Skullcandy's Director of Electrical & Acoustical Engineering, Dr. Tetsuro Oishi Visits InnerFidelity!
Dr. Tetsuro Oishi
Tet is from Japan and came to the U.S. to attend U. Mass at Dartmouth for his advanced degrees in acoustics and electrical engineering. There he designed and fabricated various prototype transducers for underwater applications such as directional broadband piezoelectric transducers and arrays, acoustic motion sensors, and bioacoustic transducers. He also developed a water pollution detection system using the acoustic resonance spectroscopy technique. Wow, cool stuff.
Out of school he went to work for Bose's Automotive division modeling audio in cars, and then into the headphone division where he worked on noise canceling technologies. He also had a hand in the AE2 design.
Early in 2010, Skullcandy recruited him to lead its effort to improve the audio design and quality of its headphones. Yet another piece of hard evidence that Skullcandy intends to become a strong and well-founded maker of headphones.
The Hesh 2.0
The Skullcandy Hesh ($50) has been around for some time. The Hesh 2.0 ($59-$69 MSRP, likely available in April at Target and Best Buy) is a complete revision, and is Tet's first full effort at Skullcandy. This headphone is a medium-low cost circumaural, sealed headphone; designed for a big-bass sound; and no doubt a potentially very popular headphone among the action sports crowd looking to upgrade from junker headphones.
I put the Hesh 2.0s through the measurements routine with Tet looking on, and we spent a good bit of time discussing how to get a good fit and seal on the head. Over the last year I've developed some techniques for getting the job done, and I was heartened to hear that Tet uses some of the very same methods in his testing. (Sorry, I've got some competing publications measuring headphones, so I'm not going to detail these techniques.)
The Hesh 2.0 measured fairly flat to 1kHz with, what I consider, an appropriate roll-off to 4kHz, and then a reduction in overall treble energy about 5-10dB reduced beyond what I would consider flat.
Subsequent to our visit, I spent a good bit of time listening to these headphones, and comparing them to the Sony MDR-XB500 and Audio-Technica ATH-WS55. I felt the Hesh and WS55 easily bested the XB500, which sounded woolly and bloated in comparison. The WS55 emphasized the bass and the mid/upper treble a bit more, but the Hesh seemed more even and coherent. I think the choice of having good bass extention; keeping the bass properly related to the mids; and then rolling off the highs to get rid of crappy harshness from compressed files, and give the impression of big bass, is the way to go for this type of can. (Overwhelming bass is overwhelming.) I think the Hesh 2.0 is going to be the go-to recommendation for the hoodie wearing, bass-heads out there.
General Headphone Talk
Tet gave me some super help interpreting headphone measurement data (and we'll get to that on the next page), but we spent quite a bit of time just talking about headphones in general. Well ... that's not quite right, we talked about a wide variety of very particular aspects of headphones. Because I'm free to opine, and he's constrained by the nature of his job, I'll quickly rattle through a few of the topics we covered and what my take was:
- Headphone mini-plugs - Should be slender and have enough "neck" on them to reach into the jack while the player has a protective cover on it. Plugs should not be straight as it tends to stress the jack more; and I believe plugs should not be 90-degree angles, as it tends to snag on things more easily. I like a 45-degree angle plug. I showed him the plugs on the V-Moda M-80 as an example of a great plug.
- Freedom of spin in "lay flat" headphones - If the headphones are laying flat with cushions down on a table in front of you, you should be able to pick the headphones up and spin the earpieces towards your ears and slightly beyond. But there should be a limit in how far they can spin so as to provide a little more pressure of the pads behind the ears than in front of the ears.
- Headphone cables should have plugs at both ends - Headphone cables should attach to the earpiece with a straight 3.5mm mini-plug, and without any weird mechanical attachments. This will allow the manufacturer to make one cable that fits all of its headphones, and alternate cables to turn the headphones into headsets for iPhones, Androids, and other phones easily. Even if a manufacturer doesn't provide those options, having a standard connector will allow the user to buy aftermarket cable to suit the customer's style of use.
- Tangle-free cables - It's a hot topic among headphone makers at the moment, and I showed Tet the cable on the Philips Citiscape Downtown. It's a flat cable you can wad to your heart's content, and when you let it go, nine times out of ten it just "sproings" open completely tangle free. Then I showed him a prototype I got from a company with a flat, woven-cover cable the is almost impossible to handle without tangling.
Most interesting to me was the feeling that we were two hard-core headphone enthusiasts, yammering on about headphones at about the highest possible level one could imagine. It was great fun, and immensely satisfying.
The coolest thing of all, though, was getting Tet's run-down on headphone measurements.