Seriously, if you find the HD800 too congested I'd just forget about IEM's (and probably even headphones) and just stick to speakers. You won't find any IEM's with the same width as open headphones (it's kind of the law of nature) and the HD800 is probably wider than 99% of the headphones out there.... If you only hear hiss with volume on zero with the Magni and your laptop I'm positive it's the source. The Magni has quite high noise floor. There's a huge difference in sensibly to hiss for a pair of IEM's and full sized headphones and as already mentioned BAs can act pretty word with sub boards sources (ie not suited for IEM's).