Sound Analysis and Comparison.

While in all my reviews I have a separate Sound Analysis and Comparison sections, I decided to do it differently this time, by combining these sections together. I covered U12, U18, and Fourte before with lots of comparison to other IEMs. Here, I feel the interest will be more in how U12t and Trio compare to U12, U18, and Fourte so people can make a decision which one suites them better. For consistency, I used the original 64 Audio SPC cable.

U12t.

U12t (M15) vs U12 (M15).

Both have a relatively balanced signature which could be referred to as W-shaped where every frequency range is well represented and balanced. But there are a few fundamental differences that give each iem its unique sound characteristics.

Both have a wide soundstage, and convincing positioning of sounds. But when it comes to layering and separation, U12t has a better technical performance since u12 is smoother and more laidback while U12t is more revealing and has more air between layers to separate and to expand them.

With bass, I hear U12t having a little more sub-bass rumble, while mid-bass is very similar in quantity between both, maybe with the original u12 having a little more mid-bass impact in comparison.

Mids is where you hear a noticeable difference, specifically lower mids. Here, upper mids are nearly identical, but lower mids in u12 have more body vs a more neutral lower mids of U12t. As a result, u12 sound could be a little bloated in comparison to u12t. Interesting how sometimes things are not as obvious until you start switching and comparing. Upper mids are very similar between both, but the lower mids really influence overall tonality and sound presentation, with U12t being leaner, more neutral, and more revealing vs u12 having a fuller body with a smoother sound.

Treble also has a lot of similarities, being well defined and with just enough crunch, but U12t takes one step further, being a little more vivid and with more sparkle and airiness.

U12t (M15) vs U18 (M20).

Both have a balanced signature where u18 has a little more forward upper mids with more energy in lower treble. While U12t holding it a bit back with a smoother, more organic tonality of mids, u18 steps more into Fourte/Trio territory with more revealing, detailed, brighter upper mids.

U18 soundstage is wider. Similar to Fourte vs Trio where Trio has a wide staging but Fourte just goes beyond that, u18 does the same in comparison to U12t, going beyond already wide soundstage of U12t. And along with that, more revealing, more airy sound of u18 has improved layering and separation.

With bass, both are very similar, I mean to the point of having nearly identical sub-bass and mid- bass. I’m not even picking up any noticeable difference. But keep in mind, I’m using u18 with M20 module which plays an important role in matching with U12t (M15). U18 with M15 loses some of the isolation which affects bass impact.

With mids, here I hear lower mids of u18 being just a little leaner in comparison to a more neutral U12t lower mids. That creates more separation between the bass and the upper mids in a relative comparison of U12t where you have a smoother transition from lows to mids with a more neutral tonality. Upper mids is where u18 shines with more energy, more forward presentation, better retrieval of details, and brighter tonality. U12t is smoother, more organic, still very details and layered, just less revealing which could be plus for some.

With treble, again, lots of similarities with the same level of crunch, definition, but u18 still has an edge with more airiness and more sparkle, extending just a little bit further too.

U12t: M15 vs M20.

Also, I compared U12t with M15 vs M20 modules. The change of going from M15 to M20 affects mostly the bass with an elevated sub-bass rumble which goes deeper and has higher quantity, and stronger mid-bass impact. I don’t hear too much of other changes, maybe a touch more body in lower mids with M20, but upper mids and treble remain the same, just a change in low end.

Trio.

Trio vs Fourte.

Both Trio and Fourte have a more revealing brighter tonality with a unique signature where it could appear as u-shaped due to elevated low end and treble, but the mids are not scooped out or recessed. Mids are quite balanced relative to the baseline of bass and treble. The sound is very resolving, but Fourte is more revealing, more micro-detailed, and airier while Trio is a little smoother and more organic, with a little more body in a relative comparison.

With soundstage, I found Fourte to be wider, while the soundstage depth is the same. Trio soundstage is wide no questions about it, but Fourte soundstage goes even further in width.

Bass difference is noticeable where I think 64 Audio decided to unleash the full power of its dynamic driver in Trio, with a deeper and a more elevated sub-bass rumble, and relatively higher mid-bass impact. In comparison, Fourte bass is more balanced and more linear. Also, I hear Fourte bass being a little tighter and more controlled, while Trio has this added layer of analog texture. I think Trio bass, especially the deeper sub-bass, is what some expected from Fourte to begin with, associating dynamic driver with a more aggressive low-end performance.

With mids, I hear a lot of similarities between these two. Lower mids sounds a little more neutral with Trio which could also be part of a perception due to a contrast with boosted lows in comparison to more neutral lows in Fourte. With upper mids, Fourte is more revealing, more analytical and micro-detailed, though it also being a little colder and thinner, while Trio is smoother and even more organic, still very detailed but not quite micro-detailed like Fourte.

Treble, and specifically lower treble region, is where you hear a more noticeable difference. As mentioned before, they both have a revealing brighter tonality at the top with plenty of energy around the treble, specifically more definition around 10k-12k region. But unlike Fourte where I hear a little more boost around 6k, Trio keeps it more natural, giving treble a more organic tonality, taking some edge off, while in comparison Fourte lower treble sounds thinner, more revealing, with more airiness. Treble in both is well defined, with a nice level of crunch, but Trio sounds fuller and more natural, while Fourte is more vivid and more revealing.

Trio vs U12t (M15).

U12t has a more balanced signature with a smoother natural tonality, while Trio is more u-shaped with a more pronounced low-end lift (in particular sub-bass) and a more forward upper mids and extra treble sparkle.

Soundstage width is nearly the same. And overall sound layering and separation is similar.

With bass, U12t has a punchy mid-bass, close to Trio, but with a little faster attack and shorter decay which makes the bass tighter and faster. One noticeable difference here is U12t having less sub-bass in comparison to Trio, making low end a little less boomy. Also, because U12t mids are more balanced, its bass comes more in focus.

When it comes to mids, U12t lower mids have a little more body while Trio lower mids are more neutral in comparison. Ironically, U12t’s bass has a shorter decay, so the extra body is not from the spillage but from the actual tuning. On a contrary, Trio bass is more analog and slower, yet due to a more neutral lower mids and more forward upper mids, there is more noticeable separation between lows and mids in Trio, versus a more coherent transition in U12t. Upper mids in Trio are more revealing, more detailed, brighter in tonality, while U12t is revealing and detailed but smoother and more organic in comparison.

Treble has more similarities here, with both having plenty of definition and crunch, though I think Trio goes a step further with more crunch and more airiness, which also makes it brighter. The perception of treble in Trio also gets influenced by its slightly forward upper mids that infuse it with more energy, while U12t treble is smoother which goes along with its more natural balanced mids.

Pair up.

For clarification, I consider sound to be balanced when there is a relative balance between lows, mids, and highs. When I talk about u-shaped sound in my description below, I don’t mean a scooped out mids, but rather a more balanced mids with elevated bass and treble which creates u-shaped sound sig perception.

U12t pair-up:

Plenue 2 – wide soundstage, balanced signature, revealing detailed sound; punchy, a little slower mid-bass with a nice sub-bass rumble, neutral lower mids, detailed natural upper mids, crisp detailed treble. Good dynamic expansion, and good layering and separation, though a little less air between layers.

LPG – wide soundstage, balanced signature, maybe pushing more toward u-shaped, revealing detailed sound; stronger mid-bass punch, a little more forward upper mids, crisp detailed treble with a little more sparkle and airiness. Great dynamic expansion with excellent layering and separation.

Opus#2 – wide soundstage with a little more depth; more sub-bass rumble and stronger mids-bass punch, neutral lower mids with smooth detailed natural upper mids, crisp detailed treble. Good dynamic expansion with nice layering and separation, just a little less air between layers.

X7ii – wide soundstage, balanced signature; a little more sub-bass rumble, neutral lower mids, detailed natural upper mids which are slightly more forward, crisp detailed treble. Dynamic expansion is good, not the best, which also results in good layering and separation, but not as much air between the layers.

AK120ii – wide soundstage, balanced signature; punchy bass with a nice bouncy mid-bass and moderate sub-bass level, a little more body in lower mids, smooth detailed upper mids, crisp detailed treble. Dynamic expansion in this pair up is OK, not super expanded but with a nice layering and separation.

WM1Z – soundstage is 3D holographic, balanced signature, revealing detailed natural tonality; punchy bass with a nice sub-bass texture, tighter/faster mid-bass, neutral lower mids, detailed natural upper mids, crisp detailed treble. The sound is very natural, with a little fuller body, detailed, good dynamic expansion, and more holographic 3D staging.

DX200 w/amp4 – wide soundstage with a little more depth, balanced signature; revealing detailed natural sound, punchy bass with textured sub-bass rumble, neutral lower mids, detailed natural upper mids, crisp detailed treble. The sound has a good dynamics expansion and above average layering/separation, natural tonality, with a little fuller body.

Trio pair-up:

Plenue 2 – wide soundstage, u-shaped sig with more forward mids; deep sub-bass rumble, slower mid-bass punch, neutral lower mids, more revealing brighter upper mids, crisp airy treble. Dynamic expanded sound, good layering and separation.

LPG – wide soundstage; u-shaped sig with more balanced mids; deep sub-bass rumble with a more elevated mid-bass punch, neutral lower mids, more micro-detailed layered brighter upper mids, crisp snappy airy treble. Excellent dynamic expansion of the sound with good layering and separation of sounds, though sound is brighter due to more treble energy.

Opus#2 – wide soundstage, u-shaped sig with mids slightly pushed back; deep sub-bass rumble with a little higher quantity, slower mid-bass punch, neutral lower mids, more revealing brighter upper mids, very crisp airy treble, actually a bit too much. Good dynamics of the sound, but I find a bit too much treble energy in this pair up.

X7ii – wide soundstage, u-shaped sig with balanced mids; deep sub-bass rumble, faster mid-bass punch, neutral lower mids, more revealing brighter upper mids, crisp airy treble with a little extra crunch. Sound is dynamic, but in this pair up not as much in comparison to some other flagship DAPs, not congested, just not as dynamically expanded with a bit less air between layers.

AK120ii – wide soundstage, the sound is u-shaped with balanced mids; nice sub-bass rumble but not as deep as with some other sources, slower mid-bass punch, fuller lower mids, revealing upper mids but a little smoother in tonality, crisp well-defined treble. Dynamic expansion is good, but not on the same level as some other flagship daps.

WM1Z – soundstage is 3D holographic; more balanced signature, though mids pushed a little bit further; punchy articulate bass with a nice sub-bass rendition, neutral lower mids, detailed warmer more natural upper mids, well-defined smoother extended treble which is not as airy. 1Z has a more natural smoother tonality, especially when it comes to upper frequencies, but without sacrificing dynamics or layering of the sounds.

DX200 w/amp4 – wide soundstage with a little more depth, u-shaped signature with more balanced mids; smooth analog textured sub-bass rumble with a punchy mid-bass; fuller body lower mids and brighter revealing upper mids; crisp airy well-defined treble. Dynamic sound with a good sense of layering and air between the layers.

Conclusion.

As I mentioned in my original reviews, going between U18 and Fourte could be a tough decision for some people. Now, with introduction of U12t and Trio, you have additional and more affordable choices where U12t and A12t expected to be priced at $1,999 and Trio expected to be priced at $2,299. If I would to summarize the differences, U12t fits somewhere between U12 and U18, keeping the smoothness of the original U12 while adding more revealing details of U18 thanks to TIA driver and the tuning optimization with lower output impedance sources. With Trio, you have transformation of Fourte which has a more solid dynamic driver impact while toning down the upper frequencies with smoother and more organic tonality.

It’s good to see 64 Audio making their new TIA tech more affordable, but at the end of the day it’s all about the sound. Without a doubt, U18 and Fourte are still the flagships in 64 Audio product line-up. But the flagship status doesn’t automatically mean it will fit everyone’s sound preference. The final choice should be based on finding the IEM with your ideal sound signature, where I think if you are interested in 64 Audio IEMs and their TIA and APEX tech, now you have a comprehensive choice between U12t, Trio, U18, and Fourte.