HIDIZS MD4 Review: Vivid resolution that can be tweaked

-Good imaging
-Good resolution
-not too agressive W shape signature
-fast attack speed
-tuning switch for adding warmth, bass or treble sharpness
-excellent construction

-slightly artificial tonality and timbre
-lack of note weight and natural resonance
-compressed vocal and mids
-rolled off and uneven bass
-treble can be distracting
-intimate soundstage

TONALITY: 7.2/10
SOUND VALUE: 7.5/10 (due to the tuning switch)


HIDIZS has been around since 2012 and are mostly known for their DAP and dongles offering, but they make earphones too! Their hybrid driver, the MS2, might be the one that get the most praise in audiophile community.
Today, i will review something different from them, the MD4, which is a 4 balanced armature IEM with a tuning switch that permit to have 4 different tonal balance.
Priced 190$, the MD4 use 4 custom BA of unknow model, have 3 way crossover and this very intriguing tuning switch.
Let see in this review if the MD4 can deliver appealing performance and charming musicality!


When it come to built quality, Hidizs rarely disapoint and here we have sumptuous design with excellent craftmanship. The built is both sturdy and elegant, with much of housing made of CNC allumium with a back plate made up of amber and gold lettering of the logo. This back plate is pure eye candy yet doesn’t feel over the top or bling bling. Glossy elegance made with taste.
And it’s comfortable due to organic housing shape, long nozzle and small enough shape.
2pin connector is perhaps the only part which could be improve, a recessed metal one would have been better to secure and guide connection.

The cable is very nice, it’s a 4 cores pure copper silver plated wires with 0.78mm 2pin. The ear hook is a bit too tight for me but construction seem durable.

When it come to packaging, that’s a quite generous one. It include 9 pairs of silicone eartips, a cleaning brush, a beautifull carrying case. It would have been nice to have the possibilities to choose between single ended and balanced cable like numerous audio companies do, alas, it isn’t the case.


(Gear used: Tempotec V6, Tri TK2, Moondrop Dawn and Questyle M15)


Tough the tuning switch did inflict on tonal balance, overall tonality of the MD4 go from warm W shape to sharp W shape where upper mids and treble is the more boosted.
Treble switch will add air and improve sens of imaging while warm or bass filter will smoothen attack edge, add a bit of lower mids warmth and just tiny bit of bass slam.

Honnestly i’m still waiting for an IEM with just one switch: Basshead and Crisp neutral tonality, something that really offer 2 different IEM instead of 4 slightly different sound dynamic presentation.

Bass is fast and gently boomy, with short sustain and resonance, it can offer a fuzzy sens of rumble, but the lack of proper edge definition make it a bit blurry in resolution-separation. BA bass is even a hint boomy with flagship IEM like the T800 that use 8 knowles BA, but here the boost is mostly in mid bass but have warm high bass too, so extension is rolled off and doesn’t dig deep, making bass line dry and foggy. We have fast non edgy punch, and warm to dry presentation depending of tuning switch choice, yet these aren’t for basshead nor bass lover.

Mids are crisp with smoothen edge, organic texture and decent transparency. They feel well layered too, and most of the energy come from upper mids which aren’t too agressive, but sometime can go shouty at high volume with bright source. With both male and female vocal, their a hint of breathyness to it, and timbre isn’t too thin for balanced armature. I mostly listen to female vocal, which are clean and centered, not very open and wide but smoothly bright with good texture and just very rare instance of sibilance, especially with Treble tuning. With Warm tuning switch, vocal gain a bit of timbre density and presence wideness and body. So I hear the mids to be lifted in lower mid which add meat and BA lushness, lean in mid mids and sharp in upper mids yet softed in dynamic loudness to avoid it getting too hot. Piano sound clean and clear enough, with impressive definition especially when the keys are hold so you even get sustain details but the release cut short as expected, yet, presentation have more energy than I expect, making fast jazz piano trio sound sometime very immersive since saxophone too sound very good. Are these made for jazz? Well, unless you wish to focus on bass player, I do think so.

Treble is fast and technical yet not very snappy and just a hint sparkly. The bite too is softed as say, so this affect attack lead and stole the air it should project after impact. In the other hand, it make the highs feel full and not too trebly or distracting, yet they have dense amount of sound info, just a bit darkened in crispness here. We have some brilliance nonetheless in upper highs and speedy attack speed as expected from BA. Treble tuning switch will add sharpness, some air and attack edge, yet it’s limited in texture micro nuance.
This is unique analytical treble section, which have concentrate sens of energy in lower and upper highs, sometime it can be a bit shouty because of this, while other time it will boost definition and dynamic of percussions section with good result. Yet, for my hearing, MD4 is the kinda IEM that is impresible in loudness behavior, so you can be tempted to raise or lower the volume depending of music type or dynamic mastering.


This is the good part to me, since MD4 is very capable in this department. Attack speed is fast with short sustain that permit to have good enough separation in imaging.
Resolution is generous in micro details and tend to extract them with enough precision, especially in not too complex tracks.
With fast busy track like ”Skink” for jazz rock band Elephant9, this short but blurry sustain-release show it’s limit and tend to go muddy-shouty.
Harmonic distortion do occur, and bass is borderline distorted at high volume or with sub bass heavy track, yet a gentle blur tend to warm these imperfection so it’s not that bad and overall sound is clean enough.
Spatiality isn’t the most open, but with eartips like Kbear KB07 its pretty wide and tall enough with decent deepnesss, just not very far from your head in spatial perception.


I will not turn around the bush too long about this: i’m not a fan of musical presentation of the MD4 and none of the tuning switch change my distant emotional response to them. These are very technical, yet safely tuned multi-BA…at the same time, while safe, pina gain is quite important and upper mid range can distract me from bass and highs. This mids-upper mids are damped in sibilance, thats good and bad since it affect definition clarity.
Vocal doesn’t sound open enough to me, they feel fowards yet compressed in middle of instrument. As well, timbre while a bit dark in texture isn’t very natural nor very bodied.
In term of dynamic, this is the type of IEM that favorize loudness impact over weight note heavyness and resonance, which is common in multi-BA IEM and not something i’m very afound off.
All in all, the MD4 have a romanticized clinical musicality to me.



The excellent Golden is more neutral and balanced, have a weightier sens of dynamic and note impact and fuller more present bass. The bass is dealed with a dynamic driver here, so even a cheap one will be superior to balanced armature in term of fullness, chunkyness, roundness and flexibility-elasticity of attack and extension. While the MD4 boom is more excited, it lack the well define authority and presence of the Golden as rumble density. Both quantity and quality is superior to me, definition too have more grip but separation is on par yet feel less artificialy detached than the MD4.
Mids are leaner and fuller with the Golden, less prompt to slight shoutyness and better define. Timbre is more textured and natural too. Sens of immediacy is higher with MD4 but more compressed-resonant in layering.
Overall treble is a bit sharper and more open airy with the MD4, while fuller and more organicaly balanced with the Golden.
All in all, Golden is a fuller sounding and better balanced MD4, with similar technicalities, yet a more natural tonality.

VS IKKO OH10 (1DD+1BA-160$)

Notably more V shape and bassy, brigther and more energic and open sounding too, the OH10 bass quantity and quality beat both Idun and MD4 here. Heavier chunkier hit, deeper more vibrant extension and better texture and definition as well as attack control and separation. Mids are brighter and more upper mids focus, female vocal have more dynamic presence and are more textured. Lower mids are thinner dryer with OH10. Treble is smooter with MD4, richer in layers amount with similar snap but perhaps more brilliance. Level of micro details feel higher yet sometime overly fowarded compared to better balanced OH10 in that regard.
Sounstage is more open wide with the OH10, deepness is similar but overall presentation feel more compressed and distant with MD4, yet hint more holographic too in a strange artificial way.
Imaging is overall superior with the MD4 due to higher amount of sound layers that are freely extract.

All in all, these 2 are very different in tuning, yet while both are no master of natural timbre, I do prefer the OH10 bassier and more evenly balanced musicality.

VS THhifi Character (1DD+1BA-160$)

Ok, those 2 aren’t similar at all, as well the MD4 have a tuning switch offering 4 slightly different signature so this comparisons is to take with a grain of salt. Tonality of MD4 is like nothing else so its hard to describe it but let say TH have a warmer W shape with more boosted mid bass and warmer mids and treble while MD4 have a vivid neutral presentation with slight bass boost and fowards lower to upper treble.
Its evident the TH is more bassy and warm, less technical and analytical, have thicker and more natural timbre even if the MD4 timbre isn’t very thin or bright. Bass is weightier, chunkier, it have more rumble while the MD4 offer a leaner dryer bass which doesn’t mix with mid range but feel a bit more detached and artificial.
Mid range of MD4 is thinner, crisper and more spiky, both female and male vocal are more recessed and a bit shoutier, while TH have more body, hint of appealing breathyness and wider more upfront presence, note weight is heavier too and timbre is more lush and natural.
Treble is more excited with MD4 too, delivering faster attack with tighter sustain, it’s less well balanced than TH and a bit more clinical. You have more air and details on top, yet less brilliance and sparkle, level of micro details is higher too but sometime overwhelming and creating saturation.
Soundstage is more compressed and tunnel like with MD4, notably wider and taller with TH, perhaps hint deeper with MD4.
Imaging is superior with the MD4, the 4ba offer more precision and accuracy and we have more clean space between instruments.
Tonality is more artificial with the MD4 and bass is underwhelming in extension, body and physical impact, technically it’s perhaps superior in term of resolution, imaging and attack speed, yet their none of the 4 signature i would call musical, so for me the THhifi is the only enjoyable IEM of those 2.


The Hidizs MD4 is a very interesting IEM with lot to love about, it’s highly revealing yet smoothed in edge to avoid agressive peak.

The tuning switch permit to add hint of warmth or treble edge as well as much needed bass weight when need. The construction is marvellous and overall tuning well balanced in it’s own unique way that will be hit or miss depending of your conception of musicality.

All in all, while i’m not charm by musical performance of MD4, i’m sure impress by it’s technical one whic offer a highly resolved sound with precise attack in treble and a sens of exciting immediacy that will be able to charm those audiophile seeking for well balanced analytical sound signature.


PS: I would like to thanks HIDIZS for sending me this review sample. I’m not affiliated to this company nor have been financially compensated. As always, this is my unbiased audio impressions.

You can buy the Hidizs MD4 for 179$ here:https://www.hidizs.net/products/md4?spm=..blog_bbe08951-c1d0-428e-bb7f-5553f37762ae.header_1.1

Leave a Reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out /  Change )

Twitter picture

You are commenting using your Twitter account. Log Out /  Change )

Facebook photo

You are commenting using your Facebook account. Log Out /  Change )

Connecting to %s