Alright so this IEM has been discussed quite extensively in the M7, M9 and Z1R thread. The M9 has even somewhat been the star of the show in that thread. But I still believe an IEM of this caliber deserves it's own thread for people who want to read about it all in one place. Plus, this is an amazing IEM and I feel this thread has the potential to be quite popular one day, which will in turn stroke my fragile ego and earn me major internet points. This is my first BA IEM and to be honest I was a bit worried before I finally got to pop them in my ear and hit play. All I ever hear about is how BA bass is lacking in everything. But this M9 has blown me away in every single aspect. It is hands down the best headphone I've ever heard (also the most expensive I've ever owned...) This purchase was funded by an Amazon return of my Sony MDR-Z7M2, which I had for a month before realizing I liked my Sony MDR-1AM2 more than it...It didn't help things considering I paid full suggested retail for the Z7M2 from Amazon US ($900) and preferred the sound of a Best Buy headphone I paid 1/3 of the price for. I'm powering this IEM from a Sony ZX-300 and it is quite the pairing. High gain and about 75 volume seems to be my sweet spot. The bass on these things has impressed me the most. My favorite thing about the 1AM2 is their bass. So I was expecting to be less than thrilled with the bass of the M9, but was immediately blown away at the first bass note. ANd then the treble...just wow. I've never in my life heard treble this good. Clap sounds and symbals and electronic music in general is something to behold. I'm currently listening to Lorde's Pure Heroine album and I swear these IEMs were made for music like this: electronic beats, sub bass and a smooth female vocal. I look forward to trying them with many different genres and I look forward to what anyone else may have to say about this splendid IEM. I'm in love... EDIT 12/08/2019- There's a lot of contradictory information in this thread in regards to proper tip fitment and insertion. A lot of this contradictory info is from me haha. It took me nearly a year to figure it out but I have figured it out. I'm going to copy a post below from myself from 12/08/2019. Tip choice and insertion depth are so important with this IEM, I feel it's important enough to address it in the first post of this thread. It's possible someone could purchase this IEM or the M7 and have a bad experience because of poor tip choice or insertion technique. So here goes: So I’ve come upon another revelation with regards to tips and insertion techniques. I actually posted this on this thread months ago, but it doesn’t work well if you’re using a tip that is too big. I’ve now found myself settled on the M tips. The cool thing with this is it allows me to use an old insertion technique that pushes the IEM in as deep as it will go. The sound and isolation are incredible. The technique is as follows. Pop them in your ears like you normally would, then with two fingers, grab the top tip (upper cartilage) of your ear and pull up and towards the back of your head. While doing this, take your free hand and push the body of the IEM in as deep as it will go. Now something to keep in mind here: if the tip you’re using is too big, the sound could possibly get congested as the hole in the end of the tip is either forced closed or forced up against the inside of your ear, effectively clogging it. But with the correct tip, you will achieve an amazing, consistent sound and fit and the best noise isolation the IEM has to offer. For me, the M tip coupled with this technique allows the deepest possible insertion I could attain, as the shell of the IEM is literally bottomed out in my ear, meaning it couldn’t possibly go in any deeper. And since the shell of the IEM is also clogging your ear hole, it provides the best isolation I’ve ever attained with the M9. It almost feels like I’m wearing a custom, since the M9 shell fits the inside of my ear so well. I know things like tips and insertion techniques are highly personal, but I feel this will work for everyone! Just remember less is more when it comes to choosing the right size! I’ve gone from LL to M! Keep that in mind. Choose the smallest tip you can that allows the deepest insertion!