MiniDSP EARs measurement rig

Discussion in 'Headphone Measurements' started by dBel84, Nov 9, 2017.

  1. cskippy

    cskippy Creamy warmpoo

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    That defeats the common reference point...

    I'm still happier with my flat plate measurements.
     
  2. Hrodulf

    Hrodulf MOT: Sonarworks

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    I'm pretty sure that our engineers would figure out how to do it reliably, however we're an evil business entity so it remains to be seen if we would do it.

    Overall EARS looks like something we built around 3 years ago. My colleague still has a large drawer full of his ears replicated in various materials. IIRC, it was a dead end with flat-ish plate couplers giving similar or better results.

    To this day we haven't encountered the perfect tool for artefact-free absolute measurements on all headphones. It's one thing being able to pull off a nice HD800 measurement, while HD25-II is a whole 'nother ballgame. In the end it's more about the hand that swings the blade, rather than the blade itself. Our guys could pull a good measurement from EARS, but only because they have thousands of measurements already behind them.
     
  3. sorrodje

    sorrodje Carla Bruni's other lover - Friend

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  4. Hands

    Hands Overzealous Auto Flusher - Measurbator

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    A reference point would be nice, but we've survived thus far without! And if the mics have too much variance, that could be hard to fully obtain if many are unwilling to go through the trouble to calibrate and compensate for each other. Not that it's too tough, but it takes time. We could end up with a shaky, variable reference point or just never see enough drive among enough people to get it to that point. But it could work, and I hope so. I for one won't use it as-is because CSDs are unusable with that plain canal. I like being difficult.

    But, really, all I meant to say is if you get tired dealing with it entirely, salvage some parts for better use. The mics and USB board alone could be very handy if it all fizzles out.
     
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  5. purr1n

    purr1n Finding his inner redneck

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    It's pretty much a pain in the ass, but having lots of legacy data and new data with the EARS does help. I spent a little bit of time every day analyzing the data since I got the EARS to arrive at the preliminary compensation I posted above.

    I wouldn't mind calibrating individual members EARS, for SBAF members that is, for a nominal fee or a good bottle of whiskey, bourbon, or scotch.

    Tyll sent me an ear many years back, but I still decided to opt for the flat plate. The flat plate coupler results are "good enough" for frequency response. It can be argued that couplers with ears might be more accurate with a larger variety of headphones where the ear may interact differently with the internal cavity inside the cups. But really, at the end of the day, most headphones are more simlar to each other than not. I've always like to point out how the flat coupler measurements here look suprisingly similar to Jude's GRAS45AC results.

    Where the flat couplers win are with distortion measurements (lower noise for not having to record at lower gain to account for ear gain), immunity to measurement variance from placement, and maybe CSDs. The GRAS45AC might be a good candidate for CSDs, but this is hard to say without more analysis (not a priority for me at this time). Likewise, it seems that moving the microphone flush to the ear eliminates ringing / standing waves from the canal - at the expense of more ragged peaks and dips in the highs.

    All that being said, the MiniDSP EARS (or the GRAS45AC) results are a good check for the flat plate coupler frequency response results. From what I am seeing so far, I do like the compensated EARS results for frequency response more than the flat plate coupler results. The EARS CodeX3 frequency response measurement I felt was more indicative of what I heard compared to the V2 flat plate.

    We can even do fun stuff like offer a compensation that translates the EAR results into compensated Jude GRAS45AC frequency response measurements. It probably wouldn't be perfect, but it might be close enough to offer meaningful measurements to compare against Jude's results. The GRAS45AC does have its own eccentricities.

    We'll definitely be getting more data in, and I would look toward you guys to help formulate an SBAF compensation curve for the MiniDSP EARs.
     
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  6. Taverius

    Taverius Smells like sausages

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    Bottle of good booze (or two) for your time and expertise, sound like a bargain.

    Learning to do measurements isn't the issue at all, calibrating with no clue or data at the same time - I ain't a superhero with sound-based powers.
     
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  7. AllanMarcus

    AllanMarcus Friend

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    Just not something one sees too often! Hope it didn’t hurt when Tyll removed it. :)
     
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  8. Tyll Hertsens

    Tyll Hertsens Grandpappy of the hobby - Special Friend

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    I've got another one somewhere if someone wants it.
     
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  9. murray

    murray Friend

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    Van Gogh was an early pioneer of the art (puns intended).
     
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  10. purr1n

    purr1n Finding his inner redneck

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    Repeating from another thread:

    The miniDSP EARS does work, and with the right compensation curve, can arrive at very similar results to Jude's GRAS45CA. The question is how consistent from headphone to headphone to the GRAS / DF compensations. I am already exploring this as we speak.

    I've already worked on a preliminary compensation curve for myself that takes an almost flat line across as the target. You guys have already seen it with the "EARS" frequency response which I post as a supplement to the "V2" flat plate coupler measurements. It would not be that hard for me to get very close to Jude's GRAS and compensations. The primary constraint is lack of data from Jude at this point.

    Sure the miniDSP isn't perfect. There is induced ringing from the ear canal which isn't anywhere as complex as the GRAS45CA. But the fact is, this behavior only adversely influences CSDs, which Jude does not provide anyway. The distortion measurements from the miniDSP EARS look good.

    Instead of SBAF selling a measurement rig, I have already offered to provide calibration curves, maybe even including a Jude curve when it becomes available, for individuals' miniDSP EARs, in exchange for a bottle of good whiskey, scotch, or bourbon.
     
    Last edited: Jan 18, 2018
  11. purr1n

    purr1n Finding his inner redneck

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    Some of you have asked what would be acceptable in exchange. Here are some general guidelines:
    1. $50+. Generally is going to be true given the inflation in whiskey, scotch, bourbon prices.
    2. I'm not into the smokey peaty scotch. A hint like Springbank (personal favorite) is good. The standards are such as Macallan are fine.
    3. I'm not into the rye stuff.
    4. Hard for me to turn down anything cask strength. Anything less than 60% alcohol seems watered down.
    5. Anything Japanese. They are coming out with some really good shit.
    6. Bookers, WIllet, Woodford, Angel's Envy, Glenmorangie, Springbank.
    7. No Johnny Walker - don't care if it's BL. Just no.
     
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  12. Taverius

    Taverius Smells like sausages

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    The chance to get something like this and take ham-fisted measurements has me a bit giddy, but questions for @Marvey :

    1) is it even possible to buy you a bottle of hooch online? If we're not US citizens?
    2) should we just have the EARS delivered to your place?
    3) if I pay extra, can I get a 'certificate of authenticity' that declares my rig to be a SBAF-Certified <liquor>-class device? I can hang it on my wall need to a picture of a certain person and his GRAS.
    4) how long do you expect your liver to last?

    And finally the most important one:

    5) Can anytime figure out a backronym so we can call it MEOW, SLIM (terrible bilingual puns are my thing) or something else fun? :D
     
  13. Hands

    Hands Overzealous Auto Flusher - Measurbator

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    I may actually be interested in setting up my EARs the same way as you so we have a common reference point. Yes, that includes mics at the bottom of the well. Once you finalize your compensation curve, if you have the calibration file, I should be able to work the numbers to make it match on my rig.

    I have something else in the works similar to but unrelated to the EARs that is meant to be more of a direct replacement for my original in-ear measurement method. So far, results are very promising, but I will remain secretive until now like the turd than I am.
     
  14. purr1n

    purr1n Finding his inner redneck

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    How is your L and R matching? I'm actually talking to Tony Rouget / MiniDSP CEO! They seem like passionate audio guys willing to colloborate. This might be really fun going forward.
     
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  15. purr1n

    purr1n Finding his inner redneck

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    1. Direct shipment of wine is permissible in the state of California. Evidently, it is not legal to ship spirits. The wine industry is strong and has been able to bribe, I mean lobby crooked politicians (for the record, I hate them all, regardless of party affiliation) to do their bidding.
    2. Probably the best way to go. The issue right now if we can trust the calibration files provided by miniDSP. The calibration files I downloaded did not result in even L and R matching for headphones with known great matching, i.e. Sennheisers. It's entirely possible that something might have gotten damaged or fell out of my unit during shipping.
    3. Yes, I'm sure @Boops can come up with something suitable for a COA.
    4. I've lost a ton of weight and fat and gained muscle from my recently hiking expeditions (totally addicted now doing 1/2 day hikes or sem-insane climbs every day of weekend or holiday). Risk of heart attack is much lower now; but at this rate, maybe 10 years for the liver. The problem lies with friends who can drink and keep going, and you can do the same. Uber also makes it easier.
    5. There is always this: https://www.head-fi.org/threads/headphone-measurements-different-setups-different-results.751100/
     
  16. Hands

    Hands Overzealous Auto Flusher - Measurbator

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    Haven't gotten around to testing that just yet. I'll try to get to that this weekend!

    Really happy to hear the CEO is in touch! That could lead to great things.
     
  17. sorrodje

    sorrodje Carla Bruni's other lover - Friend

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    It would be definitely great if everybody could work on a proper compensation curve miniDSP could deliver with the kit :)
     
  18. Drakkard

    Drakkard Acquaintance

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    Received my HEARS and played with it a bit.
    My L and R factory compensation curves are different, but I did not find a program where I can load both of them, I can load either L or R calibration at a time. It is annoying. Any suggestions?

    Thinking of turning it into a flat stand. CSD is important.
    Also, I'm planning to install some bricks to make microphone plates about 1cm further apart from each other. Seems very simple, just need to find suitable longer screws
     
  19. Lyer25

    Lyer25 Old at heart, young in other places

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    Hell, if I can get shipping halfway across the globe figured out I'm game for having a Marv-compensated rig (overcompensation via GS awards not included). I dunno shit about spirits other than I like some and absolutely loathe others, so I may just PP some cash so you can go burn your own liver, if you really find that acceptable @Marvey :p

    Jokes aside, I do think this would be the best way to help get sorta-standard measurements and help educate members, and help them educate others in their own way.

    Oh, and for the COA I do calligraphy on the side (posted in a thread on here somewhere). I could probably throw together a classic or modern looking certificate complete with bird flourishes and golden schlongs if it passes approval and send a PSD over to Marv or whomever to sign with golden Sharpie.

    I take payment in tea, thanks XD
     
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  20. purr1n

    purr1n Finding his inner redneck

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    Ideally, if we can establish confidence that the compensations with the miniDSP EARS were good and consistent, then we could do this without shipping. It's just a matter of looking at the miniDSP provided files and adjusting them to the SBAF compensation.

    I'm just worried about doing this right now because my L and R channels do not match, even after applying the compensation files.
     
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