The Titan 3 is extremely critically reacting to fit, more precisely the ear anatomy and how close the vents come to the Conchas.
With a rather shallow fit, the lows can be thin and slightly below neutral levels, with bright, somewhat squeaky and up-front mids. Depending on one's ears however, they can be on the balanced, somewhat warmer or even bassier side. For most people though, it seems that the Titan 3 sounds rather upper-mid-focused than balanced due to ear anatomy and vent positioning.
In my ears, the vents seem to be relatively closely sitting to my Conchas, so the sound is quite balanced and even very moderately warmed-up in the bass and root. Once I inserted the Titan 3 IEMs so that the vents were very freely sitting, just to experience what many members in the German community were hearing. And whoops, the balance was gone and the sound was thin, lean, bass-shy and somewhat squeaky/honky in the upper mids. So yeah, the Titan 3's sound is highly fit dependent and its tonal balance can change pretty quickly, depending on individual ear anatomy and how close the vents come to the ears. (Also see
this post where I did some measurements to get an idea of why the sound was different in a completely free coupler than it was in my ears.)
IIrc, Nik (
@nmatheis) also didn't perceive the Titan 3 as thin, lean or bass-shy at all, so it seems like in my ears, the Titan 3's vents were rather closely sitting to his Conchas. The problem though is that as a consequence, it is rather difficult to predict how especially the Titan 3 (that reacts the most critical out of the Titan series depending on vent proximity to one's ears) will sound for one individual.
I remember that some people (mainly in Germany iIrc) pointed out that a different vent placement would probably be more beneficial in order to that everybody could experience about the same tonality (with the Titan 3, as the Titan 1 and 5 are comparatively much less sensitive to vent proximity to the ears) despite different ear anatomy.
