Recommendations for headphones under $400?

Sennheiser is still excellent value for the money but IMHO you're not really getting an excellent product until you're up into the 650 range or above. And since your primary criterion was good bass response for rock music, I'm assuming you want to stay away from open backed designs (which the most beloved Sennheisers, including the 650 and especially the 800 are). 

I'd absolutely think about (and preferably try to listen first) to the PSB, M&D, and Oppo options. All are in your price range and offer strong performance.

    uberwaltz,

      If you want good, accurate bass that's able to go as deep as the music demands without sacrificing mid-range and treble performance, I'd suggest either the Oppo PM-3 or Sony MDR-Z7. 
      The Oppo use planar magnetic drivers while the Sony use exceptionally large conventional drivers.  Both are closed back, very comfortable and very good but slightly more than your $400 budget.

Tim

@noble100
Has been a couple of recommendations for the Oppo but only ones I see remotely near my budget come from Hong Kong and not sure they can be trusted to be genuine?
Have to keep searching....

At the much reduced price of around $250.00 NOTHING can compete with the HiFiman HE-400i’s!!!While they don’t go as low in the bass as some choices the wonderful rich midrange and extended sweet treble make for hours long listening sessions with no fatigue...Decent imaging and staging and fairly easy to drive...Should sound fantastic with the Schiit amp!