Taken a look around and suspect I may be more or less at a brick wall. I have a Fiio X5 and Momentums. Love the sound but, in the nature of these things can't help wondering if there is even more to be got from the Fiio. Maybe I'm spoilt but there are a few things I imagine could be better.
(Don't know if this is full of my own terminology but hope experienced audiophile types will know what I mean if what I say is a bit bespoke...)
What I like about the Momentums
a) Form factor
d) Seem "fast" the crack of drumstick on rim, real "bomp" on bass drum that kind of leading edge of sounds is rendered really well
What I think could be better
a) Depth - maybe the same as soundstage don't get much of a sense of layers of instruments (same as space around?) but do hear plenty of little details
b) Mild congestion when things get very busy - what I mean is that sometimes loud music with lots of things going on will lose a bit of separation and detail
c) Very low and very high sounds less good than mids
I'm not a bass fiend but listen to all kinds of music so it'd need to be an all rounder. I'd love to retain the "smaller" form factor of the Momentums if at all possible. I don't reject in ears but personally my (admittedly typically inexpensive) purchases in the past have always been a poor fit and fallen out of my ears. Sturdiness matters a lot. Replacement cables are important (since very many have broken in the past) and its got be practical for trains, planes and walks. The public context means it needs not to leak sound.
Don't mean to sound needy but despite a fair amount of hunting I can't get a sense of something that would be "clear blue water" upgrade. I'm hoping someone out there has been through the same sort of path and can make some clever suggestions.
Thanks for your time. All suggestions gratefully received.