HZSOUND Heart Mirror Review – Prime Audio Reviews

HZSOUND is a Chinese manufacturer specialising in in-ear monitors. In this review, I’m checking out the HZSOUND Heart Mirror earphones. The Heart Mirror has a single carbon nano diaphragm dynamic driver, alloy shells and a silver-plated OFC cable.

Disclaimer: This sample was provided for the purpose of an honest review. All observations and opinions here are my own based on my experience with the product.

HZSOUND Heart Mirror

  • Front of box
  • Back of box with specs list

Package and Accessories

The Heart Mirror comes in a standard white box with an image of an earpiece on the front and the specs on the back. Inside is the ubiquitous felt-covered foam insert plus another small box which contains the accessories. The included accessories are quite generous for something at this price point. Let’s break it all down into a list:

  • HZSOUND Heart Mirror earphones
  • Zipper carrying case
  • Carabiner
  • 6 pairs of silicone eartips
  • 1 pair of foam eartips
  • Detachable silver-plated OFC copper cable
  • Shirt clip
  • Unboxing the Heart Mirror
  • What's in the box

Build Quality and Design

The most striking physical feature of the Heart Mirror is its chrome-plated alloy shells. They are highly polished and reflective and shaped somewhat like a human heart (hence the name). Housing a single 10mm dynamic driver, the shells are fairly small but have a very solid feel to them.

There’s a vent just near the 2-pin socket and another near the base of the nozzle. The nozzles have a substantial lip so eartips stay firmly in place. As is the norm, the nozzle opening has a metal mesh cover to keep the nasty stuff out.

HZSOUND Heart Mirror with carrying case

In terms of comfort, I find Heart Sound to be really good. Despite the simplicity of the shell structure, the angled nozzles and shape of the housings provide a stable and snug fit. I found the passive noise isolation to be a little below average but it’s still good enough for commuting and everyday situations. Overall, the build quality feels great and I personally quite like the appearance of these earphones.

Bundled stock SPC cable

The included silver-plated cable is a braided 4-core type with clear insulation. There is virtually no microphonics and it handles nicely. The right-angled 3.5mm plug, Y-split and chin slider all have the same polished finish as the shells and make for a coherent aesthetic. I would say the cable quality is slightly above average for an IEM at this price point and is similar to the ones that come with the Tin Hifi T2 Plus and BGVP DN2.


Gear used for testing

  • Windows laptop -> Cozoy TAKT C
  • Sony NW ZX-300
  • Shanling M5s

The HZSOUND Heart Mirror has a neutral-bright tonality that very much fits into the category of “audiophile tuning”, i.e. a bit on the analytical side when it comes to presentation. One could also call this a budget reference in-ear monitor. There are classic Chi-Fi upper midrange and lower treble boost which puts a focus on vocals and makes the overall sound drift towards bright when paired with the stingy bass quantity.

One thing is certain: the Heart Mirror has a mature and refined tuning with a level of resolution that is not seen often in the budget arena.

HZSOUND Heart Mirror frequency response

There are certain keywords in the audio dictionary that audiophile nerds flock and cling onto. One of the recurring terms is “neutral” and it is always guaranteed to increase the heart rate of geeks sitting in their parents’ basements around the world. Well, nerds, it’s time to rejoice because the Heart Mirror has a neutral bass response.

While the extension or authority is not on par with something like the NF Audio NM2+, it is definitely impressive from a technical standpoint. It has a fast attack and decay, making it a very tidy bass but the reality is it lacks punch and overall impact. For certain music genres, such as acoustic, vocal and rock it won’t matter. But for hip-hop, dub, EDM, modern pop, jazz etc it sometimes feels lacking in quantity.


Mids is an area where the Heart Mirror really shines. Here you’ll find transparency, clarity and detail in abundance. This works particularly well for acoustic and vocal genres but in reality, the midrange resolution works in favour of every type of music.

In Anathema’s “The Beginning and the End”, every element of the midrange is rendered in a commanding fashion. In particular, the vocals and electric guitar are both forward and rich yet never feel cloying or congested. But the timbre and note weight are both good, especially considering the lean nature of the bass backing them.


The treble has good extension and is fairly even after the 8kHz peak which adds clarity and definition to the sound. It looks relatively forward in the mix but that’s mainly due to the extreme neutrality of the bass. As such, it does sit forward in terms of level but it’s not thin or brittle nor is it uncomfortably bright.

In fact, there is no harshness in the treble unless the recording is inherently sibilant or poorly mastered. In this, the Heart Mirror faithfully reproduces the treble and I would consider it another highlight of this budget in-ear monitor. There’s a touch of sparkle and plenty of detail here which in many ways sounds like the much more expensive NM2+.


The soundstage has more depth than width, which is a bit of a surprise considering the lean tonality of the Heart Mirror. However, imaging is reasonably strong despite the narrow nature of the stage. Instrument separation is very good for a single dynamic driver in this price range.

HZSOUND Heart Mirror side of shells


Tin Hifi T2 Plus ($45)

The Tin Hifi T2 Plus is another single dynamic driver IEM and is similarly priced as the Heart Mirror. The two share surprisingly similar frequency curves, both have metal shells and an over-ear design.

When listening, the T2 Plus has a little more fullness to its sound, particularly in the lower midrange. This is a result of a slightly elevated bass and less upper midrange boost. Bass notes on the T2 Plus are more rounded while the Heart Mirror has a more defined leading edge and faster decay.

Sub-bass on the T2 Plus is more tangible and gives additional physical sensation in your ears compared to the ultra-clean and lighter rumble of the Heart Mirror. Male vocals are more full-bodied and chesty on the T2 Plus and leaner on the HZSOUND. The extra lift in the upper midrange and lower treble give the Heart Mirror more clarity.

Treble is a bit crisper and cleaner on the Heart Mirror but the upper frequencies of both earphones are very similar. Overall, the T2 Plus feels a little more musical and the Heart Mirror leans more towards analytical. Having said that, however, vocals on the Heart Mirror are extremely articulate and vibrant which could make all the difference for some listeners.

HZSOUND Heart Mirror with Shanling M5s DAP
NF Audio NM2+ ($160)

The NF Audio NM2+ is a single dynamic driver in-ear monitor with a neutral tuning. Looking at the graph, you’ll see that the two share a lot of similarities in their overall presentation.

The NM2+ has superior bass extension and is more authoritative in the low-end than the Heart Mirror. Furthermore, it has more upper bass and fullness in its lower midrange. NM2+ has additional clarity in its midrange but the starkest difference is in its superior resolution. The NM2+ really dissects every element of the music and lays it out on a pitch-black background.

Instrument separation is better on the NM2+ too, which is to be expected at roughly 3 times the price. Moreover, the NM2+ has a crisper and more detailed treble which is better balanced by its meatier bass response.

This isn’t really a fair comparison but I’ve added it here because the two earphones have a very similar target response. While the NM2+ is easily the better monitor, the Heart Mirror is a fantastic alternative for anyone who can’t afford the former.

HZSOUND Heart Mirror budget Hi-Res Audio


The HZSOUND Heart Mirror is another amazing budget Chi-Fi IEM. Although it likely won’t satisfy those looking for a V-shaped or more fun sound, it is a great choice for musicians, audio engineers, video editors etc. (and let’s not forget audiophile nerds) on a budget.

The build quality is great and the bundled accessories are well thought out. If neutral, tight bass, clear, resolving mids and shimmering treble tickle your fancy, you ought to check out the Heart Mirror today.

  • Impedance: 30Ω
  • Speaker sensitivity: 106±3db/mW
  • Frequency range: 15-400000Hz
  • Earphone Interface Type: 2PIN interface
  • Cable: Silver-plated OFC