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Olasonic Flat-4 Nami

Olasonic Flat-4 Nami TH-F4N Review

Olasonic Flat-4 Nami
Reviewed March 2014

Details: Dual-dynamic earphone built for Olasonic by Japan-based Ocharaku
MSRP: $499 (manufacturer’s page)
Current Price: $499 from
Specs: Driver: Dual Dynamic | Imp: 18Ω | Sens: 104 dB | Freq: N/A | Cable: 3.9′ L-plug
Nozzle Size: 4.5mm | Preferred tips: Comply foam (included)
Wear Style: Straight down (preferred) or over-the-ear

Accessories (3.5/5) – Comply foam eartips (2 sizes) and protective tin carrying case
Build Quality (4.5/5) – The construction of the Olasonics is solid, utilizing thick plastics with metal reinforcement. It is a dual dynamic driver earphone with a metal sound pipe connecting the two driver chambers. The cable is excellent, similar in quality to that of the Dunu DN-1000. It lacks a sliding cinch, but with the large size and unique shape of the Nami, I’m not sure one would have been of much use
Isolation (3/5) – Average, limited in part by the shallow fit of the Nami
Microphonics (5/5) – The smooth and supple cable carries no noise
Comfort (4/5) – The earphones are fairly large and stick a fair distance out of the ear when worn, but are very lightweight and the nozzles are angled slightly, improving ergonomics. Overall, the Olasonics are comfortable, especially with the included Comply eartips, and sound good with a shallow insertion. They are not particularly great for over-the-ear wear, but with the noiseless cable it doesn’t really matter

Sound (9.2/10) – The Flat-4 Nami is a dual-dynamic earphone built for Olasonic by Japanese Hi-Fi house Ocharaku. The twin 10mm drivers of the Flat-4 are oriented back-to-back, with a “sound pipe” connecting the chamber in front of the rear driver to the primary sound tube just before the nozzle. This is claimed to eliminate the 6 kHz ear canal resonance that is common with in-ear earphones (the US patent for this technology can be found here). The Flat-4 Nami nonetheless doesn’t have the smoothest treble response, but it does impress in several other ways. It boasts superb clarity and very tight bass, sounds airy and open, and has a very unique overall sound signature.

The bass of the Nami offers up excellent extension but the earphones are hardly bass-heavy – I expected greater bass quantity after reading the product description. Instead, the low end of the Nami tends to be tight, lean, and delicate. On tracks that call for bass it can beat sets such as the HiFiMan RE-400 in impact but still offers less bass and a cooler tonal character than, for example, the Philips Fidelio S2 and Dunu DN-1000.

Overall, the sound of the Nami is balanced to slightly v-shaped, not so much due to the mids being recessed (they aren’t), but more because of the emphasized upper midrange/treble region. It is a little more v-shaped than the Knowles TWFK-based VSonic VC1000, for instance, but less so than the VSonic GR07. The mids of the Flat-4 are very detailed and clear, albeit at the expense of some note thickness – compared, for example, to the GR07 and Fidelio S2, the Nami is clearer, but also less full-bodied.

The Nami carries a lot of energy through its upper midrange and treble. It tends to be somewhat bright and at higher volumes the treble emphasis can cause it to sound harsh. It is brighter, for example, than the Fidelio S2, with a treble peak that’s higher up, which makes the top end of the Nami a little splashier. Compared to TWFK-based earphones such as the VSonic VC1000 and Dunu DN-1000, the Nami also has a different treble presentation, tending to be a little harsher, but more tolerant of sibilance. To its credit, the Nami seems to avoid sibilance pretty well in general, perhaps as a result of the target 6kHz reduction. It works best with warmer sources and is a treat at lower listening volumes, which is not a tough order as the Nami isn’t a very sensitive earphone.

The presentation of the Olasonic Flat-4 is wide and a little distant. It is among the more open-sounding earphones I’ve tried – more so, for example, than Fidelio S2 and DN-1000, the latter of which is limited by its slightly boomy (in comparison) bass. It lacks the 3-dimensional imaging of certain top-tier balanced armature earphones, such as the Westone W40 and InEar StageDiver SD-2, but is plenty capable overall.

Select Comparisons

VSonic GR07 ($179) 

The VSonic GR07 is a popular accuracy-oriented earphone with a fairly neutral sound signature. Compared to the GR07, the Flat-4 Nami sounds brighter and has tighter bass. The low end of the GR07 is a little more impactful and the VSonics are warmer and fuller-sounding, but also appear more mid-recessed and a touch veiled in comparison to the Olasonic unit. The sibilance of the GR07 is quite prominent next to the Flat-4, especially at lower listening volumes.

Westone W40 ($500)

Westone’s W40 is a quad-armature earphone similar in price to the Flat-4 Nami. The W40 boasts a warmer tonal character compared to the Flat-4, with more bass impact and a more full-bodied sound, while the Flat-4 is less bassy but more controlled at the low end. The W40 is a little veiled in the midrange, while the Olasonic sounds clearer. The W40 has smoother, less prominent treble, and darker overall tonality. The Nami is harsher, especially at higher volumes, but also makes the W40 seem lacking in upper midrange presence. The W40 does have a slightly more well-rounded presentation and imaging, and is significantly more sensitive than the dual-dynamic Nami.

Phonak PFE 232 ($599) 

I had to break my PFE 232 unit out of retirement as my initial listening to the Flat-4 Nami made me think of the Phonak unit many times, especially when it comes to treble and soundstaging. The most striking difference between the two earphones is at the low end – the PFE 232, even with the gray filters, offers up significantly more powerful bass. It sounds a little more v-shaped as a result, but also thicker and more full-bodied. However, the Olasonic unit has clearer, less recessed mids that are extremely nuanced and delicate in a way the PFE 232 can’t match. Both tend to have good treble energy and though their treble character differs slightly, it’s hard to put one above the other in treble quality. The earphones have similarly wide soundstages and good overall imaging ability.

AKG K3003 ($1300) 

AKG’s dynamic-armature hybrid was among the first in the current crop of $1000+ hyper-IEMs. I prefer to use the K3003 with the “Reference” tuning, though in this case the Treble Boost tuning makes for a slightly better signature match with the Flat-4 Nami. The K3003 offers up more bass impact, which gives it a slightly more dynamic sound compared to the lighter-at-the-low-end Olasonic unit. Both earphones have some treble hotness, but emphasize different areas of the treble, which is also true when comparing the Flat-4 to any other TWFK-based earphone. The Flat-4 ends up sounding a touch harsher than the AKG, but the difference is small. The K3003, like the Westone W40, also boasts a slightly more well-rounded presentation but isn’t far enough ahead of the Nami to justify the price difference.

Value (7.5/10) – In many ways the approach taken by Olasonic with these earphones makes me think of another Japanese headphone manufacturer—Final Audio. The Olasonic Flat-4 Nami has the same combination of no-frills, audio-focused design, genuine innovation, and clever marketing. The Nami is not just an interesting-looking earphone with a hefty price tag, however—the sonic signature of the earphones is very unique on the US market and listeners are sure to be impressed by the open sound with excellent clarity and bass control. To me, the Flat-4 sounds best for relaxed, low-volume listening, losing none of the sonic detail or energy and keeping its bass completely under control. It’s a niche product, but for this sort of application it’s as good as anything else I’ve tried.

Pros: Excellent clarity, open presentation, lean & tight bass; no cable noise
Cons: Mediocre-at-best noise isolation; scant accessory pack





Living in the fast-paced city of Los Angeles, ljokerl has been using portable audio gear to deal with lengthy commutes for the better part of a decade. He spends much of his time listening to music and occasionally writes portable audio reviews across several enthusiast sites, focusing mostly on in-ear earphones.


4 Responses

  1. About the same. The Phonaks have very good clarity and separation to begin with.

    And sorry, no experience with the ATH-IM02 yet. The latest generation of Audio-Technica BAs has avoided my ears so far.

  2. Yes, I am currently using the grey filters. How about the clarity and separation? Is it different that much?
    And how about the treble compared to ATH IM02? Is it brighter? Because IM02 treble is way too much for me. Thanks again, sorry for so many questions 😀

  3. Depends – if you’ve wished your Phonaks were a little more v-shaped (more emphasis on bass and treble relative to the midrange) and had a more spacious/wider presentation, then the Nami could be a worthwhile upgrade. If you’re looking for something else from your upgrade, then the Olasonics may not be the best choice.

    This is assuming you are using the grey filters on your Phonaks.

  4. Hi. THL. I want to know your opinion about teh sound of Ocharaku Nami and Phonak 1xx series? Do upgrade from Phonak 1xx to Ocharaku Nami really worth it? Thanks in advance for the answer 🙂

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