HiFi Boy OS V3

General Information

  • Brand: HiFi BOY
  • Model: OS V3
  • Drivers: 2 Balanced Armature & 1 Dynamic Driver (Ultra-high frequency Balanced Armature + high frequency Balanced Armature + 7mm strong magnetic composite diaphragm Dynamic Driver )
  • Impedance: 19 Ohm
  • Sensitivity: 109 dB
  • Frequency response 20Hz-20KHz
  • Cable Length: 1.2 m
  • Plug: 3.5mm rhodium-plated
  • Wire: 5N OFC silver-plated cable

Latest reviews

Pros: 1) Great potential for EQing.
2) Deep, powerful, clean bass with any source (due to dynamic driver itself being 7mm in diameter and use of very thin, separate sound tube).
3) Stock sound are absolutely fatigue-free without any sibilance at all. And I usually have lots of problems with sibilance due to my long ear canals.
4) Very, very light, I don't feel them sitting in my ears.
5) Good package. Included foam eartips are of very high quality, which is a surprise.
6) Instrument placement and separation is great. Imaging is good.
7) Beautiful color of both earpieces, they are a lot more transparent than they appear on official photos.
Cons: 1) Stock sound lacks any impact at all. It's like a cloud. A beautiful and detailed one, but still.
2) Logo actually sits differently (1mm difference) on left and right earpieces, build quality feels cheap compared to DM6's. Drivers sit differently, though there are no audible channel imbalances.
3) Soundstage is meh. Can be fixed through DSP's. Not much of a con, it's just not as great as everything else about this earphones.
About me: I always use EQ, usually to create a V-shaped signature, that's the way I hear the world around me.
I review this item with treble (8k+) and bass (below 60hZ) cranked up. Without that change they sound very light/relaxed and not really do much in terms of anything. However, their response to EQ is great.
I listen to everything, including noise/power electronics and dream pop.
Eh, don't look at me like that, that's just mood swings at work.
Cayin N3
as a Bluetooth receiver/Cayin N3 as a USB-DAC. I never listen to N3 using SD card, as then it sounds harsh and congested.
FiiO Alpen 2 used to expand soundstage due to it's better (less) crosstalk, though it didn't helped too much.

Reasons I don't describe sound directly: it's just not working, it all comes down to music being musical and highs being high. Or low.
However, they are fairly neutral to me, with low-mid bump that creates cloudy feeling from listening, in the best way possible. Don't like it? Use EQ, they are very EQ responsive.

  1. Sony MDR-EX800ST - Sony's have a richer overall sound, with realistic mids, but they seriously lack palpable treble even after EQing and their bass is usually muddy and just slams you in the face with itself without much control and texture. OS V3's have marvelous subwoofer-type bass which stays in it's place and will do so even if you'll crank it up to the level where you can actually feel your earphones vibrating inside your ears.
  2. Sony MDR-EX650AP - complete, absolute antipods. Sony's have realistic, cinematic, dark sound, unbearable 6kHz sibilant peak, weak sub- and bloated powerful, heavy, textured mid-bass, V-shaped signature, non-detachable cable, classic design, metal body and impactful, while less detailed, highs.
  3. BGVP DM6 - DM6's sound like OS V3's on crack (lol, sorry). DM6's have more details, more treble, great soundstage, but with impact-less subwoofer bass and not really enjoyable sound signature. I still can't quite get a grip of it, but they just don't sound realistic or pleasurable. OS V3's soundstage is mediocre.
  4. KZ ZS6 - OS V3's are just a straight-up upgrade of ZS6's, without strange dips/peaks throughout the whole range, but with tamed treble and isolated, controlled, very deep bass. ZS6's, on the other hand, have a big soundstage and sometimes dig details a bit better. In fact I have to say that ZS6's, once connected to a good source, just excavate details in treble.
  5. Tin Audio T2 - just to set some things straight, I used this IEM as an example of source independent piece of sound tech which sounds relatively great on bad sources and completely loses to any IEM in my collection after using sources other than my phone. Nothing more to say.
  6. ZhiYin Z5000 - just a fun comparison. Z5000's have the most realistic out of anything here, BUT, due to their price of 50$, that realism has to be achieved through heavy EQing (or by using earbud foam on eartips to break the seal, in fact, they arrived with that foam on 'em). Bass on Z5000's has more body and slams harder, but it feels bloated and less controlled.
Build quality:
This picture were modified to reflect their true color and transparecy:


2) Just look at these dynamic drivers:


3) Once again, modified to reflect true colors, this time without barely fixable contrast. Yeah, phone cameras isn't that great:

Pros: -Great smooth, polite and fatiguing- free Sound.
-Great Build Quality.
-Great Ergonomics.
Cons: -A little bit more accessories would be very welcome (cleaning tool and silicon eartips).
First of all: Sorry for the bad english... :ksc75smile:

One Note: This may be somewhat redundant, but this analysis is based on my subjective impressions about the handset and my experience, in general, with other IEMs/Headphones.

1- Accessories:

The HiFi Boy OS V3 comes in a very well finished package. The experience of Unboxing is quite satisfactory and makes you realize that it is not a bad product. Inside the box, you find a 1/4 TRS adapter and another for airplane; as well as a case, which will contain the IEM, already connected to the cable and A LOT of eartips. Being very demanding, I have as criticism the quality of the case, which, although not bad, is very simple, not very different from others that comes in cheaper models. Another point is that, although the earphone comes with several ear tips, including foams, there is no silicon tips. Instead, you will get common rubber eartips, like those found on most in ears of the market, besides the ones of foam. I also missed a cleaning tool. It is not very common this type of accessory in in ears in general, but I think it is essential for those that are built in this way (semi-custom), since there is no kind of mesh or protection screen on the nozzle.




2-Build Quality

The construction of this IEM is simply flawless. It is a hybrid IEM, with a dynamic driver and two balanced armatures. The manufacturer claims that they handmade, like the the custom IEMs. Its doesn't looks like a exageration...
We have here the use of acrylic resin, which apparently is the same used on the Custom IEMs from famous brands like Unique Melody, Ultimate Ears, Westone, Noble, JH Audio... The IEMs are very well polished, with no apparent imperfection. In addition, you can see the PVC tubes connected to the drivers, as well as the sound filters inside the tubes. There are two Tubes: one connected to the Dynamic Driver and one connected to the two balanced armatures.

Regarding to the cable, it is also of very High Quality. It is detachable, braided, very flexible and appears to have great resistance. I didn't notice any microphones while using the OS V3 on the go.

Ergonomics is also great. Although not the smallest size, I had no difficulty fitting it into my ear; On the first attempt I have already succeeded. The Sound insolation is also far above average.







With only 19 ohm of impedance and a sensitivity of 109 db/mW, the HiFi Boy OS V3 is quite efficient, and ia smartphone can run this IEM very well. I didn't notice any improvement in Sound Quality with amplification (fiio A5).


Now, the most important part of this review. I can describe the sound as very natural, organic, coherent, and relaxed. There is a good presence on all frequency bands and no excess in any of them. The sound signature is a very mild V-Shape, or almost an L-shape, with emphasis on bass, and with mids and treble almost at the same level of quantity, with a very small amount of treble more than the mids.

Lows: The bass of this IEM, for me, is the best aspect of its sound. It is noticeable the capacity of the dynamic driver, wich produces Sub-Basses with great presence, extension and control. The same can be said of Mid-Bass, which have great impact and definition and also very controlled. The low requencies of the OS V3 have enough presence and quantity to give you fun with musical genres that depend on bass, like EDM, for example; and at the same time they do not feel exagerated or interfere with the other frequencies. You will also not feel any lack of Bass. The Bass of the OS V3 are definitely one the best bass I've ever heard on a IEM/Headphone.

Mids: The mids are quite natural, velvety, warm, and a little dark. The most notable feature about the mid frequency of the OS V3 is the weight that they have. There is a small rise on the low-mids, which makes the general mids very meaty, palpable and gives considerable weight to musical instruments and voices, making the sound experience very pleasant. There is a small dip on the high-mids, which give a slightly darker character to the mids and favors more male voices than female voices. The positive side of this is that even the female voices are very pleasant and natural to listen, and there is no discomfort, sibilance or hashness on this frequency region. It makes the OS V3, a very safe-sounding IEM and great for long-listening sessions. Regarding to the "details" in this region, what I can say is that the Hi Fi Boy OS V3 will deliver all that are present in the recording, without any exageration or without creat "fake details".

Treble: The treble here is almost on the same quantity as the mid frequency, maybe a small amount more, in comparison. Despite this, they are quite relaxed, without any kind of exaggeration and complete absence of hashness or sibilance. I can consider the OS V3 treble as quite natural, and organic. Regarding the treble extension, I do not have anything to complain about: they are not the most extended treble I have ever heard, but they do the work very well and don't feel lacking on this regarding. The details produced by the treble are also excellent. Once again, here is applicable what I said about the detailing of the media: "what I can say is that the Hi Fi Boy OS V3 will deliver all that are present in the recording, without any exageration or without creat "fake details"". Overall, this relaxed character of the treble, as well as the slightly darker and meaty character of the mid frequency makes the sound of the OS V3 very musical, enjoyable and fatiguing-free.

Sound Stage: The sound stage of OS V3 is not much different than ones produced by almost all (good) IEMs on the market. Of course, because of physical limitations, it will not be like that of some Headphones. I prefer to describe it as having a natural Sound stage. Because it has a great stereo image, it exposes the instruments with very precise locations and will give the amount of stage provided by the recording.

5-Comparations (Sound):


Sony MH1C:

Although this IEM is in a price range totally different from the HiFi Boy OS V3, its sound quality is so high, that this comparison is appropriate.

The lows on MH1C are more emphasized than the ones of the OS V3, especially on the sub-bass region. In addition, there is a bit more definition (detailing) on the bass of OS V3, in comparation.

Regarding the midrange, The one of Sony has very distinctive personality in relation to the one of the OS V3. Since the MH1C has a frequency curve similar to the Harman IE target, it has less, body onthe midrange, however, it doesn't have thin-mids, there is enough body that are on a more neutral quantity, in comparation. The weight, brightness and linearity of the MH1C mid-range are more realistic, more neutral, natural than the ones of the OS V3. For example, guitar crunchs, trumpets, are more alive on the Sony than on the HiFi Boy. Despite this, there is no exaggeration on the high-mids of the MH1C, they basically are more neutral on this frequency range than OS V3. The good side of OS V3 by having darker and more relaxed mids is that at the same time it makes them softer and polite, against the the more linear, but "raw" mids of the Sony MH1C.

Regarding the Treble, although also quite controlled and non-exaggerated, like the OS V3, the treble of MH1C are a little higher in quantity than one of OS V3 and a little more correctly, in terms of timbre. We have here again the dichotomy: the greater naturalness of the treble of the MH1C as opposed to the greater refinement of the treble of OS V3, despite the small difference in quantity. About the sound-stage and imaging, they are very similar.

Tanchjim Cora:

Because it has a frequency response curve close to the Harman IE target, just like the Sony MH1C the two (Tanchjim Cora and Sony MH1C) have a very similar sound in terms of timbre, but with differences on the balance of the frequencies (Lows and Treble mainly).

The lows of the Tanchjim Cora are VERY similar to the ones of the HiFi Boy OS V3, both in terms of quantity and quality. I can not point out a clear difference between the two headphones. Both have similar emphasis and control, with great extension on the Sub-bass, great punch on the mid-bass and a lot of definition.

In terms of mids, the differences are remarkable. Tanchjim Cora's mids are very neutral and have more presence (in quantity) than the mids of OS V3. The naturality of the midrange of Tanchjim Cora amazing, with similar timbre to the one of Sony MH1C. The guitars have more "crunch", the voices have more (natuaral) brightness and at the same time much control. The difference here is that, although there is a lot similarities between the midrange of the MH1C and the Cora, I hear the mids of tanchjim more full-bodied, warm, refined, creamy and at the same time a little more present. I do not feel the mids of the Tanchjim "raw" as in MH1C. The HiFi boy, OSV3, compared to the Tanchjim Cora, will also have very soft and warm but also with a little more weight, because of the small rise of low-mids and less presence on the region of the high-mids. It makes the OS V3's mids more "dark" in comparison to the ones of the Cora. Like i said, the OS V3 has very natural and organic mids, however, do not reach the same naturality level of the ones of the Tanchjim Cora.

Talking aboud the to Treble, In terms of quantity, I see a lot of similarity between the treble of Tanchjim Cora and the OS V3. Both have more relaxed treble and details exposed in a natural and organic way, without exaggeration. In neither of the two i found any trace of hashness or sibilance. Both have very similar Sound -Stage.

Westone UM PRO 50:

I tested this IEM side-by-side with OS V3 for 3 days, on the final of the last year. I no longer have it in hand, so the impressions are according to what I remember at the time. Both have the very similar sound: soft, warm, relaxed and a little dark.

In terms of Lows, the OS V3 has a little higher quantity of sub-bass, You feel the OS V3 moving more air, due to the Dynamic driver wich produces the low frequencies, rather than the balanced armature used on the UM PRO 50 to this frequency range. About the mid-bass, both have similar punch as well as the definition.

Regarding the midrange, again, there are many similarities. The two have plenty of body, with a small lift on low-mids. Smoothness and detailing are also very similar. The difference that I noticed on the mids of the two is that although both are on the dark side, the ones of the UM PRO 50 are a little darker, with a slightly higher diponthe mid-high. The difference is very small, but on an attentive listening it is noticeable.

Talking about the the treble, once again, there is a lot of similarities: both without exaggeration, well controlled, detailed and relaxed. The difference is that the OS V3 has a little more qantity in treble than the UM PRO 50.
In terms of Soundstage and imaging, once again, both are very similar, with a small advantage for the UM PRO 50, in which I noticed with a bit more spatiality.

5 - Conclusion:

Great IEM for those who want a more natural and relaxed sound. There is the exchange of the "audiophile" standard with emphasized treble and highlighted details, for the musicality and fatiguing-free musical experience.

  • Brand: HiFi BOY
  • Model: OS V3
  • Drivers: 2 Balanced Armature & 1 Dynamic Driver (Ultra-high frequency Balanced Armature + high frequency Balanced Armature + 7mm strong magnetic composite diaphragm Dynamic Driver )
  • Impedance: 19 Ohm
  • Sensitivity: 109 dB
  • Frequency response 20Hz-20KHz
  • Cable Length: 1.2 m
  • Plug: 3.5mm rhodium-plated
  • Wire: 5N OFC silver-plated cable
  • Connector: 2pin 0.78mm
Link where i Bought (Penon Audio): https://penonaudio.com/hifi-boy-os-v3.html

Price: 160 USD.
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Good review. I got this pair of IEM via Penon Audio and found them quite ok for their price tag. Yes, very polite sounding but also non fatiguing SS. I gave it to a colleague of mine and he is listening to it everyday
Pros: good mids, warm timbre, tight midbass
Cons: moderate treble
«All we want to do is just to conquer your ears» — this is the slogan printed on HIFI BOY OS V3 IEMs box. Pretty intriguing declaration the meaning of which promisses better sound quality in the corresponding price range. Noted, this review would be based on higher expectations :)

Despite that there are only 3 models listed in HIFI BOY brand portfolio, the amount of reviews, comments and feedback from the customers is numerous and widespread. Sources are found in Asia, USA, Europe and CIS region. Either people around the globe really like it or brand is doing very good marketing. We believe it’s the first and sharing the proof in this review.

Short brand description:

«HiFi boy is a high-end hifi audio brand launched by China Chengdu Fallante Technology Co., Ltd. The company is an integrated research and development, production and sales technology company, mainly engaged in development, manufacturing and sales of hifi headphones, multimedia speakers and Bluetooth audio equipment.»

HIFY BOY OS V3 technical specifications:
  • Drivers: 2 BA + 1DD
  • Balanced armature drivers: ultra-high frequency BA + high frequency BA
  • Dynamic driver: 7mm strong magnetic composite diaphragm
  • Impedance: 19Ω
  • Sensitivity: 109dB
  • Frequency response range: 20Hz-20KHz
  • Cable connectors: 2pin, 0.78mm
  • Cable Length: 1.2m
  • Wire: 5N OFC silver-plated cable
  • Plug: 3.5mm

Packaging, design and build:

OS V3 box is wrapped with the additional cardboard slipcover which provides the information about main technical specifications and box contents. Removing it would reveal black matt box with shiny silver brand name and logo imprints.

Top cover features folding design with strong retaining magnet. Inner box compartment is neat and simple — most of the additional accessories as well as IEMs are packed inside the protective case while the additional adapters has their own cutouts in soft podium insert.

Box contents:
  • audio cable
  • 9 pairs of silicone eartips
  • 2 pairs of foam eartips
  • protective case
  • 3.5mm->6.3mm adapter
  • 3.5mm->2 x 3.5mm mono plug adapter

OS V3 shells are made of plastic with transparent glossy resin layer on top. This layer makes the whole construction feel very solid. Shiny silver brand logos are also protected by the resin layer.

Sound output nozzles are protruing from shells and make a single piece. Holes on top of the nozzles have different diameters and are not protected by any filters or grills.

Compensational openings are located on the back edge of the shells. 2pin, 0.78mm connector bases are slightly recessed inside the case and have pretty tight holes for the incoming pins.

Stock cable is 1.2 meters, made of OFC silver-plated twisted cores, features aluminum audio jack housing, Y-splitter, limiter and 2pin connectors made of transparent plastic and flexible earguides. There are blue (left) and red (right) channel indicating dots on 2pin connector housings.


We have defined several types of shapes for ourselves that are commonly used in different IEMs: bullet (like Rose Mini2), moon (like TFZ No.3), drop (like Earnine EN2J), triangle (like LZ HIFI A6) and custom (like Kinera Idun). Only two of these are highly universal and always comfortable — bullet and custom. HIFI BOY OS V3 belong to custom design type with complicated shape that’s, in fact, having a perfect fit. No problems with the choice of eartips and very good experience during different physical activities.


Tested with HiBY R6Pro DAP (3.5mm regular output, reference mode)

Lows and midbass:

Very good performance here. Bass presence is pretty big and accented which influences entire sound and makes it warm. Although, the extension of bass is only moderate in favor of dense and controured feel. It doesn’t bleed either into higher frequencies or lowest regions and stays perfectly audible (as if we were using closed type overheads). Texturing is above the average but doesn’t surprise too much due to restrained bass extension and mostly compact delivery.

Such behavior on lows builds very good ground for midbass section. It sound powerful, tight, equilally tinted by bass and treble and perfectly controlled. Dynamics is decent, drums sound rich, lively and full-bodied. Moreover, impedance of OS V3 IEMs makes those to be an easy load for the most of audio sources (even smartphones). This also help to maintain good articulation and dynamics at higher or lower volume settings.

Mids and vocals:

Mids feel recessed in comparison to other ranges but only very slightly — just enough to have good warm influence of bass and more resolution on top provided by treble. Female vocals don’t sound harsh or shouting even with recordings that would usually suffer from that. Male voices are pretty close to stage front and pretty thick as well. Resolution on mids might have been better with larger presence of treble but this would also lead to less smooth presentation and more sibilances. In overall, we like that mids have this nice warm timbre and enough thickness — this makes the sound more enjoyable for longer time. Additionally, there is quite good instrument separation and enough distancing from the lower range.


Treble is more emphasized than mids but still not sufficeint to make the sound feel bright. We would say that it is quite soft and thick, with moderate extension and just enough to add the adequate clarity and resolution. Such approach is much closer to dynamic drivers, rather than BA units. We’d never take the right guess about driver types in OS V3 in blind test. Hard to judge on that matter if the entire sound is on the warmer side while treble is added that much of body and little accent. Anyway, very good micro dynamics here that should have given us a clue during our guess. Some new experience with hybrid IEMs in overall and rare example of signature affiliation with dynamic models. We can think of the opposite example — TFZ King Exclusive — dynamic IEMs with surprisingly clear and emphasized treble that reminds us of balanced armature sound.


Imaginary scene width is slightly above the average. Tight bass doesn’t let it to expand further to sides while treble doesn’t help much to define huge vertical domain. What’s really good is layering and instrument separation in mids which creates a feel of tidy depth.

Sound in overall:

HIFI BOY OS V3 sound can be desribed as only slightly V-shaped, having a warm timbre, with perfectly contoured bass, decent midbass, fairly balanced vocals with good overall resolution on mids and slightly emphasized but not that extended treble. Very good for blues, jazz, vocals, instrumentals and other slow genres with limited amount of instruments.

Compared to LZ HIFI A6Mini:

A6Mini IEMs also belong to hybrid type but feature piezo-electric driver to handle the treble range. This gives the additional microdynamics, extension and clarity to treble with brighter signature in overall. Lows and midbass are pretty similar to OS V3 while A6Mini mids sound a bit thin and distant. Although, the resolution of mids is slightly higher and caused by heavier influence of sharper treble.

Compared to Shozy & Neo CP:

CP IEMs belong to pure armature set of drivers with excellent resolution and texturing. Despite that, signature is on the warmer side as well. The only two things that NEO lacks are more bass presence and more powerful midbass. OS V3 IEMs are exposing bass and midbass better while having less resolution and texturing in overall. Timbre of both models is kind of similar. We would recommend Shozy & Neo CP for faster genres with larger amount of intruments while OS V3 would be better for slower genres and for people that are more susceptible to treble.


This is the third model of IEMs in our practice that brakes the rules and broadens customer choice in corresponding type or budget. HIFI OS V3 sound differs much from its hybrid siblings by combining armature driver micro dynamics and speed with warm and mild temper mostly common for dynamic models. Such tuning results in very good vocals, pretty balanced overall perception and fatigue free long listening experience. Therefore, HIFI BOY OS V3 deserves a special treatment for its rare sound signature, interesting combination of dynamic and armature driver benefits and their will to go against modern practices of building punchy but tiring presentation.

You can get HIFI BOY OS V3 at PenonAudio store
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Another great Review! How do You compare this Hifi Boy with the Kanas Pro and the Tanchjim Oxygen? Thanks in Advance.


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