[Harito408]

Hello everyone I'm thinking about getting the sennheiser MOMENTUMs and I was wondering if these beautiful headphones need a portable amp? If so please comment on what you think it is and if not why? All comments are appreciated thank you.

 

[NA Blur]

First of all what device are you listening to?  If it is something like an iPod then there probably is no need for an amp.  If you do end up needing/wanting a portable amp I use a Bithead with my Brainwavz M2 IEM and a labmate of mine also likes it for his Grado SR-80.  The bithead is a tried and true headphone amp.
 
Have you actually listened to the Momentum?  It is a good sounding headphone, but the bass for me was out of place it somewhat boomy.  It is definitely a bass emphasized headphone.  Another option would be the B&W P5.