The Sound Of Hard Drive Enclosures

1246

Comments

  • DarqueKnight
    DarqueKnight Posts: 6,765
    edited March 2017
    K_M wrote: »
    You are obviously missing the humor I intended. Completely.

    Oh, I see, now you are using the old, "I was just playing" dodge with a side order of "gaslighting".

    For those unfamiliar with the term:

    "Gaslighting is a form of manipulation that seeks to sow seeds of doubt in a targeted individual or members of a group, hoping to make targets question their own memory, perception, and sanity."


    https://en.wikipedia.org/wiki/Gaslighting
    K_M wrote: »
    Again, where did you get this training?

    Have you passed tests or are certified?
    Is this a seminar, something online, something you created yourself?

    Like are you simply "willing" it away in your mind?

    All of these questions have been addressed thoroughly in this, and other, threads.

    I understand that you are frustrated by your inability to scientifically impugn my positions and that, to a much greater degree, you are embarrassed by your inability to scientifically articulate and justify your positions. As is typical, all that is left for you now is personal attacks to deflect from your inadequacies.

    I further understand that insults are the last refuge of the outwitted. Since this thread has gotten too "hot" for you, perhaps you should move on.
    Proud and loyal citizen of the Digital Domain and Solid State Country!
  • I wonder how a researcher would evaluate what method of bias reduction is most effective.

    Still haven't seen where taking away the knowledge of what devices are under testing is problematic.
  • K_M
    K_M Posts: 1,629
    K_M wrote: »
    You are obviously missing the humor I intended. Completely.

    Oh, I see, now you are using the old, "I was just playing" dodge with a side order of "gaslighting".

    For those unfamiliar with the term:

    "Gaslighting is a form of manipulation that seeks to sow seeds of doubt in a targeted individual or members of a group, hoping to make targets question their own memory, perception, and sanity."


    https://en.wikipedia.org/wiki/Gaslighting
    K_M wrote: »
    Again, where did you get this training?

    Have you passed tests or are certified?
    Is this a seminar, something online, something you created yourself?

    Like are you simply "willing" it away in your mind?

    All of these questions have been addressed thoroughly in this, and other, threads.

    I understand that you are frustrated by your inability to scientifically impugn my positions and that, to a much greater degree, you are embarrassed by your inability to scientifically articulate and justify your positions. As is typical, all that is left for you now is personal attacks to deflect from your inadequacies.

    I further understand that insults are the last refuge of the outwitted. Since this thread has gotten too "hot" for you, perhaps you should move on.

    I made no insults at all.

    I have no position for nor against you. I asked a question multiple times, do not see an answer.

    Again, How and where did you do this training. You elaborate on everything but this one simple question.

    Are you not able to answer it for some reason?
  • DarqueKnight
    DarqueKnight Posts: 6,765

    Still haven't seen where taking away the knowledge of what devices are under testing is problematic.

    It is not that it's problematic, it is that it is unnecessary. I have already provided the scientific basis for this. Good luck.


    Proud and loyal citizen of the Digital Domain and Solid State Country!

  • Still haven't seen where taking away the knowledge of what devices are under testing is problematic.

    It is not that it's problematic, it is that it is unnecessary. I have already provided the scientific basis for this. Good luck.


    You really haven't supported your position. I've asked two times now how a 30% bias reduction (your quote) is equivalent to removing knowledge of the DUT from the participant.

    Mark Waldrep released tracks @ various encoding formats and participants didn't need to know what encoding rates the various tracks were to properly evaluate. This blinding was actually key to this.

  • DarqueKnight
    DarqueKnight Posts: 6,765
    K_M wrote: »
    I asked a question multiple times, do not see an answer.

    Again, How and where did you do this training. You elaborate on everything but this one simple question.

    Are you not able to answer it for some reason?

    Didn't I say that I had already answered this question IN THIS THREAD? :s

    Are you not able to read and comprehend for some reason? :s

    So sad.
    Proud and loyal citizen of the Digital Domain and Solid State Country!
  • DarqueKnight
    DarqueKnight Posts: 6,765
    edited March 2017
    You really haven't supported your position. I've asked two times now how a 30% bias reduction (your quote) is equivalent to removing knowledge of the DUT from the participant.

    Now you have given me cause to wonder if your forum screen name is in reference to your IQ.

    As with any concept, some people will "get it" and others won't, no matter how many times and ways the concept is explained.

    Again, good luck with your studies.
    Proud and loyal citizen of the Digital Domain and Solid State Country!
  • ZLTFUL
    ZLTFUL Posts: 5,651
    Fun fact, look at the way a symphony orchestra is laid out.
    The reason it is laid out in such a manner is because certain instruments produce certain sounds in the frequency range and thus arrive at the listener at different times. Arranging the symphony in this way reduces the differences so that these sounds arrive at the listener as closely to the same time as possible.

    To think that there is no such thing as imaging or soundstage in a live performance (and in the stereophonic methods of *reproducing* said stereophonic performances) is naive at best and flat out ignorant at worst.

    "Some people find it easier to be conceited rather than correct."

    "Unwad those panties and have a good time man. We're all here to help each other, no matter how it might appear." DSkip
  • K_M
    K_M Posts: 1,629
    edited March 2017
    K_M wrote: »
    I asked a question multiple times, do not see an answer.

    Again, How and where did you do this training. You elaborate on everything but this one simple question.

    Are you not able to answer it for some reason?

    Didn't I say that I had already answered this question IN THIS THREAD? :s

    Are you not able to read and comprehend for some reason? :s

    So sad.

    Sorry, only found a Google link to "Debiasing", you provided, and some stuff you copied and pasted from the google article itself.

    No actual mention of what training you took, where, when, or what it involved.

    Is there another reference you made that answers that specifically, I am not seeing?
  • You really haven't supported your position. I've asked two times now how a 30% bias reduction (your quote) is equivalent to removing knowledge of the DUT from the participant.

    Now you have given me cause to wonder if your forum screen name is in reference to your IQ.

    As with any concept, some people will "get it" and others won't, no matter how many times and ways the concept is explained.

    Again, good luck with your studies.

    Say you have a person/s that think blue jacketed cables sound terrible

    Do you train them to de-bias that thinking?

    Do you simply remove from them the knowledge of the color of the cable?
  • K_M
    K_M Posts: 1,629
    You really haven't supported your position. I've asked two times now how a 30% bias reduction (your quote) is equivalent to removing knowledge of the DUT from the participant.

    Now you have given me cause to wonder if your forum screen name is in reference to your IQ.

    As with any concept, some people will "get it" and others won't, no matter how many times and ways the concept is explained.

    Again, good luck with your studies.

    Is it really necessary to insult people that are merely discussing something with you?

    Seriously, you lost me totally with this comment. Uncalled for.
    Get some sensitivity training.

    Gonna find it very hard to take you seriously, after rude comments to me and that guy.
  • ZLTFUL
    ZLTFUL Posts: 5,651
    Says the biggest passive-aggressive insulter of them all. @K_M you really need some time for self inspection before you can start throwing around hypocritical accusations.
    "Some people find it easier to be conceited rather than correct."

    "Unwad those panties and have a good time man. We're all here to help each other, no matter how it might appear." DSkip
  • DarqueKnight
    DarqueKnight Posts: 6,765
    Getting back to the subject of hard drive enclosures:

    I made the following inquiry to Sabrent about a upgrade power supply for my enclosure and their response is shown:

    Question from me:

    "I am using my EC-UEIS7 to house a 2TB hard drive that contains digital music files. The enclosure is connected by eSATA cable to a music server. I would like to upgrade the power supply to a higher quality, low noise power supply. Do you offer such a power supply or can you suggest options that will work with the EC-UEIS7?"

    Answer from Sabrent:

    "Thank you for contacting us at Sabrent.
    Sorry but we only recommend using it with the included power.
    The power adapter shouldn’t be making any sounds.
    The enclosure does have a fan so it will make a little noise."


    ***Big Sigh*** :/
    Proud and loyal citizen of the Digital Domain and Solid State Country!
  • Why don't you do away with physical connection and go with network attached storage and wireless?

    If you are that concerned about electrical noised and mixed signal systems wireless seems like a really good approach.

  • txcoastal1
    txcoastal1 Posts: 13,300
    Possibly dependent on the DSD rips
    2-channel: Modwright KWI-200 Integrated, Dynaudio C1-II Signatures
    Desktop rig: LSi7, Polk 110sub, Dayens Ampino amp, W4S DAC/pre, Sonos, JRiver
    Gear on standby: Melody 101 tube pre, Unison Research Simply Italy Integrated
    Gone to new homes: (Matt Polk's)Threshold Stasis SA12e monoblocks, Pass XA30.5 amp, Usher MD2 speakers, Dynaudio C4 platinum speakers, Modwright LS100 (voltz), Simaudio 780D DAC

    erat interfectorem cesar et **** dictatorem dicere a
  • txcoastal1 wrote: »
    Possibly dependent on the DSD rips

    You can get very high throughput, and certainly low latency wireless.

    I'm hitting on average 38MB/s with a $14 adapter with ping rates sub 1ms.
  • txcoastal1
    txcoastal1 Posts: 13,300
    Many DAC's will only see DSD-64 via NAS
    Many DACs only see DSD via USB
    2-channel: Modwright KWI-200 Integrated, Dynaudio C1-II Signatures
    Desktop rig: LSi7, Polk 110sub, Dayens Ampino amp, W4S DAC/pre, Sonos, JRiver
    Gear on standby: Melody 101 tube pre, Unison Research Simply Italy Integrated
    Gone to new homes: (Matt Polk's)Threshold Stasis SA12e monoblocks, Pass XA30.5 amp, Usher MD2 speakers, Dynaudio C4 platinum speakers, Modwright LS100 (voltz), Simaudio 780D DAC

    erat interfectorem cesar et **** dictatorem dicere a
  • This content has been removed.
  • DarqueKnight
    DarqueKnight Posts: 6,765
    edited March 2017
    Why don't you do away with physical connection and go with network attached storage and wireless?

    If you are that concerned about electrical noised and mixed signal systems wireless seems like a really good approach.

    A wireless NAS is something on my list of future investigations.

    Wireless transmission has its own set of noise issues, although I am not sure they are of the type that would affect sound quality.

    The noise I was concerned about in the previous post was electrical noise from the power supply.
    DarqueKnight:

    I've been reading through some of your claims that "through training" our bias can be removed. This statement is too strong. Through training, we may reduce, but certainly not eliminate our bias. Nor can we eliminate our past history and our best guess judgments from coloring how we approach today and the future.

    When I was in accounting and auditing, we followed GAAP and strict auditing procedures. Everything I did was reviewed by at least one other professional. The entire audit was planned, supervised, and carefully reviewed. We documented everything. Despite our best efforts, we could not eliminate the risk of audit error. We could only reduce it.

    It appears that you might be confusing bias with error. Bias is the tendency of a procedure or process to over-estimate or under-estimate a measurement. Error is the amount of deviation from a true value. An accounting error would not be an example of bias unless the accounting process had a tendency to consistently over-estimate or under-estimate true values.

    Again, for the 1,000,000th time, I never said that eliminating bias was necessary. It is the EFFECT of bias that must be removed. It is the same principle as being inside an air conditioned office and working comfortably during a 100 degree, 100% humidity day. Did you remove the sun's heat? No. You removed the effect of the sun's heat on your body.

    With regard to audio, the basic measurements I use are:

    1. Height, width, and depth of sound stage.
    2. Clarity and detail of sound images.
    3. Palpability (realistic sonic weight) of sound images.
    4. Tactile sensation.
    5. Bass quality: weight, articulation, and detail.

    In view of the above measurements, the cost, appearance, and brand name of an audio component are irrelevant. If a less expensive, less attractive, less prestigious brand of amplifier generates a larger, more life size, more lifelike, more holographic, more three dimensional sound stage than an uber-expensive, diamond encrusted, boutique brand amplifier, I am not going to lie to myself and say the lateral width of the expensive amp's sound stage is 20 feet when I know I don't hear anything outside of 15 feet.

    It also appears that you did not really read my prior comments. Maybe you just glanced over them. I plainly stated what my biases were and what my selection criteria were. With regard to the subject of this thread, I ended up choosing equipment alternatives, based on the selection criteria, that were in opposition to my personal biases. This is not the only thread where I have documented such an occurrence.

    The issue that all you have, that are gagging and choking on these concepts, is that you do not understand how stereophonic audio systems work. Without that understanding, you don't know what performance parameters to test. If you don't know what performance parameters to test, you can't possibly know what kind of test to use.

    That's all there is to it.
    Proud and loyal citizen of the Digital Domain and Solid State Country!
  • littlewoodboats
    littlewoodboats Posts: 823
    edited March 2017
    Its not an attack Ray they just don't get your thought process. The most briliant person I have met in my life was an EE. I can do analytical calculus in my head and am certain in your presence I am a moron.

    In Ray's own system he is able to hear differences and posts his thoughts.

    Ray simply offers his thoughts. Take them for what they are worth or don't but to argue testing methods with the man when he is testing within his own system is just silly.

    Thought and Bias are two different things. I "think" my OPPO is nice. If you brought your player to my house for a listen using the same media do you think we would both hear the same differences? In a perfect world we should. If I brought my player to your system could we sit and listen then hear the same differences? We should.

    I "think" my OPPO is nice but would a "bias" preclude me from hearing differences in the players?

    I love Ray for all he brings to the forum and at the same time thank the gods I do not have his critical listening thought process.

    Post edited by littlewoodboats on
  • DarqueKnight
    DarqueKnight Posts: 6,765

    Ray simply offers his thoughts. Take them for what they are worth or don't but to argue testing methods with the man when he is testing within his own system is just silly.

    There is nothing wrong with arguing about testing methods, as long as you can articulate a rational basis for what you are doing or what you believe. The silliness comes from saying things like "I tried ________ once and it didn't work, so I don't believe it worked for you" or "I believe ___________ because I read it on a popular website", or "I believe _________ because a lot of people accept it as truth".

    I always appreciate it when people take the time to write a thoughtful review. I never take it as they are saying that their results are what I, or everyone else, can achieve in their systems. If it sounds interesting, and plausible, I take their experiences as something that I might achieve.

    The enjoyment of stereo is not about proving to other people that you can hear certain things. It is about creating a reasonably accurate and satisfying reproduction of a musical performance in the home. That is why I disregard "reviews" and "technical articles" and "tests" that mention nothing at all about stereophonic performance.

    Proud and loyal citizen of the Digital Domain and Solid State Country!
  • Absolute_Zero
    Absolute_Zero Posts: 72
    edited March 2017

    Ray simply offers his thoughts. Take them for what they are worth or don't but to argue testing methods with the man when he is testing within his own system is just silly.

    There is nothing wrong with arguing about testing methods, as long as you can articulate a rational basis for what you are doing or what you believe. The silliness comes from saying things like "I tried ________ once and it didn't work, so I don't believe it worked for you" or "I believe ___________ because I read it on a popular website", or "I believe _________ because a lot of people accept it as truth".

    I always appreciate it when people take the time to write a thoughtful review. I never take it as they are saying that their results are what I, or everyone else, can achieve in their systems. If it sounds interesting, and plausible, I take their experiences as something that I might achieve.

    The enjoyment of stereo is not about proving to other people that you can hear certain things. It is about creating a reasonably accurate and satisfying reproduction of a musical performance in the home. That is why I disregard "reviews" and "technical articles" and "tests" that mention nothing at all about stereophonic performance.

    Dr. Sean Olive (Harman Listening Lab) talks about The Dishonesty of Sighted Evaluation:

    A Blind Versus Sighted Loudspeaker Experiment

    This question was tested in 1994, shortly after I joined Harman International as Manager of Subjective Evaluation [1]. My mission was to introduce formalized, double-blind product testing at Harman. To my surprise, this mandate met rather strong opposition from some of the more entrenched marketing, sales and engineering staff who felt that, as trained audio professionals, they were immune from the influence of sighted biases. Unfortunately, at that time there were no published scientific studies in the audio literature to either support or refute their claims, so a listening experiment was designed to directly test this hypothesis. The details of this test are described in references 1 and 2.

    Just wanted to post another point of view.




  • This content has been removed.
  • K_M
    K_M Posts: 1,629
    Its not an attack Ray they just don't get your thought process. The most briliant person I have met in my life was an EE. I can do analytical calculus in my head and am certain in your presence I am a moron.

    No, even far simpler. People do not ever all agree. Just how it is.
    Go to other audio forums, views are all over the place.

    Has nothing to do with "Getting" someone's thought process, has to do with the fact that everyone will never agree on many things.

    Has virtually nothing to do with brilliance or intelligence either.
    Discussing and debating ideas and theories and methods can be fun and educational.
    There is no totally right and wrong answer or method.





  • lightman1
    lightman1 Posts: 10,789
    hot dogs with ketchup
  • txcoastal1
    txcoastal1 Posts: 13,300
    edited March 2017
    lightman1 wrote: »
    hot dogs with ketchup

    WRONG....NEVER...MUSTARD YOU S-CH-MUCK...ONLY MUSTARD :p
    https://youtu.be/dqu7PTwb0go
    2-channel: Modwright KWI-200 Integrated, Dynaudio C1-II Signatures
    Desktop rig: LSi7, Polk 110sub, Dayens Ampino amp, W4S DAC/pre, Sonos, JRiver
    Gear on standby: Melody 101 tube pre, Unison Research Simply Italy Integrated
    Gone to new homes: (Matt Polk's)Threshold Stasis SA12e monoblocks, Pass XA30.5 amp, Usher MD2 speakers, Dynaudio C4 platinum speakers, Modwright LS100 (voltz), Simaudio 780D DAC

    erat interfectorem cesar et **** dictatorem dicere a
  • machone
    machone Posts: 1,510
    DK,
    Why can't you purchase a better power supply with the same voltage/amps and build a cable?
    My experience has been very positive with cleaner/faster power supplies.
    Mojo Audio Illuminati v3>>Quantum Byte w/LMS>>Rpi/PiCoreplayer>> Starlight 7 USB >> Mojo Audio Mystique v2 SE>>ModWright SWL 9.0 SE Signature>>Hafler DH-500 Amp+ (Musical Concepts Fully Modded)>>
    SRS 2.3TL (Fully Modded)...Velodyne Optimum 8 subwoofer
    1KVA Dreadnought

    Marantz SA 8005
    Pioneer PLX-1000 Turntable - Shure SC35C/N35X - V15III/VN35HE
    Yamaha TX-540 Tuner...Sony BDP-S570
    Sony PS4

    Separate subpanel with four dedicated 20 amp circuits.
    1. Amplification 2. Analog 3. Digital 4. Video

    "All THAT IS LOST FROM THE SOURCE IS LOST FOREVER"
  • DarqueKnight
    DarqueKnight Posts: 6,765
    Dr. Sean Olive (Harman Listening Lab) talks about The Dishonesty of Sighted Evaluation:

    A Blind Versus Sighted Loudspeaker Experiment

    This question was tested in 1994, shortly after I joined Harman International as Manager of Subjective Evaluation [1]. My mission was to introduce formalized, double-blind product testing at Harman. To my surprise, this mandate met rather strong opposition from some of the more entrenched marketing, sales and engineering staff who felt that, as trained audio professionals, they were immune from the influence of sighted biases. Unfortunately, at that time there were no published scientific studies in the audio literature to either support or refute their claims, so a listening experiment was designed to directly test this hypothesis. The details of this test are described in references 1 and 2.

    Just wanted to post another point of view.

    Hate to burst your bubble again, but... (apologies to the short attention span readers) ...

    For future reference, it would be great if you would use the forum's search function prior announcing a "revelation". Similar to your "news" about Bell Labs doing ABX tests (for monophonic audio evaluation), the Olive article you just cited, and the 1994 paper it is based on, has been discussed before in this thread from 2012:

    http://forum.polkaudio.com/discussion/131718/stupid-things-you-hear-from-the-dbt-null-test-crowd/p1

    If you read carefully, you will find that your views and comments in this thread mirror those of forum member Syndil's.

    I provided a brief critique of the Olive/Toole 1994 paper on page 8 of the thread referenced above, please pay particular attention to the parts highlighted and underlined in red:

    Olive said they were trained audio professionals, not trained listeners. Every "medical professional" is not trained in the practice of medicine. Nurses, EMT's and medical doctors are all medical professionals, but all do not have the same medical training and experience. Saying that someone is a trained medical professional is not the same as saying they are trained in brain surgery. Saying that someone is an audio professional is not the same as saying they are trained in stereophonic evaluation.

    Actually, the paper ("Hearing is Believing vs. Believing is Hearing: Blind vs. Sighted Listening Tests, and Other Interesting Things", Floyd Toole and Sean Olive, 1994) makes it very clear that the difference between being an experienced stereo listener is quite different from being a trained stereo evaluator:

    "Experience is one of those variables among listeners that is very difficult to quantify. For example, musicians are experienced listeners but, is experience in focusing on musical attributes equivalent to that of focusing on timbral and spatial attributes? Some evidence suggests that it is not.

    Gabrielsson found that musicians who were not also audiophiles, were not especially good judges of sound quality[4]. The famous pianist Glenn Gould came to appreciate the insights of non musicians[5]. Our own tests have confirmed this. So, listeners with different backgrounds could be expected to have differing abilities or preferences in subjective evaluations. This is an enormously broad topic, but we thought that it would be interesting to take a first step towards understanding the importance of this variable."
    (p. 2)

    The 1994 Toole and Olive study divided subjects into two groups: inexperienced and experienced listeners as follows:

    "The effects were tested using male experienced listeners and both male and female inexperienced listeners. In these tests, listeners were considered to be inexperienced if they had no previous experience in controlled listening tests. Other definitions are possible, which might include persons with no critical listening experience whatsoever. The participants were categorized under the following headings."

    Therefore, "experience" in this case related to participation in controlled listening tests. There is no indication that any of the experienced listeners had training in stereophonic sound evaluation. Furthermore, the tests in this study were conducted in monophonic sound! (p. 3)

    "The tests were conducted over a period of 1.5 weeks using a multiple ( 4 loudspeakers at a time) presentation method. The monophonic tests were conducted with the loudspeakers adjusted for equal loudness within 0.5 dB using B -weighted pink noise. Playback levels, which were constant throughout the tests, were set for typical "good listening." (p. 3)

    http://forum.polkaudio.com/discussion/comment/1760298#Comment_1760298

    Many blind test cultists like to throw up the Toole/Olive studies, while being totally ignorant of the fact that most of their work was done with monophonic sound, and therefore have little to no relevance to stereophonic sound evaluation. Make sense?

    One thing you should understand about me is that I have been studying this topic for a long time. I'm not just some guy on the Internet parroting what was read from questionable sources. ;)

    Questions for you @Absolute_Zero : I have repeatedly said that I am a stereophonic sound enthusiast, which means I am interested in the spatial aspects of music reproduction.

    1. What sense did it make to throw up a study done in monophonic sound, when this is a thread, and a forum, devoted to stereophonic sound, which is sponsored by a manufacturer of stereophonic loudspeakers?

    2. What relevance would a study done in monophonic sound have to stereophonic sound system performance?

    3. Did you even read the 1994 paper that is referenced in the article you linked to and quoted, or did you just get excited about seeing something that apparently supported your position and ran with it?
    Proud and loyal citizen of the Digital Domain and Solid State Country!
  • DarqueKnight
    DarqueKnight Posts: 6,765
    Further Thoughts on the Toole/Olive Study:

    Dr. Olive stated: "My mission was to introduce formalized, double-blind product testing at Harman. To my surprise, this mandate met rather strong opposition from some of the more entrenched marketing, sales and engineering staff who felt that, as trained audio professionals, they were immune from the influence of sighted biases.Unfortunately, at that time there were no published scientific studies in the audio literature to either support or refute their claims, so a listening experiment was designed to directly test this hypothesis. The details of this test are described in references 1 and 2."

    I did a study on the history of subjective stereophonic audio evaluation in 2010. I provided many references from the scientific literature that supported the idea that blind and double blind studies were unnecessary due to the multidimensional nature of stereophonic sound and due to the performance criteria that must be evaluated:

    http://forum.polkaudio.com/discussion/104701/a-survey-of-early-stereophonic-system-subjective-evaluation

    Here is the introduction to the article:
    Introduction

    Subjective non-blind evaluation methods, based on listener training, careful listening, and documentation, were preferred at the inception of stereophonic sound by its inventor, Dr. Harvey Fletcher, and by other scientists at Bell Telephone Laboratories, the General Electric Corporation (GE), the Radio Corporation of America (RCA), the British Broadcasting Corporation (BBC) and by scientists at many other reputable research organizations who worked on improvements to stereophonic sound equipment.

    This article provides an overview of the subjective stereophonic sound evaluation methods from the 1930's to the 1960's. The term "stereophonic" did not enter the literature until it was introduced in 1927 by Bell Laboratories (the research and development division of the Western Electric Corporation). Up to then, multichannel audio systems were known as "auditory perspective" systems. After 1927, the terms "auditory perspective" and "stereophonic" were used interchangeably in the scientific literature. "Stereophonic", or "stereo" for short, can correctly be applied to any multichannel audio system using two or more speakers where the intent is to generate a three dimensional sound stage.

    Here are my references from the scientific literature listed at the end of the article (particularly note the references in red and their dates of publication):

    [1] World Book Dictionary, 1973 ed. Vol. 2., p. 2033.
    [2] Fletcher, Harvey, "Symposium on Wire Transmission of Symphonic Music and Its Reproduction in Auditory Perspective-Basic Requirements", Bell System Technical Journal, Vol. 13, 1934, pp. 239-244.
    [3] Moor, J. and Leslie, J. A., "The Stereophonic Reproduction of Speech and Music", Journal of the British Institution of Radio Engineers, London, September 1951, pp. 360-366.
    [4] Fletcher, Harvey, "Hearing, The Determining Factor for High-Fidelity Transmission", Proceedings of the I.R.E., Columbus, OH, June 1942, pp. 266-277.
    [5] Steinberg, J. C., and Snow, W. B., "Symposium on Wire Transmission of Symphonic Music and Its Reproduction in Auditory Perspective-Physical Factors", Bell System Technical Journal, Vol. 13, 1934, pp. 245-258.
    [6] Somerville, T., "Survey of Stereophony", Proceedings of the Institution of Electrical Engineers, Convention on Stereophonic Sound Recording, Reproduction and Broadcasting, London, March 1959, pp. 201-208.
    [7] Harvey, F. K. and Schroeder, M. R., "Subjective Evaluation of Factors Affecting Two-Channel Stereophony", Journal of The Audio Engineering Society, Vol. 9, No. 1, January 1961, pp. 19-28.
    [8] Moore, H. B., "Listener Ratings of Stereophonic Systems", IRE Transactions on Audio, September-October 1960.
    [9] Schjonneberg, K. and Olson, F., "Listening Test Methods and Evaluation", Journal of the Audio Engineering Society, Vol. 9, No. 1, January 1961, pp. 29-36.
    [10] McCoy, D., "Distortion of Auditory Perspective Produced by Interchannel Mixing at High and Low Audio Frequencies", Journal of the Audio Engineering Society, Vol. 9, No. 1, January 1961, pp. 13-18.
    [11] Moore, H., "Effect of System Parameters on the Stereophonic Effect", Journal of the Audio Engineering Society, Vol. 9, No. 1, January 1961, pp. 7-12.
    [12] Beaubein, W. H. and Moore, H. B., "Perception of Stereophonic Effect as a Function of Frequency", Journal of the Audio Engineering Society, Vol. 8, No. 2, April 1960, pp. 76-86.
    [13] Fowler, Charles, "As The Editor Sees It", High Fidelity Magazine, Vol. 1, No. 1, September 1951, p. 8 and cover.
    [14] Clark, D., "High-Resolution Subjective Testing Using a Double-Blind Comparator", Journal of the Audio Engineering Society, Vol. 30, No. 5, May 1982, pp. 330-338.


    Again, @Absolute_Zero wishing you success with your studies.
    Proud and loyal citizen of the Digital Domain and Solid State Country!