Ranking (almost) ALL of the 64 Audio IEMs! (Updated for 2025)

So most of you watching this have probably heard of 64 Audio. They are the most well-known North American brand when it comes to in-ear monitors and they have a big presence in the live music scene where their primary clientele are stage musicians. They make customs for lots of famous artists you might be familiar with. But of course they also serve the enthusiast crowd like us. They have 10 different models excluding the Aspire series which they primarily market for more professional use and today I'm going to be ranking all of them. So if you didn't know, I actually did something like this a couple years ago where I took all the 64 Audio IEMs that I reviewed and put them together in a single ranking article over at the AudioFiles. This video will be an updated version of that for 2025. But before that though, I do want to clarify two really important things for how I'm going to do this. The first is that I will be accounting for price in addition to sound quality. Now 64 Audio's products are all firmly within the luxury price region, so I'm not going to focus too hard here on pure price to performance, but you will see where price kind of comes into play in terms of actually ranking them relatively, you know, here and there. The second is that, you know, this goes without saying, but this is purely my subjective opinion. The other members on the team will have their own opinions. For example, listener and resolve will probably disagree with me on most of these rankings because they don't tolerate treble as well as I do. Okay, sorry, that's going to be one more disclaimer. As many of you already know, the headphone show is supported by headphones.com who does sell most of the 64 audio IEMs. It's because of the shop that I'm able to get them in for review. So, you know, do consider headphones.com for your next audio purchase if you want to support videos like this. That said, as you'll quickly see, that has nothing to do with how I'm going to rank these IEMs. Us reviews at the headphone show are kept totally separate from the actual business itself. All right, now on to the rankings. Let's start with the 40, and right off the bat, I'm going to give this an F. Yes, you heard me right. 64 Audio's flagship IEM that costs $3,600 is the worst one that they have, and no, I'm not doing this just for shock value. The problem that I have with the Forte is that its tuning is just super duper wonky for me. I like coloration, but I have to draw a line somewhere and the Forte blows right past it. In my original review, I basically just made a list of all the instruments that I thought sounded wrong on the Forte and it basically comes out to every instrument on a modern pop and rock track. And as far as those perceived technicalities go, I didn't think there was anything special on it either. And it definitely does not make up for the fact that the Forte's timbre is just really off. Next is D for Duo. Okay so for this one I don't mind the sound of the Duo. It is very colored and outside of my preferences more often than not but I am okay with this level of coloration with a little bit of brain burning as opposed to something like the Forte. The biggest problem that I have with the Duo is that for me I don't think it's a very good primary IEM. It's more of a collector's piece, one that you kind of break out every now and then if you purposely want something that's different for your music. And for that you're going to be paying $1200 which is quite a bit of money for something that isn't that good anyway and mainly serves just as a contrast to your primary listening piece. Like I said though, I don't hate it. I just think there's, you know, a couple dozen IEMs that you'll probably look at before you even consider the Duo. All right, and as I was just editing in this video, I noticed that 64 Audio doesn't even list the Duo on their website anymore. Go figure. Now we come to 64 Audio's newest IEM, the Solo. And for this one, I'm going to give it a C. Okay, so it is actually a good sounding IEM and that's because it's basically a Chinese planar IEM in a 64 audio shell. Here's what I'm talking about. There's a graph of some of those Chinese planar IEMs that got really popular in the past couple years like the 7Hz Timeless or the Led Shure S12. There's a very distinct upper midrange that follows that 2kHz peak and plateauing of around 3-4kHz. The solo follows that exactly. Now to their credit, they did clean up some of the treble issues that the planar drivers have quite well, but that nowhere justifies the price of $1400, which is why it gets a C. It sounds good enough and I do like the Solo in a vacuum, but it rubs me the wrong way that 64 Audio basically got really lazy and tried to jump on the planar hype train a couple years after it already left. However, I will say that the copper shell design of the Solo is probably one of my favorites of all the IEMs. It's just gorgeous. Up next is the U18S. I'm gonna give this a B. This might be a little controversial because I do think this is actually a really really good IEM. It has this really nice reference style tuning to it and great technical performance all around. The only knock I have against it is that it has this sort of odd upper treble wispiness and exaggeration as a result of the TIA drivers that 64 Audio likes to use. So why is it a B then? Simply because it costs $3,000 and there are other 64 Audio products that I like more. But from a pure sound perspective, I could argue it as an A-tier product. As far as its brother, the U18T. I'd also give that a B for about the same reason, so take that with a little bit more of a grain of salt. I didn't get a chance to fully review that one, I just heard it at an audio shop. And while we're giving out Bs, I'm gonna add the Velour to that list. Honestly, it does kind of pain me to say that because I really do think that 64 Audio was trying to do something special with the Velour. They have it as their premier bass hit IEM, and the bass sounds fantastic on it while still having lots of mid-range clarity. Importantly, the way that the Velour is tuned allows it to have this contrasty type of sound, lending a strong sense of those perceived technical abilities. That's particularly true in the bass department where I deliver some of the biggest dynamic swings I've heard in an IEM. Unfortunately for the Velour, where I deducted marks was in its upper treble. Here is where we see the impact of those TR drivers again. Unlike the U18S which got a bit of an exaggerated wispy sort of sound which was okay for the most part, in the Velour, it becomes this unnatural treble peak. The effect of this peak is that it basically kind of just warps the timbre of treble-focused instruments and can be kind of grating to listen to if you notice it. It's not painful at least for me, but I can definitely see where it becomes a deal-breaker for a lot of people. The other reason I give it a B is because at 2500, it costs almost 50% more than the Neo which was 64 Audio's previous basshead IEM. Speaking of the Neo, I'm actually going to give it an A. While it isn't as technically proficient as the Velour's upgraded isobaric dynamic drivers or whatever, it is a straight guilty pleasure IEM that's a ton of fun with an indulgent almost 30 bass feel to it without becoming bloated. I think the reason I like its tuning more than the Velour is because the Nio doesn't have the upper treble timbre issues and instead sounds smoother, a little more coherent which in this context I think glues everything together. At $1,700 the Nio is obviously still expensive. But relative to the other 64 Audio products, that's actually not too bad. For something that isn't quite as affordable, we have the Trio at $2,300. But I'm still gonna give that an A. The Trio is an interesting IEM. It's quite colored and its graph isn't very pretty. But somehow I really, really enjoy its sound. It's lively, it's energetic, it's vivid, there's great dynamics and resolution throughout. I like a lot of modern rock and alt rock, that type of music, and that to me is where the trio just shines. When I listen to the trio, I stop analyzing the IEM and I start focusing more and more on the music itself and finding new notes to appreciate within it. And that to me is the mark of a great IEM and the trio passes with flying colors. The only complaint that I have about it is that it's not a very safe buy by any means, but you can live a little dangerously sometimes. While that and the trio isn't quite as good as the S-Rank IEM that's coming up. But if you're talking about living dangerously, the U6C is not it. However, it is worthy of an A-tier ranking and listener and resolve would tell you it's the best product in 64 Audio's entire lineup. As for me, I find it a very solid IEM. It has all the fundamentals down pat, a good relaxed, warm sort of tuning paired with good perceived technical performance. I think it really sets the baseline for what 64 Audio is all about. The upper mids in particular is pretty well tuned and aligns closest to the population average HRTF out of all the 64 Audio IEMs. Personally though, I do wish that it had a little bit more lower treble energy to give hats and cymbals a little more crispness in its sound and to also provide vocals with a little bit of extra breathiness to help balance out all of its warmth. Coming in at 1400, I'd say it's a fair price as far as luxury IEMs go and that's probably why it was positioned as the entry level offering in 64 Audios lineup when it first came out. But then 64 Audio released the U4S and changed the game. The U4S takes a lot of what I enjoyed about my favorite 64 Audio IEMs and brings it down into its most accessible one yet at $1100. And that's why I give it an S- ranking. The U4S to me sounds the closest to the NEO out of all the other IEMs. It has a bass boost that's almost just as big as the NEO but is elevated in the upper mids and treble in key areas to give it it a more balanced overall sound profile. This extra treble also helps bring notes closer to the foreground than the Neo does and gives extra clarity up top. The only tuning nitpick I have is that I wish its upper mids peed closer at 3kHz like the U6T does rather than at 2kHz. I think this would help it clean up its sound just a little bit more. Otherwise, the perceived technical ability of the U4S is just as good as the Neo with great bass dynamics and impact and arguably better resolution. While I wouldn't crown the U4S as the best $1000 IEM out there given how competitive the IEM space is, the U4S is top of mind for me as the very first one I'd recommend at that price. And lastly we have the U12T. You all knew this was coming, it gets an S tier ranking. I'm gonna be honest, I did not expect to like the U12T. When I saw all these highly respected reviewers like Android and PrecogVision and Clinical, basically everyone give it universal praise and call it one of the best IEMs in the world, there was some contrarian part of me that wanted to just call it mid, you know like I went in with a bit of a buy-in against it even before I even heard it. But I just can't. The performance of the U12T is a clear step up against the rest of the 64 audio IEMs and in particular, I can't argue against its perceived technical ability. While it doesn't have a fat dynamic driver for its base, the U12T's balanced armature still deliver a great dynamic presence while having exceptional articulation and control. That sets the tone really for the rest of its techs. Soundstage, imaging, layering, all of that stuff is top tier. But most of all, its resolution still ranks among the best for all IEMs that I've heard even to this day. The main complaint I've seen with the U12T is that its tuning is boring. And honestly, I do kinda agree with that, but that won't stop me from giving it an or rather, I can't justify giving the U12T anything less. So there you have it, all the 64 Audio IEMs ranked except for the Aspire series which I'm not going to touch. But if you are interested in that, Precocvision does have a full written review up over at the audio files which you can read. Speaking of which, I do have full written reviews up for all the products that we talked about today if you want a little bit more nuance than you can get in a 10 minute video or so. Otherwise, you can let me know in the comments below what you think of my rankings or if you have a different opinion. Anyway, don't forget to join us over at the Headphones.com Discord and forum to talk all things audio, like and subscribe, all of that stuff. Have a great rest of your day.