Modi 2U and D30 DAC: Deconstructing Amir's Hack Job Part II

Discussion in 'Source Measurements' started by purr1n, Jun 8, 2018.

  1. Dzerh

    Dzerh Friend

    Friend
    Joined:
    Apr 1, 2018
    Likes Received:
    112
    Dislikes Received:
    6
    Trophy Points:
    43
    Location:
    San Ramon, CA, US
    Yes, except you forgot to add "with perfectly developed methodology on test-set that covers all aspects of human hearing".
     
    Lyer25 likes this.
  2. trl

    trl Acquaintance

    Joined:
    Apr 23, 2017
    Likes Received:
    30
    Dislikes Received:
    10
    Trophy Points:
    18
    Location:
    Iasi, Romania
    I see your point, let's find couple of devices measuring similar in regard only with the below:
    - 2nd and 3rd harmonics
    - mains freq and it's 2nd and 3rd harmonics
    - square sines @20Hz and 20KHz
    Like atomicbob said and proved, THD number means nothing without knowing exactly how harmonics and mains hum look alike. Let's hear in A/B test if we can spot any diffs.

    I do have some devices at home that measure pretty close in the aspects mentioned above and I'm unable to spot any differences. Instead, devices that have similar FFT ARTA graphs, but different square-waves representation do sound different. It's probably me...don't know.
     
  3. Biodegraded

    Biodegraded Friend

    Friend
    Joined:
    May 28, 2017
    Likes Received:
    1,014
    Dislikes Received:
    0
    Trophy Points:
    93
    Location:
    Calgary AB, Canada
    Which measurement(s) will illustrate how any two pieces of equipment present soundstage or imaging differently?

    Genuine question. But if you were being sarcastic with the quoted statement, my apologies for misunderstanding.
     
    wormcycle likes this.
  4. trl

    trl Acquaintance

    Joined:
    Apr 23, 2017
    Likes Received:
    30
    Dislikes Received:
    10
    Trophy Points:
    18
    Location:
    Iasi, Romania
    Crosstalk and channel imbalance, but also phase delay might help here.
     
  5. purr1n

    purr1n Finding his inner redneck

    Staff Member Friend BWC
    Joined:
    Sep 24, 2015
    Likes Received:
    39,703
    Dislikes Received:
    62
    Trophy Points:
    113
    Location:
    Antarctica
    With square waves, we get a peek into some aspects of transient response.

    -

    As far as contributing to HF, I'm persona-non-grata. To keep up appearances that Jude is not the bad guy, there is no banned label on my account. My account is active but I cannot post anything - I am restricted via custom permissions in XF.

    If I am not wanted in Jude's house, it makes no sense for me to contribute to HF under my wife's account. The fact that these restrictions were carried forward from the old Huddler platform to XF is confirmation that I am an undesirable person there.

    In the end, it doesn't matter. Everybody already knows about SBAF. And the people who bitch about SBAF being too vicious to newcomers still voraciously read SBAF.
     
  6. Biodegraded

    Biodegraded Friend

    Friend
    Joined:
    May 28, 2017
    Likes Received:
    1,014
    Dislikes Received:
    0
    Trophy Points:
    93
    Location:
    Calgary AB, Canada
    I note the 'might', so let me rephrase the question: if two pieces of equipment present soundstage and/or imaging differently, will they have different phase delay and/or channel imbalance (or any other measurement)?

    Edit: add crosstalk.
     
    Last edited: Dec 12, 2018
  7. purr1n

    purr1n Finding his inner redneck

    Staff Member Friend BWC
    Joined:
    Sep 24, 2015
    Likes Received:
    39,703
    Dislikes Received:
    62
    Trophy Points:
    113
    Location:
    Antarctica
    Rtings has a methodology behind certain vague aspects of headstage, although the explanations seems kind of convoluted / hokey. I haven't studied them in depth. It's hard for me to believe what they say about headphones when they didn't even understand that Sean Olive's f'd up FR targets were "consumer" preference targets*, not perceptual neutral targets: rtings suggested that the HD650 needed a massive bass boost. Ugh. No thanks.

    Channel imbalance negatively affects imaging precision with speakers. Maybe we could assume the same with headphones.

    Crosstalk maybe. I actually started doing crosstalk measurements, but I rather not make any conclusions until more data is examined. Crosstalk is highly related to isolation and leakage for obvious reasons.

    One area that might be worth exploring is the design of the pads, cup, baffle, and driver mounting. And how much of the ear structures influence the FR with each design.

    Perhaps a difference plot with a flat (no ear) coupler and the EARS might yield interesting results. You never find me making any strong claims correlating measurements to subjective experience until I have sufficient data (from many headphones) to feel comfortable about it.

    *The fact that in 2018, we still see terms like "Harmon neutral" or "Olive neutral", say in IEM guides on HF, just shows the harm that has been done. It's actually possible to derive a perceptive neutral target from Olive's work, but application and use of that would require a head and ears simulator exactly like the one he used. Different head and ears simulators do have different responses.
     
    Last edited: Dec 12, 2018
    trl, Pillars, Vtory and 1 other person like this.
  8. Clemmaster

    Clemmaster Friend

    Friend
    Joined:
    Sep 28, 2015
    Likes Received:
    784
    Dislikes Received:
    0
    Trophy Points:
    93
    Well that’s a feat!
     
  9. Pillars

    Pillars Embarrassment to Colorado crew

    Contributor
    Joined:
    Sep 26, 2016
    Likes Received:
    125
    Dislikes Received:
    2
    Trophy Points:
    43
    Location:
    Northern Colorado
    I like it.., satire or not. Interested in measuring a DX7s?
     

Share This Page