The Nocs NS400 use 8mm dynamic drivers. At around £70, they sit at a price where the most tenacious headphone manufacturers start to move to balanced armature drivers - Phonak's 012 use this kind of driver.
Balanced armature drivers tend to offer greater accuracy, making them a good choice for earphones that strive for a highly-detailed analytical sound. Dynamic drivers are renowned for their meaty bass performance. The Nocs NS400 prove that the kind of driver used doesn't have to dictate sonic personality to the letter.
These earphones are highly detailed, with a prominent treble that once again reminds of the immensely revealing Ultimate Ears UE700. The high-end is less intense than that dual-driver model, but among dynamic driver buds of its class, the NS400 is one of the brightest. Aiming for a bright sound signature is as dangerous as focusing on bass (which can result in a boomy mess), with a high risk of sibilance and harshness. That deadly duo can make listening at a decent volume tiring or, at worst, outright painful.
We subjected the NS400 to dozens of tracks prone to sparking off sibilance and found that they performed extremely well, with adequate treble resolution to render bright material without any nasty effects. The tone of the high-end is uncoloured too, making them some of the best trebly earphones you can get for under £100. This is a definite improvement over some previous Nocs models, which over-did the top-end resulting in an unbalanced listen.
UPDATE: Further burn-in has resulted in an increase in bass response that has somewhat unbalanced the sound. Non-bassheads beware. As a result, we've dropped a point off the score.
Bass performance is also very good. It has the generous spatial volume associated with dynamic drivers, but doesn't over-do it. The Ultimate Ears 400 offer greater low-end power, but the balance here is better, fitting in more convincingly with the rest of the output. Those willing to spend more (as in over £100) will be able to enjoy tighter, deeper, faster bass, but they're commendable nevertheless.
What we'd really like to hear from the NS400 is a little bit more mid-range texture and detail, to complement the top-end. However, if it managed this they'd be able to compete admirably with earphones costing a lot, lot more. Fingers crossed this is exactly what the dual-driver NS800 will offer.
If you don't want to spend more than £70 on tiny little ear speakers, though, the Nocs NS400 are fantastic, offering more detail than the Jays a-JAYS Four and a sound signature with a high-end style that won't tire your ears. We won't be knocking Nocs any time soon but if you don't care too much about looks the Phonak 012 offer better mid-range performance and slightly higher fidelity sound.
An attractive pair of earphones made using quality materials, the Nocs NS400 deserve more attention than they'll probably get. Crucially, though, they sound great too, with performance that matches the very best available at the price. Plenty of detail, without trading in bass clout as a result.