Fiio e7 or e11? Dac worth it?

Depends on what you'll be using as a source.  If you're gonna be amping your computer's headphone out, then definitely use an E7 since the E11 won't be suitable for several reasons (main one being you can't charge it and use it at the same time).

A DAC converts the digital signal from a PC to analog, and this is sometimes necessary because the built-in headphone amps in most desktop PCs is awful.  The E11 would be better if you were gonna amp a portable device though, like an iPhone, iPod or the like.

It really just depends on what you want to use them for though.  The E11 is more powerful, sure, but you're not gonna be using most of that power for IEMs.  In fact, most IEMs don't even need amping.  Still, you'd be able to bump the bass up a bit with either the E11 or E7, so it's just up to whether you want the DAC or not (keep in mind though that the E11 is better than the E7 as an amp, as well as cheaper).

you got a typo, its MOAR bass lol... E7 is spoken pretty highly of here + it has the added bonus that if get some more power hungry cans you can match it with the E9.  search the forum thou cause there a bunch of threads with info and reviews of both

This ^^ (DaBomb's post)

Plus if you're looking to simply add bass boost - the E7's boost is bigger (more change) but tends to colour the entire spectrum IMO - bleeds into the mids for setting 2 & 3.  For me it muddies things too much.  The E11's bass boost is smaller - but is more cofined to just the bass frequencies.  I'd call it "more targeted' - it actually doesn't work too bad.

As DaBomb said though - E7 if you need DAC primarily with added benefit of lowish power amp with bass boost.  E11 if you only going amp (ie portable) - more powerful, but doesn't have the DAC component.

Also - I notice far more impact with my cans than my IEMs.

For my comparison between the two - look here (http://www.head-fi.org/forum/thread/556783/fiio-e11-review-and-comparison-e7-amp-section-only)

This was my opinion only - YMMV.