I stumbled upon to some free stuff over the last few weeks so here you go:
Miasmah appears to be an ambient/idm label which released many many things for free and recently started releasing CDs. I have not checked out much of their catalog, but the tracks on their myspace page are quite good. If nothing else you should check out Xhale - 'Slugabed' because it reminds me of old Warp stuff and despite being free it fucking kicks ass.
miasmah at discogs
Xynthetic is another netlabel. They focus on sort of industrial/ambient/idm/drum and bass. Again, I haven't checked that much out, but I recommend their first compilation "Statement Of Purpose" because it has fucking awesome tracks from Dryft, Displacer, Keef Baker, Amorph and a few others I can't remember at this time. Some suck, but hey it's free. Again, even though it's free it is very professional sounding. They've also very recently put out a second compilation, so that's probably good too. This label feels like Tympanik Lite, so if you like Tympanik you'll probably find some good stuff here.
Statement of Purpose: