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Wednesday, August 21, 2013

Apple ME186LL/A: A budget wonder [Revised]

[Updated on 08/21/13: Rick has provided a pair of MA850G/B for comparison. A brief comparison is presented here along with the result of his personal request.]

In September of 2012, along with the release of iPhone 5, Apple introduced their innovative earbud, Earpods. In addition, they revised their classic dual-balanced armature IEM, MA850G/B, to ME186LL/A. Other than the remote configuration, nothing is known about the detail of the revision.


First released in September 2008, Apple In-Ear Headphones was one of the earliest dual-balanced armature IEMs that were actually marketed for affordability, whereas its dual-driver competitors, such as Shure SE420&SCL4, Ultimate Ears Super.Fi 5 Pro, and Westone UM2 were considered high-end. Highly praised for its value by many Apple product users, nothing was really known about its electroacoustic property, other than the official frequency response graph shown above. Enigmatically, Apple not only set the y-scale unusually high, the x-scale was also unconventionally ranging from 1 Hz to 21,000 Hz, making visual assessment rather tricky.





PRO: Not only the channel tracking is tightly matched to be less than 0.7 dB from 20 Hz to 10,000 Hz, the frequency response is exceptionally diffuse-field oriented. The bandwidth is very wide too, easily reaching 20,000 Hz.

CON: There is a 3rd harmonic distortion of 2%, which is equivalent to -34 dB, at 3 kHz as the IEM hits 100 dB SPL @ 1 kHz. Such amount of distortion shall be critically audible due to the fact that 3 kHz is the frequency of which human hearing is most sensitive.

ON SECOND THOUGHT #1: The optimum insertion depth of ME186LL/A is roughly at 3 mm away from the reference plane, which is about 16 mm away from the eardrum theoretically. A slight shallower insertion won't interfere the IEM's linearity, but deeper than 3 mm yields a peak in the frequency range above 10 kHz.


ON SECOND THOUGHT #2: The frequency response of Apple ME186LL/A becomes closer to an ideal diffuse-field target, as the source impedance increases, up to 240 Ω. However, even with addition of 100 Ω, the IEM's linearity outperforms some of the most accurate headphones, and even becomes on par with my modded Sony MH-RC. Moreover, since additional source impedance gradually decreases the 3rd harmonic distortion at 3 kHz as well, this modification is definitely recommended.

ON SECOND THOUGHT #3: The stock metal mesh effectively kills off the harshness in the high frequency range. Although additional acoustic resistance further tames the peaks, as it also decreases the bandwidth, such practice shall be done with caution.

ON SECOND THOUGHT #4: As expected, the rear vent only works as a depressurizer.

ON SECOND THOUGHT #5: The choice of ear sleeves for ME186LL/A is extremely limited. Sony hybrid sleeves, or Comply Whoomps get close to the stock quality, but other sleeves that alter the bore size/length more than those dramatically either decrease the overall frequency response bandwidth, or totally change the sound signature of the IEM. Insertion depth equally matched, above comparison data indicate the effect of longer/thinner bore. In other words, introducing additional bore resonance to the IEM works in harm's way.

ON SECOND THOUGHT #6: I hate to admit it, but with 33 Ω added in series, Apple In-Ear sounds damn good even with shallow insertion. I'd love to apply additional modification, but there is really nothing to tinker with as the stock configuration is so precisely optimized. What a brilliant job done by Apple. And surprisingly, even in stock, Apple In-Ear is very close to Harman's Hi-Fi reference target.

ON SECOND THOUGHT #7: The difference between MA850G/B and ME186LL/A is extremely subtle. Whether it is due to the change in acoustic damper configuration(acoustic), to the revision of its tweeter transducer(mechanical), or to the modification in the internal crossover network(electrical), the mid-high has been increased by 3 dB, along with more emphasis in the high frequency extension. Other than that, two IEMs are identical in every way.

ON SECOND THOUGHT #8: This is Rick's personal request. While Goldenears.net's iOS app, Accudio™, helps tame MA850G/B somewhat, it completely skews ME186LL/A's frequency response. 

44 comments:

  1. Hello Rin, looks like you really like these. Just wondering if they compare to IEMs that are over $100 and if so which ones.

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    1. Generally speaking, when it comes down to critical listening, headphones with high distortion level do not stand a chance as they seriously lack fidelity.

      Thus, this IEM should be compared against other products that exhibit similar distortion characteristics, such as PFE 112, FAD Heaven series, Sony XBA-4, and T-PEOS H100. And personally, I prefer ME186LL/A out of all above for its satin-smooth tonal balance and tight fit.

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    2. why would you prefer apple instead of phonak? according to your review you said that the phonak is right on the reference target where apple is not that accurate in this regard.

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    3. First of all, Phonak PFE lacks bandwidth. Second, PFE is right on the diffuse-field target as long as the insertion depth is right at the reference plane, which is virtually impossible to achieve: I wonder if anybody is able to insert PFE up to at which ER4 is inserted..

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    4. I had a discussion about this with a head-fier and he told me that with the foam tips it is possible to go deeper than the silicone tips. I didnt see a frequency graph with foam tips in your review but looking at golden ears you will see the difference.

      http://en.goldenears.net/2184

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    5. Yup, it seems the conical tapering of foam certainly lowers acoustic output impedance, and offsets some of the harshness caused by shallow insertion. However, the problematic peak/dip are still there.

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  2. Rin Choi taking the distortion into account and disregarding the bass boost how much would you say these are worth?

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  3. what do you mean by "with 33 Ω added in series"?

    Do you add 33ohm impedance resistor or something?

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    1. Alright.

      With it how does this IEM compare to TDK BA200?

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    2. Smoother than BA200 in terms of tonal balance but with more distortion.

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  4. Rin choi I know this the wrong place to ask this but I can't find a way to pm you. How do I take tyll's measurements:

    http://www.innerfidelity.com/images/MonsterBeatsbyDrDreSoloHD.pdf

    and turn it into diffuse field instead of id?

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    1. The deviation between ID AND DF is:

      -2 dB @ 200 Hz
      -4 dB @ 500 Hz
      -5 dB @ 1 kHz
      -4 dB @ 2 kHz
      -2 Db @ 3 KhZ

      IOW the Solo HD will have slightly more recessed mid-range response from 200 Hz to 3 kHz.

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    2. Thanks that weirdly makes it look like a straight downward line from 1k to 10k. Can that be considered linear?

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    3. Nah, it can't possibly be called linear.. The slope is -6 dB/oct progression!

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  5. How audible is the distortion at 3 kHz when played at approximately 80-90 dB while using a 33-Ohm resistor?

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    1. Rock, Hip-hop and House: no problem
      Classical and Jazz: quite audible!

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    2. Even at low volume levels? I ask because Innerfidelity graphs suggest that these IEMs suffer from less distortion at low volumes at the problem frequency.

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    3. Does that distortion decrease even more when the volume is lowered further? I rarely, if ever, listen at an average level of 90 dB. My average listening level is more commonly 80-85 dB. In conjunction with a 33-Ohm resistor, I feel like the 3rd harmonic distortion product may fall to a point at which it is inaudible. If nothing else, I feel it may become so much less noticeable that it will no longer be a problem even with more critical genres such as jazz and orchestral.

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    4. You should be fine. I just tried it with mine. The distortion on a pure 3kHz tone doesn't start to become obvious until you reach around 35 mV rms. That's around 90 dB SPL I think. The distortion is primarily 3rd harmonic--9 kHz, where human hearing is less sensitive.

      More damaging to music is IMD. I mixed 3 kHz at <35 mV with other tones, even 60-100 Hz at almost full volume on an iPad, and the distortion is harder to detect, maybe because of masking. Here, the distortion products are clustered around 3k.

      If it's hard to detect distortion with pure tones, it'll be harder still with music until you crank the level way up. For one, the elevated distortion only happens within a very narrow band of the audible spectrum. Several things need to happen simultaneously in music before it becomes a problem. The probability for that is low, even if you listen at concert level.

      If you search online and look at distortion measurements of loudspeakers, you'll see many products that have measured distortion levels that are worse. And that's only at 90 dB and 95 dB SPL, and taken at only 1 m or 2 m. Nobody bats an eyelash about the THD when talking about those. So just plug in and enjoy!

      BTW, I'm using a cheap Monoprice passive inline volume control. It lets you use the volume and the play/pause/track advance controls while adding an adjustable amount of effective series resistance (up to several hundreds of ohms). I think it sounds just lovely with the Comply Whoomp tips. The drawback is the build quality and the manufacturing tolerance on the pot. I had to go through several ones to find acceptable inter-channel matching.

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    5. ADDIEM's distortion may or may not be subjectable around at 90 dB, depending on the sensitivity of your hearing. I'd say watch out for odd-order harmonic distortion, not THD, cause they are simply annoying even with loudspeakers.

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    6. So I've heard. I don't know exactly what to expect. I have a strange feeling that at my generally low listening level and with the resistor, it may not be bothersome. Thank you for answering these questions. I appreciate it.

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  6. Rin:

    Where are you based? (USA or other?) I have early versions of the Apple in ear that I can send (as well as some others you might be interested in checking out.

    My handle is Wembely over on Headfi - PM me

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  7. 75 ohm resister is awesome! Much higher resolution than the stock configuration and still plenty loud enough out of my portables. Thank you! Great idea!

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    1. You're welcome, Seth. I am glad I could be helpful.

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  8. Rin
    Do you think the 3rd order distortion dropped at 3khz with the 100 ohm resistor because of a commensurate drop in relative amplitude at 3khz? Or do you think the cause is from something other than that?

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  9. I believe the perceived increase in resolution is due to a decrease in overall output below 1khz. Now I can hear way further into a recording. Listening to mog was fine before the resistor, but now the graininess of 320kbps is fully exposed. High resolution recordings sound incredible now, whereas before, it was much harder to tell if I was listening to one or not.

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  10. A distortion test on the older model would be very interesting also. It could possibly explain why they revised it.

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    1. Distortion wise, two IEMs are pretty much identical: http://i.imgur.com/fVd6o98.gif

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  11. Is there any reason why one might wanna add 33 Ω instead of 100 Ω, when choosing the latter results in flatter fr?

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  13. Hi Rin, Dirac DSP now support apple IEM. Could you test it again with Dirac ON, maybe there is improvement especially in distortion area. Thanks.

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  14. hey rin I was wondering which ohm should I buy. you said 33ohm sound damn good but in the graph above it is more flat with 100ohm added. is there any reason for this? and also what's the difference using accudio and adding ohm?

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  15. Good post....thanks for sharing.. very useful for me i will bookmark this for my future needs. Thanks.
    askmebazar coupon

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  17. The Whoomp! tips that Comply introduced for these earbuds really helped the bass and noise isolation, making these perfect for such activity as cutting the lawn.

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  18. Please do these graphs for the AirPods, would be really interesting!

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