More important, the NS400 upgrades the NS200s drivers (the tiny speakers inside) with a titanium coating, which makes them stiffer and, in theory, should improve sound quality. Indeed, in practice the drivers provide a noticeable upgrade. High-frequency sounds are better defined, while midrange frequencies are more detailed and bass is tighter (which also benefits other parts of the spectrum and gives a more-spacious sound). However, the NS400 isnt perfectbass is still somewhat bloated (and louder than Id prefer), and the NS400 doesnt draw me into the music as well as the more natural $90 Spider Realvoice ( Macworld rated 4.5 out of 5 mice ), or the more accurate $99 Etymotic mc3 ( Macworld rated 4.5 out of 5 mice ). On the other hand, I found the NS400s midrange and high frequencies to be an improvement over those of the $80 Maximo iP-595 ( Macworld rated 4 out of 5 mice ), though the iP-595 offers tighter, cleaner bass.
Macworlds buying advice
While I found the Nocs NS200 to be a little bland, the NS400 represents an improvement in looks and sound that more than compensates for the $30 price increase. There are better sonic values around this price point (although the NS400s street prices are often substantially lower than the list price), but the NS400 will appeal to anyone looking for good headphones that match their Apple products.
R. Matthew Ward got a little nostalgic for the bygone days of the titanium PowerBook G4 while writing this review. In addition to regularly contributing to Macworld, he writes about audio, Apple, and other cool stuff on his personal blog.