CSDs and What They Tell Us

Discussion in 'Headphone Measurements' started by purr1n, Sep 28, 2015.

  1. Maxx134

    Maxx134 Dunning–Kruger effect poster boy

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    I am observing it as like ripples in a pattern.

    I see it looks like in general bumps can be ripples of "reverb" effects of enclosure.

    Assuming other considerations to arrive at this, like already Knowing/hearing the headphone...
     
    Last edited: Sep 22, 2017
  2. Maxx134

    Maxx134 Dunning–Kruger effect poster boy

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    I can agree that reverby or resonant aspects of sound,
    And that "closed sounding" or "open sounding" can be all separate aspects of sound not necessarily dependant or reliant on each other.

    The Eikon have more open sound for a closed,
    yet still will have the reverby cup resonance,
    Especially if you open slightly the center hole behind the driver which is partially covered with wool.

    I see Marvey info pointing out the results of an enclosure, namely reverby and resonant aspects.
     
  3. Serious

    Serious Inquisitive Frequency Response Plot

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    Depends on your CSD windows. I believe the windows and settings Marv uses are optimized more for higher frequencies.

    @Marvey I agree IEMs weren't the best example, that was just the first thing that came to my mind. Maybe TH-X00 (especially Ebony) would be another example, which seems to measure pretty well, but doesn't sound very open to me. The measurements don't really make it seem like the TH-X00 should be less open sounding than the Elear, for example.
    I specifically chose the left channel for the LCD-X, which looked far better. Now of course you could argue which one is more accurate. Left channel LCD-X, even with the other CSD settings (which are really not all that different - 3ms vs 5ms and 32 vs 36db and "remove antialiasing range" on vs off, right?) should still look very good between 700Hz and 1.5kHz. Also you used 5ms for your comparison, not 3ms. And with the HD800 treble peak 32db might be more comparable anyway.

    You generally don't see any bad effects from putting a lot of felt behind the driver (like say with HD6X0 mods). There will be no reverb from the felt, but it will definitely reduce the sense of openness IME.

    Anyway, those are just my thoughts. More damping can often get you better measurements, but subjectively I tend to like to keep damping to a minimum.

    Good point.
    This is probably it. Reverby effects cause FR wiggles. Even then I wonder if it's actual delayed energy that cancels out or overlaps with the initial driver signal, or if it's just an enclosure effect that changes FR and phase accordingly. Essentially what I discussed with @ultrabike at length LOL. I don't think I've seen big deviations from minimum phase that could stem from reverb in the headphones I've measured.
     
  4. Maxx134

    Maxx134 Dunning–Kruger effect poster boy

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    Haha that happen to me one night modding I was getting all excited with better looking measurements to only be disappointed with some muted dead sound lol.
    Thought I could skip a few listening steps in my modding ha.
     
  5. AstralStorm

    AstralStorm Friend

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    Well, overdampened muted sound is kinda fine if anechoic chambers or recording studios are your thing. Unfortunately many tracks are mastered for live rooms and not dead ones.

    If you overdo it you might get even order harmonic distortion too as the driver is dampened too asymmetrically. (Often sounding like bass boost or flabby bass.) Or lose way too much efficiency and have to crank the loudness too much, again costing distortion. Which again means that a very low distortion driver is more forgiving in tuning.

    If you dampen in front of the driver, you may also get distortion due to turbulent airflow instead of laminar. This generally shows up as a higher area in THD graph, depending on material used - TP gets mid frequencies, foam ~3k - 5k, cotton wool ~6k - ~9k depending on density. Same range as maximum of sound dampening. Details are something about speed of sound, fiber length and tangling, better left to actual material scientists.
     
    Last edited: Oct 24, 2017

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