JVC says its HA-S400 headphones are powered by the world's first "Carbon Nanotubes diaphragm." It's a 30mm driver and while I can't tell you how special that diaphragm is or isn't, the results are good.
The headphones sound pretty dynamic with a little extra sizzle in the teble, and deep bass that's reasonably tight. They've got what what we like to call a happy-face sound profile, with both highs and lows that are a little amped and mids that aren't. In fact, I'd say the mids are these headphones' weakest area -- there's just not a whole lot of warmth to the vocals -- but in all, this pair sounds quite decent for the money.
After having my initial listen, I ran them by Steve Guttenberg, our resident audiophile and author of the Audiophiliac blog, who assessed them favorably.
"Not bad," he said. "There's nothing offensive about them. And they're fairly comfortable."
From a high-end audio guy listening to $26 headphones, that counts as an endorsement.
I don't expect a whole lot from sub-$30 headphones, so when I find a pair that's a bit better than usual, I'm pretty happy. Among other models, these compete with Panasonic's RP-DJS400-K headphones (around $23 online, about £27 in the UK) and Sony's MDRZX300 headphones (around $26 online, about £18 UK). I haven't tested the Sonys -- I'll have to pick up a pair -- but I thought the JVCs sounded slightly better and were slightly more comfortable than the Panasonics.
In all, the Nanotubes may not deliver quite as much bang for the buck as the Flats, but they're also a very good bargain at their modest price.