BLON BL-03 vs HZSound Heart Mirror Shoot Out – Which is the Better Earphone?

Blon BL03 vs HZSound Heart Mirror

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The Blon BL03 and the Hz Sound Heart Mirror are two great-sounding pairs of IEMs that are well-loved by the audiophile community. 

They’ve already been reviewed on the site but this time, we’ll be looking at them side by side to see which is the better pair of IEMs. 

BLON BL-03 vs HZSound Heart Mirror: Sound Signature

The BLON BL-03 in-ear monitors have a warm sound signature, which means that there’s a good amount of bass presence that colors the sound. 

This tends to give the vocals a very lush and rich quality to them. Sets with warm tuning will generally sound fuller and have heavier note weight. Having these attributes help a playback avoid sounding thin, giving you that full-bodied sound.

The BLON BL-03 is for you if:

  • You like heavier note weights on your songs.
  • You like a warm-sounding playback.
  • You like a colored sound.
BLON BL 03 - Silicone Tips
BLON BL-03 in-ear monitors | Make Life Click

The HZSound Heart Mirror has a cold sound signature, which means that its treble region is heightened compared to the other frequency ranges. 

This kind of sound signature is very resolving and will have more clarity at the expense of the bass frequencies. This allows you to hear the small details and micro nuances in your songs.

Sets with cold tuning signatures will generally sound more engaging and will render vocal clarity extremely well. 

The HZSound Heart Mirror is for you if:

  • You like a more neutral sound.
  • You like clear vocals.
  • You like more treble sparkle.

BLON BL-03 vs HZSound Heart Mirror: Sound Quality

Considering that the BLON BL03 and the HZSound Heart Mirror IEMs are complete opposites when it comes to sound signatures, it’s interesting to note their differences in sound quality across the frequency range.

The BLON BL-03 IEMs are praised for their pleasing tonality and timbre. 

These IEMs render instruments and vocals to be life-like and as natural as possible while injecting some warmth into them. 

The bass is one of their strong suits and may even be sufficient for a bass head’s taste. The sub-bass can reach quite deep and produces a rich and textured rumble. The mid-bass isn’t a slouch either and is quite articulate with its speed and punchiness. 

The midrange is recessed but is very present and doesn’t sound scooped at all. It has great note weight and its tonality rivals even more expensive sets. 

The treble has great extension and air to it, weaving a sense of space into the tracks that you listen to. The decay on the treble is adequate and makes songs sound more akin to real-life delay.  

HZSound Heart Mirror - Cables
HZSound Heart Mirror in-ear monitors | Make Life Click

The BLON BL-03 is for you if:

  • You like boomy bass.
  • You like heavy note weight.
  • You like a relaxed and laid-back listening experience.
  • You like a warm sound.

The HZ Sound Heart Mirror is revered for its holographic vocal prowess. 

The midrange of these IEMs allows the vocals to be more forward and sound closer. This creates a new sense of involvement for the listener, making it an intimate listening experience. 

The bass on the Heart Mirror is good but for sub-bass, you’ll be left wanting more. Its mid-bass is elastic and speedy, plus it has great dynamics to it. It delivers an engaging and punchy response that renders transients and drum sequences with relative ease. 

The midrange is the pièce de resistance and comes across as very clear and forward. Vocal-centric genres like K-Pop benefit greatly from this midrange emphasis. 

The treble has great extension and has the right amount of splash without getting sibilant and there’s also a good representation of the air frequencies. 

The HZSound Heart Mirror is for you if:

  • You like a clean bass profile.
  • You like forward vocals.
  • You want an intimate and engaging listening experience.
  • You like treble sparkle and details
BLON BL 03 and HZSound Heart Mirror
BLON BL-03 vs HZSound Heart Mirror | Make Life Click


The BLON BL-03’s weakness would be the resolution. 

On busier tracks, the sound occasionally gets blended into one another and loses its definition. This happens when different types of instruments are playing simultaneously. 

The imaging on these IEMs is fairly average and you get to roughly point out where each instrument is placed. 

The stage has decent height and width but it remains confined as an in-your-head auditory experience.

The Blon BL-03 isn’t picky with the source, but I’ve had great results pairing it with a colder source such as the Shanling UA1 DAC dongle. 

This made the bass sound fuller and punchier, the midrange a little richer and more detailed, and gave the treble more air and expressiveness.

The HZSound Heart Mirror’s weakness would be the source pairing. 

It’s pretty mediocre when used with sources like phones and tends to be fatiguing to the listener during long listening sessions. These IEMs need a source that has more power to push them to their full potential. 

On this note though, it’s not enough to provide it with just any source. 

I had the best results pairing it with a warmer-sounding source. Swapping the original silver-plated cable for an oxygen-free copper wire cable also helped as well. 

BLON BL-03 - Finish
Shimmery deep blue finish
HZSound Heart Mirror - Finish
Shiny mirror-like finish

These modifications improved several aspects instead of making the sound seem stale and lifeless. 

The bass frequencies were able to dig deeper, the sound was colored with just a little amount of warmth, making the midrange more emotional, and the treble frequencies were tamed by a few notches significantly reducing listening fatigue.


Ultimately, your choice between these two IEMs will depend mostly on the attributes that you gravitate towards more. 

It will also depend on the kind of playlists you have and whether either IEM ticks enough boxes for song synergy. 

In the end, both the BLON BL-03 and HZSound Heart Mirror are great-sounding IEMs. I consider them treasures in my collection and I can safely say that you won’t regret picking either one.

Gavin is a college student who has a lot going on. From collecting IEMs and modding mechanical keyboards, to different hobbies like digital drawing, music mastering and cooking. It is safe to say he is a complete multi-faceted geek (and he's kinda cool too)

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