So I have this brand spanking new M11. My old AKG 501 headphones don't really do the job. My Sony MDR-7506 headphones (which probably retailed for $130 a few years ago, and which I think I got on sale for about $79), sound pretty good. But after listening to my CD-ripped flac files for a bit, now there's an itch I can't quite scratch. I'm wanting just a bit more clarity in the mids, a bit more bass depth. A bit more ... stage. I listen to to many kinds of music, though I take the most audio delight in certain classical pieces. While I'm sure the FiiO IEM's are great, I really want over-ear stuff and they don't make any. Is there a headphone you can recommend as a _substantial_ upgrade to my old MDR headphones, preferably under $300, that will work well with the M11? I'm looking for an over-ear experience that is matched to this particular device (so balanced connections may be a better option, if applicable, I have no idea). Thanks for any advice.