3 quantities have More effect, or Less effect . . . depending on both the amplifier and the speaker that they connect together.
I hope that is a statement that many readers can agree on.
The DCR, inductance, and capacitance of speaker cables do matter.
How much do they matter?
The amounts of those 3 quantities have More effect, or Less effect . . . depending on both the amplifier and the speaker that they connect together.
I hope that is a statement that many readers can agree on.
Positron,
My answers to your questions and observations are contained between "My answer, text.
I only asked for pertinent information of your dbts so I can continue to analyze your audio dbt. I have yet to see an audio dbt that is not
similar, only mentioning sight as a variable.
*My answer: my only mentions of sight were: double "blindfold" test; and an archer who was blindfolded trying to hit a target.
Do those mean everybody had a blindfold over their eyes during the dbt listening test. I hope my words were not interpreted that way.*
I wish to thank you for posting your additional dbt information, as your information supports that you know even the basics of how to perform a scientific audio dbt test. As indicated earlier, your test misleads consumers/members of the audio community with a false claim of accuracy. Your audio dbt test is skewed toward no sonic difference 100% of the time. The article will add nothing to help your case.
*My answer: I fail to understand how asking listeners to listen for differences "is skewed in any direction" I never stated to the listeners that the dbt test was accurate, or not accurate. Unfortunately for the readers of this thread, none of the readers (as far as I know) were at VSAC 2008. If they were, and they did not pay the higher VSAC fees, they were not allowed in the breakfast music sessions; and dinner music sessions; nor in the seminar sessions, such as mine.
Thank you Smersh as well for revealing to us all that you also support such an anti scientific, skewed, inaccurate approach.
Let’s go through a few points.
Could this test be run for 4 hours straight."
Cochlea fatigue. 6A3 never accounted for cochlea fatigue! How many ABs? That is one of the very first basic variables to performing an accurate audio dbt test. The switcher nor subjects had any idea they were sabotaging the dbt test toward no sonic difference. And 6A3 glories over such, thought it was a great idea.
No wonder 6A3 refused to list any variables in his test besides sight. I hope he responds to this point.
No wonder he could not show any proof that dbt testing even equated to normal listening.
That reminds me of an individual, for years, who bet subjects they could not pass a dbt test at his venue. The subjects could run the test anyway they wanted just as 6A3 allowed (his Pt #4). Unfortunately, not one passed, but the individual made ~$150,000 off the subjects. Interestingly, the losers had no idea they sabotaged themselves, and they paid for it.
pos
*My answer: You are confusing my first series of 3 dbt tests at 3 venues. That was the successful dbt listening tests; no $$$ changed hands.
. . . Now, I will talk about the Flawed dbt test I ran at VSAC 2008:
I am an Amateur, I was never paid for doing dbt tests, other seminars, etc.
As to ear fatigue, I should have had an Audiologist, hearing testing machines, and a Doctor who could determine whether the listener was qualified, including the ear fatigue, or still valid non-fatigued hearing. How about using a Biorhythm expert to see what state the listeners were in.
With all those professionals, and the aforementioned professionals, we could sell tickets for medical tests. dbt, no! medical test event, yes!
As to paying for ALL the many seminars, NO seminar presenter was paid anything.
Only the Food contractors, the Piano player, Guitar Picking Champion, and one Jazz Group were paid (Oh, and the Vancouver Hilton).
Don't assume why the seminar presenters did their presentations.
The Carrot for the Organizers of VSAC 2008, was not the food and music, the Carrot was the Seminars; which the seminar presenters gave to the VSAC Organizers for free.
I guess that closes the issue: a flawed dbt listening test run for free.
Thanks to all the energetic readers of this complicated and long discussion.
6A3sUMMER
My answers to your questions and observations are contained between "My answer, text.
I only asked for pertinent information of your dbts so I can continue to analyze your audio dbt. I have yet to see an audio dbt that is not
similar, only mentioning sight as a variable.
*My answer: my only mentions of sight were: double "blindfold" test; and an archer who was blindfolded trying to hit a target.
Do those mean everybody had a blindfold over their eyes during the dbt listening test. I hope my words were not interpreted that way.*
I wish to thank you for posting your additional dbt information, as your information supports that you know even the basics of how to perform a scientific audio dbt test. As indicated earlier, your test misleads consumers/members of the audio community with a false claim of accuracy. Your audio dbt test is skewed toward no sonic difference 100% of the time. The article will add nothing to help your case.
*My answer: I fail to understand how asking listeners to listen for differences "is skewed in any direction" I never stated to the listeners that the dbt test was accurate, or not accurate. Unfortunately for the readers of this thread, none of the readers (as far as I know) were at VSAC 2008. If they were, and they did not pay the higher VSAC fees, they were not allowed in the breakfast music sessions; and dinner music sessions; nor in the seminar sessions, such as mine.
Thank you Smersh as well for revealing to us all that you also support such an anti scientific, skewed, inaccurate approach.
Let’s go through a few points.
- The reader cannot intelligently decide if an audio dbt test is accurate because the only information provided is by 6A3, who cannot
- mention let alone address a single variable besides sight. (The variables he does not know are called “confounding variables”.)
- My answer as I said above: sight had nothing to do with my dbt Listening test.
- You continue to refuse to prove that dbt testing equates to normal listening. But then, so far no one has presented such proof over the decades, which tells us the lack of education the dbters have.
- My answer: I am not very well read, I am not aware of any scientific test that either proves, or disproves, the difference between normal listeners, and Ab-normal listeners at a dbt listening test. When are people normal, and when are they Ab-normal, is a very large subject for scientists, psycologists, and psychiatrists.
- You added switches, wire, connections, and associated parts, resistance, capacitance to the existing audio system/component under test, thus altering the test of the component. Just because you say it does not, does not make it so.
- My answer: There were 2 very small size relays (open and short) one which connected very short wires from the input tube's plates, and the other relay connected very short wires to the output tube's plates. 4 states of connected or not connected, 00, 01, 10, and 11. It is important to know that the umbilical cord and the switches, were only connected between the relay coils, and the relay power supply. If you are concerned with the sound changes the relays, relay supply, umbilical cord, and switches made on the sound; . . . you might, or you might not, need to be worried about the wiring positions and lengths in your own amplifier.
- This contains extra solder, which contains lead, tin and maybe more vs its natural connections in the audio system.
- What is the quality of the switch contacts?
- No timing done. That is really scientific.
- What other associated parts were used?
- *My answer: solder, lead, and connections that are not in the signal path; except for a pair of short wires and quality relay contacts.
- The relays did not have to withstand high voltage differences, because the plates voltages were always close to each other. Now you know the total "added" parts in the signal path, 4 short wires, 2 small relays.
- total "added" parts that were Not in the signal path, 2 relays, and a relay power supply. Timing, yes I answered that it was variable in my earlier answers.*
- How does 6A3 know the mental listening state of all the subjects. Magic. By the way, he only needs a very few “incorrect” A/Bs answers
- to fall below 95% confidence, thus claiming No sonic difference.
- My answer: I should have employed a Psychiatrist, a Psychologist, and a Professional to run his Lie detector. Then, for the few listeners who were willing to go through that "gauntlet" of professionals, they would be allowed to listen. However, after that grueling, I expect they would Not be Normal listeners, but by then, they might be Ab-normal.
- 6A3s pt. #2, the switcher flung the jig across the room. Not surprising since 6A3 accounted for no variables, the test was skewed 100% towards no sonic difference. In other words the test was in “rigged”, unknowingly or knowingly, to no sonic difference.
- *My answer: The purpose of the dbt listener test was to prove, or to disprove, that there is a difference in the sound of non-parallel tubes, versus parallel tubes. 2 years before the dbt test was done, we believed that there is a difference in the sound of non-parallel versus parallel.
- We set about to prove the difference in sound was there. We found that by carefully following some good engineering rules, paralleling could be done with no difference in the sound, versus not paralling. Michelson and Morley ran an experiment to prove the existence of Aether (no not the the ether was used in early operating rooms). Michelson's and Morley's experiment Disproved the existence of Aether. We considered it an honor to be disproving what we originally thought, and reporting it for those who might be interested.*
- Back to point 4, 6A3 tells us, very generally, how the switcher and others flipped the switches, different intervals, lengths of music, beginning with music reference. And it was not 15 minutes, but let's quote:
Could this test be run for 4 hours straight."
Cochlea fatigue. 6A3 never accounted for cochlea fatigue! How many ABs? That is one of the very first basic variables to performing an accurate audio dbt test. The switcher nor subjects had any idea they were sabotaging the dbt test toward no sonic difference. And 6A3 glories over such, thought it was a great idea.
No wonder 6A3 refused to list any variables in his test besides sight. I hope he responds to this point.
No wonder he could not show any proof that dbt testing even equated to normal listening.
That reminds me of an individual, for years, who bet subjects they could not pass a dbt test at his venue. The subjects could run the test anyway they wanted just as 6A3 allowed (his Pt #4). Unfortunately, not one passed, but the individual made ~$150,000 off the subjects. Interestingly, the losers had no idea they sabotaged themselves, and they paid for it.
- Point 8. You can perform a dbt test, just like 6A3. However, you will sabotage your own dbt test toward no sonic difference. It is much much more involved than 6A3s amateurish attempt.
- I would like to thank 6A3 for providing information, that unfortunately demonstrates how unscientific, amateurish, skewed his (and typical) audio dbt testing is. That includes individuals attempting to perform their own audio dbt testing (with second individual).
pos
*My answer: You are confusing my first series of 3 dbt tests at 3 venues. That was the successful dbt listening tests; no $$$ changed hands.
. . . Now, I will talk about the Flawed dbt test I ran at VSAC 2008:
I am an Amateur, I was never paid for doing dbt tests, other seminars, etc.
As to ear fatigue, I should have had an Audiologist, hearing testing machines, and a Doctor who could determine whether the listener was qualified, including the ear fatigue, or still valid non-fatigued hearing. How about using a Biorhythm expert to see what state the listeners were in.
With all those professionals, and the aforementioned professionals, we could sell tickets for medical tests. dbt, no! medical test event, yes!
As to paying for ALL the many seminars, NO seminar presenter was paid anything.
Only the Food contractors, the Piano player, Guitar Picking Champion, and one Jazz Group were paid (Oh, and the Vancouver Hilton).
Don't assume why the seminar presenters did their presentations.
The Carrot for the Organizers of VSAC 2008, was not the food and music, the Carrot was the Seminars; which the seminar presenters gave to the VSAC Organizers for free.
I guess that closes the issue: a flawed dbt listening test run for free.
Thanks to all the energetic readers of this complicated and long discussion.
6A3sUMMER
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Much more could be said about proper DBT procedures. Its a big, complicated subject. Someone who used to frequent this forum was @Jakob2, whom so far as I know was involved in DBT testing, but probably in area of food taste most of the time (much more money is spent on that than is spent on hearing research). There are some books he recommended:
Perceptual Audio Evaluation–Theory, Method and Application, (2006) John Wiley & Sons
Sensory Discrimination Tests and Measurements: Sensometrics in Sensory Evaluation, (2015) John Wiley & Sons\
Some related reading:
https://en.wikipedia.org/wiki/Thurstonian_model
https://www.mdpi.com/2304-8158/11/3/255
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC10027970/
https://www.researchgate.net/public...Quality_In_Cars_By_The_Auralisation_Technique
Perceptual Audio Evaluation–Theory, Method and Application, (2006) John Wiley & Sons
Sensory Discrimination Tests and Measurements: Sensometrics in Sensory Evaluation, (2015) John Wiley & Sons\
Some related reading:
https://en.wikipedia.org/wiki/Thurstonian_model
https://www.mdpi.com/2304-8158/11/3/255
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC10027970/
https://www.researchgate.net/public...Quality_In_Cars_By_The_Auralisation_Technique
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Folks my response is in the [ for my replies to 6A3s misleading comments.
“*My answer: I fail to understand how asking listeners to listen for differences "is skewed in any direction"
“I never stated to the listeners that the dbt test was accurate, or not accurate.”
“. . . Now, I will talk about the Flawed dbt test I ran at VSAC 2008:
I am an Amateur, I was never paid for doing dbt tests, other seminars, etc.
As to ear fatigue, I should have had an Audiologist, hearing testing machines, and a Doctor who could determine whether the listener was qualified, including the ear fatigue, or still valid non-fatigued hearing. How about using a Biorhythm expert to see what state the listeners were in.”
“With all those professionals, and the aforementioned professionals, we could sell tickets for medical tests. dbt, no! medical test event, yes!”
“Thanks to all the energetic readers of this complicated and long discussion.”
“*My answer: I fail to understand how asking listeners to listen for differences "is skewed in any direction"
“I never stated to the listeners that the dbt test was accurate, or not accurate.”
“. . . Now, I will talk about the Flawed dbt test I ran at VSAC 2008:
I am an Amateur, I was never paid for doing dbt tests, other seminars, etc.
As to ear fatigue, I should have had an Audiologist, hearing testing machines, and a Doctor who could determine whether the listener was qualified, including the ear fatigue, or still valid non-fatigued hearing. How about using a Biorhythm expert to see what state the listeners were in.”
“With all those professionals, and the aforementioned professionals, we could sell tickets for medical tests. dbt, no! medical test event, yes!”
“Thanks to all the energetic readers of this complicated and long discussion.”
- Preparing for the “mechanics” of the listening test.
- Preparing for the mental aspects, the variables, which are many, for the listening test.
- 6A3 is completely ignorant of, except for sight.
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"But then there are the not so special conductors at either end of the cables in your system."
Are you meaning the connectors on the cable ends?
I ask because I solder one cable end directly to the crossover on my test speakers, eliminating plugs, jacks, solder connections.
The other end I connect bare, no plugs, to the amps output jacks. Thought about eliminating those jacks as well, but a mess soldering and unsoldering multiple times to test different parts in the amp.
If I may, what type of speaker cables are you using and how connecting?
cheers
pos
Are you meaning the connectors on the cable ends?
I ask because I solder one cable end directly to the crossover on my test speakers, eliminating plugs, jacks, solder connections.
The other end I connect bare, no plugs, to the amps output jacks. Thought about eliminating those jacks as well, but a mess soldering and unsoldering multiple times to test different parts in the amp.
If I may, what type of speaker cables are you using and how connecting?
cheers
pos
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