This thread got me interested enough to try out the TD100, so here's my noob impressions of it. Caveat: I only have eterna rev.2 as my main point of reference, and zero eq'ing done. I've also listened to klipsch X10, Westone 1, AudioTech CKS90, CX300 in shops, but I'll refrain from making comparisons to those as I haven't listened to them enough (I can say with confidence the CX300 is the weakest of the bunch tho).
First impressions out of the packet: the TD100's treble sounded very harsh, mids recessed esp. the lower mids, Bass was anemic compared to eterna.
Burning in period: Very dramatic improvements, esp. to the treble.
After 50 hrs burning: Overall sounds quite smooth now, esp. compared to when I first got it. Unlike some others in this thread, after 50hrs of burning I'm not noticing anymore improvements to the sound, but maybe more experienced listeners would hear more changes. I still think the lower mids are slightly recessed, and upper mids a bit too loud. Soundstage is great, instruments/voices are clearly defined and separated. Picks up a lot of details.
td100 vs eterna rev.2:
I realize that this is probably a terrible comparison, as they are quite opposite. At the lowest registers, eterna's bass beats td100 hands down, eterna's bass goes much deeper with much more quantity (and no amt of eq'ing will be able to bring the td100's bass up to eterna's levels). For lower mids I found td100's a bit too soft, while eterna's was overwhelming (too loud). Upper mids is the opposite, td100 slightly too loud, eterna a bit too soft. In terms of soundstage, I think the td100 does much much better, eterna sounds a bit flat. td100 also picks up a lot more details.
Eq'ing:
As you can guess, my equalizer setting for td100 and eterna look almost opposite of each other. Eq'ing can bring eterna's low mids down a bit and upper mids up, and opposite applies for the td100, with the only caveat that you can't bring the td100's bass up to eterna's levels, so in that sense, eterna gains more from eq'ing.
Overall:
I love and prefer the td100 for listening to pop music. After eq'ing tho, I still prefer eterna for heavy rock music. For something like rage against the machine, i must have my bass
! The drums sound more alive, and overall more fun. Judging by the reviews I've read on this forum, I'm guessing I would be considered a total basshead, so take my opinion with a huge grain of salt.
td100 vs N3 vs XNR120PRO(pre burn-in):
I sold off the N3 and XNR120PRO to friends, so I've only had quick listens to them. N3 sounds very similar to td100 but with less bass. I listened to XNR120PRO when I passed them to my friend, so it hadn't been burnt in yet. Initial impression is that its bass is more punchy than td100; treble sounded harsh, but I expect that like the td100 it mellows down after burning in.
Noob questions for my senpai:
What do you mean by driver flex? Do you mean the sound slightly "skips"?
What is a warm sound and what is a cold sound?
Why do people prefer Y cord over J cord for non-over the ear IEMs? I prefer J-cord better myself...