I found my favorite tips for the H1, which are the large ortofon tips. They are the most comfortable tips I've tried for the H1 thus far and allow for shallow insertion with a vacuum like seal. This combination has greatly helped the issue I had with the highs. They still sound soft but are more open and less subdued. The soundstage sounds taller as well. I recommend the ortofon tips over the hybrid tips to get the best out of the H1's. I still love how the midrange is presented, which differentiates it from other iems I have owned.
More XBA-H3 sound impressions and a short comparison to the XBA-3 after 20 hours of "burn-in":
I don't think these have been changing much since yesterday, bass is still boomy and dominant no matter which test track I choose. Trying to get a better idea of their tonality, I bring the XBA-3 into the mix... and sure enough, these are even closer to the H3 than the XBA-4. There's nothing of the XBA-4's strangely skewed upper frequencies in the H3 and in fact I'd say the latter's mids and highs sound pretty darn close to the XBA-3's. Their bass, however, is good deal more bloated and obnoxious, so I try to equalize it down to XBA-3 levels.
EQed down by -4db @ 80Hz , the H3's bass quantity starts sounding about on par with the XBA-3's and I can finally try to compare their quality, which, to my ears, is somewhat of a mixed bag. On the one hand the H3's dynamic driver adds slightly more natural timbre and effortlessness to the bass range, but strangely enough, even at comparable amplitudes, the H3's bass sounds a tad worse defined and slightly more blurred than the XBA-3's. There's seems to be something odd going on down there, maybe some kind of interference between DD and BAs, idk, but the H3's low end doesn't sound entirely clean and well controlled to these ears.
Once again bringing the EX1000 into the comparison, it's so immediately apparent how different these are to me, much more linear and controlled in bass and overall just leaner, cleaner and more sophisticated.
That said, for those who love the XBA-3 sound, but would like significantly more bass, the XBA-H3 may be the ticket. As someone who thinks the XBA-3 have more than enough bass punch and would rather trade some mid-bass for a little more deep bass extension, I'd say the XBA-H3 are barking up the wrong tree, as they just add an evenly distributed heap of bass on top of what's already there in the XBA-3.
XBA-H3 vs. XBA-3 comparison update after blocking the H3's vents, as suggested by Inks / Rin:
Believe it or not, but it's amazing how much of a difference two tiny pieces of duct tape can make for the H3. Blocking the housing's vents results not only in reduced bass quantity, but first and foremost in significantly better control. A bloated and blurred offering for the Beats crowd turns into a pair of serious top tier IEMs. They still remain quite bassy though, even after the mod, but timbre and coherence are greatly improved across the whole frequency range.
The XBA-H3 basically sound like a slightly darker / warmer version of the XBA-3 now, with better deep bass extension and more low-end authority. I still feel tempted to EQ them down by 2 or 3 db @ 80Hz to get them to where I really want them, but even on flat EQ, this is a significant improvement over the stock sound.