[Scrib]

I have a XB700 and have loved it on my laptop. However when I want to use it portably I find it's disappointing simply because I can't eq it the way I want (I have an ipod),  It sounds duller and the sub-bass that I love on it just doesn't come out unless I crank the volume to unacceptable levels. 
 
I bought a Fiio E11 to fix this very problem but it barely does better and may even be worse because I can't tell when the volume is cranked up too high. When I have both the Fiio's and Ipod's bass boost on it's tolerable but otherwise it's not as good as I know it can be. I have a nagging sensation that some of my friends may have spoiled the headphones a bit when they turned the volume knob all the way up. I could hear the cans vibrating and I was nowhere near them.
 
So I was wondering if anyone knew any good portable amps to use with the XB700 that would really bring out the bass. Preferably in the <$100 dollar range, but I'll make an exception if it's good enough.
 
I was originally looking at the ZO2 but after my experiences with the E11 I think I'll ask first and check peoples impressions.
 
Thanks in advance.

 

[Posam]

The ZO2 will give plenty of bass, I believe it is up to 12 db at max contour. I have not heard the the Fiio and I haven't tried the ZO2 with my xb500s yet because I didn't have enough space to bring them to college. When paired with my V-MODA M-80s it really cranks up the bass.
http://www.youtube.com/watch?v=ptuXzlNgn8c
http://www.youtube.com/watch?v=nWL817WlqSo&feature=youtu.be
Those are a good way of guestimating what it will do.