Ocharaku Flat4-粋 (SUI) part.2: General analysis

Disclaimer: This IEM is owned by my friend, James. His curiosity is as good as mine!

Ocharaku(音茶楽) Inc. is a tea store located in Tokyo, Japan. Not quite sure why, but the company somehow got into the in-ear monitor industry with an unique brand name, 音茶楽Sound Customize. 

According to Ryo Yamagishi 山岸亮, the representative & the director of acoustic research at Ocharaku Inc., Ocharaku Sound Customize's ultimate goal is to create a gentle sound signature with high frequency well-extended, derived from a ground-breaking technological innovation. 

And that is how Flat4-SUI is created, after Full-range 2-element 4-way effect, with two dynamic driver connected with an acoustic transfer tube, which is named as Phase Correction tube. The placement of the tube is claimed to be precisely calculated in order to achieve optimum performance of the IEM. 

Yamagishi-san claims that Flat4-SUI's double driver configuration not only expands the low frequency bandwidth by cancellng off any anti-resonance induced mechanical vibration, but also improves the sensitivity of the low-mid frequency range. Moreover, while the proprietary Phase Correction tube offsets acoustic interference caused by closing off the ear canal, without using any acoustic resistance at the output of the IEM, an ultra high frequency reproduction is acquired. 

And of course, Yamagishi-san does not end there. By utilizing a driver with no tangential grooves corrugated on the diaphragm, Ocharaku successfully reduces distortion in the mid-high frequency range. If all five of these claims happen to be for real, it is no doubt that Ocharaku would surely become one of the most technologically advanced headphone manufacturers, along with Sennheiser and Etymotic Research.

Ocharaku Flat4-粋 (SUI) part.3: In-depth analysis

Continued from part 2, General analysis.

According to Ryo Yamagishi 山岸亮, the representative & the director of acoustic research at Ocharaku Inc., Ocharaku Sound Customize's ultimate goal is to create a gentle sound signature with high frequency well-extended, derived from a ground-breaking technological innovation. 

And that is how Flat4-SUI is created, after Full-range 2-element 4-way effect, with two dynamic driver connected with an acoustic transfer tube, which is named as Phase Correction tube. The placement of the tube is claimed to be precisely calculated in order to achieve optimum performance of the IEM. 

Yamagishi-san claims that Flat4-SUI's double driver configuration not only expands the low frequency bandwidth by cancellng off any anti-resonance induced mechanical vibration, but also improves the sensitivity of the low-mid frequency range. Moreover, while the proprietary Phase Correction tube offsets acoustic interference caused by closing off the ear canal, without using any acoustic resistance at the output of the IEM, an ultra high frequency reproduction is acquired. 

And of course, Yamagishi-san does not end there. By utilizing a driver with no tangential grooves corrugated on the diaphragm, Ocharaku successfully reduces distortion in the mid-high frequency range. If all five of these claims happen to be for real, it is no doubt that Ocharaku would surely become one of the most technologically advanced headphone manufacturers, along with Sennheiser and Etymotic Research.

In this in-depth analsis, two of Ocharaku's claims will be discussed:

1. The principle of 特許第４９５３４９０号
2. A driver without tangential corrugation

The effect of ear sleeves: TDK IE800

Disclaimer: Measurement has been carried out at the reference plane.

TDK IE800 exhibits a good amount of harshness in the treble. No matter how the fit is changed, the harshness is always present. Upon assessing the acoustic effect of various types ear sleeves, the optimum setting for IE800 shall be discovered.

TDK IE800

Along with BA200, TDK IE800 is developed by the acoustic research lab at Imation. These IEMs are tuned to have a very smooth frequency response in order to closely emulate the tonality of a reference loudspeaker system, according to the manufacturer.

And most importantly, the acoustic research lab currently uses a conventional artificial ear fixture, G.R.A.S. 45CA, which has a pair of occluded ear simulator installed within, thus the accuracy of their acoustic tuning is absolutely guaranteed.

One notable feature of IE800 is its double driver configuration connected in parallel, without any kind crossover filter implemented within. While a 5.8 mm microtransducer handles the high frequency response, a 8mm driver takes the role of a woofer. As a conventional single driver is fully capable of covering the entire frequency spectrum, TDK's approach is rather intriguing.

TDK BA200 [UPDATED]

[Updated on 04/15/2013: The impedance stabilizer has been analyzed.]

Disclaimer #1: This IEM is owned by Inks. Much thanx to my good friend.
Disclaimer #2: Unlike that of Sony MDR-F1 or MDR-MA900, the impedance stabilizer implemented on BA200 turns out to be something other than a simple voltage divider. Read on!

BA200 is TDK's top-of-the-line IEM equipped with dual balanced armature drivers. Developed by the acoustic research lab at Imation, it is claimed to be tuned to have a very smooth frequency response, which is closely emulating the tonality of a reference loudspeaker system.

And most importantly, the acoustic research lab currently uses a conventional artificial ear fixture, G.R.A.S. 45CA, which has a pair of occluded ear simulator installed within, thus the accuracy of their acoustic tuning is absolutely guaranteed.

Accudio™: Accurate Audio Player by Goldenears

Intro
Released in August 2012, Accudio™ is an iOS music player developed by Goldenears. In addition to its powerful 9-band parametric equalizer, this app also comes with brilliant acoustic enhancement features called "Reference/Simulation mode". As long as headphone measurement data are stored in the database consisting of frequency response measured from over 300 headphones, users can tune any of their headphones to match Goldenears' proprietary diffuse-field target, or simulate them into nine different kind of headphones from various brands.

As many of inexpensive portable headphones lack in quality, such features shall definitely improve the user experience by a great degree. However, the legitimacy of Goldenears' claims is yet to be known. By analyzing Accudio™'s sound enhancement features in detail, their technological validity will be assessed.

T-PEOS H-100K

It was July of 2012, when T-PEOS of South Korea introduced their flagship model, H-100. A hybrid of balanced armature & dynamic drivers, H-100 was targeted for users who prioritize fidelity and accuracy.

In order to accommodate such requirement, T-PEOS teamed up with Goldenears.net, and tuned the IEM to precisely match Goldenears' proprietary target curve, which was a modified diffuse-field response that I do not approve of, especially due to the bloated bass.

And inside the box, included a certification card indicating the proof of performance assessment done by Goldenears. Now the question would be, could this certificate really prove its worth?

LG HSS-F450: Quadbeat

Disclaimer: This IEM was donated from an user at SEEKO.co.kr, named 궁금중. I should appreciate him for the contribution.

In September of 2012, upon releasing their high-end cellphone, Optimus G, LG also introduced an IEM called HSS-F450, which was better known as Quadbeat. Manufactured by iSound of South Korea, Quadbeat was designed by Y.H. Na, a senior manager of the core technology lab, mobile communications division at LG. As a stock IEM of Optimus G, the MSRP of Quadbeat was set at around 20 USD, which was quite affordable.

And as Goldenears.net further provided its frequency response certification, the publicity of the IEM just sky-rocketed, with some even claiming that the Quadbeat's electroacoustic performance is on par with or better than Ultimate Ears Triple.Fi 10 Pro. (And my take on the claim is here) The Korean public's demand well-exceeded the manufacturer's supply, and Quadbeat was considered an absolute steal.

MEElectronics A161P

Disclaimer: This is Inks' pair. Measured couple of months ago, but never had a chance to upload the data. Sorry for the delay, Inks.

A161P is MEElectronics' top-of-the-line IEM with a single balaced armature transducer installed within. Although the manufacturer is well-known for great value per performance products, A161P has been marketed for high accuracy and fidelity.

In order to prove their claim, the manufacturer even has their own frequency response plot, which is diffuse-field compensated, on the product description page. The plot is definitely not of hi-fidelity, but since not many manufacturers disclose their measurement data, such gesture from MEElectronics is very informative nonetheless.

Etymotic Research HF-3: An ER-4 equivalent?

Disclaimer: This is Inks' pair!

Etymotic Research has been best known for their extremely strict quality control, and that is why their flagship IEM, ER-4 is pair-matched by their engineers. Although the official tolerance limit is 2 dB, almost all of ER-4's interchannel deviation is usually within ~1dB from 20 Hz to 10 kHz. Such accuracy is absolutely critical, especially when the IEM is used for professional/research purposes.

However, that is also the reason why ER-4 is quite steep in price, keeping regular users unapproachable to Etymotic Research's great quality & fidelity. In order to mediate the situation, in January 2002, the manufacturer re-branded Star Micronic PH-001A, and sold it as ER-6. ER-6 was as accurate as ER-4S, and was very affordable too with an MSRP of $140.

And in 2008, as a successor to ER-6, the HF series was introduced. Because its design and official measurement data were almost identical to ER-4P, it was considered to be ER-4P equivalent. While some said HF's core element, a balanced armature driver, is identical to ER-4's Knowles ED-9689, others argued that it was actually ED-29689.

And recently, some of my fellow Twitterian named @Fontek_Research reported that Knowles ED-29689 measured very different to what's installed in ER-4. Can this IEM possibly be an economical version of ER-4?

Sony XBA-30

Disclaimer: This pair is owned by Flysweep, who generously let me borrow his IEM for a full month. I truly appreciate your contribution, my friend.

Sony XBA-30 is a revised version of XBA-3. As there isn't much to complain about XBA-3's original performance, the question is: What has been actually "revised" from its predecessor?