Astrotec AX60: A K3003 Clone from China?

Disclaimer: This IEM, which is not released in the US yet, is owned by a mutual friend of mine. Measurement has been carried out approximately 3 mm away from the reference plane with a pair of reference filter attached.

AX60 is Astrotec's new flagship hybrid IEM, featuring a dual balanced-armature transducer as a tweeter, and a dynamic transducer as a woofer. Currently, there are many hybrid IEMs, such as Audiofly AF78, Atomic Floyd SuperDarts, T-PEOS H series and Ultrasone IQ, in the market; The competition is indeed stiff. What is so special about this particular product then?

According to the manufacturer's calibration data, AX60 is precisely tuned to match the sound signature of AKG K3003, of which I consider as one of the best IEMs ever made. (but not my favorite)

The secret of K3003's articulate tonality lies in varying the size of front cavity and utilizing a tailor-fitted acoustic damping scheme. And of course, the technique is patent-protected not only in the US, but also even in the mainland China. If Astrotec have successfully reverse-engineered the sound quality of K3003 without infringing the patent, AX60 will certainly become one of the top contenders.

Phiaton PS210

Disclaimer: This IEM is owned by a friend of mine.

Phiaton is a high-end brand of South Korean company, Cresyn, which was formerly known as Leemax. As they have been manufacturing OEM products for Panasonic, Audio Technica, and many other well-known companies for a very long time, they must be well-aware of what they're doing.

...Or are they?

HiFiMAN HE-500

Disclaimer: Finally I am completely done with Rick's headphones- Now I need to work on his IEMs. In less than few weeks, the current batch will be finished! :)

As previously verified with Audeze LCD-2 Rev.2 and Fostex T50RP, planar technology finds its versatility in a dipole driving mechanism. Due to less physical constraint given on the moving-mass, a planar headphone generally has low acoustic output impedance, low distortion, and wide frequency bandwidth.

Since HiFiMAN products usually exhibit an acceptable level of electroacoustic peformance, such as that of the classic RE-series IEMs, expectation is higher than ever.

HiFiMAN RE-262: A glory from the past

Disclaimer: This is owned by a mutual friend of mine. Measurement was carried out at 3 mm away from the reference plane using a pair of stock single flange sleeves.

Along with its low-impedance sibling, RE-272, HiFiMAN RE-262 has been known for its superb sound quality. Now their successors, RE-400 & RE-600, have proven to be rather a disappointment, it is perhaps a good idea to look back and check what's changed from the past. Have the current RE-models really devolved?

Sennheiser PX100

Disclaimer: This is one of the loan units Rick has generously provided for me. I'll get to the IEMs once I am completely done with headphones first. Measurement was little tricky to carry out, as the stock earpads were continuously being disintegrated due to aging. I did my best not to worsen its current condition.

PX100 is Sennheiser's classic supra-aural headphone. Although the model itself has been revised as PX100-II, and is not manufactured anymore, it is still considered as one of the best sounding portable headphones ever produced.

STAX SR-003 MK1: Electrostatic in the Ear

Disclaimer: This loan has been provided by my friend, vAsurada. This particular pair is SR-003 mkI, not mkII. Measurement has been carried out at 6 mm away from the reference plane with its headband removed.

Released as a Pro-bias version of SR-001 mkII in 1997, STAX SR-003 features small form factor compared to other full-sized headphone from the manufacturer for portable usage, and a 1.5 μm diaphragm, which is the same thickness as the diaphragm of current Lambda models.

And the question is, can this IEM perform as good?

Sony MDR-EX210

Disclaimer: This is the biggest surprise from Inks' stimulus package!

松尾伴大-san, who is the developer of MDR-EX1000 and the 5th ear mold master of Sony, states EX-series is designed to be as acoustically transparent as possible, by utilizing the essence of Sony's moving-coil driver technology, so that musicians and Hi-Fidelity enthusiasts can enjoy the sound quality alike. And although MDR-EX210 is just one of those random introductory models of the series, I see a great potential in it.

Maxell HP-CN40

Disclaimer: This is a part of the loaner provided by Inks, a good friend o' mine.

Not only Maxell is not a well-known IEM manufacturer, actually, I have never even heard of this Japanese company until very recently. 

Regardless, one of the main features of HP-CN40 is its oval-shaped nozzle. The manufacturer claim that the shape of the nozzle ensures a tight fit within the ear canal. Due to its unpredictable nature in acoustic design, changing the shape of the bore has never been realized by any IEM manufacturers as far as I know. 

Sony MDR-ZX700

Disclaimer: I am not even half way done with Rick's loan.. IOW, I've got a long way ahead! :)

Although ZX700 is a part of Sony's new generation of Studio Monitor headphones, according to 角田直隆-san, who is the mastermind behind the development of E888, D777, Q010, and 1R, the headphone is tweaked to suit the taste of ordinary listeners, rather than of studio engineers. 角田-san clearly distinguishes the difference between his Studio Monitor headphones and Sony's classic monitors:

from http://www.sony.jp/headphone/special/park/products_ms/tech1.html

"MDR-Z1000 is meant to be used outside of a recording booth, while MDR-CD900ST is specifically made for musicians residing inside of the booth. ... The sound, of which a musician hears on stage, is basically a cacophony of noise from various sources. Yet, by clearly distinguishing his performance from that of others, a harmony is created. ... On the other hand, a mastering engineer listens to the entire session, and accurately checks the tonal balance of the result."

And unlike its sibling, Z1000, which is equipped with a liquid crystal polymer diaphragm, ZX700's diaphragm material is made of a plain PET.

Sennheiser HD219

Disclaimer: This is another pair I borrowed from Rick.

Sennheiser HD219 is a low-cost, closed-air/closed-back supraaural headphone, which is designed for portable usage.

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.

Creative Aurvana Live!

Disclaimer: This headphone is one of whooping 18 loan pairs generously provided by Rick. I can't describe how grateful I am..

Along with Denon D1001, Creative Aurvana Live! is known as a clone of Foster's OEM model, 443741, which features a ∅40 mm bio-cellulose driver. Not only the specifications are identical, but also their exterior designs are very similar to one another. Of course, it doesn't necessarily mean 443741, D1001, and Live! should sound the same, but at least their electroacoustic potentiality should be on par.

Foster's patent documents indicate the mix ratio of bio-cellulose to carbon fiber is between 3:20 to 1:2, depending on how much of flexural rigidity is required in contrast to internal loss for a particular application, or vice versa. And in order to achieve ideal elasticity of the diaphragm for faithful bass reproduction, a separate edge, which is made of urethane elastomer, is utilized. Consequently, the driver is durable, water-resistant, and highly elastic with much lower 2nd/3rd harmonic distortion below 200 Hz compared to the electroacoustic characteristic of any of conventional PET drivers.

Sony MDR-XB300

According to the designer of XB series, 松尾伴大-san, this first generation of XB-series (XB300 to XB1000) is specifically tuned for club-goers, who are frequently exposed to fast-paced bassy dance music. In order to accommodate their musical taste, 松尾-san prudently shapes the frequency response to be heavily bass-oriented, while keeping the transient characterstic as quick as possible.

This has been realized by utilizing a pair of huge closed-air ear pads, which effectively eliminates acoustic leak from its source, thus preserving the sub-bass response largely intact.

Sony MDR-XB700

Disclaimer: At last, the loan Danganronpa has generously provided is now completed. I sincerely send my gratitude to him.

According to the designer of XB series, 松尾伴大-san, this first generation of XB-series (XB300 to XB1000) is specifically tuned for club-goers, who are frequently exposed to fast-paced bassy dance music. In order to accommodate their musical taste, 松尾-san prudently shapes the frequency response to be heavily bass-oriented, while keeping the transient characterstic as quick as possible.

This has been realized by utilizing a pair of huge closed-air ear pads, which effectively eliminates acoustic leak from its source, thus preserving the sub-bass response largely intact.

A fundraiser for M.R.O

[Updated on 8/16/13: Since Paypal have deliberately taken down their donation widget, this is now a simple fundraiser for this blog.]

Ultrasone HFI-780 and S-Logic

Disclaimer: I am finally down to Danganronpa's second last pair!! Oh you have no idea how bad I wanted to talk about this manufacturer.. 

Ever since Ultrasone introduce their proprietary technology, S-Logic™, the legitimacy of their claim has been disputed quite heavily within the headphone enthusiast community.

"...In studying the past, it is clear that S-Logic is the only way to influence stereo or channel tone signals to produce a 3-dimensional auditory event without any digital, binaural processing..." from http://ukrtech.com/root/faqfileref/27049.pdf

According to the manufacturer, S-Logic™ is an acoustic passive filter that promotes a front-localized surround sound. In short, this is done by creating an accurately controlled acoustic passage through an opening at the bottom part of the front baffle, and the reflected sound wave originated from the port yields directional pinna notches along the frequency spectrum.

B&K 4128C's HRTF characteristic: 0° / 45° / 90° / 135°

Since conventional headphone auralization techniques, such as Focusrite VRM, Creative CMSS, WaveArts Panorama, or even ToneBoosters Isone involve with actively simulating a specific HRTF target acquired via different head & pinna models, Ultrasone's approach seems rather passive and dull, like that of a simple cross-feed network.

AKG K702

Disclaimer: Yet again, this is Danganronpa's fourth pair. Now I only have two more to go..!

Along the history of headphones, AKG have continously made many technological innovations, such as K340, the ultimate electrostatic-dynamic hybrid, and K1000, which is driven like a pair of loudspeakers. AKG's reference headphones surely have a great heritage to carry on!

And K702 has two notable features: The first one is its bi-layered diaphragm, which is claimed to improve the high-frequency response characteristic, and the second one is a flat voice coil. Although the electroacoustic effect of a flat voice coil is not verifiable, AKG's patent, US6185809, states the diaphragm with variable thickness "significantly improves the vibration behavior of the diaphragm".

Westone UM3X

Disclaimer: This IEM was sent all the way from Singapore. Much appreciated, Nate! Measurement h as been carried out at the reference plane with a pair of small Westone mushroom tips. Unfortunately, it turned out his pair is faulty on the left.. :-/ Thus, only the electroacoustic performance of the right unit will be discussed in this analysis. 

I first auditioned this IEM at the CanJam 09, which was held in Los Angeles, California, along with Westone 3. As far as I can recall, my initial impression was just "OK" and UM3X was slightly more linear than Westone 3, at least to my ears.

And four years later, one of the regular visitors of my blog, Nate, sent in his pair for analysis with specific requests. And as always, I never turn down a friend's request ;)

Sennheiser HD280 PRO

Disclaimer: This is Danganronpa's third pair, and I still have three more to go after this. As I am trying to analyze everything as fast as I possibly can, please bear with me for just a few more weeks! :)

Sennheiser HD280 PRO is a closed-air/closed-back circumarual headphone, which is specifically made for a studio monitoring purpose. 

Sennheiser Momentum

Disclaimer: This is another loan provided by my good friend, Danganronpa. I shall return his generosity with an accurate analysis! 

Dr. Axel Grell of Sennheiser holding a pair of Momentum
from http://www.aes.org/conferences/51/invited_speakers.cfm

Introduced in the late 2012, Sennheiser Momentum is a closed-air/closed back portable circumaural headphone featuring a real leather ear pad & sleek design. At the CES 2013, Dr. Axel Grell, the designer of Momentum, has mentioned:

"The sound is still sennheiser-like and the style meets the sound quality."

As Sennheiser have always been very truthful to their reference sound, which is a downward sloped diffuse-field response, it can be assumed that Momentum is accurately calibrated to match the target as well.

XTZ EarPhone-12 Part 1: Aesthetics

Introduction

EarPhone-12 is the very first IEM made by XTZ, an audio equipment manufacturer originated from Sweden. As their philosophy aims for a high price per performance ratio, the IEM shall reflect their value as well.

XTZ EarPhone-12 Part 2: General analysis + XTZ Player

Continued from Part 1, Aesthetics


XTZ EarPhone-12 is designed with an appropriate philosophy in mind:

IOW, unlike other random IEM companies, the manufacturer actually employees a conventional ear simulator for calibrating their products. As such practice is essential for making an accurate, high-quality headphones, it can be assumed that XTZ certainly know what they're doing.

And most importantly, in collaboration with Dirac, XTZ provide an iOS app dedicated for EarPhone-12. XTZ  According to the manufacturer, the app yields:

- An improved soundstage

- Clearer voices

- A tighter and deeper bass reproduction

- Improved timbre

- Perfect Balanced Sound

Since Dirac's HD technology has been proven to be very legit, a huge improvement in sound quality can be expected.

SONY MDR-CD1700: The heir of the throne?

Disclaimer: I purchased this headphone in 2004 from an UK distributor. The model was already discontinued in 2000, so the price was £63 + shipping. Not a bad deal, I guess.

MDR-R10, also known as the king of headphones to SONY enthusiasts, debuts in 1988. And the economic downgraded version, MDR-CD3000, follows right after along with other introductory models. These are known as the first generation CD series. SONY have had a great success with the first generation, but none of the headphones really sound like R10; they are all too bright! And finally, in 1996, the second generation, starting with MDR-CD1700, equipped with 50 mm bio-cellulose & Vectran composite drivers, rocks the scene with its neutral tonality close to that of R10.

Sony MDR-CD780

from http://www.sonicstudios.com/mdr-f1.htm

It has been 10 years since the release of the last generation of Sony's CD-series headphones. While Sony MDR-CD2000 is featuring a Vectran-bio cellulose composite diaphragm, MDR-CD780 simply utilizes a PET diaphragm, while sharing most of the technical specifications with its sibling. Although CD-series mainly consists of a closed-air/closed-back design, this generation adapts a radical open-air/open-back configuration, like that of MDR-F1, for better airiness, but with more isolation and comfort.

Sennheiser HD650

Sennheiser HD650 has been known for its deep bass and neutral tonal balance ever since its release. After 12-consecutive-years of dominance, does this headphone still have a chance against new-bloods?

Stax SR-207: Back to the basic

Disclaimer: This unit has been generously provided by my good friend, Danganronpa. And this is what I call a Southern hospitality, thank you very much! In order to minimize the linear error in the low frequency range, measurement has been carried out with acoustic leak minimized, by using a silicone putty as a sealant.

Although SR-207 is STAX's cheapest entry model, it is still a part of SR-Lambda series, which has a great heritage and legacy in the history of headphones. And since all of the current Lambda series models from SR-207 to SR-507 share very similar technical specifications, this entry model indeed deserves a good look as well.

On the modification of Sony MDR-1R: It's as easy as ABC

Several months ago, a friend of mine asked me to see if there is a chance of modification with Sony MDR-1R. So here I am at it. The goal of this modification is to be quick, simple, and reversible, while taming the mid-bass range effectively. All you need here is a scissor, a masking(duct) tape, and a screw driver! (And preferably some foam pads with various density)