Sound Analysis.

Prior to starting my critical listening, I did put TIA Fourte through 100hrs of standalone burn in, just to be sure that its dynamic driver, cable, all the solder joints, internal wiring, and crossover components have reached their prime condition. Either if you believe or don’t in a burn-in, many manufacturers do recommend it, especially when it comes to dynamic drivers. Also, it’s hard to talk about Fourte without direct comparison to U18, thus you are going to read many references to both as I describe Fourte sound using a stock cable.

Soundstage: a very similar 3D spacing, with U18 being a touch wider, while Fourte having a touch more depth. Not sure if it’s a placebo effect, considering U18 has removable apex modules while Fourte has one built in, but I felt like U18 sound was a little more expanded with an “open back” perception, while Fourte gave me a sense of just a little more intimacy. Both have an excellent imaging with a convincing placement of instruments and vocals, though I found Fourte to excel a little more here due to an improved layering and separation between the sounds, with more air between the layers. Both U18 and Fourte exhibit a good level of transparency and the sound dynamics, the sound never feels congested, but layering and separation goes to a brighter tuned Fourte. With Fourte, spatial positioning details are more precise and some of the sound nuances popped out of nowhere from a few tracks I’m intimately familiar with. I felt like a noob, surprising myself with a discovery of percussions in one of the songs, positioned far left which I never knew even existed in that track.

While U18 has a more balanced coherent signature with a smoother natural tonality, I hear Fourte as having a more fun sound with slightly mid-forward signature with a brighter, more revealing tonality supercharged by two TIA drivers. The multi-BA tuning of U18 has coherent driver tuning where despite the low-end impact, you still hear all the drives working together in unison. Fourte’s hybrid design is tuned with a solid foundation of distinct layer of smooth velvety analog bass under layers of revealing, brighter mids and treble. It reminded me of a few ultra-wide bandwidth single dynamic driver IEMs, though Fourte is not v-shaped like those other drivers, and has a more balanced mid-forward sound perception.

Bass: here, I hear Fourte going deeper, even with a little more sub-bass rumble, while U18 has an edge with higher quantity and faster mid-bass impact. I never considered U18 bass to sound like a typical fast BA performance, it has a speed of BA drivers, but the bass is more rounded with a slower decay. Coincidentally, Fourte dynamic driver is also a bit of a mixed breed where I do hear a medium speed attack with a more rounded textured tonality, perhaps a little faster than a typical dynamic driver, but the decay is slower than U18 bass, yet still has plenty of control while creating this layered separation between the bass and the lower mids. While neither U18 nor Fourte have bass performance typical of their corresponding type of drivers, upon closer listening you can still hear U18 bass being a little faster, more layered, and with cleaner edges, while Fourte bass is more visceral, smoother, and with a more analog flavor.

Mids: Lower mids are closer to neutral, keeping the body of the sound lean, and then going to upper mids is where you have a slightly forward push, especially around 1k mark. The mids in Fourte are more revealing, more micro-detailed, more layered, and at the same time a little colder and dryer in comparison to U18. If you are a fan of smooth, organic, laid back mids and a more natural vocals tonality, you might find Fourte to be a bit too revealing. But if you are a fan of micro-detailed level of analytical performance and want to hear all the nuances in sound, you will be pleased with Fourte tuning.

Treble: Both U18 and Fourte have a great treble extension, with treble being crisp and well defined, but Fourte takes it to another level with more airiness and a little boost around 10k to add more definition to upper frequencies. Even with all this enhancement, I never detected any sibilance, but at the same time Fourte tuning makes it less forgiving when playing poorly recorded audio or when paired up with brighter or even some neutral audio sources. In comparison, U18 is smoother and more forgiving, and not as picky when it comes to pair ups with different sources.

All this comparison was done between U18 w/M20 and Fourte, making a difference in tonality a little more obvious. But when you switch U18 to M15 module, you get performance a little closer to Fourte where the mid-bass of U18 goes down a bit in quantity to be more aligned with Fourte, and U18 mids become a little more forward and brighter, not on the same level as Fourte, but somewhere in between of U18 w/M20 and Fourte. Even with M15, U18 is still smoother and not as micro-detailed as Fourte. But at the same time, this is one of the advantages of U18 by having a flexibility to switch between M20 and M15 to fine-tune the tonality.

But everything is up to a personal preference. For example, I noticed when switching between Fourte and U18 w/M20 modules, going to Fourte felt a bit bright to my ears until I let my brain adjust to the sound, and going back from Fourte to U18 w/M20 felt like sound was a bit congested until I adjust to it as well. With M15 module in, the brain adjustment was a lot faster.

Pair up.

In my pair up test with different sources, I decided to be consistent and use TIA Fourte with an included 3.5mm SE stock cable. While Fourte has 114dB sensitivity, I wasn’t sure what to expect due to its 10 ohm impedance and how it will affect the hissing with different sources, a similar concern I had with U18.

Plenue 2 – the sound is very expanded, great bass texture; bass is lifted but not exaggerated; mids are more forward with nearly analytical retrieval of micro-details, a little on a colder side, very nice layering and separation; treble is crisp, bright, airy, well extended. No hissing.

LPG – wide soundstage, nice expansion; bass has more rumble and stronger mid-bass punch, mids are smoother more balanced, treble is bright and crisp. Overall, the tonality is a little more balanced because of a slightly more elevated bass and smoother mids. A mild hissing.

Opus#2 – wide soundstage with some improvement in depth too; bass has a similar rumble as P2, but mid-bass is a little stronger; mids are a little forward, very detailed and revealing, but now have a touch more smoothness, treble is crisp, bright, airy, well extended. A very mild hissing.

DX200 – wide soundstage with some improvement in depth; bass has a nice textured rumble with a smooth mid-bass punch, quantity of bass is not overexaggerated which makes mids perception more forward, still very detailed and layered, but with a touch more naturalness in tonality; treble is bright, crisp, airy, with a good extension. No hissing.

AK120ii – here soundstage is wide, but a bit less then with other daps, and instead I hear a lot more depth in staging; bass has a great sub-bass texture and nice mid-bass punch, but it’s a little bit more behind mids which are leading the way, being more forward in this pair up; mids are still revealing and detailed, but a little smoother and with a touch more body; treble is crisp, well defined, airy, but a little less bright. No hissing.

i5 – wide soundstage; nicely textured sub-bass rumble, stronger mid-bass punch, bass is a little more elevated, mids are a little more balanced, very detailed, layered, revealing, not as forward, and more organic in tonality; treble is crisp, well defined, extended, but not as bright as I hear it with other daps. No hissing.

X7ii – wide soundstage, even with some depth improvement; very nice sub-bass rumble and a well-controlled mid-bass punch, bass is very articulate and well controlled. Mids have a forward perception, with excellent retrieval of details, maybe a little less analytical and a little smoother; treble is crisp and airy, very snappy and extended. No hissing.

Note 4 – soundstage is still wide, but not as much; the sound also changes its signature, becoming more balanced with bass coming up and upper mids and treble becoming smoother, warmer, more organic and a little less forward. That micro-detailed revealing tonality is no longer there, but I hear the sound to be more toned down, smoother, more laidback. I did miss the resolution and transparency, but it wasn’t too bad, there were still plenty of details, just not as vivid. 

Comparison.

Using Plenue 2 as my source, I kept TIA Fourte with a stock SPC cable, and volume matched every pair by ear.

Fourte vs Vega – Fourte has a wider soundstage while Vega has more depth; both have a similar quality of sub-bass rumble, while the quantity is more elevated in Vega, and the same with mid-bass which is a little faster in Vega – it has more impact with a stronger punch. Lower mids in Vega have a little more body, while upper mids are pushed a little back in comparison to a brighter, more revealing, more transparent, and more forward mids of Fourte. Fourte treble is crisper and has more airiness. These have a noticeably different signature with Fourte being a little more mid-forward while in relative comparison Vega is more L-shaped.

Fourte vs SEM9 – Fourte has a wider soundstage while SEM9 has a little more depth; both have a rather similar sub-bass rumble, but Fourte is more textured. With mid-bass, both seem to have a similar quantity, but Fourte is tighter and with more body while SEM9 is more hollow and more relaxed. Lower mids a little more neutral in SEM9, but upper mids have a similar quantity, though Fourte has a better retrieval of micro-details and more analytical sound. Fourte treble is better defined, crisper, and has more airiness.

Fourte vs RE2000 – RE has a wider soundstage with more depth; both have a very impressive low-end performance with a deep textured sub-bass rumble and analog quality mid-bass with a strong punch, though RE bass is a touch faster. Lower mids have a similar amount of body, but upper mids is where I hear the most difference with Fourte being a little smoother and more natural, while RE is brighter, thinner, and more splashy in comparison. Both have a very revealing micro-detailed upper mids, but Fourte sounds just more natural in comparison. Also, RE treble is brighter, crisper, with a little more airiness. Overall, these two are not too far apart, just that for my own personal taste Fourte is a little smoother and has more natural mids.

Fourte vs W900 – Fourte has a wider soundstage while the depth is the same; W900 sub-bass goes deep but it’s not as textured as Fourte which has a little more rumble as well, but W900 mid-bass punches through a lot stronger and has a higher quantity in comparison. Lower mids are similar, but upper mids in W900 are warmer, smoother, not as layered or revealing, while Fourte is more layered, more micro-detailed, and more revealing. While W900 treble extends far, it’s nowhere near having the same amount of sparkle, or airiness, and in general it’s smoother.

Fourte vs K10UA – Fourte has a wider soundstage while the depth is the same; K10 sub-bass goes deeper, with a little more rumble, and mid-bass punch is faster and more articulate. Fourte has a little more bass quantity, but the bigger difference here is in quality where Fourte has a more dynamic analog bass while K10 has a faster BA bass with a short decay. Lower mids are similar, while upper mids in Fourte are more analytical, more micro-detailed, a little brighter. Treble has a lot of similarities, being bright and crisp, but I just hear Fourte having a little more control and airiness. 

 

Conclusion.

If you take a closer look at “Fourte” name, you will see a combination of “four” and “forte” which defines this flagship as a four-driver hybrid which suppose to excel in the sound tuning and the design. Just like U18, Fourte is not for everyone, these high-end flagships are intended for serious audiophiles whose focus and priority is more on the performance and the unique technology rather than price/performance ratio. And even if we talk about the price, like I mentioned in U18 review, some of the other $2k-$2.5k flagships with premium cables can reach the price bracket of U18/Fourte. I’m not making excuses for 64 Audio price, it’s high. But if you are willing to look into TOTL flagships and to pay the premium price, you need to consider every available option, especially when you have a specific sound sig target in your mind.

But as a reviewer who was given a unique opportunity to test and to compare these IEMs, considering how much I enjoyed U18, I thought it will be an easy decision to choose which one I like better. But the more time I spent with these IEMs, the more I got addicted to both because they are not competing but rather complimenting each other. I like the strong authoritative impact of U18 bass, but I also like the deeper analog texture of Fourte bass. I’m a fan of U18 smoother, resolving, natural upper mids and lower treble, but I also enjoyed Fourte with its more transparent, revealing, detailed mids/treble that wasn’t too fatiguing. Both have an open sound. Another thought, they both have an all-metal shell where for the first time I was able to handle expensive IEMs with more peace of mind due to their durability. And while U18 offers a flexibility of using either M15 or M20 modules, I think Fourte would sound the best with its built-in M20 (vs M15) without compromising the bass quantity.

Based on talking to my readers, as well as seeing the comments on Head-fi in 64 Audio threads, it seems that many U18/Fourte customers are those who tried these flagships either at CanJam events or store demos (e.g. at Music Sanctuary) or recent participants in Head-fi tour. Either of these flagships is a serious investment which you need to spend your time with to listen, to compare, and to appreciate, but if you don’t have access to it – I hope my review can provide some helpful guidance. Also, keep in mind, 64 Audio offers occasional B-stock deals and holiday sales, and once they even offered a trade-in program for those who have their previous flagships.