Now onto my biggest concerns.....with the M6 I couldn't get a good fit with any of the tips they provide. I settled on a pair of clear silicone tips from another set I got just for the clear tips. If they are pushed in too far the treble response is cut off. I have to pull them out of my ears to bring back the upper range and for some reason they slowly go further into my ear canal ......a first for any iem since most want to fall out. They need to be in far enough for the seal but not too far to kill the upper frequencies. This happens only on my left ear.
The other problem with the M6 is driver flex. If they into the ear too far the driver on my left unit crackles like crazy ....if I move my head, open my mouth ....crackle....crackle....crackle.
Theres a very narrow range of fit for me that works and I'm sure it's the same for others. I will contact MEE about this and see what they can do for me. I LOVE the sound signature of the M6 so I'm hoping that it's possibly just my pair which is black. It's possible that the driver isn't secure in the housing and I'll contact MEE about this matter.
the M9....I used the double flanged tips which are different than the ones supplied with the M6....they're a bit more narrow at the tip which is a good fit for me. But the angle that they're inserted is the make it or break it for me.
If the tip isn't pointed at an upward angle I lose the seal and 1/2 the bass is gone.
The M9 can't be worn over the ear because of the rigid plastic strain relief at the base of the unit and have to be inserted with the strain reliefs pointing straight out...not a deal breaker but I like to wear my iems over the ear if possible.
And of course the upper midrange emphasis on the M9 is a concern and I hope it corrects itself with more burn in.
The only other thing I have a gripe about with both pairs is the cord. While it's nice it holds memory. The cord on the JVC HAFX34 and HAFX35 is PERFECT....holds no memory and is of sufficient gauge. I actually use the M6 case to hold my HAFX35 since it fits in perfect and doesn't get all kinked up after being in there for several hours.
I'll provide an update on the M9 sound signature and if I can get MEE to do anything about my M6.