Maybe or maybe not an upgrade, but the Oriolus Isabellae is VERY similar in tuning, just done in a great DD instead of Planar/BC. While it doesn’t have more bass on paper, the impact on the Isabellae is greater (to my memory, sold my Hook a while back).
If you want to stick with a planar and get everything you mentioned as well as a more natural timbre and a significant upgrade in technical performance I would look at the Campfire Supermoons. The bass has some nice punch and tactility to it, more than any of the other planars I have tried which includes most of the major players aside from HeyDay and the Hook retune. The timbre is much closer to a dynamic driver in its accuracy and presentation. It extends well at both ends and brings great detail retrieval, separation, and layering to the table. I have admitted before that it’s probably a bit overpriced, but then again, I don’t know of another planar based IEM that touches it performance wise. Supermoons were the first thing that came to mind when I read your post.
Edit: Forgot to mention that it’s soundstage is very good. Width, depth, and height and source placement within the stage is sharp and accurate. The whole presentation sounds very effortless which I think is the best wors to describe it.
For me the Hook has more than enough bass. I’d say it’s bordering on bass head levels. That said, if you want to improve on the Hook, the only thing I can think of is the Mangird Top.
The difference is not night and day but I do consider it to be a bit better.
You initially rec’d the Hook-X to me, which I’m still ultra pleased with.
Allow me to (maybe) return the favor and suggest demo’ing the Sennheiser IE 600. The note of caution being the treble may be fatiguing/spicy for you.
General shape of the curve tracks well, though, so it could also be a matter of insertion depth differences between each sample (note that the 8khz peak shifts a little early on sample 1 compared to sample 2). That’s what it appears to be to me, at least. I’m sure someone with 711 coupler experience could chime in a give us a better idea.
The universal version, as far as I understand it, was a limited run. There are very few out there. I’ve seen custom units go for as little as $800 - I’m not sure how much a reshell would cost but that’s also an option.
Isabellae in. Definitely more treble-centric/bright/fatiguing than Hook-X. Bass is there, but there’s not enough warmth or relax here. Definitely very clean, accurate treble, with nice detail and sense of space.
Symphoneum Meteor in. Using the stock red tips, and a XINHS balanced cable.
These sound fairly interesting… This driver really kicks. Probably too much.
Quite nimble and physical.
Large presence without being very boomy(there is some).
Excellent blend of large presence and perceivable detail.
Relatively low fatigue. More fatigue from the bass, probably, or equal amounts. Not as breathable/effortless as Hook-X, however. Certainly not as low fatigue as a BA driver, either. Fatigue seems to be a general point of failure for DDs(or at least for non-open back DD IEMs, contrary to FD5’s design).
Detail retrieval seems pretty good, and very controlled, but is often masked by the bass or overly-warm tuning.
Vocals sound excellent(my favorite part?); organic, rich, detailed, and perfectly placed in the stage.
Tonality seems a bit off; scooped/sucked in.
Soundstage seems straight average; not claustrophobic/closet-like, nor amphitheater-like.
Aerosmith - everything sounds pretty great here; vivid/energetic, smooth, and hard hitting. Possibly my favorite IEM for Aerosmith, or all “classic rock”, so far.
Jazz and smooth jazz - sounds great, but too much fatigue can occur.
Acoustic stuff sounds great, where the treble detail, vocals, and warm nature of these IEMs can shine.
Piano key strikes are nicely emphasized.
The less aggressive the track, the less problematic these will be. If you thought FD5 was U-shaped, Meteor is definitely next-level.
Hook-X does a better job here, with less fatigue + more detail(=planar ), better tone, and better balanced, cleaner bass.