Measurement Setups - Post Your Rig!

Discussion in 'Measurement Setups, Systems, and Standards' started by Luckbad, Oct 5, 2015.

  1. JK47

    JK47 The Beer Houdini

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    Made this today, UMIK1 USB mic and 4" PVC fitting from Lowes with built in stand, stuffed with foam. Hot glued the CD to one end, then acoustic dampening foam and a small piece of felt.

    So far my HD650 measurements drop a few dB in the midrange compared to you guys... Gonna play with them in the next few days.

    Edit: Getting there, still a small dip from 7-10kHz, but other wise very very close
     

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    Last edited: Oct 31, 2015
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  2. OJneg

    OJneg The Most Insufferable

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    You guys have some weird ass fleshlights
     
  3. Ushi

    Ushi Rando

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    what is the diameter of the felt piece? And could you please post your setting for ARTA, mine get cut off at 50hz and CSD dont start at 0ms like you guys ( it start at middle of the graph).
     
  4. sorrodje

    sorrodje Carla Bruni's other lover - Friend

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    Question for experimented people : How do you the mic ? Should the mic be set right at the level of the coupler, or should it be sticking out a few mm.

    For the HD800 it makes a significant difference :

    HD800 3 Measurements.jpg

    1 : Weak clamp - Mic at the level of the coupler
    2 : Stronger clamp - Mic Sticking out 1cm
    3 : Strong clamp - Mic at the level of the coupler

    All graph with 1/12 smoothing and Y axis scale choosed in order to emphasis differences .

    It does not make that much difference for the HE400S though.
     
    Last edited: Nov 8, 2015
  5. OJneg

    OJneg The Most Insufferable

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    Move mic closer to the HD800 driver > less enclosure resonance > less peak

    One of the many pitfalls of trying to measure the HD800.
     
  6. sorrodje

    sorrodje Carla Bruni's other lover - Friend

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    Yup. this fucker isn't easy to measure accurately. Clamp force makes a difference as well and the "haircut" difference is probably related to the variations of the distance between driver and ear.

    But overally is there a "better" choice for the mic positionning ?
     
  7. OJneg

    OJneg The Most Insufferable

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    You can take an approach similar to Merv's V1 stuff. Mic super close to headphone driver in "open-air" and combine that with a coupled measurement to fill in everything below ~1k. Or just try something else and stick with it for consistency, as that's all you can really hope for (if that).

    I actually think most folks with their homemade couplers are chasing a moving target. That's why I don't put much stock in any hobbyist made measurement device that hasn't been scrutinized. No one is calibrating to flat against a known reference. Take any microphone and surround it with a rigid material and you're going to change the response. That calibration file that came with the omni mic is for measurements taken in the free-field and your coupler is in no way a free-field system. This can be easily verified against a known reference. There's a reason why they build these omni, wand mics to be very slim with the diameter at the end being not much wider than the capsule inside.
     
  8. sorrodje

    sorrodje Carla Bruni's other lover - Friend

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    OK . got it. So a bit sticking out the couple is probably better as I expected.

    I don't trust really in the accuracy of my results but at least I want something somewhat comparable to what other guys ( Marv, UB, Hands for example) produce here and something I can correlate a bit with my own subjective impressions. But I definitely think the only reliabla result I can obtain is to have consistent and comparable results . At least, doing ourself a measurements rig helps to understand how what we read here or there is not gospel.

    Will borrow a HD600 , measure it and use it as benchmark.
     
  9. logscool

    logscool Friend

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    Yeah I definitely think consistency is the most important factor as we try and get our measurements to be meaningful and correlate to subjective experiences. Obviously having something of a standard method would also be nice but as long as you get a good understanding at how the measurement system works you can begin to realize where certain methods are better at isolating or focusing on certain components of the system.
     
  10. Ali-Pacha

    Ali-Pacha Friend

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    My brave old Lambda measured :bow:

    Ali
     
  11. sorrodje

    sorrodje Carla Bruni's other lover - Friend

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  12. UltraShock

    UltraShock Rando

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    Ah, this is wonderful! I've never seen a guide yet on how to properly measure your headphones. Can't wait to set up a mic with my SR-X Mark III's and see how they fare :)
     
  13. purr1n

    purr1n Finding his inner redneck

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    Level with strong clamp is most similar to my current version 2 measurements.
     
  14. Ali-Pacha

    Ali-Pacha Friend

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  15. sorrodje

    sorrodje Carla Bruni's other lover - Friend

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    Will do some more measurements tomorrow before I post it to the future owner.

    @purrin : Measurement 2 or 3 ?
     
  16. sorrodje

    sorrodje Carla Bruni's other lover - Friend

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    Last improvements of my coupler.

    I used some groundsheet used for gymnastics. cut the right band and rolled it around the mic. I put Ducktape around the whole thing so I obtain a cylinder. I choosed a bent USB connector .

    2015-11-25_20-53-44_1.jpg 2015-11-25_20-50-46_1.jpg

    I glued some strips of soft open cell open cell behind a circle of Creatology foam. the foam is soft enough to be able to spouse the pads hence a very god seal.

    2015-11-25_20-50-54_1.jpg 2015-11-25_20-52-11_1.jpg

    The mic sticks a bit and the creatology circle is not perfectly flat


    2015-11-25_20-52-19_1.jpg

    As Marv does , I add a little piece of felt. sometimes it has some effects sometimes not that much.

    2015-11-25_20-52-42_1.jpg


    2015-11-25_20-53-13_1.jpg

    See the FR of my SR-507 :

    SR-507 - Good vs Bad seal.jpg

    Red is the measured FR wih the coupler described above. the yellow/green is with a flat coupler made of open cell foam.

    I'm quite happy with the result. I'll measure a HD600 in next days in order I can have benchmark for all measurements of Open cans.
     

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  17. purr1n

    purr1n Finding his inner redneck

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    Add a used CDR underneath to simulate bone and to provide better support for earpads.

    #3. microphone flush.
     
  18. sorrodje

    sorrodje Carla Bruni's other lover - Friend

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    CDR under the foam ? I don't see how it could be useful . I I put it under the creatology I lose all the benefit of the soft foam for the best seal.

    Do I miss something ?
     
  19. feilb

    feilb Coco the monkey - Friend

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    Alright. After getting measurements on the Empiric back from @ultrabike and @Tyll Hertsens, I had to put together my own setup. You know. For science.

    I wanted to come up with something cheap and decent, so I decided to build a cardboard box.

    Boxhead

    The parts:
    [​IMG]

    All of the structural pieces are made from some double wall cardboard I scavenged from a dumpster... The foam blocks are some left over acoustic dampening foam. All of this was laser cut.

    Bracing
    [​IMG]


    The sides, bottom, and top have smaller pieces glued w/ some Super 77 to support the ribs and end caps.

    Attaching the sides
    [​IMG]

    A little paper tape to hold things in place.

    The ribs
    [​IMG]

    The ribs friction fit into the channels.

    Foam
    [​IMG]

    The foam blocks slide into the spaces between ribs

    [​IMG]

    The cardboard holes are oversized and the foam slightly undersized to ensure the microphone is well supported, but only by foam.

    Installing the microphone

    [​IMG]

    I was inspired by @Bill-P and the face on his rig. Because I'll be measuring mostly my own creations, the expression seemed appropriate.

    The Coupler
    [​IMG]

    I used some 4mm EPOM acoustic foam for the coupler. It is slightly springy and should provide a decent seal. I put some tick marks on it to aid in repeatable positioning. Each is 1cm from the axis of the microphone.



     
    Last edited: Dec 11, 2015
  20. feilb

    feilb Coco the monkey - Friend

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    First results seem promising. Pretty good agreement w/ @ultrabike's measurements on the Empiric:

    Ultra's
    [​IMG]
    Mine
    [​IMG]

    Ultra's
    [​IMG]
    Mine
    [​IMG]
     

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