Mark Smith, Resident Advisor
The 4000s' true strengths are its sound, price and portability, making them ideal for travel and casual usage.
A huge part of the reason why the 4000s are easy to wear is the way they sound. The low-end is rich without feeling woofy or unnatural, and the soundstage is refreshingly wide for an enclosed model.
In an effort to get a rough idea of the 4000s' frequency response curve, I A-B tested them against the 770s using Sonarwork's (highly recommended) headphone calibration plug-in, which effectively flattens the 770's hyped top-end and scooped low-mids. The comparison emphazised even further the 4000s' wide soundstage, which felt vivid and 3D while remaining faithful to the parameters of the production
I also compared the 4000s with AIAIAI's TMA-2 and Sennheiser's ubiquitous HD-25s, while running vinyl through Rane's MP2015 mixer. It was here that I got a clearer sense of the 4000's strengths. While the TMA-2 and HD25 were more in-your-face, you also had a far greater sense of how they were colouring the music, even to the point of it feeling claustrophobic. The 4000s in comparison felt a lot more genuine, clean and open, with a more satisfying sense of velocity, making them a joy to use for long periods. The low-end in particular has a sense of vitality and air about it that's fairly unusual for a headphone in this price bracket.
See the full review here
More info on the Phonon SMB-02
More info on Phonon 4000