Measurement Requests

Discussion in 'Measurement Systems and Standards' started by Cspirou, Oct 26, 2015.

  1. Cspirou

    Cspirou Friend

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    Basically this is a thread for people to request measurements from people that have the ability and equipment. Just whenever anyone feels generous or is bored. If anyone knows a link of a requested measurement that has already been done then this would also be a good place to post it.

    I'll start things by saying I'd like to see some measurements of basic headphone outputs like for laptops from Dell or Apple. Mainly because while headphone amps publish quite a few specs, headphone outputs publish almost none so I can't really get a good comparison.
     

  2. Cspirou

    Cspirou Friend

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    I got a request and might as well use my own (dead) thread.

    I'd really like to see the difference between vacuum tubes and LISST on the Lyr 2 and Mjolnir 2.
     
  3. ipm

    ipm Rando

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    I'd like to see a power spectrum or an FFT analysis of each of the M40x, HD650, HD600, and the HD800 (or some other handy high-end cans) to see the different frequencies a recorded signal contains while using a WAV, MP3/320, and a FLAC source for the same music.

    My point is to see if there is a mathematical difference in the recorded information content of these formats pending compression settings given that a certain headphone, dac/amp/mic, and rig/headphone setup is chosen and not changed during the testing.

    Are the MP3/320 and FLAC signals noticeably different via each headphone? Can the differences be measured and plotted as a function of compression? Is this repeatable?

    Signal comparisons are done all the time in various fields. This should extend to headphone measuring fairly easily, I would think.

    Note that I am not interested in starting arguments about what is audible to certain people at certain times, subjectivity, etc. I am just curious to see how this works on a measurement rig via a few selected headphones.

    If this already exists, please post a link. I would like to see the power spectra and comparisons.
     
  4. 9suns

    9suns Acquaintance

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    Airbow headphones, please! :)
     
  5. OlafR

    OlafR Rando

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    Acoustic Research new planar magnetic headphone AR-H1.
     
  6. spwath

    spwath Friend

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    What has AR come to?
    Making a 2k Bluetooth speaker, 5k planars...
     
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  7. 9suns

    9suns Acquaintance

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    AR-H1 will cost 599usd, not 5k...
     
  8. OlafR

    OlafR Rando

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    AR was once known for some ground-breaking products,of

    course, among them the famous AR3 speaker with its "acoustic

    suspension". But not all of them were prestigious or had an

    "audiophile" price tag. Take their first turntable:

    "The initial price was $58, on which the company lost money.

    It was sub-sequentially raised in steps, in 1972 it was still

    only $90.

    The turntable quickly gained profitability, and AR sold

    hundreds of thousands of them. Although it was the least

    expensive quality turntable on the market, many reviewers and

    consumer organizations rated it the best-with one exception.

    Stereophile thought it was good, but said that the spindle

    was too big. In fact that was an incorrect call; the spindle

    diameter was precisely what industry standard specified".

    From an article on
    http://vinylnirvana.com/ar-turntable-history/


    In fact: Of all the audio products I know, and despite the

    brilliance of many of them, the one I always admired most of

    all was this "modest" AR turntable, even if I never owned

    one.

    Remember that when defining technical excellence, cost

    consideration is an important part of it.(Outside today's

    silly audiophile world, that is...)...

    The weak little motor, the thin belt, the heavy platter, the

    3 point spring suspension.. it is an unbeatable combination,

    when you start thinking about it!



    (My first turntable was a Thorens 150, build closely on the

    AR principles, and it works perfectly today after 30 years of

    heavy use and one change of a worn-out motor.. With an

    improved arm board and a decent arm/pickup I find no

    weaknesses with it whatsoever. Like in the AR advertisement

    (found on the mentioned site) I can hit the turntable edge

    with a hammer while playing, and the music continues

    unaffected... not that I do it that often..)

    Cheers, Olaf
     
  9. cskippy

    cskippy Friend

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    Why are you structuring your sentences like that? It hurts my brain.
     
  10. OlafR

    OlafR Rando

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    Sorry, it was a copy & paste job.
     
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