But audiophile headphones like the Sennheiser HD 6XX go another route ... Of the ones not already mentioned above, the HD 560S ($230) and HD 660 S2 ($600) are the most compelling.

Generally speaking, 500-series headphones have enjoyed wide frequency ... Perhaps the most compelling alternative, though, is Sennheiser’s own HD 600 – they’re a step up in performance ...

Sennheiser's consumer audio division has released a wallet-friendly headphone by way of the HD 505. It's a wired, open-back circumaural headphone that sits under the vaunted HD 600 series ...