rlw6534
Headphoneus Supremus
That is a somewhat surprising statement, I have both the IER-M9 and the IER-Z1R and they really sound very different to me, despite having almost identical frequency response.
Z1R is clear and powerful with a clear midrange that takes a step back on the stage, flanked by energetic bass and treble, all very clearly defined and energetic.
M9 is focused on that warm, relaxed and slightly veiled midrange, supported and complemented by excellent treble detail and extension and a decent bass, even good bass for BA. Overall a darker and relaxed listening experience.
Both are ver good at what they are doing, but sound really different to me.
To come back to @Hinomotocho 's original question - the XBA-N3 might be a nice complement, and it's cheap, if you manage to find one. Guilty pleasure type of bass (quite a lot with warmth, rumble and extension) paired with a smooth yet detailed midrange-treble area. Overall a really nice cheap option, Crinacle put it well "a little smoothed over"
EX1000 is also interesting, the bass quality is great, but it's not very practical for everyday use and the midrange is a bit strange.
Personally I am using the DUNU SA6 Ultra in rotation with the Z1R and IER-M9.
Great fit and comfort, bass is surprisingly extended, textured and rumbly (better than M9 IMO), neutral-forward midrange and well extended treble.
Somewhat limited in detail, layering, separation and soundstage, but a very balanced and versatile IEM
I agree that the XBA-N3 is probably the "closest cousin" to the Z1R. They use similar technology and were designed by the same individual (N3 first, then Z1R).