I made the mistake of listening to these bad boys first. Before listening to their M7 and M9. Mistake as it pretty much ruined the M7 and M9 for me.
These are summit fi earphones from Sony. The IER-Z1R at $2300 MSRP is absolute authority with the type of 3D imaging and full bodied sound which is best described is like listening to floor speakers. These don't sound like earphones or even headphones. The dynamic range on these earphones are 2nd to none. For me easily the star of the show. Start saving your cash fellas these are for real. Substantial progress of Sony sound on these like you have never heard. I was more impressed with these than their flagship headphones Z1Rs. I hope these goes down to a more reasonable price. One to look out for. Oh by the way the fitment in my averaged sized ear was very comfy. Excellent design.
The M9 reminded me of Campfire Audios Andromedas. Similar staging the bass end is no joke on these new BA based Sony earphones the M9 sounds like it has a full on dynamic driver for the bass. Easily matching any dynamic performance. These have wide stage with a spacious sound. Excellent detail and imaging hearing these out of Sonys Flagship player the WM1Z. At $1500 these are definitely compelling.
The M7 is the most neutral tuning out of the 3 and these remind my of my old EX600 monitors. A bit rolled off on the treble but very great even balancing from treble to bass. A bit smooth with a slightly warm tonality. These sound good for the $799 MSRP.