Hidizs MM2 Review

Nero Peña
Nero Peña

Updated · Oct 18, 2022

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With excellent sound reproduction, playability, and comfort, the Hidizs Mermaid MM2 is a great choice for high-fidelity junkies. Curious? Tune in to our hands-on Hidizs MM2 review to discover all the bells and whistles.

Sound Quality



Lightweight and durable


18 Ohms

Tuning control


Frequency Response

20Hz - 40kHz

Driver Type

Hybrid Configuration


3.5mm jack

Fit & Comfort


Hidizs MM2


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Best for: Music production

Strengths Great audio quality
Strengths Detachable tuning valves
Strengths Nice bass response
Strengths Lightweight and comfortable
Weaknesses No wireless connectivity
Weaknesses Midrange tones could sound better
Weaknesses Shells are a bit large

If you’re into the HiFi life, you need a good pair of monitor earphones to hear those clear and crisp tunes. Something that caught our eyes – and ears – are the Hidizs Mermaid MM2 earphones.

Hidizs is a brand that speaks to audiophiles. From digital players to analog converters, it’s got great audio devices built to reproduce sound in all its glory.

Taking center stage is the Mermaid MM2s – the newest addition to the company’s pocket HiFi lineup. With superior sound quality, they feature a hybrid configuration: 

  • 6mm magnetostatic BM driver for the treble 
  • 10.2mm dynamic driver for the bass and mids. 

They also come with removable tuning screws for enhanced playability.

This build is precisely what sets monitor earphones apart from the typical ones on the consumer market.

But let’s make a clearer distinction.

What Are Monitor Earphones?

Also known as in-ear monitors (IEMs), they’re pro-grade versions of regular stereo earphones. Just like studio monitors, they’re designed for lossless and accurate playback. They feature advanced specs like multiple drivers, self-tuning mechanisms, removable cables, etc.

Professionals in the music industry often use IEMs for recording, editing, or mixing. They’re also made for people who simply enjoy listening to high-fidelity music.

Although they have a different build compared to gaming headsets, many gamers also prefer IEMs due to their detailed presentation.

The MM2, in particular, can fit all of these use cases – which is quite rare for a budget option.

But how well does it perform?

Moving on to our Hidizs MM2 review, here’s why we think it’s an absolute standout.

What’s in the Box?

The audio set includes the following pieces:

  • Earphones
  • 3.5mm audio cable
  • Leather travel case
  • Vip card
  • 6 pairs of silicone eartips
  • 2 additional output nozzles – for bass and for treble
  • User manual

Hidizs MM2 Review - What's in the box

The IEMs come in two color variants – black and silver. For this review, we went for the latter option, which sports a transparent shell, silver faceplate, and rose gold accents.

Now, let’s unravel their inner workings.


Much of the MM2’s amazing sound quality comes from its intricate build and design. Here are its stellar components:

Hybrid Dual Drivers

These IEMs boast a High-Res Audio (HRA) certification, which we can attribute to their solid driver configuration.

To handle the treble tones, the MM2 uses a 6mm Magneto-static Balanced Membrane driver. Along with a thin micron-level diaphragm, it delivers crisp dynamics, resulting in fast, smooth, and detailed high frequencies.

As for the bass and mids, it adopts a 10.2mm dynamic driver and macromolecule polymer diaphragm. This accounts for the tight and punchy bass response, with the mids rolling off smoothly and detailed. 

Vocals are clear and sweet. Although the timbre seems a bit manufactured, the instruments still sound natural.

Self-Tuning System

Aside from the drivers, the scene-stealers here are the interchangeable valves for self-tuning. And they aren’t just a gimmick; they actually change the sound character of your tracks.

You get three tuning valves – Bass, Treble, and Balanced

At the back of the earphone’s body, you’ll find a hole where you can screw in your preferred valve by hand. The Balanced one comes pre-installed like this:

self-stunning system

The Bass and Treble valves are laid on a small metal sheet with the appropriate labels. They also come in different colors for identification. 

Here’s the catch – when you change the valve, the frequency response also changes. Each one delivers a unique sound style that you can match with various music genres!

Two-pin Audio Cable

Aside from the detachable tuning screws, the MM2 also adopts a standard 0.78mm two-pin design for input. Thanks to it, you can use other cables with the same specs. That way, it’s easier to upgrade the sound or increase your playability with different cords.

Another noticeable upgrade on the cable is the gold-plating, which isn’t just a design touch; it also ensures a more stable audio signal transmission.

Build Quality and Design

Many Hidizs MM2 reviews point out the model is a chunky one – and it truly is. Its thick frame, faceplate shape, and tuning valve system are to blame. 

But that’s not necessarily a bad thing. Despite their size, the earphones are actually lightweight and stylish.

The capsules are built with two different materials. On the outside, the lozenge-cut geometric planes form a diamond shape, which looks stunning. Meanwhile, the inner surface is made of eco-friendly resin for max comfort. 

The transparent shell lets you see the IEM’s skeleton composed of the drivers and wires.

Hidizs MM2 Build quality and Design

Both the capsules and outlet nozzles are made of aluminum alloy with small holes. It’s all-metal, which adds a premium touch.

Fit & Comfort

IEMs typically have a chunky body, so it’s best to get a unit you can wear comfortably. Even with its diamond frame, the MM2s sit well and are super comfy. They offer great ergonomics and stability regardless of the chunkiness.

The capsules also fit snugly. They could’ve gone a bit deeper, but it’s still within the sweet spot. Fun fact – good fit can do wonders for sound quality, too. For one, if it’s nice and secure, it can help the IEM isolate or block out background noises better.

Also, if you use the included cable, you’ll find that it curls at the top of the earphones. Not only does it add extra comfort, but it also helps eliminate noises every time you move around.

The bottom line is that your ears won’t hurt even after long hours of listening.

Connectivity and Compatibility

Like its older sibling, the Hidizs MS2, the MM2 offers a 3.5mm SE gold-plated jack for connectivity. Although the cables are removable, there’s no wireless setting

But on the bright side, the earphones have a low impedance of 18 Ohms and a sensitivity of 104dB. Needless to say, it’s easy to pair them with relatively weak input sources like laptops, smartphones, or tablets.

Leather Carrying Case

An extra accessory to this IEM is the clamshell protective case. It’s customized to house the whole MM2 set. Plus, it’s eco-friendly and stain-resistant! 

The material is of Napa leather,  with full drop protection coverage. The six zinc alloy double buckles also provide solid support.


With the dual-driver configuration, tuning system, and high-purity cables, the MM2 performs excellently on all sound aspects. 

The 20 - 40,000 Hz response covers a wide frequency range. The drivers provide ample soundstage, great sound imaging, and low distortion. And most of all, they can retain excellent layering.

Acoustic isolation is where it falls short, as noted in many Hidizs MM2 reviews. This feature reduces or eliminates external noise for uninterrupted listening. 

Now, the unit doesn’t have a full-blown noise canceling feature. Instead, it uses passive noise isolation to block out background noise. It’s not the most robust tool. We recommend using the earphones at home, in a studio, or places with moderate noise.

Hidizs Mermaid MM2 Pricing

The MM2 retails for $81.00 – clearly an affordable IEM option. With its specs, it definitely stands out among other budget variants like the Ikko OH2 or NF Audio NM2. With almost similar price points, we think the MM2 offers the best value for money, especially with its exclusive features.


Hidizs ships its items across the globe. It offers free standard shipping, except for remote areas. The company notifies its buyers via email if their address is listed as such on the DHL website. If that’s the case, a $20 shipping fee will be applied.

It usually takes 5-10 days for the item to arrive.


When you run into some technical issues on your MM2, you can take advantage of the company’s warranty program. Its period is up to 12 months for players and 6 months for cables.

Note that the warranty doesn’t cover accessories and spare parts. 

Return Policy

Hidizs accepts returns within 14 business days after you receive the product. The company only accommodates products with quality issues, though. If you simply don’t like the product, you could still return it, but you’ll have to cover the shipping expenses.


All things considered, the MM2s offer an appealing pocket HiFi experience for a wide range of users. 

The ability to tune your own sound with the interchangeable valves is truly a game-changing feature. Not to mention the robust driver configuration. It delivers the perfect blend of full, warm, and punchy tones.

With this type of build, you can almost experience the same HiFi quality offered by premium headphones for music

However, the lack of wireless connectivity might set you back. The MM2s are a mile behind Bluetooth earbuds and other models with wireless monitoring.

But for an IEM designed with high-powered cables, it’s clear that the MM2 isn’t lining up for that race. It caters to audiophiles who want traditional music gear with advanced and upgradeable parts. 

So, to wrap up our Hidizs MM2 review, we totally recommend the unit to anyone looking for cheap monitor earphones that sound great.


Nero Peña

Nero Peña

Nero is an all-around wordsmith with a degree in Communication Arts— not the vicious emperor you might know in history books. He's an avid reader. A frisky writer. A tech enthusiast and occasional binge-watcher. He likes long walks on the beach. Enjoys deep thinking and shallow conversations. Hates ketchup. Panic! At The Disco.

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