Thanks for the replies and the info! I ended up going with the Sennheiser's for the extra bass and I'm looking forward to trying them out.  I'm new to all of this and these are the first pair of decent headphones I've ever bought.  I have a set of Beats earbuds that I won a while ago that were...

I'm hoping someone with a bit of experience with both could help me decide between the Sennheiser HD7 DJ's and the ATH-M50X with a Creative Sound Blaster E1 amp that are both on Massdrop for 169.99$ right now.  I'll be using them mostly with an iPhone 6, iPod and Macbook pro and would be picking...