[NCUS]

I haven't tried to EVO (still waiting for it), but to me the U12t is closest to the Utopia. I'd have to A/B them again, but I am constantly thinking that every time I put them on. I'd give them a listen before you buy and see if they're right for you. The Utopias are usually my fave followed by LCD4/Empy.

I don't think the u12t has a similar tonality to the Stellia. I have a pair of Focal Stellia, a Focal Arche, and a u12t. The u12t has more low bass frequency rumble than the Stellia, but the Focals extract more detail out of the mix and sound more dynamic than the u12t. Overall, the Stellia is more neutrally tuned in my opinion. The u12t has more of a fun tuning. My impression from reading these forums is that IEM listeners are more focused on bass than headphone listeners, so this difference in tuning makes some sense to me. I like both.

 

[Chill iLL]

I don't think the u12t has a similar tonality to the Stellia. I have a pair of Focal Stellia, a Focal Arche, and a u12t. The u12t has more low bass frequency rumble than the Stellia, but the Focals extract more detail out of the mix and sound more dynamic than the u12t. Overall, the Stellia is more neutrally tuned in my opinion. The u12t has more of a fun tuning. My impression from reading these forums is that IEM listeners are more focused on bass than headphone listeners, so this difference in tuning makes some sense to me. I like both.

I haven't heard the Stellia tbh, but the Utopia's detail and controlled bass (with mx/m15 modules) along with tonality and space give me Utopia vibes. Again, it's nothing exact, but I'm trying to find the closest thing in IEM form that carries over that kind of tonality and out of my collection that's the closest.

 

[NCUS]

I haven't heard the Stellia tbh, but the Utopia's detail and controlled bass (with mx/m15 modules) along with tonality and space give me Utopia vibes. Again, it's nothing exact, but I'm trying to find the closest thing in IEM form that carries over that kind of tonality and out of my collection that's the closest.

My general view is that the biggest tone difference between the Stellia and u12t is in the bass. I should have said that the Stellias are generally perceived to have more bass than the Utopias. So if I think the Stellias don't don't sound similar to the u12t, I'm guessing the Utopias are even less similar. This is just a guess though as I don't have a pair of Utopias.

 

[iDesign]

I don't think the u12t has a similar tonality to the Stellia. I have a pair of Focal Stellia, a Focal Arche, and a u12t. The u12t has more low bass frequency rumble than the Stellia, but the Focals extract more detail out of the mix and sound more dynamic than the u12t. Overall, the Stellia is more neutrally tuned in my opinion. The u12t has more of a fun tuning. My impression from reading these forums is that IEM listeners are more focused on bass than headphone listeners, so this difference in tuning makes some sense to me. I like both.

Agreed. The U12t bears more differences than it does similarities to the Utopia. The tuning is wildly different between the two and comparing headphones and in ear monitors is a pointless exercise due to the physics alone. That said, both are among the best in their categories.

 

[Razza1974]

I haven't tried to EVO (still waiting for it), but to me the U12t is closest to the Utopia. I'd have to A/B them again, but I am constantly thinking that every time I put them on. I'd give them a listen before you buy and see if they're right for you. The Utopias are usually my fave followed by LCD4/Empy.

I haven't tried to EVO (still waiting for it), but to me the U12t is closest to the Utopia. I'd have to A/B them again, but I am constantly thinking that every time I put them on. I'd give them a listen before you buy and see if they're right for you. The Utopias are usually my fave followed by LCD4/Empy.

Well i have got an u18t, and i like the sound of it, a lot of detail (and lacking a bit of bass but with the dark grey modules the bass improves).
So the u18t is also fairly close to utopia then (cause i would think u18t and u12t are comparable (i know majority seems to think u12t is better than u18t)?
I like the u18t, gives a lot of detail but when compared to Utopia it is lacking a bit: check out Nine Inch Nails "this isn't the place", i expected u18t to deliver the upper mid glitches, i think it is a distorted piano (anybody who knows the song will know what i mean, which seem a bit dissonant, but that is the interesting detail in the mix ) in the song just as detailed as the Utopia but they are lacking, part of the sound seems te be missing even (!). On all other songs they sound fine, so there is no issue with the u18t's
I thought the u18t were the absolute detail king but to my surprise there is a fairly big gap in detail

 

[Earbones]

Everybody’s ears are different. The Stellia is one of my favorite headphones, and I fell in love with the U12T precisely because of it’s similarities to the Stellia (actually I fell in love with an A12T first, but there were persistent fit issues due to my weird ears).

I certainly wouldn’t classify either the U12T or the Stellia as simply a “fun” sound… both feature reference tuning… and let’s say a “touch o’ fun” veneer.

I will say that a lot of people, even owners, have trouble getting the bass response the Stellia is capable of. Much discussion on this (on most of the Focal cans, honestly) with many people suggesting different “best” ways to wear the cans… I can share that for me, finding the correct seal was somewhat counterintuitive to what I usually do… I actually went looser. This allowed the cups to hang so that they could settle correctly and seal properly over my ears… only then was I able to experience the bass that the Stellia is really capable of.

I get bass roughly in Audeze LCD-2 territory, but cleaner and with better timbre... In short, around the same extension, and same ballpark for punchiness, but overall articulation and quality goes to the Stellia. Sub-bass is more prevalent with the Audeze. Mid-bass isn’t a contest… It actually quantitatively exists and is executed on the Stellia, whereas on the LCD-2, it is something merely indicated at, somewhere within the smudge of bloat bleeding from the lows into the mids.

But I’m digressing into a shootout, and that’s not my intention here. The point I’m trying to make is not that the Stellia bests a headphone from a decade before it’s release -a lot of advancements were made in that time- it’s that the Stellia is indeed capable of some very deep, very eloquent bass, similar to the U12T… assuming one achieves the proper fit. Which again, can be pretty tricky for some.

In any event, I encourage anybody not getting truly fantastic, deep bass with the Stellia to experiment a bit with their fit. I seriously didn’t even find my perfect fit until after like three months… I thought I’d found it after the first 2-3 weeks of listening and fiddling, then tried something completely different a couple of months later, and wham. And now? Well I wouldn’t want the Stellia any bassier. Ditto the U12T. Just enough bass to be almost too much. To clarify, I’m referring to the U12T with the m20 modules.

Regarding a fun-sounding IEM from 64… when I think of that, I think of the Nio, which I also love, although I usually listen to mine with the mX or m15 modules, which make it somewhat a less “crazy fun” sound, but still very fun. The Nio with the m20’s will blow a house down. Good lord. It will rattle the teeth out of your head, if you’re not careful.

 

[Precogvision]

I wanted to share some more thoughts on the Duo because I brought one back with me from CanJam. As far as I can tell, 64A basically has three flavors of sound: their "reference" audiophile tuning (which consists of the U12t, U6t, U18s, and to some extent the Nio), their audiophile tuning (the Tia Trio and Tia Fourte), and their mainstream tuning (the U18t). The Duo straddles the line of the previously somewhat lone Nio while adding on some extra flair up top, presenting a comparatively new flavor, if not one that will be readily familiar to fans of the brand. But before I get ahead of myself, I should share some thoughts on the Duo's physical design.

In a nutshell, I LOVE the Duo's design. The grill doesn't look cheap at all to me and it's super pleasing aesthetically. Something different about the shell of the Duo is that it has been anodized what appears to be a slight shade of midnight blue (or maybe I'm just colorblind). Either way, the Duo looks fantastic. And it's just as ergonomic too. While I didn't get in a size comparison in the photos above, it's the shortest of 64 Audio's IEMs in terms of shell depth. I spent about 5+ hours jamming out to them today and not once did I feel the need to remove them outside of instinctively yanking them out when someone spoke to me. I say "instinctively" because you don't really need to remove them; you can actually hear people talking if you just pause your music. Anyways, that's more than enough talk about build coming from me - let's talk about the actual sound.

As stated above, the Duo shares some similarities to the 64A Nio, and that's primarily in one aspect: the fat bass shelf. That said, the Nio sports more of a sub-bass focus and for a sense of digging into the deepest frequencies and generating them with a sense of thickness and weight, the Nio comes out ahead in A/B. In this respect, at least intangibly, I do find the Duo's bass to be more reminiscent of the DD used in the Tia Trio. The Duo's bass is more nimble than the Nio's bass response thanks to less decay, and it sounds fairly rich whilst avoiding the wooly thickness of the Nio. I also have no qualms on the fronts of bass texture. As far as I'm concerned, the quicker bass response of the Duo's DD was the right tradeoff, as the Nio's subwoofer generally sounds more sloppy when it comes to the mid-bass. The Duo generally has pretty good bass - not the best I've heard for this price point, that honor goes to the Sennheiser IE900 - but certainly enough to merit comment. And remember, the Duo's DD is tokening the entire midrange too.

Speaking of the midrange of the Duo, it's pretty alright. The overall amplitude of the pinna compensation has not changed too much - it still leans toward the more relaxed side - but it does not peak until 3kHz unlike most of 64A's other IEMs which tend to peak a bit earlier at around 2kHz. This lends the Duo to a slightly more upfront center image, but 64A has recessed the presence regions from 3-4kHz to avoid sibilance per usual. Intangibly, vocals consequently hang slightly higher on the stage while staying upfront for me. I don't think this midrange presentation is quite perfect, but it is an interesting tuning decision I have not encountered before that, again, demonstrates to me that 64A really knows how to tune. Expectedly, the timbre of this midrange is quite pleasant with none of the timbral inconsistency that characterizes most hybrids between bass and midrange. This part was really was nice to hear.

The treble on my unit seems to be somewhat different from the unit I heard on the show floor. I remember the show floor unit sporting more of a lower-treble emphasis which beget a more V-shaped sound signature. However, I will assume for now that the unit I have on-hand represents the ideal sound, as the Duo's product page markets it as having a more laidback sound signature. This is indeed a boon with respect to coherency, as I felt that the tia treble on the show floor unit was a tad too distinct from its DD counterpart. But make no mistake: This can still be a bright IEM depending on the ear tips you're using, your hearing, and the volume you're listening at. In fact, I feel that the tia peaks on this Duo are higher in amplitude than on my U12t - they're definitely higher than the Nio - and almost sharp on certain tracks with wide-bore tips. This was consistent among all three units I heard; hell, I hear what sounds like a 16kHz sheen when Taeyeon enters on "I Found You" that I didn't know was there before. Further along the lines of frequency response, I'd say the Duo's treble is about 40% lower-treble, 20% mid-treble, and 40% upper-treble. I don't know if it's quite right to market this as a relaxed IEM but, to be fair, you can definitely mitigate any unwanted shimmer by tip swapping.

Imaging on the Duo is interesting. It's good, but it's not mind-blowing within the context of the more open nature of the IEM. The Duo's biggest weakness on this front would be localization of instruments. They're somewhat undefined and clearly not as sharp as the Symphonium Helios. But to reiterate, the Duo definitely sports above-average imaging, and I think the best way to describe it would be simply "natural". Sounds mesh into the backdrop pleasingly and there's a good sense of ambiance to the Duo's staging. However, there'll be no cop-outs on the front of detail, I'm afraid. The tia treble holds its own in terms of detail, but I simply don't find the Duo particularly detailed in the midrange which is why I called the midrange "pretty alight" earlier. It sounds slightly smoothed over in A/B with the 64A U6t which I don't even consider a strong performer for detail, and the Sennheiser IE900 which has a disgusting upper-midrange recession. This is ostensibly a limitation of using a single dynamic driver to cover both the bass and the midrange frequencies, even a high-quality one at that.

The best part of the Duo's intangibles would be its dynamics. They're surprisingly good; I wouldn't have bought one for myself if I thought they weren't. Now, I do not think the Duo has great micro-dynamic distinction - a sense of individual instruments and vocalists popping with subtle fluctuations in volume - but it stands that the vast majority of IEMs lack this quality anyways. In fact, the only IEM I have heard with good micro-contrast at this price point would be the Symphonium Helios. That said, macro-contrast on the Duo has the good sense of weight and authority that characterizes the likes of the 64A Nio. I found myself jacking up the volume and going back to swings like Sawano Hiroyuki's "Tranquility" at 0:50 repeatedly just to catch more of this quality while testing the Duo at CanJam. I do not know how 64A does it, and maybe you can consider it the "oh, he's just a 64A shill" effect, but there is definitely something about the likes of the U12t, Nio, and the Duo that catches my attention and gets my head bobbing.

As for some concluding thoughts, the Duo is definitely a good IEM and I like it! But I also cannot ignore the price in good faith, and I don't want to make the mistake of hyping something that won't get near-universal praise. It's crucial to recognize that the Duo sports a more niche design; it heavily emphasizes comfort and it doesn't befit outside use like traditional IEMs unless you're indexing more strongly for situational awareness. For me, that's what I wanted as a compliment to my Symphonium Helios. I'd imagine this would work great for walking outside too and, as the reps at the 64A booth mentioned to me, streaming and gaming. But it still pays to recognize that not everyone else will have these use cases; solely on the basis of sound quality, I find the Duo to be solid for the price but not necessarily outside the scope of the lofty expectations I hold for 64A.

All that said, there is a lot of unique technology and innovation packed into the Duo. Friends better versed in the construction of IEMs than myself have commented on the complexity of 64A's crossover design, and I enjoy the emphasis placed upon the user-experience with technologies like Apex Core - after all, the best sounding IEM doesn't mean much if one can't wear it comfortably.

 

[Deezel177]

I wanted to share some more thoughts on the Duo because I brought one back with me from CanJam. As far as I can tell, 64A basically has three flavors of sound: their "reference" audiophile tuning (which consists of the U12t, U6t, U18s, and to some extent the Nio), their audiophile tuning (the Tia Trio and Tia Fourte), and their mainstream tuning (the U18t). The Duo straddles the line of the previously somewhat lone Nio while adding on some extra flair up top, presenting a comparatively new flavor, if not one that will be readily familiar to fans of the brand. But before I get ahead of myself, I should share some thoughts on the Duo's physical design.





In a nutshell, I LOVE the Duo's design. The grill doesn't look cheap at all to me and it's super pleasing aesthetically. Something different about the shell of the Duo is that it has been anodized what appears to be a slight shade of midnight blue (or maybe I'm just colorblind). Either way, the Duo looks fantastic. And it's just as ergonomic too. While I didn't get in a size comparison in the photos above, it's the shortest of 64 Audio's IEMs in terms of shell depth. I spent about 5+ hours jamming out to them today and not once did I feel the need to remove them outside of instinctively yanking them out when someone spoke to me. I say "instinctively" because you don't really need to remove them; you can actually hear people talking if you just pause your music. Anyways, that's more than enough talk about build coming from me - let's talk about the actual sound.



As stated above, the Duo shares some similarities to the 64A Nio, and that's primarily in one aspect: the fat bass shelf. That said, the Nio sports more of a sub-bass focus and for a sense of digging into the deepest frequencies and generating them with a sense of thickness and weight, the Nio comes out ahead in A/B. In this respect, at least intangibly, I do find the Duo's bass to be more reminiscent of the DD used in the Tia Trio. The Duo's bass is more nimble than the Nio's bass response thanks to less decay, and it sounds fairly rich whilst avoiding the wooly thickness of the Nio. I also have no qualms on the fronts of bass texture. As far as I'm concerned, the quicker bass response of the Duo's DD was the right tradeoff, as the Nio's subwoofer generally sounds more sloppy when it comes to the mid-bass. The Duo generally has pretty good bass - not the best I've heard for this price point, that honor goes to the Sennheiser IE900 - but certainly enough to merit comment. And remember, the Duo's DD is tokening the entire midrange too.

Speaking of the midrange of the Duo, it's pretty alright. The overall amplitude of the pinna compensation has not changed too much - it still leans toward the more relaxed side - but it does not peak until 3kHz unlike most of 64A's other IEMs which tend to peak a bit earlier at around 2kHz. This lends the Duo to a slightly more upfront center image, but 64A has recessed the presence regions from 3-4kHz to avoid sibilance per usual. Intangibly, vocals consequently hang slightly higher on the stage while staying upfront for me. I don't think this midrange presentation is quite perfect, but it is an interesting tuning decision I have not encountered before that, again, demonstrates to me that 64A really knows how to tune. Expectedly, the timbre of this midrange is quite pleasant with none of the timbral inconsistency that characterizes most hybrids between bass and midrange. This part was really was nice to hear.

The treble on my unit seems to be somewhat different from the unit I heard on the show floor. I remember the show floor unit sporting more of a lower-treble emphasis which beget a more V-shaped sound signature. However, I will assume for now that the unit I have on-hand represents the ideal sound, as the Duo's product page markets it as having a more laidback sound signature. This is indeed a boon with respect to coherency, as I felt that the tia treble on the show floor unit was a tad too distinct from its DD counterpart. But make no mistake: This can still be a bright IEM depending on the ear tips you're using, your hearing, and the volume you're listening at. In fact, I feel that the tia peaks on this Duo are higher in amplitude than on my U12t - they're definitely higher than the Nio - and almost sharp on certain tracks with wide-bore tips. This was consistent among all three units I heard; hell, I hear what sounds like a 16kHz sheen when Taeyeon enters on "I Found You" that I didn't know was there before. Further along the lines of frequency response, I'd say the Duo's treble is about 40% lower-treble, 20% mid-treble, and 40% upper-treble. I don't know if it's quite right to market this as a relaxed IEM but, to be fair, you can definitely mitigate any unwanted shimmer by tip swapping.



Imaging on the Duo is interesting. It's good, but it's not mind-blowing within the context of the more open nature of the IEM. The Duo's biggest weakness on this front would be localization of instruments. They're somewhat undefined and clearly not as sharp as the Symphonium Helios. But to reiterate, the Duo definitely sports above-average imaging, and I think the best way to describe it would be simply "natural". Sounds mesh into the backdrop pleasingly and there's a good sense of ambiance to the Duo's staging. However, there'll be no cop-outs on the front of detail, I'm afraid. The tia treble holds its own in terms of detail, but I simply don't find the Duo particularly detailed in the midrange which is why I called the midrange "pretty alight" earlier. It sounds slightly smoothed over in A/B with the 64A U6t which I don't even consider a strong performer for detail, and the Sennheiser IE900 which has a disgusting upper-midrange recession. This is ostensibly a limitation of using a single dynamic driver to cover both the bass and the midrange frequencies, even a high-quality one at that.

The best part of the Duo's intangibles would be its dynamics. They're surprisingly good; I wouldn't have bought one for myself if I thought they weren't. Now, I do not think the Duo has great micro-dynamic distinction - a sense of individual instruments and vocalists popping with subtle fluctuations in volume - but it stands that the vast majority of IEMs lack this quality anyways. In fact, the only IEM I have heard with good micro-contrast at this price point would be the Symphonium Helios. That said, macro-contrast on the Duo has the good sense of weight and authority that characterizes the likes of the 64A Nio. I found myself jacking up the volume and going back to swings like Sawano Hiroyuki's "Tranquility" at 0:50 repeatedly just to catch more of this quality while testing the Duo at CanJam. I do not know how 64A does it, and maybe you can consider it the "oh, he's just a 64A shill" effect, but there is definitely something about the likes of the U12t, Nio, and the Duo that catches my attention and gets my head bobbing.

As for some concluding thoughts, the Duo is definitely a good IEM and I like it! But I also cannot ignore the price in good faith, and I don't want to make the mistake of hyping something that won't get near-universal praise. It's crucial to recognize that the Duo sports a more niche design; it heavily emphasizes comfort and it doesn't befit outside use like traditional IEMs unless you're indexing more strongly for situational awareness. For me, that's what I wanted as a compliment to my Symphonium Helios. I'd imagine this would work great for walking outside too and, as the reps at the 64A booth mentioned to me, streaming and gaming. But it still pays to recognize that not everyone else will have these use cases; solely on the basis of sound quality, I find the Duo to be solid for the price but not necessarily outside the scope of the lofty expectations I hold for 64A.

All that said, there is a lot of unique technology and innovation packed into the Duo. Friends better versed in the construction of IEMs than myself have commented on the complexity of 64A's crossover design, and I enjoy the emphasis placed upon the user-experience with technologies like Apex Core - after all, the best sounding IEM doesn't mean much if one can't wear it comfortably.

Excellent, excellent write-up, man. 'Heavily agree with everything you've said there, most especially in the midrange. I look forward to your full review!

 

[Razza1974]

I wanted to share some more thoughts on the Duo because I brought one back with me from CanJam. As far as I can tell, 64A basically has three flavors of sound: their "reference" audiophile tuning (which consists of the U12t, U6t, U18s, and to some extent the Nio), their audiophile tuning (the Tia Trio and Tia Fourte), and their mainstream tuning (the U18t). The Duo straddles the line of the previously somewhat lone Nio while adding on some extra flair up top, presenting a comparatively new flavor, if not one that will be readily familiar to fans of the brand. But before I get ahead of myself, I should share some thoughts on the Duo's physical design.





In a nutshell, I LOVE the Duo's design. The grill doesn't look cheap at all to me and it's super pleasing aesthetically. Something different about the shell of the Duo is that it has been anodized what appears to be a slight shade of midnight blue (or maybe I'm just colorblind). Either way, the Duo looks fantastic. And it's just as ergonomic too. While I didn't get in a size comparison in the photos above, it's the shortest of 64 Audio's IEMs in terms of shell depth. I spent about 5+ hours jamming out to them today and not once did I feel the need to remove them outside of instinctively yanking them out when someone spoke to me. I say "instinctively" because you don't really need to remove them; you can actually hear people talking if you just pause your music. Anyways, that's more than enough talk about build coming from me - let's talk about the actual sound.



As stated above, the Duo shares some similarities to the 64A Nio, and that's primarily in one aspect: the fat bass shelf. That said, the Nio sports more of a sub-bass focus and for a sense of digging into the deepest frequencies and generating them with a sense of thickness and weight, the Nio comes out ahead in A/B. In this respect, at least intangibly, I do find the Duo's bass to be more reminiscent of the DD used in the Tia Trio. The Duo's bass is more nimble than the Nio's bass response thanks to less decay, and it sounds fairly rich whilst avoiding the wooly thickness of the Nio. I also have no qualms on the fronts of bass texture. As far as I'm concerned, the quicker bass response of the Duo's DD was the right tradeoff, as the Nio's subwoofer generally sounds more sloppy when it comes to the mid-bass. The Duo generally has pretty good bass - not the best I've heard for this price point, that honor goes to the Sennheiser IE900 - but certainly enough to merit comment. And remember, the Duo's DD is tokening the entire midrange too.

Speaking of the midrange of the Duo, it's pretty alright. The overall amplitude of the pinna compensation has not changed too much - it still leans toward the more relaxed side - but it does not peak until 3kHz unlike most of 64A's other IEMs which tend to peak a bit earlier at around 2kHz. This lends the Duo to a slightly more upfront center image, but 64A has recessed the presence regions from 3-4kHz to avoid sibilance per usual. Intangibly, vocals consequently hang slightly higher on the stage while staying upfront for me. I don't think this midrange presentation is quite perfect, but it is an interesting tuning decision I have not encountered before that, again, demonstrates to me that 64A really knows how to tune. Expectedly, the timbre of this midrange is quite pleasant with none of the timbral inconsistency that characterizes most hybrids between bass and midrange. This part was really was nice to hear.

The treble on my unit seems to be somewhat different from the unit I heard on the show floor. I remember the show floor unit sporting more of a lower-treble emphasis which beget a more V-shaped sound signature. However, I will assume for now that the unit I have on-hand represents the ideal sound, as the Duo's product page markets it as having a more laidback sound signature. This is indeed a boon with respect to coherency, as I felt that the tia treble on the show floor unit was a tad too distinct from its DD counterpart. But make no mistake: This can still be a bright IEM depending on the ear tips you're using, your hearing, and the volume you're listening at. In fact, I feel that the tia peaks on this Duo are higher in amplitude than on my U12t - they're definitely higher than the Nio - and almost sharp on certain tracks with wide-bore tips. This was consistent among all three units I heard; hell, I hear what sounds like a 16kHz sheen when Taeyeon enters on "I Found You" that I didn't know was there before. Further along the lines of frequency response, I'd say the Duo's treble is about 40% lower-treble, 20% mid-treble, and 40% upper-treble. I don't know if it's quite right to market this as a relaxed IEM but, to be fair, you can definitely mitigate any unwanted shimmer by tip swapping.



Imaging on the Duo is interesting. It's good, but it's not mind-blowing within the context of the more open nature of the IEM. The Duo's biggest weakness on this front would be localization of instruments. They're somewhat undefined and clearly not as sharp as the Symphonium Helios. But to reiterate, the Duo definitely sports above-average imaging, and I think the best way to describe it would be simply "natural". Sounds mesh into the backdrop pleasingly and there's a good sense of ambiance to the Duo's staging. However, there'll be no cop-outs on the front of detail, I'm afraid. The tia treble holds its own in terms of detail, but I simply don't find the Duo particularly detailed in the midrange which is why I called the midrange "pretty alight" earlier. It sounds slightly smoothed over in A/B with the 64A U6t which I don't even consider a strong performer for detail, and the Sennheiser IE900 which has a disgusting upper-midrange recession. This is ostensibly a limitation of using a single dynamic driver to cover both the bass and the midrange frequencies, even a high-quality one at that.

The best part of the Duo's intangibles would be its dynamics. They're surprisingly good; I wouldn't have bought one for myself if I thought they weren't. Now, I do not think the Duo has great micro-dynamic distinction - a sense of individual instruments and vocalists popping with subtle fluctuations in volume - but it stands that the vast majority of IEMs lack this quality anyways. In fact, the only IEM I have heard with good micro-contrast at this price point would be the Symphonium Helios. That said, macro-contrast on the Duo has the good sense of weight and authority that characterizes the likes of the 64A Nio. I found myself jacking up the volume and going back to swings like Sawano Hiroyuki's "Tranquility" at 0:50 repeatedly just to catch more of this quality while testing the Duo at CanJam. I do not know how 64A does it, and maybe you can consider it the "oh, he's just a 64A shill" effect, but there is definitely something about the likes of the U12t, Nio, and the Duo that catches my attention and gets my head bobbing.

As for some concluding thoughts, the Duo is definitely a good IEM and I like it! But I also cannot ignore the price in good faith, and I don't want to make the mistake of hyping something that won't get near-universal praise. It's crucial to recognize that the Duo sports a more niche design; it heavily emphasizes comfort and it doesn't befit outside use like traditional IEMs unless you're indexing more strongly for situational awareness. For me, that's what I wanted as a compliment to my Symphonium Helios. I'd imagine this would work great for walking outside too and, as the reps at the 64A booth mentioned to me, streaming and gaming. But it still pays to recognize that not everyone else will have these use cases; solely on the basis of sound quality, I find the Duo to be solid for the price but not necessarily outside the scope of the lofty expectations I hold for 64A.

All that said, there is a lot of unique technology and innovation packed into the Duo. Friends better versed in the construction of IEMs than myself have commented on the complexity of 64A's crossover design, and I enjoy the emphasis placed upon the user-experience with technologies like Apex Core - after all, the best sounding IEM doesn't mean much if one can't wear it comfortably.

Funny, surpised by youre categorising of the iems: u12t as reference and fourte as audiohile and u18t as mainstream. I always thought of the u18t as reference and u12t and fourte as more fun! But then again what is mainstream/reference/audiohile and what is not.........that's the question

 

[toaster]

…yeah, you sure you meant to classify that way, @Precogvision?

Seems flipped.

 

[aaf evo]

I wanted to share some more thoughts on the Duo because I brought one back with me from CanJam. As far as I can tell, 64A basically has three flavors of sound: their "reference" audiophile tuning (which consists of the U12t, U6t, U18s, and to some extent the Nio), their audiophile tuning (the Tia Trio and Tia Fourte), and their mainstream tuning (the U18t). The Duo straddles the line of the previously somewhat lone Nio while adding on some extra flair up top, presenting a comparatively new flavor, if not one that will be readily familiar to fans of the brand. But before I get ahead of myself, I should share some thoughts on the Duo's physical design.





In a nutshell, I LOVE the Duo's design. The grill doesn't look cheap at all to me and it's super pleasing aesthetically. Something different about the shell of the Duo is that it has been anodized what appears to be a slight shade of midnight blue (or maybe I'm just colorblind). Either way, the Duo looks fantastic. And it's just as ergonomic too. While I didn't get in a size comparison in the photos above, it's the shortest of 64 Audio's IEMs in terms of shell depth. I spent about 5+ hours jamming out to them today and not once did I feel the need to remove them outside of instinctively yanking them out when someone spoke to me. I say "instinctively" because you don't really need to remove them; you can actually hear people talking if you just pause your music. Anyways, that's more than enough talk about build coming from me - let's talk about the actual sound.



As stated above, the Duo shares some similarities to the 64A Nio, and that's primarily in one aspect: the fat bass shelf. That said, the Nio sports more of a sub-bass focus and for a sense of digging into the deepest frequencies and generating them with a sense of thickness and weight, the Nio comes out ahead in A/B. In this respect, at least intangibly, I do find the Duo's bass to be more reminiscent of the DD used in the Tia Trio. The Duo's bass is more nimble than the Nio's bass response thanks to less decay, and it sounds fairly rich whilst avoiding the wooly thickness of the Nio. I also have no qualms on the fronts of bass texture. As far as I'm concerned, the quicker bass response of the Duo's DD was the right tradeoff, as the Nio's subwoofer generally sounds more sloppy when it comes to the mid-bass. The Duo generally has pretty good bass - not the best I've heard for this price point, that honor goes to the Sennheiser IE900 - but certainly enough to merit comment. And remember, the Duo's DD is tokening the entire midrange too.

Speaking of the midrange of the Duo, it's pretty alright. The overall amplitude of the pinna compensation has not changed too much - it still leans toward the more relaxed side - but it does not peak until 3kHz unlike most of 64A's other IEMs which tend to peak a bit earlier at around 2kHz. This lends the Duo to a slightly more upfront center image, but 64A has recessed the presence regions from 3-4kHz to avoid sibilance per usual. Intangibly, vocals consequently hang slightly higher on the stage while staying upfront for me. I don't think this midrange presentation is quite perfect, but it is an interesting tuning decision I have not encountered before that, again, demonstrates to me that 64A really knows how to tune. Expectedly, the timbre of this midrange is quite pleasant with none of the timbral inconsistency that characterizes most hybrids between bass and midrange. This part was really was nice to hear.

The treble on my unit seems to be somewhat different from the unit I heard on the show floor. I remember the show floor unit sporting more of a lower-treble emphasis which beget a more V-shaped sound signature. However, I will assume for now that the unit I have on-hand represents the ideal sound, as the Duo's product page markets it as having a more laidback sound signature. This is indeed a boon with respect to coherency, as I felt that the tia treble on the show floor unit was a tad too distinct from its DD counterpart. But make no mistake: This can still be a bright IEM depending on the ear tips you're using, your hearing, and the volume you're listening at. In fact, I feel that the tia peaks on this Duo are higher in amplitude than on my U12t - they're definitely higher than the Nio - and almost sharp on certain tracks with wide-bore tips. This was consistent among all three units I heard; hell, I hear what sounds like a 16kHz sheen when Taeyeon enters on "I Found You" that I didn't know was there before. Further along the lines of frequency response, I'd say the Duo's treble is about 40% lower-treble, 20% mid-treble, and 40% upper-treble. I don't know if it's quite right to market this as a relaxed IEM but, to be fair, you can definitely mitigate any unwanted shimmer by tip swapping.



Imaging on the Duo is interesting. It's good, but it's not mind-blowing within the context of the more open nature of the IEM. The Duo's biggest weakness on this front would be localization of instruments. They're somewhat undefined and clearly not as sharp as the Symphonium Helios. But to reiterate, the Duo definitely sports above-average imaging, and I think the best way to describe it would be simply "natural". Sounds mesh into the backdrop pleasingly and there's a good sense of ambiance to the Duo's staging. However, there'll be no cop-outs on the front of detail, I'm afraid. The tia treble holds its own in terms of detail, but I simply don't find the Duo particularly detailed in the midrange which is why I called the midrange "pretty alight" earlier. It sounds slightly smoothed over in A/B with the 64A U6t which I don't even consider a strong performer for detail, and the Sennheiser IE900 which has a disgusting upper-midrange recession. This is ostensibly a limitation of using a single dynamic driver to cover both the bass and the midrange frequencies, even a high-quality one at that.

The best part of the Duo's intangibles would be its dynamics. They're surprisingly good; I wouldn't have bought one for myself if I thought they weren't. Now, I do not think the Duo has great micro-dynamic distinction - a sense of individual instruments and vocalists popping with subtle fluctuations in volume - but it stands that the vast majority of IEMs lack this quality anyways. In fact, the only IEM I have heard with good micro-contrast at this price point would be the Symphonium Helios. That said, macro-contrast on the Duo has the good sense of weight and authority that characterizes the likes of the 64A Nio. I found myself jacking up the volume and going back to swings like Sawano Hiroyuki's "Tranquility" at 0:50 repeatedly just to catch more of this quality while testing the Duo at CanJam. I do not know how 64A does it, and maybe you can consider it the "oh, he's just a 64A shill" effect, but there is definitely something about the likes of the U12t, Nio, and the Duo that catches my attention and gets my head bobbing.

As for some concluding thoughts, the Duo is definitely a good IEM and I like it! But I also cannot ignore the price in good faith, and I don't want to make the mistake of hyping something that won't get near-universal praise. It's crucial to recognize that the Duo sports a more niche design; it heavily emphasizes comfort and it doesn't befit outside use like traditional IEMs unless you're indexing more strongly for situational awareness. For me, that's what I wanted as a compliment to my Symphonium Helios. I'd imagine this would work great for walking outside too and, as the reps at the 64A booth mentioned to me, streaming and gaming. But it still pays to recognize that not everyone else will have these use cases; solely on the basis of sound quality, I find the Duo to be solid for the price but not necessarily outside the scope of the lofty expectations I hold for 64A.

All that said, there is a lot of unique technology and innovation packed into the Duo. Friends better versed in the construction of IEMs than myself have commented on the complexity of 64A's crossover design, and I enjoy the emphasis placed upon the user-experience with technologies like Apex Core - after all, the best sounding IEM doesn't mean much if one can't wear it comfortably.

Nice impressions, does that aggressive 4k dip impact the upper mid range clarity?

 

[Deezel177]

Funny, surpised by youre categorising of the iems: u12t as reference and fourte as audiohile and u18t as mainstream. I always thought of the u18t as reference and u12t and fourte as more fun! But then again what is mainstream/reference/audiohile and what is not.........that's the question

…yeah, you sure you meant to classify that way, @Precogvision?

Seems flipped.

I personally agree with @Precogvision's classifications. It's been a while since I heard the U18t or the U12t, but I'd definitely categorise the A18t as mainstream or fun. It's got a slight W-shape to it, which is why it's my monitor of choice for drumming. The A18s (and, by extension, the U/A12t from what I've heard) has a much more subdued, flat, unassuming sound, which makes it perfect for monitoring. It's been my mixing and mastering tool since I got it last year, in fact. It doesn't add much to the music, which is what makes it reference to me. Whereas, there's a bit of a low-treble sizzle and a bit of a low-mid dip that the A18t carries wherever it goes. Of course, I'm speaking from an engineer's perspective. What constitutes as neutral or fun to an audiophile or a listener may very well be different.

 

[gLer]

I've always had the perception, false though it may be, that bright = reference/audiophile, warm = fun. Not even sure how I got that impression, but it's stuck with me since the early days of this hobby.

 

[Razza1974]

I've always had the perception, false though it may be, that bright = reference/audiophile, warm = fun. Not even sure how I got that impression, but it's stuck with me since the early days of this hobby.

Well that's what I mean, tuning of the u18t is bright, certainly not bassy and I think quite balanced, nothing is emphasized and some have refered to it as boring, i would not call it boring but certainly not mainstream. u12t is more bassy, more dynamic and adds more colour, less neutral apparently ( haven't heard it just what i picked up here and there), in my book that's more mainstream. While fourte apparently is anything but mainstream, with the divisive treble and disappearing mids , so how's that audiophile )))
Just funny how we use these terms......... I am inclined to call dr Beats reference now
Joking guys, its really of no importance but shows that reading used terminology can have wildly different implied meaning........

 

[Deezel177]

I've always had the perception, false though it may be, that bright = reference/audiophile, warm = fun. Not even sure how I got that impression, but it's stuck with me since the early days of this hobby.

I think it was perpetuated by a common interpretation of reference back then, which was more detail = more reference. A treble boost (or a bass cut) is the easiest way to amplify perception of detail, and it also coincided with the marketing philosophy (or propaganda) of reference = more detail = better that most companies tried (and are still trying, to a degree) to push to consumers. That created a wave of bright-leaning headphones/IEMs that were labelled reference or studio quality, and that label or association has stuck ever since.

For me, the term reference has always been more closely tied to tonality than detail. After all, the term reference comes from being viable as a mixing or mastering reference, and you’re mostly shaping a track’s tonality, balance or colour when you’re mixing and mastering, right? So, a reference product, to me, will always be one that adds as little colour as possible to the music. If I hear the same treble peak or low-mid cut between track A and track B, even though those tracks are entirely different genres, then that in-ear isn’t wholly reference to me. Parts of an IEM or headphone can also be reference or not reference, but that’s a can of worms for another time.

Whereas, warm = fun is an idea that at least has some objective truth in it. The bottom-end in 90% of music is conducive to rhythm and groove (instruments like the bass drum or the bass guitar), so we tend to associate funkiness or musicality to an elevated bottom-end.

Well that's what I mean, tuning of the u18t is bright, certainly not bassy and I think quite balanced, nothing is emphasized and some have refered to it as boring, i would not call it boring but certainly not mainstream. u12t is more bassy, more dynamic and adds more colour, less neutral apparently ( haven't heard it just what i picked up here and there), in my book that's more mainstream. While fourte apparently is anything but mainstream, with the divisive treble and disappearing mids , so how's that audiophile )))
Just funny how we use these terms......... I am inclined to call dr Beats reference now
Joking guys, its really of no importance but shows that reading used terminology can have wildly different implied meaning........

I believe the common consensus is that the opposite is true, actually. The U18t is generally-considered the more dynamic one, while the U12t is the flatter, more relaxed, more neutral one. The U12t is only considered more bass-y than the U18t because the latter has more upper-mid forwardness and more treble. That’s what I personally thought when I heard them, at least.