Preamble for Listening to Fugaku
The listening environment was set up using Fugaku’s original cables and amplifier/DAC without any additional amplifiers or IC cables from different brands. The early-bird Shirogane Ultimate IC cable was used for connecting between Fugaku amplifier and the DAP. The source player was Lotoo LPGT2 with the 4.4mm output and with the power option on high. Fugaku is a very tip-sensitive IEM. Also, for this review, I won’t be doing separate IEM comparisons due to the significant differences in many ways (including the price…), but will instead be mentioning several TOTL IEMs and comparing them as I go through the in-depth sound impressions of Fugaku.
Starting with the lows: Tactile, Full-bodied Bass
Fugaku overall has a gentle, w-shaped sound signature with a very balanced sound signature. The overall timbre is neutral-bright, yet that doesn’t mean Fukagu is light in bass. Speaking of bass, let’s start talking about Fugaku’s sounds, starting with the bass response. The bass is tight and elastic, oozing with elastic and realistic dynamics. Fugaku plenishes the low ends with a dark, solemn timbre, adding stability to the music. The ultra-low extension is also impressively detailed and nuanced despite its only slightly v-shaped sub-bass quantity. It won’t be enough for bassheads, but otherwise, the bass quantity won’t really be lacking for most, even for me, who often listens to hip-hop and grand OST soundtracks.
Fugaku has a revealing nature for the bass, staying just in the neutral area in terms of ‘moisture level’ or dampness, sitting just between damp and dry. To be more specific, it’s slightly on the drier side, which makes the bass be more resolving, higher in resolution, and better expose the texture grains, yet Fugaku’s bass doesn’t get far enough to the point of getting crunchy or dry. Fugaku still holds onto a plentiful enough of moisture for the bass to keep a smooth bass flow. The bass density is also quite decent. It’s not ultra-thick in color and density as PMG Apx OG / PMG Apx SE, though definitely far way up to par. I’d say the bass density is only slightly less than Subtonic Storm. The bass is deep and solid. You’ll only be surprised by how deep, thick, and prominent the ultra-low extension is while keeping extreme cleanliness along with the bass quantity not sinking the upper frequencies.
Heavenly Vocals with Ultra Clarity
The bass was very impressive, though where Fugaku makes your pupil expand begins once we move on to the mid-range. Frankly, my view on Fugaku was skeptical, thinking, “How better or next-level could it be to someone who already got used to listening to summit-fi IEMs?” Though with my already-skeptical stance I had towards Fugaku, once plugging into my ears, I must say, Fugaku gave me chills. I was surprised. Then, I had to reflect on the pre-listening bias I had on Fugaku.
What’s truly impressive about Fugaku is its ‘light-speed agileness’ and extreme high-resolution it shows throughout the entire spectrum – but especially for the mids and highs (spoiler alert: I’ll be mentioning high-resolution and agileness a lot from now on). Fugaku shows a strong vocal presence with incredible resolution and natural decay, yet its reaction speed and sound resolution simply feel several steps above, even compared to the summit-fi IEMs I’ve reviewed and listened to until now, even matched against Oriolus Trailli Ti, Subtonic Storm, PMG Apx SE, and so on. I’m confident enough to say that Fugaku achieves the #1 highest clarity and resolution in sound.
It’s not about simply making the vocals brighter and shinier. The higher resolution is just the base of what makes me consider Fugaku to be overall no.1 in vocal performance – the vocals’ liveliness, ambience, natural timbre, and texture overall combined is what makes the vocals sound realistic and lifelike. The vocal density is neutral/reference, presenting a pure water-like timbre. This means you won’t get much of that thick, thoroughly meaty density for the mid-range like PMG Apx or Oriolus Traillii. But then again, Fugaku completely differs in sound signature from those.
Sibilance would probably be the highest concern if we’re talking about absolute next-level resolution and clarity, yet Fugaku is surprisingly consistent in tone without getting shouty, metallic, or warped. Sibilance is basically nonexistent and shows flawless control. However, the 1% touch of sharpness (which I find not bothering at all, even with the picky perspective) and the high resolution itself may be overwhelming for those who are used to listening to a highly warm, soothing sound (or less resolution-pentrative sound). When it comes to fatigue, I wouldn’t worry too much as long as your ears are familiar with neutral-bright sounds. However, the fact that fatigue comes relatively earlier is true.
Lightening-speed, Next-Level Trebles
Fugaku’s true acoustic sensation makes its finale once it reaches the highs. Trebles are extremely high-resolution, and the lightning-speed agility and responsiveness hit their maximum dosage. Just by listening, you could already tell them apart from our ‘general’ summit-fi IEMs (yeah, I know, but they aren’t general, but they’re matching against a $20,000 Fugaku).
The reason why I repeat “lightning speed” is because the trebles really do sound like they’re bleeping in front of me out of nowhere, and after dancing its magically treble details and liveliness, the trebles once again disappear in the speed of light. Don’t take this ‘speed of light’ statement to mean that Fugaku eliminates the natural treble decay – trebles do decay in a very natural, airy manner. What I’m saying is that when they need to react and disappear quickly, they do it REALLY fast. Fugaku’s trebles also differ in power compared to our usual summit-fi IEMs. Fugaku’s trebles carry much more weight, scale, and power, making the trebles bring liveliness and dynamics that are differentiable from traditional summit-fi IEMs.
Another major difference is the fineness. It’s so ridiculously refined that I wasn’t able to experience it from other IEMs so far. Simply tuning into the tracks that make bold treble lines may not seem like a significant difference, though once you listen to those tracks that highlight velvety and micro treble details, the difference becomes more than prominent – it leaps to the next level once again.
I hate to say it, but Fugaku makes it difficult for all those flagship IEMs I’ve complimented to pull out their name cards, especially in this field. There are many IEMs capable of bringing such power and dynamics for the lows and mids, yet so far, I haven’t seen any that could get trebles as lively and refined as Fugaku – and especially the refinedness. This also leads to incomparable separation, somehow keeping the sound natural and not overly or artificially manipulated to sound extra separative. Yet Fugaku manages to keep the separation razor sharp to the next level while keeping the smooth harmonics.
Fugaku’s sound staging is oriented to the upper ends. Bright, expansive, open-ended, and endless towards the sky. The solid and deep bass that brews details even towards the ultra-lows gives a good establishment, yet the soundfield is surely focused on the upper-ends. It once again impresses me how the bass could be this prominent and in quality despite the extreme resolution Fugaku shows throughout the entire spectrum (which, sure, I know the answer, it’s due to its dedicated portable-audio DAC system).
Final Thoughts and Verdicts
Fugaku is an eye-opening IEM that most would find unheard of (even including me), especially when it comes to unprecedented high resolution, realistic dynamics, and almost scary-like instrument separation and clarity. It’s a gentle, w-shaped sound signature with basically perfect phasing and separation, topped with immensely transparent and airy resolution, as if penetrating the music with 100% purity. The flow from the ultra lows to ultra highs is very natural yet extremely technical as well
After reading my sound impressions, some might say I’m exaggerating or even say it’s not appropriate to compliment such an extremely detailed earphone setup. Well, I’ve got nothing else to say except that this is my humble and honest opinion, and the purpose of this review was to inspect and ‘review’ the performance, characteristics, pros and cons, and personal experience with an objective viewpoint, not to make judgments about the pricing. Fugaku is, of course, not meant for everyone, even including the users who have already been using summit-fi IEMs, as Fugaku’s pricing is also in another world. I mean a far, far world.
Fugaku is a special product for the most hardcore audiophiles who’ve been thoroughly enjoying various high-end IEMs and have been rolling between different flagship upgrade cables, amps, and DACs. Even still, it may not be your cup of tea for many; due to spending this much on an IEM just doesn’t seem sensible, the bulky listening environmental limitations, or simply the sound preference, and last but most importantly, the extremely high price. However, after extensive listening sessions and this review, my objective pitch and final conclusion are that as much as the pricing of this product is in another world, its performance also heads to another dimension, and Fugaku makes it undeniably factual once you listen to it yourself—even I was very skeptical about Fugaku once hearing the reveal and announcement post. However, a product is born and sold because there’s a need.
Next-level Investment for a Permanent, Interstellar Performance, if your taste aligns with it.
By changing passive filters to active filters, and externalizing those filters to the DAC/AMP to power them up instead of housing everything within the earpieces like we’re familiar with, Fugaku as an IEM system, provides a truly unique sound and incomparable performance that I doubt traditional IEMs and their design structures could ever achieve. The performance gaps that Fugaku has shown me were clearly different from contrasts made between traditional IEMs, regardless of their prices.
Fugaku’s differences overall felt like a different breed, as it is, or a supercharged sound that couldn’t be achieved if it weren’t its mechanical design. While I feel careful to say due to the controversial reactions across the communities due to the pricing, I’m at least confident enough to say, if your taste of sound aligns with it, Fugaku is and will remain as an irreplaceable, interstellar-level endgame choice that would permanently end your wanderings of portable audio setup.