The Sony IER-M9 (the “M9”) was on my mind for months. From my research on the M9, it was discussed as being a warm neutralish IEM that doesn’t fatigue you out from listening to it for hours. Some stated that it is a more musical tuning without going in the deep-end. Others love the bass boost that isn’t overwhelming. Few stated they love the gradual downward sloping in the treble region. Since I been researching the M9 just a little too much for my own good, I picked up a pair. This is a five BA driver setup, which I believe one driver handles the lows, two handles the mids, and two handles the highs. I guess “high-five” to Sony on this one? Packaging and Design: We already know Sony has $$$ in the bank to go all out on designs and have the economy of scale to do it. Packaging is a box that is covered by an outer slip packaging. You just push the box from the outer slip packaging and you open the box in the middle. The paperwork included with the M9 is in a “paper slip” inside the outer slip packaging. All the paperwork is in a paper container/folder for easy storage. This is a smart move by Sony for those who might lose their paperwork. Great location to put away the receipts or a secrets like a hidden money stash. Here’s my last pic that shows you what I mean. The box that holds all the contents are laid out nicely. You get both the 3.5mm/4.4mm cables, tons of tips with all the sizes to get you covered, the carrying case, tip cleaner, cable clip, and the M9s themselves. If you are paying this much for an IEM, at least Sony got you covered on the experience of opening up your wallet. The M9s feel pretty light, almost cheap plastic light. But when you feel the M9, it doesn’t feel like cheap plastic. I think Sony design the plastic so you can grip it pretty easily when holding them/inserting/removing them from your ears. It has the magnesium design in the heart of the outer shell, which is cool I guess. The stock cables are not memory based, but they already have a bendend hook for your ears. They are very light, kind of thinish but not cheap feeling, and they have this plastic coating to cover the wires. It doesn’t get too tangled up, which is what I care about it half the time. I feel like Sony put some focusing on the wires so they don’t look too stereotypical audiophile thick IEM cables, but more based in real world usage. I like them. I also really like that it is pretty easy to remove their cables from the M9, but the connection with the cable/M9 is firm. I do believe Sony spent some time designing the M9 where it doesn’t wear down the MMCX connector when swapping their cables. I believe they used part of the M9 shell to maintain the MMCX connector without wearing the connector down. This part is also great since I get pissed when a cable is really hard to remove from an IEM. On third-party cables it doesn’t use the outer shell of the M9 for the MMCX connection. This mean those cables for the most part are relying heavily on the actual MMCX connector for the connection. This also means removing those cables from the M9 will also be harder/stiffer. I don’t really use 4.4mm that much at the moment, so I’ll be using the Sony default 3.5mm cable for my daily driver. The M9 feels pretty good in my ears. Fit is heavily based on the tips you are using. Sony included a HUGE load of tips (which is a common Sony IEM joke nowadays). You only have two different default tips you can use: Triple-comfort tips (marshmallow comfort based ones), and the Hybrid silicone rubber tips (feels like silicone in my ears). I prefer the Triple-comfort tips in my ears, but keep in mind that those tips will provide a little more bass impact due to the nature of the material and the seal in your ears (your mileage may vary of course). The Hybrid silicone rubber tips kind of made the sound a little brighter, which could be useful depending on your setup. The Gaudio Nair are the comfort/fit king for my ears, but the M9 isn’t too far behind on the comfort/fit ratio. I said while the design of the M9 is very comfortable, I did notice just a very slight ear sore from using the M9 about a whopping five hours straight. Yeah, five hours straight. The carrying case is kind of weird for my waste. It is a hard case, but on the top of the case is a hard flat surface with the Sony logo. The rest of the outer hard case is this cloth stitching thingy. Good for grip, but kind of weird for my taste. The inner case has enough room to store the M9 and its cable of your choosing. It works, but I prefer the pleather cases that the JVC IEMs are using. The tip cleaner and the cable clip are nice, but meh if I’ll ever use them. Gear List at time of Impressions/Review: Thinkpad X260 via Roon or Foobar2000-UPnP > Schiit Eitr > Massdrop x Airist R-2R DAC (RDAC) > Zampotech SW51+ Roon or UPnP > PI2AES [Coax Output] or Pioneer DV-79AVi DVD Player (CD Transport) [Toslink Output] > Schiit Bifrost 2 > DNA Starlett Sony WM1A & Drop x JVC HA-FDX1 Tone/Staging/Details: Some are calling the M9 a warm neutral IEM, but I have to disagree with this. Warm they are, but these aren’t truly neutral. Then again, people keep throwing out these terms left/right that it is hard to tell what is what. I’m just going to say this: If you mostly a referenced tuning bias person but want to get a more musical turning without the stupidly of the extremes, then these could do the trick. I noticed some hills and sloping when listening to them, which I’ll explain in a bit. Staging isn’t flat, and I noticed some minor-3D stuff going around. However, it is an IEM so this part is going to be limited. The Solaris revisions have more staging than the M9, but in the world of IEMs that isn’t much. You will be able to hear different parts of a recording for the most part very well. The M9 is very good on pulling details, but it won’t shove it up your face. You have to listen for it since it sounds relaxed a bit. This was a big reason on why I could listen to the M9 for hours, I didn’t any get fatigue from listening to them. The relaxed type of sound also helps on poor recordings by not having their flaws being shoved up your face. Some wished the M9 was more aggressive, but I don’t think it is a good idea for BA IEMs since they have that super ISO on a camera setting sounding thingy at times (too much sound information for some users). The Three Big Parts Of Sound: The treble is mostly downward sloping. There is no rebound in the upper treble like the OG Andromeda, it goes down like that Publix sub sandwich (you guys who don’t live in the South are missing out). I think this is the reason why the M9 sounds relaxed to me. This also means that it isn’t full of airiness and not having the “lively sounds” effect. As stated above, the benefit here is you can listen to them for hours. With that being said, I did notice a minor bump in the lower treble. Normally a minor bump in the lower treble can drive me crazy, but there is a minor bass boost that helps counter the sticking out of the lower treble. Sibilance can be a minor issue if the recording of an album was recorded with emphasis on the “S.” An example is Television – Marquee Moon. If the volume is a little too high when playing this album, Tom Verlaine’s voice can have a little too much sibilance for my liking. Such a bump/emphasis in anything in the lower treble is a fact of life. Not really hard to solve it, just slightly lower the volume down just slightly if it happens. Here’s a funny thing about it, the M9 does beg you to turn it up. The midrange I believe has a minor bump in the upper mids. I noticed it in the Marqueen Moon album, and a few other albums as well. Is it me or the lower/middle mids are kind of dipped down a bit? I don’t know this is the best area to explain it, but listening to guitars on Metallica – Kill ‘Em All and Judas Priest – Sad Wings Of Destiny doesn’t fully have its crunch on the M9. I thought it might due to the minor bump in the upper mids/lower treble, but it doesn’t sound like it. Instruments do sound right on the M9 on the most part (to me at least), but I can tell that sound might find some instruments to be kind of dull due to the treble and maybe the not truly neutral in the mids. On vocals it mostly got it right. Maybe Grace Jones in her Nightclubbing album could be slightly too deep for neutral, but great on a musical sense. I found vocals to mostly be coming from their heads, not their chests. David Sylvian’s voice in Brilliant Trees sounds mostly right to me, but I did notice that his voice might not be fully focused since he sings in a deeper baritone voice. As I’ll discuss in a monent, there is a bass boost on the M9 and it prevented David Sylvian’s voice from going too behind the musicial mix. I think what Sony was trying to aim for the midrange was to make it mostly engaging but mostly smooth with minor hint of excitement in the upper mids. I didn’t find the Midrange to have a serious flaw, but it may not be your preference and that’s something you have to decide on if considering getting the M9. I already pointed a few times already that the M9 as a bass boost. I think due to this bass boost it helps the upper mids/lower treble not stick out too much. The bass boost I feel like adding +2 on a EQ, but it isn’t a crazy bass-cannon IEM (which is fun at first but gets old quick). Albums where it sounds like it had no bass will benefit here (those 80s/90s digital recordings). On real heavy bass albums, you will feel the bass slam and be smiling here. Sony was not aiming the bass to be a boring tactile tightness stereotypical BA standard. Sony wanted people to move their butts but at the same time adding just enough bass that it doesn’t ruin the tonality of the M9 (avoid face-slamming bass). At times I thought the bass in the M9 was like the DD bass that I am familiar with on the JVC x Drop HA-FDX1 and the CA Solaris revisions. However, it feels like the bass impact is kind of being forcefully pushed out with minor airiness to it. On the DD drivers I feel the bass is not forcefully pushed out and you get more airiness to boot. With that being said, the bass on the M9 doesn’t bug me at all. I’m thankful for the bass impact since it isn’t the stereotypical wimpy BA stuff. In conclusion, I enjoy the tuning of the musical sound range on the M9. It may not be perfect with some minor quirks in sibilance and the upper mids/lower treble weirdness at times, but honestly this is minor stuff for me. I bet if people audition the M9 they wouldn’t care too much on the minor quirks. I think for some they would say the M9 doesn’t suck but it isn’t for me. It’s nice not having fatigue issues in the musical tuning of things. Neutral the M9 once again is not, musical with some minor quirks/sins it is. Desk Amps and Stuff: The M9 is not a sensitive IEM at all, which makes them great for desk amp usage. I enjoy using the M9 a lot on the DNA Starlett and on the SW51+. The catch is that they sound best in low impedance setting/input on both of these amps. The high impedance setting/input brought up the treble just a little too much to the point of brightness. If I have to be honest, I didn’t like it at all. I believe Sony designed the M9 for DAPs and low impedance amps. I didn’t detect any noise on the M9 also through these two tube desk amps, which is nice. Out of all the BA IEMs that I used up to today, I found the M9 to be the easiest IEM to use with regards to telling the delta/differences between my two desk setups. It is a little more mellow on my DNA Starlett due to the house sound of the DNA amps. It is a little more aggressive on my SW51+ due to using the stock tubes. The M9 running through the IEMatch to me didn’t make a noticeable difference. It could be useful to use it on super powerful desk amps where it could blow up the BA drivers of the M9 in a few volume steps. I did enjoy using the M9 on the WM1A DAP. However, it could be too much of a good thing for some. The relaxed highs of the WM1A and the downward sloping treble of the M9 might be too boring for some. Of course if you want the full benefit of the M9 with the WM1A, then use the 4.4mm input. However, I was pretty happy with casual listening on the WM1A by using the 3.5mm input. I also want to say this: I found the M9 to work well on handle console gaming devices, but you might need to raise the volume just a little bit higher for a good volume. M9 and Other IEMs: JVC x Drop x JVC HA-FDX1: M9 surpass the FDX1 on all technicalities, which it better for the M9 MSRP. However, the FDX1 is still a great value because it nails the tonality down with its three different filters you can use with the FDX1. Also, the DD driver on the FDX1 feels a little more natural to me than the pure BA design of the M9. Both are great, and FDX1 still a crazy value in a world of IEMs. The Campfire Audio IEMs: CA IEMs as I stated before work best o DAPs and transportable devices. Their super sensitive, so IMO they don’t work well on desk setups. Honestly, the M9 is different from the higher end CA IEM offerings. I think most will compare the M9 with the OG Andromeda. M9 treble is downward sloping, while OG Andromeda has sparkle. OG Andromeda to me is leaner, the M9 is not that lean. I don’t think one is better than the other, they are just different. The Solaris revisions has the DD driver for the bass, but it isn’t boosted a bit like the M9. The 2020 Solaris (not the OG Solaris) has the same quirk of the upper mids/lower treble emphasis, but it sticks out more for me due to there isn’t a bass boost on its DD driver. Yeah the Solaris is better on certain things, but not 100% for the better. The CA Ara beats the M9 on being honest with the bass (and its superior bass textures), but does the Ara has fun bass? The answer I think is no, but that isn’t the point with the Ara. I think Ara has slightly more details than the M9, but at the end of the day I consider them two different IEMs with two different goals. Gaudio Nair: Nair is honest with the source, while M9 is more funnier. Nair will tell you the truth if a recording sucks, the M9 will smooth it out a bit. Same if a recording is bright. The Nair will give you the brightness, the M9 will tone it down. I found both IEMs to work together when someone gets bored of a tuning from an IEM. If you get too bored with the M9 after a while, the Nair is a wonderful refresher on a reference tuning to clean out your system. I won’t be shocked if people get the Nair for the reference tuning while others might get the M9 for the funner tuning without the extreme U/V/W-shaped tuning BS. Conclusion: I just wanted a higher end IEM that has a very enjoyable musical tuning, but at the same time not being extremely stupid on emphasizing on an extreme (bass, treble, low dip mids). The M9 offers that for me, and I think it is worth the cost of entry. I believe Sony’s goal was to make the M9 great for long-term listening without the fatigue, but at the same time make it an audiophile IEM where it wouldn’t offend listeners. I think it is a great IEM to have when you are burnt out from extreme stereotypical tuning stuff that is the norm in the IEM world. Note: I never heard the IER-M7 or the IER-Z1R. I know the IER-Z1R was not liked during its SBAF loaner period. I do believe there was a revision of the Z1R that improved some of the issues from the first batch. I think I heard it from @netforce …?