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Thursday, August 15, 2013

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".

PRO: Accurately matched drivers; this is the best I've seen from any dynamic(moving-coil) headphones. There is a lot of second order harmonic distortion in the bass, which may contribute to the enhancement of perceptual bass quality.

CON: The response above 5 kHz may completely be equalized depending on how the headphone is placed on the pinna. The effect is even greater than that of Sennheiser HD650, which is already well known for its high amplitude deviation in the treble.

ON SECOND THOUGHT #1: Surprisingly, even under a good amount of acoustic leak, the sub-bass is still well-sustained. This indicates that K702's diaphragm mass is much lower compared to those of other dynamic headphones.

ON SECOND THOUGHT #2: None of the acoustic modifications presented here seems to substantially "increase" the electroacoustic performance of the headphone, which means the manufacturer have precisely optimized the sound of this headphone using a computer simulation model.

ON SECOND THOUGHT #3: With a small boost in the bass & at 4 kHz, K702 will accurately follow Dr. Olive's reference target.


  1. Nice research like always!
    Could you please make a recommendation on what needs to be done so that AKG K240DF would follow Dr. Olive's target?

    1. Thank you! In order to answer your question, I need a pair for analysis first LOL

  2. Have you tried this mod and measured it?

    1. I don't open up headphones unless I get a permission from the owner- and K702 is going back very soon.

  3. Hi Rin
    Thank you for your answer.
    Nice and interesting blog btw ;-)

  4. Adding 100ohm impedance will be beneficial.