Orthodynamic Sennheisers

Perhaps out of boredom with the limited range of available headphones in the market, my good friend Ian went and created two very special “Sennheiser” headphones. I don’t even know if they should be called Sennheisers anymore, as the drivers have been replaced with Yamaha and Audio Technica orthodynamic drivers, and the only thing Sennheiser thing in the headphone is the housing.

There are two headphones here, one using a HD497 housing, and the other a HD202. The HD497 doesn’t look so stock, as the pads have been replaced with a stiffer leather pads, and the recable job gives away the fact that the headphone has been modded as well (though nobody would’ve guessed the Yamaha drivers inside). The HD202, on the other hand, is the ultimate sleeper as it looks totally stock. The only thing that may give some hint is the weight of the headphones, as the ortho drivers inside are significantly heavier than the stock drivers. But even then, I know that the weight is different because I own a stock HD202. The headphones felt comfortable to wear, mostly due to the generic low-end Sennheiser housing. They require an amplifier to work properly, but the amplifier requirement is relatively light compared to the big Hifimans.

Breaking news: "Sleeper phones kick the butt off of $300 full size cans."

With custom damping methods and a proper combination of housing and driver, the result is two very well tuned and very likeable headphone. Tonal balance wise, the two headphones are among the best I’ve heard. And the midrange is so satisfying — clean, smooth, seducing midrange with good clarity. The treble has a soft extension, and though both drivers’ rolls off early, the smoothness quality of the treble is very lovable. The transients are smooth and effortless — after all, it is a planar design, and planars are famous for this quality. Take a listen to these two headphones, and you’d wonder why people spend so much more money on $300 headphones, as the latter group often has far more polarizing weaknesses while these orthos are so well balanced and are so musically pleasing. On local meets, the HD497 is a constant crowd favorite — as anyone with some decent experience with headphones would be surprised to see this beater phone having a tonal balance far superior than their expensive full sizes.

The HD202 is equipped with an Audio Technica ATH-1 driver, while the HD497 has a Yamaha YHE-50A driver. Listening to the HD202 by itself is quite pleasing. The orthodynamic driver was able to strike a nice balance between laid-back and forward, hitting it perfectly in the middle, so you never feel the sound to be too laid back or too forward. Generally superb tonality, good midrange, good transients, good treble, but a little weak in bass. The YHE-50A equipped HD497 is clearly in a superior class, as three dimensionality, midrange and treble quality, even bass weight and punch are all very good.

"Ortho inside"

If I’m being picky, sure, there are things to criticize about these headphones. Micro level details, frequency extension, imaging, low bass, all are nothing to be proud of, as vintage planars are known to be limited on those areas. But the bottom line is that the average guy is not likely to be bothered by those, and yet the pleasing tonality, incredible midrange, and the effortless transients are bound to put a big jaw dropping effect. You won’t be able to find these headphones off the shelves, and even if I asked Ian to build me a copy, he probably won’t be able to, seeing that the drivers are taken from rare vintage ortho headphones.

Kudos to Ian for his creativity, and thanks to Kopilaki, the lucky owner of the two Sennheisers for lending these babies to me.