HD800 (S) Ultimate Mod

Discussion in 'Modifications and Tweaks' started by Maxx134, Apr 27, 2018.

?

Are you satisfied with HD800 bass?

  1. yes

    14 vote(s)
    32.6%
  2. Its ok

    10 vote(s)
    23.3%
  3. Not really

    10 vote(s)
    23.3%
  4. Hell no, I want planar bass

    12 vote(s)
    27.9%
Multiple votes are allowed.
  1. gixxerwimp

    gixxerwimp Professional tricycle rider

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    I wouldn't say it's hard, but it requires a bit of effort. After pulling off the bulk of it, you can use a ball of it to remove the bits that are stuck on, similar to the technique used to remove tape residue with a bit of tape. I mass loaded my T50RPs with Dynamat Xtreme and was able to return them to stock. The corners of the baffle were the hardest parts to clean up, so a flat surface should be easier to deal with. A plastic surface has more texture and the Dynamat will stick to it more. A smooth metal surface should be easier to clean up.

    Edit: I live in a warmer climate, so maybe that's why it was goopier for me to deal with than it seems to be for u guys.
     
    Garns and Maxx134 like this.
  2. ThePianoMan

    ThePianoMan Almost "Made"

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    I have very similar dynamat damping mods to you, and find they make the most difference, but the pad swap helps get rid of the pverly large headstage and also flattens out bass significantly and generally smooths treble peaks and valleys. I am of the opinion that a mire solid sidewalk tyoe material helps act almost like a soundtube for the hd800, and the additional cup volume reduces cup resonance by shifting where and how much the sound can bounce around. I might try comparing your tape modded pads to mine and see what the diff is.
     
  3. Maxx134

    Maxx134 Friend

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    Having similar dynamat is not the same...
    I cannot stress enough to use Dynamat Extreme in specific location.

    Remember I do not suggest in any way to fill the unit up with Dynamat.

    The Dynamat Extreme is used in what is essentially two circle shapes.
    The shape of the driver edge to be exact, and for a specifically good exact reason.
    No guessing and splashing dynamat all over in less important areas.
    One in circular mass in front, and one behind.

    The idea is to stop the vibration at the source area (where driver meets structure).

    In order to do so, we place an almost equal and opposing mass in front and behind the driver(!) in the same locations...

    Not in any locations far away which do not have same effect.

    Think of the HD800 speaker as a car tire, in which the nuts are loose...it will vibrate.

    If you want to tighten, you must have TWO SIDES, or you can tighten forever without a rear surface to push up against.

    Same effect when you load only the rear with Dynamat,
    without doing the front.
    Your not getting optimal vibration attenuation.

    Think of a bell ringing and only touching the inside (rear) .
    It not stop same as pinching both sides...

    So what is done to the front, we need to do similarly to the rear,
    or it is not effective for the "horizontal plane" damping.

    Also, we are addressing damping in the "angled-plane" of the basket...

    If you take notice, the rear would have sligtly less dynamat mass than the front, because it is in a smaller circle.
    So there is a "line-of-sight "angle" between the inner and outer dynamat rings.
    This is also in line with the basket trajectory.

    So not only is the dynamat on both sides,
    but it is also on the inner and outer sides of its donut "ring radiator" in proportion to the angle of the basket...

    Physical (not diaphram sonics) Vibration is thus optinally attenuated in the angle of the structure,
    Which is essentially shaped like a megaphone,
    so would naturally amplify vibrations from the center (the driver)..

    We want the diaphragm sound vibration to not be transmitted to a structure induced vibration.


    So my point is, that although we are finally getting good results with SBAF carpet material, or the Pads mods,
    Or even the SDR insert & my "S" insert...

    They ALL are NOT addressing the root of the Problem.
    They work to work to "absorb" resulting sound.

    None are "Vibration control".

    Its like taking medicine for a cold to stop the symptoms, but adds its owm drowsy effects, and is not the actual cure.


    Only the Dynamat Extreme, "Anti-resonance Mod" will control the root of the Problem.

    It "sandwiches" the driver in the "horizintal & basket-angled planes",
    to attenuate the driver initial vibrations which are then transmitted along the basket,
    in similar way a horn speaker amplify.
    This is where we get the diffused exageratted soundstage.

    The lack of it being a "driver problem", was known here a long time,
    as Marvey pointed out in an old thread that the driver was not the cause of the ringing.

    This was known, and I remember BILL-P trying other, less resonant structures to his HD800.
    Also by replacing or covering the metal mesh screen.

    The issue there, is that the initial vibration from the driver edge,
    gets transformed and skewed into type of dispersion which are known in horn loaded speaker designs (because of cone shape basket).
    It is transmitted along the cone, making what is heard as a diffused exaggerated soundfield.

    Controlling the "initial" vibrations to structure is the key .
     
    Last edited: May 8, 2018
  4. Maxx134

    Maxx134 Friend

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    If the desnsity (mass) of the HD800 design were increased,
    I don't believe we would be having these discussions,
    but then the HD800 would not be so light (think LCD weight lol)
     
  5. Maxx134

    Maxx134 Friend

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    How have you placed your Dynamat?
    Is it the "Extreme" version?

    If you are still getting excessive (diffused) headstage,
    then that is proof your damping is innefective..

    Another problem with signature to even out, is you don't necessarily want a flat response.
    Measurement rigs are known to exagerate bass and not be as accurate in trebles...

    I myself prefer to preserve the signature HD800 upper end sound and not have a "flat" sound,
    Because in doing so (excessive treble absorbtion) ,
    Can have a side effect of muting the transients.
     
    Last edited: May 8, 2018
  6. ThePianoMan

    ThePianoMan Almost "Made"

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    My initial mods were identical to yours. They measure flat after compensation. I prefer a slightly laid back presence region because I have to listen to music for my job all day, which can be fatiguing.

    That said, I did exactly your mods, but found i preferred also damping the outter plastic ABS ring. I also tried slathering synamat everywhere, which as you noted, doesn’t work. And yes Imm using dynamat extreme.

    My HD800 does not have diffuse, unfocused treble, its a very focused transient sound. I’ve altered it slightly for more bass and a sightly sweeter, slightly laid back presence range because that is my taste.
     
  7. Maxx134

    Maxx134 Friend

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    This is good, because doing one side only (rear), can produce added energy to the front.
    Like a ball hitting a (padded) wall (dynamat) , yet still bouncing back in(!) at a lesser strength, and adding to the overall vibrations...

    Look at the dynamat, as "padded" walls for bouncing balls (vibrations)
    :)
    The black side will attenuate, but not same the silver side.

    You will enevitably be both slowing down and boucing back the "ball" depending how it is configured.

    That said, I would appreciate and value you posting any your Dynamat work and experience here.
    I would link it to first page.
    More the merrier as I would like to make known its importance to the mods.

    IMHO...
    Every HD800 & 800S, no matter which "mod" version,
    needs to be Dynamat moded.
     
    Last edited: May 8, 2018
    Boss302 and Jerry like this.
  8. Boss302

    Boss302 Rando

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    Excellent write up OP. I am getting ready to install the SDR. Your S mod sure looks tempting too. thanks for the nice write up.
     

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