
HIDIZS has been around since 2009, but begin to gain success with there best selling DAP the Hidizs AP80. Mostly known for making portable music players and DAC-AMP, Hidizs decide to expand their horizons and create their own earphones.
In 2019, they make the audacious move to launch a flagship Hybrid IEM as their first IEM attempt. The Mermaid MS4 quad hybrid drivers were born and get good reception among curious audiophiles. Soon later, they use very same housing to create a more budget-minded IEM with a single 10.2mm dynamic driver using a bio-diaphragm moving coil.

This one is called Mermaid MS1, which has a flagship construction and an affordable price tag of 100$. It seems that they even push value boundaries by using the same driver for MS1-Rainbow which is priced 65$ but has cheaper plastic housing.
Today, I will review the Mermaid MS1. Let’s see if this TOTL looking IEM is more than just a beautiful piece of engineering.
You can buy the Mermaid MS1 from trustable HIFIGO STORE HERE.
SPECS

PACKAGING & ACCESSORIES



Did the Mermaid is a pricey flagship earphone or a 100$ one? Well, if you look at the whole package and don’t know it’s budget price, you will surely think the Mermaid is a luxurious IEM selling in 300$ price range. In fact, the whole packaging presentation reminds me a lot of FIIO FH7. When you open the box, the beautifully crafted IEM are put in valor in the front panel. Under it you have 12 pairs of quality ear tips in a display that explain the type of sound they deliver. You have as well a small pelican case and a carrying pouch. The pelican case is well built with a nice metal plate with Hidizs loge on the top. But packaging presentation and accessories are irreproachable and surpass any expectation a consumer could have. No doubt about it, the Mermaid MS1 offers the most generous and luxurious product package I ever encounter in its price range.
CONSTRUCTION&DESIGN




If you read some FIIO FH7 review, you surely notice how people praise it’s high-end CONSTRUCTION. Well let me tell you straight up, the Mermaid MS1 have as good construction as the FH7 and use very same high-density CNC alloy material and sandblasting coating. You just can’t expect this type of construction quality at this price range and when I have the MS1 in hands I get overly excited about how refined shapes and finish is as well as how incredibly solid and durable it feels. Whole housing is made of metal apart 2pin connector which is plastic. The housing is VERY big, bigger than most of my IEM including the FH7, it’S quite heavy too but not to the point of creating discomfort. It’s very thick and has an ”universal ear mold” shape. The finish is very smooth and does not get hot or cold fastly like a lot of other all-metal IEM I have. Even if I take a magnifying glass to try to find micro imperfection, I just can’t, all pieces are perfectly assembled with great care for proper quality check.

The cable is very nice too. It’s a 4 strand silver-plated OFC cable that has a very sturdy 2pin connector and a very nice metal jack. It promises durability and doesn’t justify you to rush buying an upgrade cable because it pairs well with MS1 tonality.
Why the housing need to be this gigantic? My guess is that Hidizs decide to use MS4 housing and don’t want to invest in a new costly manufacturing process. Sure, the DESIGN is nicely done and for somebody with big ears like me the chunky metal body doesn’t create a fitting issue, but for people with small ears it’s hard to imagine how they would fit this in their ears. The nozzle being short, whole housing tends to create a rather strange protuberance which is a shame because of how beautiful is the whole esthetic….its like wearing a luxurious hat that makes you look awkwardly oversized. So, the Mermaid MS1 needs the help of an ear hook cable to stay perfectly in place, otherwise, it will perhaps slowly fall. Apart from the big size and slightly heavy housing, I find the design smoothly comfortable, free of any problematic asperity.
DRIVEABILITY
These are thought to be easy to drive and it sure is with it’s impedance of 18ohm and high sensitivity of 112db. You don’t need portable amp to open the sound of MS1 and any audio source including your phone will drive them properly.
ISOLATION
Surprisingly, even if you got a big tank in your ears it doesn’t mean it will intensely block outside noise. Deeper you can insert an IEM, more the passive isolation will be intensify and as you can’t push the MS1 short nozzle far in the ear canal, it means the isolation is just average and you will need to listen to music at high volume to cut outside noise. As well, due to it’s 2 venting hole, noise leakage is notable.
SOUND

Audio gear used: Xduoo X20, Ibasso DX90, Xduoo X3, Audirect BEAM2
OVERALL SOUND is U to W shape with boosted sub-bass presence, upper mids, and upper treble. Tonality is bright, timbre is dark, and the overall attack is slightly shouty. Macro-resolution is better than micro-details. Bass slam is hefty yet light in body. Mids tend to enlighten female vocal more than male vocal or other instruments. Treble is a little harsh.
SOUNDSTAGE is the Highlight of Mermaid, as if the whole tuning project was about offering the biggest, widest, deepest stage possible. If the housing is This Gigantic, it’s surely for this very purpose: offering a hall like out of your head soundstage experience.
IMAGING, alas, doesn’t fully take advantage of all this acoustic space and will tend to push certain instruments or sound more forwards, giving you the impressions you have good instrument separation, which is true for simple tracks but as soon as you put busy music things became more messy and hollow.
BASS presentation is very unique with the Mermaid, we have the typical sub-bass presence boost of U shape sound signature but it has a resonant extension in lowest range instead of thick well rounded meaty slam. As well, the high low that give proper body definition to kick is tamed a bit which affects bass tonal balance but pushes the mids presence very forward. Timbre is not very textured but have good transparency. The attack is rather slow with long decay. The low end is the darkest part of Mermaid sound and is hit or miss depending of music style, for fast rock, it lacks speed and kicks punch, but for pop, folk, jazz and classical, even is acoustic bass lack a bit of natural extension, if find the transparent bass oomph very appealing and adding weight to the music foundation.
MIDS are clear, bright and forwards with better macro-resolution than micro-resolution. Female vocals sound fuller than male vocal, they are just a hint hot in upper mids but not to the point of creating harsh sibilance. Timbre has an average thickness, making piano sound quite nicely rounded. The mid-range is clearer and more articulate when you don’t have big bass in music, otherwise, some instruments can sound more hollow. Even if quite clear, I don’t consider the mid-range very crisp, because more there instrument more you will hear the limit of singular instruments resolution. Like the bass, you don’t have lot of texture or micro-details, this isn’t highly refined mids but for female vocal lovers, the wide forwards voice presentation will sure be enjoyable even if tonality isn’t the most natural.
TREBLE is bright and energic, with tamed edge and it feels it’s customized for rendering simple drums tracks like snare and hit hat, less so for cymbals crash and crazy fast highs range percussions. To my ears, it lacks a bit of lead attack to offer proper snap but I’ve been surprised by how appealing and lively sound harp and classical guitar, which have nice sparkle and show extra bite in the upper treble region which add both air and brilliance to the metallic instrument. Still, again, the slapped instrument will lack a bit of tonal balance, some will have more lower harmonics, and others will have more higher harmonics. Listening to folk singer is very enjoyable, the presentation is vast with perfectly separated guitar and voice, but if the violin enters the music it can affect overall realism.
QUANTITY | QUALITY |
BASS: 8.5/10 | 7/10 |
MIDS: 8/10 | 8/10 |
TREBLE: 8.5/10 | 7.5/10 |
ATTACK-DECAY: 7/10 | 7/10 |
SOUNDSTAGE-IMAGING: 9/10 | 8/10 |

VS MOONDROP STARFIELD (110$)
Let’s begin by saying Starfield has way better tonal balance and overall more natural-realist timbre. SOUNDSTAGE go to the MERMAID, which sound more hall like and out of your head. It’s more open in every angle possible: tallness, wideness and deepness…but it’s a TRICK.
Because IMAGING is darker in definition than Starfield and can suffer from bass resonance veil. As well, Starfield being more neutral and balanced, it has more layers to its sound, which reveals some instrument the Mermaid hide behind it’s boosted mids or mid-bass bleed. Yep, Mermaid hide some ghosts far it the back of its hall-like-staging!
BASS is notably more U shape and boosted, offering more slam but less control and body than Starfield, which has a more linear and natural extension in both directions. Mermaid has this peculiar resonance that sure affects tonality accuracy, while the Starfield is faster in articulation and clearer in separation. Quantity go to Mermaid, while quality go (big time) to Starfield.
MIDS are more colored and push forwards in upper mids with the Mermaid, a hint more shouty and bright, and overshadowing some instruments in lower mids range, while the Starfield have fuller thicker mids due to more lower mids and better balanced upper mids, making vocal more intelligible and instrument in mid-range sounding more accurate, clearer and realist.
TREBLE is again less balanced and spikier with the Mermaid, pushing some percussions aggressively forwards and shadowing micro-details and texture. The Starfield have flatter fuller treble with more nuanced and controlled highs, less splashy impact, and more realist timbre.
All in all, the Starfield offers a more refined and balanced sound with more natural tonality and better technicalities. Mermaid ‘’guilty pleasure’’ might be a crime after all.
VS Kbear Diamond (80$)
Let’s begin by saying the Diamond have notably faster transient response which inflicts on technicalities advantage.
SOUNDSTAGE again is bigger with the Mermaid, this time it has about the same wideness but it’s taller and deeper.
IMAGING is sharper with the Diamond due to better overall clarity that keeps clean instrument placement.
BASS is U shape too, with emphasis sub presence and tighter thicker weightier impact, making the Mermaid sound sloppy and thin in timbre.
MIDS are slightly more recessed and thinner but has a crisper definition and better separation than more shouty and bright Mermaid. Instrument sounds tonally better too, and attack is edgier and controlled.
TREBLE is crisper, sparklier and has more brilliance with the Diamond, it digs more micro-details too. Mermaid has brighter, thicker, splashier treble that lacks control and snap.
All in all, the Diamond is technically superior with tighest attack and higher clarity, but the vocal is thinner and soundstage is less out of your head.
VS FIIO FD1 (60$)
How does a 13mm Berylium-plated dynamic driver compare to a 10mm Bio-diaphragm driver? Well, here it’s all about transient response and tonal balance.
SOUNDSTAGE is notably wider and deeper with the MS1, IMAGING too is more accurate and less condensed in layering than FD1. BASS is thicker, fuller and flatter with the FD1, it has more high bass so the kick sound fuller, as well, it’s better balanced and controlled than the more boomy and resonant low end of MS1. MIDS are fuller but more opaque too with FD1, the male vocal is more bodied than MS1, presentation is more intimate and forwards with FD1 and cleaner due to slower transient response of MS1. TREBLE is again fuller and thicker with more natural tonality and less splashy cymbals, making the MS1 highs sound thin in mid-treble and peaky in the upper region, so you have more micro-details but less texture and nuances with MS1.
All in all, the MS1 sounds more U shape, fun and immersive due to its bigger hall-like soundstage and more boosted bass while FD1 is more neutral and natural in tonality.
CONCLUSION

Hidizs first attempt in budget-minded earphones is extremely promising. While tonal balance isn’t perfect and overall tuning lack a bit of refinement, the Mermaid MS1 succeeds in delivering a very immersive holographic sound experience that favorise fun over accuracy.
If you take in account the tremendous amount of accessories as well as the mind-blowing construction, you sure get more than asked for your money.
I see the Mermaid MS1 more targeted towards audio enthusiasts that like boosted bass and sudden wow effect than mature audiophile searching for neutral and natural sounding IEM.
If you’re a sucker about soundstage size, bass slam, and listen mostly to slow music like pop, folk, chamber classical, or soul, I think the Mermaid MS1 worth your consideration. One thing sure, your friends will be bluffed about the price you pay for such pristine crafted earphones.