Here's my take on the IER-M9s.
Background
I don’t write reviews much but I hang around Head-Fi sometimes. I pulled the trigger on the M9s a few weeks ago and they have really inspired me to write a review because these IEMs are really quite special. My knowledge of audio terminology is pretty basic; I’m not too comfortable with using some of the descriptors familiar to many on these forums (as I’m not sure I’ll be using them correctly or in the right context) so sound review wise it’ll be a bit different than a normal review, it’s more notes on my experience to date, plus it’s a bit heavier on real usage scenarios.
I come from someone who owned quite a few IEMs in the past usually all in the mid-range and test-drove quite a few higher range ones incl. Sony Ex1000, multi-BA Westones and UEs, never really liked them, either too sibilant or just plain tiring to listen to. Lately I owned the Sony XBA-N3 (which I annoyingly lost at the airport) and recently I’ve been using the iBasso IT01. I play these through my Sony ZX300 and sometimes through an original dragonfly black connected to a Samsung S8 phone and I also have a Beyerdynamic T1 at my desk through my Sound Blaster ZXR on my PC. My Beyer T1s are clearly on another level but it’s not exactly a correct comparison as they are open ended headphones. I also have a pair of Quad floor standing speakers in the Living Room. I won’t be comparing them directly all the time but these are all context to my music experience.
I was fairly pleased with my Sony N3s but there was way too much bass echo that it would overwhelm some male vocals and mid-range instruments on some pop tracks. They gave a kind of boominess to everything I play, much like the JVC FX range of wooden IEMs which I also used to own (and lost, at the airport). The IT01 were really quite a surprise, they were quite an upgrade on everything I ever owned in the past, and they sounded as good as the N3s I had without the boomy echo yet still had sufficient bass.
I listen to all kinds of music, rock, classical, pop, dnb, dance music, jazz, acoustics. I like my base but I also like texture, detail and a wide feel to the music and a separation to the different instruments that are being played. I do not like the original Dragonfly that I plug into my phone sometimes and generally stuff with an ESS Sabre DAC; they make very detailed music but it sounds flat with no-timbrey sibilance, it’s like everything is presented in front of you which is nice, but there’s no sound coming at me from any other direction. I generally like the Sony house sound of having sound in my head and all around with a slight V-shape.
Sound
They sound absolutely sublime, they have that perfect tonal balance to the music, ever so slightly v-shaped. It’s also got that high-end mid-to-high range zing to it, where certain synths or guitars are played on a track and you realise after hearing the M9s that it’s textured rather than just a single note that you thought it was in the past. I get that with my Beyer T1s also, and I know comparing it with headphones is apples vs oranges, but it’s the only time I’ve heard this effect before in an IEM.
The detail is remarkable and the magic is it doesn’t sound sibilant at all. It’s as if Sony tried to make a Beyer earphone but gave it the “Sony depth”. I’ve been hearing stuff in tracks that I haven’t heard before (cliched I know) but even when compared with my T1s. The isolation of the IEMs obviously helps, but it’s also the presentation of where the instruments are, it’s like they kind of have a separate little tweeter just for that particular instrument (given the amount of BAs in this device, it probably has..). I can hear the harmonics (intentional or otherwise) and plucking of guitars that again I’ve never heard before on some vocal/instrumental heavy tracks. I think it also has something to do with timing, it’s like I hear the flailing strum of a final flick of a cymbal or the click of a tongue as a word falls off that I never heard before because previous devices I’ve heard weren’t quick enough to pick it up.
Bass is strong, very deep, but it does not have that boomy bass echo that my N3s had. When the instruments/vocals kick in on a bass heavy track they do not sound recessed or covered as some earphones/headphones tend to present. There were certain bits in tracks, especially in EDM, between mid-bass and low-mid-range, that with past earphones would be muddy sounding which I just put down to poor recordings --nope they actually have detail there(!) that just weren’t translated properly. Again, it seems like a timing thing, I think some of the changes in bass attack are just so fast that some earphones (especially dynamic drivers?) just can’t pick it up. The best part about the bass: I can really crank the volume, the bass will go with it but there is zero loss in detail, I just get more detailed bass and it just scales, whereas I do that with a dynamic driver and at some point, it all just begins to sound rumbly.
Do you remember when you first got your first Discman, then you went and played your favourite song back on the cassette player and thought -wow, that sounded cack? Well I got that exact feeling listening back to some sub-300kbps MP3s. I know most of you can tell the difference but the difference gap is hugely magnified with the IER-M9, it felt the jump was as big as the Walkman --> CD-player in difference for me; especially the bass which was clearly very, very muddy on the MP3s. I can blind test this with the M9s and tell you whether that was a low bit rate MP3, high bit rate MP3 or a FLAC. Basically, anything sub 300kbps sounds like a cassette recording, high bit rate MP3s just sound thin but more remarkably though, 96-24 FLACs felt clearly thicker and had more “spatial separation” between instruments and voices than they do with a normal FLAC. This is something that normally I cannot tell much difference from on my normal IEMs or on my T1. Basically, these IEMs are really going to show up your MP3s or badly mastered tracks.
They require quite a bit of power, I’m usually on 76 volume (no gain) on my ZX300, whereas these need mid-90s for the same volume. I can also pick up very minor electronic disturbance from my PC where I couldn’t do before from my T1 headphones.
Ergonomics
The cable is very comfortable, it has no microphonics unlike the stock XBA-N3 cable. It’s got a 2 layer-protection thing going on; plastic on the outside and another inner-fabric layer, the combination somehow keeps it from tying itself in knots -this is really useful. The plastic is not overly thick either (looking at you Sony Kimber cable). The earhooks are perfect, there’s some microphonics if you rub the earhooks hard enough but nothing that’s going to affect everyday use, I imagine I can go running in these but I haven’t yet tried.
The box comes with 2 full sets of hybrid silicone rubber and triple comfort earbuds. The triple comforts don’t work well for me whereas the hybrid silicone ones are perfect. They’re not your standard silicone buds, these are different to the Sony XBA-N3 ones I had; these are thicker and they don’t get slippery after extended contact with your ear canal (grease). The seal is perfect, it totally isolates noise from the inside and out [had some DnB played right next to my wife, she couldn’t hear a thing (or chose not to?)]. You might want to be careful as well when you take them out because the seal is so good it always gives me a “suction effect” when I take them off.
Here’s the kicker: you know the little notch at the bottom where it labels the L and R. Well that’s not for aesthetic reasons, you use it to leverage the earphone in to your lower ear canal (as your ears are angled upwards ever so slightly) to get that seal. At least I’m using them for that purpose, and at first, I was hesitant to do so, fearing it might snap off but they’re completely solid. It’s such a quality of life plus that I don’t ever want to use another IEM without the notch. I really liked my N3s because it was fairly easy to push into my ears as it was designed to be slim laterally (although it still took some wiggling), whilst with my IT01’s I literally had to spend half a minute to push both of them in to get that good seal before I can start playing music. The M9s are just on another level in terms of ease-of-use: I just push the notch and I get a good seal, no more faffing around.
It’s also the combination of being built like a tank whilst being also fairly light and easy to insert that it really ticks one of my boxes for that “end-game-IEM”. Another box ticked is the understated look, no-bling or other BS so I can actually walk around the office and not have people think I’ve had a mid-life crisis or are able to look right through into the BA drivers and my ear canal (srsly What is with the design these days?).
Conclusion
In all, for me, I’ve been subconsciously going after *that* earphone, I’ve been chasing it no doubt but I was never willing to spend the silly money on some CIEMs on offer. This was an expensive purchase no doubt and although I currently own nothing of a similar price-point in the IEM space that I can compare directly with, I can assure people that are looking to jump up from the mid-range that it is indeed worth it for this set of earphones, they sound absolutely superb and technically the best thing I’ve heard. If you were to look for an alternative in the price-range, the points on ease-of-use (which I wouldn’t have factored in before making the purchase, but in hindsight I would, make these essential points knowing the quality-of-life differences that it would bring) would (at least for me) probably push this IEM well over the line vs the competition.
