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Monday, July 1, 2013

Audeze LCD-2 Rev.2 part 2: General analysis

Disclaimer: This review is made possible with the support from Audeze, the manufacturer of LCD-2 Rev.2. I sincerely appreciate them for loaning me a demo sample.

Continued from part 1, Aesthetics.



In October 2012, a study dedicated to finding the optimum spectral characteristic of a headphone, has been presented at the 133rd AES Convention in San Francisco, California. Written by Sean Olive and Todd Welti of Harman International, the research paper involved with an extensive subjective assessment test by utilizing various headphones, including models from AKG, Beats by Dre, Bose, and V-Moda. Audeze's LCD-2 Rev.2 is included among them as well.

And here is the test result: It turns out that LCD-2 Rev.2 beats every single headphones it is compared against, registering it at the very top of the list in terms of sound quality. Surprisingly, this headphone turns out to be subjectively the most linear even in the sub-bass frequency response range, compared to the bass-bloated headphones from Beats by Dre and Bose.

Can Audeze LCD-2 Rev.2 really be a game-changer... a headphone to rule them all?




PRO: LCD-2 Rev.2 not only features a well-extended, very linear frequency response, and a lightning-fast transient characteristic, but it also has virtually no distortion even at -60 dB, which is 0.1% of distortion relative to the fundamental signal. On top of that, LCD-2's impedance is extremely flat, almost purely resistive. No mere moving-coil headphones come even close to such electroacoustic performance.

CON: The weight of this headphone is almost half a kilogram, which is roughly equivalent to a pound, suggesting that the headphone is most likely not for a simple portable use.

ON SECOND THOUGHT #1: By blocking the rear vents air-tight, air compliance in the rear chamber decreases, radically changing LCD-2 Rev.2's tonal quality especially in the mid-frequency range. The resulting harshness is due to the reflection within the housing, and can be damped effectively once a proper modification scheme is carried out. The sound quality will further be improved by such modification for sure. Is it a game changer, as claimed by the manufacturer? You bet it is, and on top of that, there's a lot more to it.

ON SECOND THOUGHT #2: As expected, the new reference target of Olive and Welti does not quite suit LCD-2 Rev.2's electrically flat frequency response. However, a modification which will be presented once my fundraiser reaches its goal, can be used to match the target.

ON SECOND THOUGHT #3: A free-air analysis, along with an infra-sound analysis will be discussed in the upcoming part 3, in-depth analysis for further assessment of the headphone's electroacoustic performance. In addition, Audeze's calibration chart will be compared against my own data for a peer-review.




References

S. Olive and T. Welti, "The Relationship between Perception and Measurement of Headphone Sound Quality," presented at the 133rd Audio Eng. Soc. Convention, preprint 8744 (October 2012).

S. Olive, T. Welti, and M. Elisabeth, "Listener Preferences for Different Headphone Target Response Curves," presented at the 134th Audio Eng. Soc. Convention, preprint 8867 (May 2013).

10 comments:

  1. Those distortion figures are really something! And looking at the IR I'm quite surprised how fast the LCD2s are considering their accentuated lows.

    Just a small question, the compensated curve doesn't really match Audeze's, does that mean their head & torso jig utilizes a different EQ compared to yours?

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    1. If you're referring to the last graph, that's a Olive-Welti compensated data. Otherwise, I'd confidently say my compensated data and their calibration are in good agreement from DC to 10 kHz: http://2.bp.blogspot.com/-nVCA5LnMAIg/Ucy_jSjUl3I/AAAAAAAAHKU/zNmw2tpH_a8/s1024/Untitled-2.gif

      There's a slight deviation past that, but it is simply due to difference in pinna geometry/testing methodology, as mentioned in the in-depth analysis. Please keep in mind that my HATS, EURI, has a urethane skin covered, which may contribute to the overall damping in the low-mid range.

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  2. I was referring to this one: http://3.bp.blogspot.com/-PDVpOJ-hDM8/UczI40Y0qZI/AAAAAAAAHKk/B0OS30FVP80/s768/IMG_3691.jpg

    The response is rolling off at 5db/oct within the midrange in that chart but yours is nearly 10db/oct? Maybe it's because of the angle that makes it looks like Audeze's slope is steeper.

    Just looked at the link, seems like my eyes were playing trick on me :P my bad.

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    1. Hieu, my eyes do that all the time! :P LCD-2 is a nice headphone for sure, and I think I can further improve the sound. Just need a scratch pair to play with tho. A toy worth a grand LOL

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  3. Hi Rin, just to reiterate, the Audeze were preferred, in general (by majority but not all of the subjects), AMOUNG THE HEADPONES TESTED. I think some readers might jump to the concusion that the Audeze are the best headphones overall, which of course is not the case at all. Also, subsequent research by us, which you also cited, shows that flat is NOT the preferred curve. Actually I don't believe anyone knows what that curve is yet. But, I believe a curve with more midrange peak, and moderate amount of bass lift is preferred over the "flat"-ish Audeze response. Somehing like the K701, but with more bass. ... something more like the in-room curve.

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    1. How are you Mr. Welti! Thnx for dropping by again. You are absolutely right: Such assumption will totally be an over-generalization, as the journey in search of a perfect headphone has only begun. I am currently utilizing your 'modified RR' at the end of each article to show my gratitude to the scientific significance of the convention paper #8867.

      I really appreciate you and Dr.Olive for all the works you've done so far. A new era is neigh :)

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  4. Thanks Rin! Every time I look in your blogs i find something more interesting.

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    1. Haha, that's exactly what I am trying to do :) Please drop by more often!

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  5. When I see this response charts they seems like the Hifiman RE 262/400 ones. Are their sound signatures similar? What do you think is the most similar iem to LCD-2 in your opinion?

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    1. Oh.. I really have no idea- Unless then come up with an isodynamic IEM..

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