Fostex T50RP Mods Compendium

Discussion in 'Headphone Measurements' started by DEATHxMACHINE, May 10, 2019.

  1. ultrabike

    ultrabike Measurbator - Admin

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    Yup. Never was a fan of the stock T50RP early versions either. Mods help it quite a bit. There might have been product variations in the past. Dunno if that is no longer an issue.

    The better seal from the Alpha Pads help indeed with low frequencies relative to the stock pads.
     
  2. Vtory

    Vtory Audiophile™

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    This is and will be a very interesting data archive!

    Btw, what calibration level are you using? The graph says 50dbSPL@300hz, which seems too low imo. 90-95db (at your reference freq) would be more consistent with other measurements. (As far as I remember, IEC-60208-7 standard was 94db@500hz.)

    Also which compensation? Stock HPN and HEQ have different strengths and weaknesses. I am guessing you're using either of these but not sure which. SBAF-comp would be the most desirable, as it is the closest to what we actually hear. But doing so needs fair amount of work to integrate marv's results to your EAR calibrations. At this stage, getting more familiar with measurement artifacts in your system should be more prioritized.
     
    Last edited: May 11, 2019
  3. DEATHxMACHINE

    DEATHxMACHINE Friend

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    Currently using minidsp HEQ. Current db is based on what I found to be a normal listening level for me. But will adjust measurements to be more consistent with other results.

    Thank you for the feedback. I wanted to publish one graph tonight to get feedback just like what you just provided. My posts are going to be living for the next few weeks.
     
    Last edited: May 11, 2019
  4. Jinxy245

    Jinxy245 Vegan Puss

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    Really nice idea, I'm intrigued. Are these all units that you own? Either way, thanks for the effort.
     
  5. Taverius

    Taverius Smells like sausages

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    Wow, that's quite the collection!
     
  6. DEATHxMACHINE

    DEATHxMACHINE Friend

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    Sadly, yes.
     
  7. DEATHxMACHINE

    DEATHxMACHINE Friend

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    Updated stock t50rp mk3 and added Dekoni Blue, T60rp and ZMF Classics. Will add more tonight. Going to try and finish off T50rp mk3 based mods; Argon mk2, Talos v2 and Vibro mk2. But I need to turn my air conditioning back on.
     
  8. ultrabike

    ultrabike Measurbator - Admin

    Staff Member Pyrate MZR
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    I'm liking what I see. Moving to Measurements thread. Great job!

    ZMF Classics do indeed seem like a great set of cans if into the classic Orthos. @zach915m knows his stuff.
     
  9. Vtory

    Vtory Audiophile™

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    To help (primarily my and maybe others') understanding of these great results, I quickly calculated decibel amount required to transform HEQ compensated results to sbaf-comp ones.

    upload_2019-5-11_22-10-43.png

    Technically it is equivalent to HEQ(f)/SBAF(f), because of the following (I feel equations are easier in this case)

    Results compensated by SBAF (henceforth known as "R(f|SBAF)")
    = R(f|raw) / SBAF(f)
    = R(f|raw) / HEQ(f) * HEQ(f) / SBAF(f)
    = R(f|HEQ) * [HEQ(f) / SBAF(f)]
    = "Results compensated by HEQ" * "Equalization curve"

    (f means frequency)

    And note that product and division in the equations above are transformed to plus and minus in log-scale (decibel).

    Or simply apply this curve to any results based on HEQ (using our own brain lol), then we can have some idea how it will look like if sbaf-comp'ed.

    PS1. This implicitly assumes mics are calibrated very reliably across products, which might be too strong. So be aware.

    PS2. The sbaf comp discussed in this post is one step older than Marv is currently using. See this post for more.
     
    Last edited: May 11, 2019
  10. DEATHxMACHINE

    DEATHxMACHINE Friend

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    I have noticed some patterns in my rig. Going to get my hands on another closed headphone and see if same patterns show. Then manually adjust spl.
     
  11. ultrabike

    ultrabike Measurbator - Admin

    Staff Member Pyrate MZR
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    My suggestion is to not discard your current results. They look pretty decent to me. That said, it would be nice to see results with the latest SBAF correction factor as well.

    If you would like to do that then please post both results to compare.

    In the end, whatever you choose to do, results tend to make more sense when seen relative to other cans. A good description of what you hear is a most, to correlate with your measurements (which you have already done concisely). I personally see the measurements as a tool to convey and compliment descriptions about how the cans sound.
     
  12. DEATHxMACHINE

    DEATHxMACHINE Friend

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    Added the ZMF Vibro mk2, Cascadia Audio Talos V2 and the Modhouse Argon mk2.
     
  13. Elnrik

    Elnrik Super Friendly

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    Damnit... Stop tempting me.

    I'm trying to save up to afford my own gangster lawn gnome.

    :p
     
  14. Jinxy245

    Jinxy245 Vegan Puss

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    BTW I'm curious how much 'burn in' there is on the Dekoni Blue.(?) I may be off my rocker, but I was surprised that I heard a difference after a while.

    Here's the story if you shive a git.

    I had the Head Fi loaner & hated it at 1st, but the sound morphed on me and it wasn't subtle. I was quite surprised, I'd never had that happen before, or I'd never noticed it.

    When I asked Dekoni about it, the did say that there was an oddity on the tour. There were 2 units on tour, and the unit I had (and I was the last one) had all the negative reviews. We speculated that it's possible that the 1st person with my unit didn't like the sound & never listened again, or listened very little, and that the process was repeated with each stop.

    It still sounded rough around the edges, but it smoothed out considerably...still harsh in the upper registers, but not as bad, and the lows were still quite pronounced, but a bit tighter.

    I'm sure you did your due diligence, but I couldn't help but be curious since I was surprised myself.
    *edited multiple times for stupidity*
     
  15. DEATHxMACHINE

    DEATHxMACHINE Friend

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    After a initial hour of listening and being dissappointed with the sound, I gave it a 24 hour burn in with pink noise. The highs calmed down a little bit but bass remained bloated and loose to me. So it was relegated to strictly videogame duty where it was actually pretty good.
     
  16. rendyG

    rendyG Acquaintance

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    awesome!
    Could you provide measurement of stock mk2/mk3 with stock pads for comparison? Your graphs could be even more helpful if we had a baseline as not a lot of people actually heard/measured the t50 variations you have :)
     
  17. roscoeiii

    roscoeiii Acquaintance

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    Great thread. Looking forward to seeing how the Ori (that I bought from you) measures.

    Not sure if you measured the ones I bought before you sent them out or have another pair, but I'd be happy to shoot my Ori back to you so that there can be comparisons of different woods...
     
  18. DEATHxMACHINE

    DEATHxMACHINE Friend

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    Just heads up. Compared to the pair I will be measuring for this thread (borrowing from a friend), yours is noticeably more V shaped and forward sounding. Which is why I am going to measure the Ori in different configurations with dampening materials in the hope that I can replicate my pair (now yours).
     
  19. roscoeiii

    roscoeiii Acquaintance

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    Happy to arrange to ship mine back to you to compare measurements and to help in those mod efforts. That's what community is for...
     
  20. DEATHxMACHINE

    DEATHxMACHINE Friend

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    Put up measurements for ZMF Master Class V2, Vibro mk1 and work in progress Vibro Labs TP1.
     

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