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Monday, January 14, 2013

Sony MH1C: Is a bad excuse better than none? [UPDATED]

[UPDATED ON 2/2/2012] A brand-new analysis has been carried out, and it simply settles everything. I will still keep this article for reference purposes. Please keep in mind all the information below have been fully revised!

[UPDATED ON 1/14/2012] After having a nice little chat with Mr.Sead Smailagic in regards to his designing philosophy via email communication, I am convinced Mr.Smailagic really tried everything he could in terms of electroacoustic design in order to make customers happy with their purchase. If everything clarifies, I awe Mr.Smailagic, and to him only, a big public apology. I've thought all this time, MH1C is worth only a couple of dollars in terms of sound, but this will be changed in no time. And the data deviation listed here is possibly due to manufacturing error. Once I obtain the original version MH1 along with MH1C version, I will post a separate entry with everything newly analyzed. Before that, please keep in mind all the information below is preliminary and inconclusive!

[UPDATED ON 11/29/2012] Reworded the part# 2, the role of MH1C's top vent to make my point clearer.

[UPDATED ON 11/28/2012] Added possible explanation on why Mr.Smailagic's and my data are different in the low to mid frequency range. I didn't know there were two different versions! Also added some new datasets.

Sony MH1C has been causing quite a stir lately among users who fancy budget-fi, partly due to the designer's voluntary background check. Unless very confident with their products, it is exceptionally rare for original designers to submit themselves for public verification.

According to the designer, Mr.Sead Smailagic of Sony Mobile, MH1's acoustic signature revolves around the very basic; how the human hearing system works. He mentions that all kinds of factors related to a human HRTF(head related transfer function), including the missing 6 dB effect, the directional notch of a free-field response, and finally, the equal loudness contour, are accounted for designing the IEM.

First of all, the missing 6 dB effect has been debunked.

Second, when MH1C is compensated with a free-field target, the mid-high frequency range becomes very linear.

So it seems Mr. Smailagic's approach works. But then again, it shall be noted that the free-field reference has been long gone ever since it was challenged more than 30 years ago by Germans. On top of lack of a natural interchannel leakage, due to much interpersonal variations, this approach simply introduces a linear distortion in the high frequency range.

Third, according to Toole, as long as the output volume is well above the realistic hearing level, this kind of equal-loudness compensation is not preferred for a high fidelity reproduction.
"The curves tell us that different frequencies at the same sound level may be perceived as having different loudness. This is not a message that anything needs correcting. We live with these characteristics from birth, and they are a part of everything we hear, whether it is live or reproduced. That is why audio equipment must exhibit flat-frequency responses—uniform output at all audible frequencies—so the sounds we perceive have the correct relative loudness at all frequencies, assuming they are reproduced at realistic sound levels."
It can be argued that the compensation is to maintain a spectral balance at lower volumes as well. Even if the boost is relative to the contour, due to the +20 dB with such small Q factor, the argument will not hold water at all.

IMO, his explanations are commercially oriented excuses to sell a product. not to mention that there is an affiliated blog blatantly advertising the IEM. Is a bad excuse better than none? No, I don't think so. (to whom may it concern: I have no interest in bashing anybody with the above statement, absolutely no reason to do so. To my standard, whether there's a monetary transaction involved or not, if a blog is in close relation with a representative of a special interest, then it's as good as an affiliation. AND if the blog actually shows off the product with manufacturer bias, then it is an advertisement. Even I had a phone chat with Mr.Jonathan stewart of Etymotic Research, thus I should be affiliated as well with Etymotic Research in a way.)

PRO: CHEAP & WIDELY AVAILABLE. Audible even-order harmonic distortions in the sub-bass range, which can be beneficial for the perceived bass increment along with its slow decaying characteristic. Due to its linear impedance characteristic, a simple underdamping with a serial resistor does not affect the sound at all. Bundled ear sleeves are of very high quality.

CON: A lot of uncontrolled bass. This bass will simply mudify the overall perceived fidelity.

ON SECOND THOUGHT #1: It is important to look into MH1C's sub-bass response. Never seen anything like this. The bass response is pre-ringing and lagging at the same time. Quite odd.

ON SECOND THOUGHT #2: There is a vent on top of MH1C, which works as an acoustic filter, although the low frequency drops down only to a few decibel when the vent is blocked.

Since depressurization is occurring elsewhere (most likely at the strain relief), excursion caused by over-pressurization should not be of an issue here. However, as the sonogram on the left clearly shows blocking the vent actually worsens the sub-bass response by causing more delay, it may also contribute to a better transient characteristic of an IEM within the ear canal.

ON SECOND THOUGHT #3: MH1C performs a lot better in the upper region, when it is inserted shallow.

Let us not even talk about measurement accuracy, as it's right on target.

ON SECOND THOUGHT #4: Some people wonder why my plot is different from that of Sony, especially in the low-mid frequency range as much as 6 dB, even though we are both using occluded ear simulators. No, there is no compensation involved in my raw measurement. The answer is simple. They seem to have created MH1 with two different variations, one that suits "today's popular mixes", while the other suits "more natural balance". Above comparision shows what is really going on, shallow inserted. Buyers beware! Mr.Smailagic tells me that my pair of MH1C is going over the tolerance limit. That solves the mystery.


  1. I think it is important to listen with your ears as well as measure stuff. Firstly, when using the provided tips of the appropriate size, do they go closer to your "reference plane" or "shallow insertion" condition? I feel that the "reference plane" insertion condition is a very unrealistic one, at least for universal IEMs, as just about no tips I use (and I'm 6 feet tall with a big head) even with the etymotics have made it past the second bend no matter what I try.

    Secondly, I recommend that you try the by-ear listening test method outlined here (admittedly not in a very organized fashion, but I hope you get the gist of what I'm doing)

    These $20 MH1C are the only phones I've tried with a linear treble. The Etymotic MC5 that I currently own, one of your gold reference line I believe, has a ~11dB spike at 7-8kHz (bandwidth ~0.2, moving in frequency depending on the tips I use and how far in I try to stuff them) no matter what tips I use.

    From your article it seems you're telling me there *should* be a spike there to reproduce a natural sound field. Perhaps. (I'm led to believe that open-canal resonance naturally occurs at more like 9kHz) But modern pop recordings are close-miked and for those recordings that aren't de-essed with heavy multiband compression, sibilance cuts like a knife if I don't EQ this 7-8kHz spike out.

    Your own measurement of the MC5 shows a similar spike at 9k. Perhaps you'd say it's part of the design? All I can say is I hear a spike at 9k with my loudspeakers as well and I find it highly unpleasurable with most program material such that I EQ it out all the time.

    In any case it seems that your major remaining beef with the MH1 in the shallow insertion condition would be the bass boost. Have you tried applying a corresponding bass cut?

    Best regards,
    Joe Bloggs at head-fi

    1. Thnx for your comment, Joe.

      First, my very initial step for reviewing a headphone is to listen. With the smallest sleeves, I can get MH1C all the way up to the 2nd bend of my ear canal.

      Second, you DO NOT WANT TO MESS WITH THE EQUAL LOUDNESS CONTOUR, as stated above. That is not a natural way to listen.

      Third, MC5 shall be inserted deeper for you IMHO. 7~8 kHz peak means you are about 9 mm short from the reference plane. Try using Shure olives, they will do the job.

      Fourth, no. Peaks are not preferred. MC5 has its flaws, and they are budget-fi, just like MH1C, and is not my golden standard at all. A bass cut should do a trick, but that is not the part I'd go into.

  2. 1. I'm using smallest sleeves for MH1C and they reach about as far in as the etys with shure grey flex, which is to say not far at all

    2. The equal loudness contour is there in my test EQ chain *to prevent an equal loudness contour from being baked into the EQ profile* for the phones themselves. I think you had a knee jerk reaction to what is actually the solution to the problem you see. The equal loudness contour is taken out of the chain after the testing phase for actual music listening. As I make changes to phones' EQ to improve music listening experience the changes are fed back to produce a customized equal loudness contour for myself.

    3. Just as I thought, I ain't sticking nothing 9mm further into my ears...

    4. I heard the same peak in the ER-4P? Are the ER-4 without treble peaks to your ears? The MH1C are without treble peaks to my ears. They are the first phones I've found that require no parametric EQ to sound right.

    Sorry for the brief reply made on a phone

    Best regards,
    Joe Bloggs on head-fi

    1. 1. You must have a sensitive ear canal!

      2. That will only work only if all of your samples normalized at a specific level, with the headphone / source gear calibrated at the same time at certain SPL. Otherwise it's as good as a pseudoscientific mumbo-jumbo.

      3. That is how Etymotic, Shure, and Westone IEMs are designed. If you can't hit that half-wave resonance at 13 kHz, you are missing a lot from these IEMs.

      4. That also means your insertion with ER-4P is too shallow; the IEM's quarter-wave resonance is hitting the 7~8 kHz range. It sounds like you can't reach the ideal depth, unfortunately. That means you need to look for IEMs that can perform as good when inserted shallow.

    2. 1,3. I do go the whole nine yards with the pull back ear, open mouth thing. Not gonna put lube on the dam things though. If I have to practically violate myself in order to get the designed fit I'd rather EQ to the target response. What is your thought on that?

      Anyway it seems that achieving flat treble response with an easily attainable shallow fit is a more credible feat than achieving the same with an uncomfortable deep fit.

      2. Yes, I know the equal loudness curve will only work at one volume. No, I don't have any way of measuring that volume. I start off each test session with a 1kHz tone and try to maintain this tone at the same volume for all the earphones / headphones I profile.

      As far as I know, there is no currently viable method to measure SPL at the eardrum with IEMs in place without severely disrupting ear canal acoustics. Until such methods exist, this "pseudoscientific mumbo-jumbo" will have to do. The worst that can happen is that my measurements will be off by a few dB caused by the difference in the curve of say, a 60dB and a 70dB equal loudness curve. The standard deviation of my own reported loudness levels matching the 1kHz tone becomes a significant factor.

      4. Any recommended models in particular?

      Joe Bloggs at head-fi

    3. 1,3. If you don't have an electroacoustic analyzer at your disposal, you can't expect much from a simple EQing. On the other hand, abiding with the principle of in-ear-acoustics is much more accurate IMHO. No, I am not trying to diminish the importance of a handy EQ! :)

      2. I see your point. Going for the best bet with your specific circumstance. That is a hell of effort, and I should honor it.

      4. Not many, but Grado GR10 and Vsonic GR07 mkII shall meet your demand along with Yamaha EPH-100. I'd love to find more and help you out!

    4. 1,3. It's an infinite band unlimited bandwidth parametric EQ though! :)

      2. You may discover acoustic idiosyncrasies specific to your own ear canal with this approach. Although it's not very accurate for correcting gross tonal balance it is a very sensitive method for pinpointing specific resonant frequencies for your own IEM/tip/ear combination! :)

      4. Looking at your reviews, the MH1C still looks more linear with shallow insertion than either of these expensive sets... :D

      Regarding the "missing 6dB", from what little I understand in those articles it seems you're saying the bass needs to be delayed for the perception of bass to return to normal... and the MH1C has delayed bass built into the design? Is this a good thing then?

    5. 1,3. Yet again, if an electroacoustic analysis is not accounted for, there is no guarantee the compensation you made is on target, not to mention that even a 1 mm insertion shall cause a compensation target mismatch, considering how quarter-wave resonances radically change the overall sound.

      2. I've done it so many times in order to analyze ACS custom sleeves. The simulator measurement corresponds with my ear canal very well. Unless you are in a desperate circumstance calling for such compensation, the closer you get to the in-ear rule, the better fidelity you end up with.

      4. Indeed, except with the gross bass. Yes, there's a time delay along with an audible even-order harmonic distortion along the sub-bass range, which means extra boost is not needed at all. Recent studies published in 2012 at the AES convention reassure what I mentioned.

  3. I have small canals and can easily place the Etymotics at the reference plane, that long thin nozzle enables that for me.

    Unfortunately, I don't think you're getting to the reference plane at all Joe, peak at 7k is never there with a 2nd bend fit, matter of fact there's usually a slight dip there with the right fit, with an inoffensive, small peak higher in the 9-10k range. Many IEMs with balanced armature drivers are designed to be fitted to the reference plane, maybe dynamics would be a better bet for you for the most part

    1. I just spent an hour trying to stuff the etys in far enough to resonate at 13kHz. Not possible. The closest I was able to get was by decoring the stock foam tips and stuffing the bare tube all the way up my ear. Even then the thick end of the tube snags on my outer ear canal and the resonant peak just sounds like it moved from 7.5k to 8.5k, not sure. ?.?

      What's wrong with my ear canal? Is it too narrow or is it too long? Both?

    2. You mustn't try too hard for deep insertion as it can fatally damage your ear canal. Stock sleeves are not that user-friendly, so you might want to try Klipsch bi-flanges, or Shure Olives. If they don't do the job, then so be it.

  4. I have to say, I wasn't expecting to see something like this on here. That said, kudos to you for apologizing. Not trying to sound mean or hostile, but I do think that ClieOS does deserve some words as well, if I'm not mistaken some harsh words were used against him. Again, very professional and tough thing to do to apologize publicly like this, give you big rep for doing it :)

    1. Thanx, TM. Words from Sead was very truthful, and we both understood each others' circumstances very well. It is right to make things right!

    2. Clieos deserves an apology? LOL, not considering how he reacted, he was disrespectful himself, using tounge-in-cheek. Rin never said anything personal, he criticised the approach of the review.

    3. @udauda: always great to make things right, makes your credibility go up as well.

      @Inks: ClieOS' credibility was questioned, and somewhat tarnished. From a reviewer's standpoint, that becomes extremely personal. From what I got in the exchanges that I read, the tone read like ClieOS was "paid off" to write what he did. It was how I read the statements anyways; I tend to read between the lines looking further than just words and taking into account tone (tone of a message usually says more than the message itself).

      Just having that brought up to question is in many ways personal and disrespectful in my opinion. I know I'd be quite angry if anyone made the same statements about myself. That may be just me that sees it this way though.

  5. Rin had stated that he assumes there's an affiliation, regardless of monetary compensation or not. Reading between the lines, sometimes can be reading what is not there. If Sony or whatever company had some connection to Rin's review, there would be an affiliation as well and Im sure he'll be the first to admit and bring it up. That is all Rin stated...

  6. I try to test an old version of MH1 made for SONY-Ericsson(Buy it on e-bay for a very little price). As in your first review it sounds boomy and very unbalanced. Im just wonder why there is a lot of discussion about such a descent unimpactfull sound?

    Than i have try more newer version of MH1c called SONY name. And it really shines! it has more refined sound signature and really impress me. All except the bass line which is overemphasized IMO. Next i plan to work with it to correct the bass behaivour.
    @udauda have you measure the thd after your modification? Is it stil emphasized odown to the infra-bass and for what factor? is it stays below the 1% botomline?