HZSOUND HEART MIRROR Review: Sub-100$ King of technicalities

SOUND: 9.5/10
VALUE: 10/10

THE PLUS: Crisp refined neutral sound, Clean and clear, Sharp imaging, realist timbre, Fast transient response, bass control, Bright but smooth, Forwards vocal without sibilance, detailed treble that keep its balance, excellent construction, comfortable, beautifull design, generous accessories, Good value
THE SO-SO: Not biggest sound stage, Need amping
, need (non included) right ear tips to shine, shell is finger print magnet and easy to scratch

It’s unclear since when Hzsound has been around, but it’s at least since 2014 when they launch the HZ-EP001 single 8mm dynamic driver, a wooden earphones that got good reception among budget audiophile but didn’t get that much noticed due to the fact it look like to be the same IEM than some other OEM Chi-Fi companies.

Lurking around on Aliexpress lately, I fall on the Hzsound Heart Mirror and get hooked by 2 things: the use of Carbon nano coating (CNC) dynamic driver and the very eye appealing and sturdy looking construction. As well, it was on sale at 30$, making it extremely budget friendly for such serious looking audio products.

Then out of the blue Keephifi contact me with a list of IEM reviews offering and the Hzsound was in this list, so I jump on it as well as the extra cable offering (which I will make small review of too in this article).

Now, let’s see if HZsound know how to properly tune a single dynamic earphones.

You can buy the HZsound Heart-Mirror for 50$ directly from KEEPHIFI Store HERE.


1. Product Name: HZSOUND Heart Mirror
2. Brand: HZSOUND
3. Model: Heart Mirror
4. Earphone type: In-ear
5. Impedance: 32Ω(±15%)
6. Speaker Sensitivity: 106±3dB
7.Microphone sensitivity: -42±3dB
8. Frequency range: 15Hz-40kHz
9. Connector: 2Pin 0.78mm
10. Plug Type: 3.5mm L type
11.Cable: 1.2m, OFC silver plated
12.Color: Silver
13.Driver unit: 10mm driver unit


Well, that’s a great surprise, the packaging look very professional and have quality cable included with it as well as a beautiful carrying case. The box feel nice and presentation is well care off. As well, you even have a metal carabiner included with it if you plan climbing the Everest with the carrying case solidly attached to your belt. We have a good amount of ear tips too, 6 pairs of silicone ear tips and 1 pair of memory foam, but neither of them do justice to extract full potential of the sound because of too small nozzle hole compared to bigger nozzle hole of the HZ. All in all, you are very spoil in term of overall accessories for 50$ product.

So, as said, my expectation were high about construction, but it surpass these by good margin and even make me think of Final Audio A8000 construction in a more basic way because it’s like 3 times smaller. Yes, these are quite small which will permit universal fit whatever the size of your ears. The mirror finish is both eyes and finger prints catching, so you need to take care of those as micro-scratch happen easily with mirror finish IEM, even if it cost 2K like the Sony ZR1 or A8000. Cherish your beauty. So the construction is 2 piece of solid alloy stick together perfectly, no maladjustment often found with sub-100$ iem. The nozzle is angled and long enough so you can use any type of ear tips you want without fitting issue. The 2pin connector is solidly embedded in body and near flush so again, you can use a wide range of cable without issue which is a big plus for me that hate it when 2pin connector are deep inside the shell. The CABLE is a nice 4cores OFC silver plated cable of above average quality for it’s price range and it have a metal L shape jack, smooth braiding and not too thigh ear-hook. I really think the whole construction and design package with Hzsound is irreproachable for it’s price.


This section isn’t always important, but this time it’s Crucial. The Hzsound sound completely different once well amped, the soundstage dramatically improve in wideness and tallness and timbre sound fuller lusher. I don’t use high gain on my L30 and it’s plenty enough of power. At 32ohm of impedance and rather decent 106db of sensitivity, one would think they are just enough easy to drive but perhaps the diaphragm composition make it harder to drive. For example, the Starfield use similar carbon nano diaphragm and have super high sensitivity of 122db with same impedance and still benefit from enough amping to open the dynamic. To make things even more complicate, the Hzsound benefit from different type of cable, in my case the Kbear mixed copper silver plating cable coming with the Kbear Diamond. In this case, it’s mostly timbre that is affected, making everything sound weightier and fuller.


TO NOTE: This sound impressions is based on stock cable included, but not the stock ear tips. As well, it’s based on portable audio gear, not using stand alone amplifier which greatly improve soundstaging. Changing cable for a mixed copper-spc one will probably improve timbre fullness.

Audio gear used for this review: Qudelix 5K, Ibasso DX90, Xduoo X20, FIIO BTR5


Overall sound signature is clean and bright with a neutral to analytical approach. This will be familiar territory for those who have listen to Hifiman RE600-400 or Vsonic GR07, but the HZ have rounder and more extended bass than HE600 and a more organic timbre. We have a very mature tuning, which is very surprising from a newcomer, especially a Chi-Fi one. The presentation is crisp and intimate, and the timbre is on thin side which affect dynamic weight impact.

SOUNDSTAGE is rather compressed and lack some extra wideness and tallness but have impressive deepness and good amount of air even in this small tunnel-like presentation. This is when amped with normal gear. Use an amp and the soundstage expend drastically, offering wide tall holographic presentation.

IMAGING is excellent both in transparent layering and instrument placement, but it most be noted it’s note super wide between every instrument but we have both stereo and centered spatial placement.

TONALITY is on the crisp and cold side, gently bright without tonal imbalance.

TIMBRE have great transparency and just enough texture nuance, transition is organic not shouty.

TRANSIENT RESPONSE is impressively fast, so you don’t encounter congesting or lack of control that can create bass bleed or highs splash.

BASS is flat, light but not dead due to micro boost in mid bass, it extend naturally and have a realist timbre. We have more bass extension in lower end than higher end, so it’s not a very punchy bass, neither weighty. Still, it have good amount of air in bass line and its strangely perhaps the most textured aspect of the sound, so it present better synth line with boosted texture than clean sub that need rumble and air moving. Yep, the bass didnt move lot of air but it isn’t dry and ovelry flat as I can easily discern well rounded bass line sitting in the back, thanks to the super clean sound. As well, using stock ear tips can seriously make the HZ sounding more bassy and V shape and push the bass in front, which isn’t a plus at all and would make both mids and highs distant sounding. Clean and well controlled and articulated, but polite too is the bass. Due to great driver flexibility, you can boost the bass with EQ quite a lot and still achieve a clean sound.

MIDS are forwards, clean and transparent without any hearable peaks, they are gently fowards but not that much more than the bass, about 5db max I would say, which avoid agressive or shouty presentation with too high sound pressure. Sure, it’s noth to lusher or must emotional mids we can ask, but more a reference monitor kinda mids that find the sweet spot between brightness and coldness. Clarity is very impressive, as well as instrument separation, and the HZ are very accurate in presentation with an above average articulation that avoid busy tracks too sound messy even if it lack grandeur in soundstage. The mid range is energic, but timbre being smooth it avoid sibilance or violent brightness, still, it isn’t laid back or warm, it’s all about well pushed clarity. Both male and female vocal sound crisp and lively, never recessed even with bassy music.

TREBLE is fully extended without any serious dip, so it dig lot of micro-details even in upper highs which can be unforgiving for bad recording with noisy background. The attack is fast and sharp, no splashiness neither overly metallic brilliance, not a lot of sparkle neither due to lack of space for proper decay. Timbre is very realist, and the percussion have great micro-details textures making, like the bass, we have a micro-boost in treble region that help clean articulation but not in an unbalanced way, nothings sound to upfront with the Hzsound, it’s really that well tuned. The lower highs are smoothed a bit, to avoid sibilance and bright saturation, this can affect some instrument fullness like violin and accordeon which will sound a bit thin but still have good attack edge and great transparency. While i would like a little more air on top, i consider the treble very refined and well controlled, especially with good recording using acoustic guitar or complex percussions.

BASS: 7/108/10
MIDS: 8.5/108.5/10
TREBLE: 9/108.5/10
ATTACK-DECAY: 8/108/10


At first the Hzsound didn’t hook me in term of musicality, but unlike some IEM that can impress me at first and became annoying with multiple listen, HZ do the opposite and grow on me. Firstly I have to change ear tips for a wide bore one to make the sound more open, secondly using a different cable that have copper+spc seem to thicken timbre a bit. Lastly, using a amp did open even more the sound and enrich timbre fullness as well as bass weight….this show that the driver in those have a complex persona, and a capricious one too. Oh, and burn in might have improve imaging too.

So, now I prefer them over both Blon BL-03 and Kbear Diamond, but that’s just me.
I find the tonal balance excellent even if we have slight mid and upper treble boost, the upper highs are delicate and mid highs very lively and snappy. I don’t know how the HZ have been able to tune these so well so everything have an energic snap to it, but it’s very mature and refined, offering what I consider a true audiophile experience at very budget price.
Unlike some reviewer, I do not have specific ‘’house sound’’ preference, what I care about is timbre, should it be bright or warm, it need to be either natural (gently thicken and warm) or realist (gently bright and textured) and overall tonal balance should be both dynamic and cohesive whitout over emphasis frequencies range.
The Hzsound deliver just that, a near neutral sound with sharp non sibilant mids that sound very lively, punchy well articulate bass that stay in the back as it should and delicate revealing treble that enlight details. Apart from slight lack of air and somehow intimate presentation of instrument and vocal, this is how I wish Vsonic GR07 sound: less grainy with better rounded upper mids and crisper clarity.


VS BLON BL-03 (35$):

Tonality is more V shape and warmer with the BL-03 and have more emphasis in lower treble but less upper treble. SOUNDSTAGE seem notably wider and more out of your head but lacking the HZ deepness. IMAGING is more precise with the HZ and will not sound hollow in very busy music.
BASS is more boomy and grainy with BL-03, as well it isn’t as thigh and warm-veil the lower mids way more, it have more weight and impact and offer a more fun bassy energy. MIDS are thicker and messier, lacking the HZ transparency to permit proper separation of instruments, it’s less bright and detailed too and have less edge to attack, making it prompt to congestion with fast busy music. The transient response speed is notably superior with HZ. Highs are more relaxed with the Blon, especially in uppe treble were it fail to dig as much details as the HZ, percussions sound fuller and better resolved as well as more snappy and clear with HZ, while Blon struggle to keep proper control and feel less balanced between mids and highs.

All in all, the Hzsound is technically superior and better balanced than the BLON but more serious sounding and less impactfull in bass department. For R&B, electronic and Soul I will choose the BLON, for anything else and especially fast music like math rock, I’ll jump on the HZ.


Again, Diamond is more V shape but brighter and less bassy than BLON, lower and mid treble is more fowards than HZ making the timbre grainier and rougher.
SOUNDSTAGE is notably wider and taller and even deeper with the DIAMOND, presentation is more holographic too, IMAGING is overly in center stage compared to the HZ so it’s harder to pin point instrument even if it seem we have more space in staging.
BASS is thicker, with more sub bass boost but less natural and transparent extension, it can take front seat while HZ bass always stay in the back, kick drum are less clean than HZ which have thigher, cleaner and leaner bass that doesnt feel as colored as Diamond.
MIDS are more upper mids centric with the Diamond, they aren’t as smooth, accurate and clear as the HZ, vocal sound more natural with the HZ too while some tonal imbalance can happen with Diamond due to lower mids dip and upper mids boost. Mid range is more transparent and have higher resolution with the HZ even if its timbre is smoother.
TREBLE is where the HZ take serious leap over Diamond, it dig more micro-details, is crisper, more controlled and snappy, as well, it’s more sparkly than crunchy treble of Diamond.

All in all, HZsound do everything better than the Diamond apart from soundstage and sens of airyness.

VS FINAL AUDIO E2000 (40$):

Final always nail it in term of natural timbre even when sliding to the bright side, and E2000 offer fuller more even timbre that offer a smooter tonality at they end. SOUNDSTAGE is again (again) wider and taller with similar deepness, IMAGING is a little less crisp.
BASS is warmer with more sub bass boost and less control than HZ, separation between sub and kcik is less clean than HZ too, the slam is weightier but lack definition edge of HZ so it tend to bleed more on lower mids. MIDS are slightly more recessed but fuller with more natural timbre, while vocal can be a bit cold with HZ, it never is with E2000 but clarity of mid range is higher with HZ and permit to extract more well resolove instrument. TEBLE is more agressive with the HZ, its snappier and more detailed too and can be less permissive with bad recording that have background hiss than more relaxed E2000.

All in all, Hzsound have faster technicalities and higher resolution and cleaner colder sound than E2000 which have a smoother more musical tonality and bigger soundstage.


The Hzsound Heart-Mirror aren’t your typical chi-fi iem and more something you would expect from a company like Final Audio (E2-E4) and Hifiman (RE600). It’s maturely tuned and offer a crisp balanced sound that doesn’t ovelry boost any frequencies area. While it’s on the bright side, it isn’t on the harsh side due to excellent control in attack, thanks to the fast transient response of it’s CNC dynamic driver. This isn’t a super fun sound IEM, but sure not a boring one either, you got the punch, you got the forwards mids that extract both male and female vocal sharply, and you got this tremendous amount of details that keep their balance in the mix.

True audiophile sound on budget, and a versatile one too that can deal with fast complex music even if the soundstage isn’t the most spacious, the Hzsound will find it’s niche market whitin those that favorise precision of execution instead of a romanticized tonality.


  1. i have spring1 which only bother me with too much mid bass (sub bass is ok, i don’t want less sub bass), is HZSOUND HEART MIRROR or geek wold gk10 a possible upgrade over spring1 ? thanks


    1. Geek world isnt musical at all….better go with the big champ: HZ Sound Mirror, bass is wonderfully realist and deep, but lean and not boosted….to fully enjoy bass good amping is mandatory (min of 300mw@32ohm) and your right about intense mid bass of spring2, that the only drawback i can think of as well. Moondrop Aria might be of interest to you if you want more sub bass extension and smoother tonality than HZM an Spring1. And yes, HZM is superior to spring1, better balanced, cleaner and more transparent as well as faster in attack.


  2. You said e2000 more musicality. You said the tone is better and the stage…isn’t there good quality music from the mirror.Is the stage too narrow or too tiring? Is just a dongle enough?


    1. yes, mids are a bit fuller and timbre a bit more dense but not as transparent. I dont use E2K anymore, but still use HZsound mirror due to highly superior technicalities-clarity-imaging-bass control and resolution etc.
      Hum, the stage is exactly what improve the most with proper amping….and clean source (for deepness), its not stock in your head but still intimate in a 3D spatiality. Wider-deeper than taller.
      A dongle like Audirect Atom2, Xduoo BAL2, FIIO BTR5-KA3, with 240-270mw@32ohm is about the minimum it require IMO


      1. my 2 daily iems are heart mirror (bass mod) and shuoer s12 that is even more resolving and with both iem i could not hear a significant difference between my $10 apple dongle and my btr5 on 240mw balanced output, so maybe my ear is not trained enough to get these improvements with better sources


  3. S12 seem great mate. well, i dont know what to say, i dont have your ears, if you enjoy them this way don’t bother about extra amping. bass mod might have something to do. i mean, i can still enjoy the HZ with my LG V30 (high gain unlock). I just mean it will scale up. These can handle ALOT of power. I adore them with TRI TK2 (1250mw@32ohm). oh, and i consider both Apple and BTR5 to have rather lean dynamic. I enjoy apple dongle with my Dunu DK2001 and sensitive IEM like Audiosense T800.


  4. Hi, I am using LG g7. I don’t use dongle and amp. Does the heart mirror perform impressively with the g7? Is it detailed and mature enough? Or do you think there are other models that will perform better with the g7 at this price?


    1. sorry for late answer mate….hum, my V30 can drive them good enough if i unlock high gain mode by using 3.5male to female cable…if G7 is the same, it will be good but scale up with better source and more powerfull amping. ill say 300mw@32ohm is what it need to really open up and have this bass rumble people say it lack.


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