HIDIZS MK12 IEM Review

[amirm]

This is a review, listening tests, detailed measurements and equalization of HIDIZS MK12 IEM. It was sent to me by the company. I only see the "Turris" version on their site which goes for US $179.

The metal shell resembling mask of an alien in science fiction, gives the unit fair amount of heft. While it felt cold when first put in my ear, I quickly acclimated to it and found it comfortable.

MK12 comes with three different types of screw on filters and selection of three types of silicone tip in different sizes. For all of my testing, I used the "balanced" silicone tip. I tested another one and the variation in mount/remounting was larger than any difference it would show. I did test all the filters (see next section).

Company provides some measurements but on a fixture that doesn't comply with research:

Let's see how it measures on my GRAS 45CA.

HIDIZS MK12 IEM Measurements
I started the measurements using the default filters. Seeing fair amount of deviation from target, I tested the other two as well:

The red seemed the most behaved to me although it has shortfall in both bass and high treble, in addition to too much energy from 100 to 400 Hz. So for the rest of the tests, that is what you see.

Deviations from target are not too bad and should be reasonably easy to correct due to their broad nature:

As noted, you may be able to use less filters if you moved the levels higher. I can't do that as it would mess with the distortion measurements. Speaking of which, the performance is superb, sans one region at high playback levels:

It is essentially distortion-less at 94 dBSPL in most of the range!

Group delay is not revealing in IEMs and such is the case here:

Impedance is on the low but reasonable side:

Combined with good sensitivity, it should be easy to drive with most sources:

HIDIZS MK12 Listening Tests and EQ
Going from my everyday headphone to MK12, I immediately noticed the extra energy above bass. It gave it a warmer but what I call "wooly" response. That is, too much of a good thing. Next to that I noticed the brilliance gone from high frequency notes. Both characteristics follow the measurements so out came the EQ filters:

I had to pull down the filter at 6300 Hz to taste. I also had to reduce levels fair bit to avoid clipping.

Once there, I was shocked with the fidelity. Sub-bass was deep and tight. Sound was now much more open with high clarity treble. I sat there enjoying track after track. So at least to my ears, the target the company is using is not correct.

Conclusions
The MK12 seems like a high quality unit with many options for tonality. Alas, they did not use a standardized fixture and target, resulting in tuning that has too much upper bass and too little treble. I am unclear how this would be a preferred tuning unless someone listens to bright music all the time. I wish at least one of the filter/tip combinations would provide something close to our target.

Fortunately, distortion is kept to near minimum, making it a breeze to equalize resulting in delightful response. Even with my eyeballed filters, the transformation was massive resulting in superb fidelity.

I can't recommend the HIDIZS MK12 IEM as is. If you can EQ it though, it turns into a wonderful butterfly with excellent response.

------------
As always, questions, comments, recommendations, etc. are welcome.

Appreciate any donations using: https://www.audiosciencereview.com/forum/index.php?threads/how-to-support-audio-science-review.8150/

 

[ZolaIII]

Red filter with levels pushed +2 dB actually looks fine and then you only need to EQ slam area (200 Hz PEQ). Not sure I am into alien looks.

 

[Talisman]

I tend to forgive the need for equalization in large, open-back headphones used for critical listening, since they generally use amplifiers or DAPs that are easy to equalize with, but I can't stand it in earbuds. I might want to plug them into a tablet jack or a cheap Bluetooth receiver, and they should sound fine. Besides, there are so many earphones under €50 that are superb and have an optimal curve, that I don't see any reason to want this one.

Thanks, Amir.

 

[Berwhale]

Not a fan of the looks. Styling by Khan Noonien Singh? "Allow me to introduce you to Ceti Alpha V's only remaining indigenous IEM."

 

[Cote Dazur]

Love the look.

 

[FrantzM]

Not "crapping" on the product but ... The competition is strong.. True, the MK12 boasts stellar THD but ... so do the TCZ Blue, Red , and countless IEM reviewed here, that basically do not require EQ ...
At 3 to 9 times their prices, is The MK12, worth it?

 

[solawind]

I might want to plug them into a tablet jack or a cheap Bluetooth receiver, and they should sound fine. Besides, there are so many earphones under €50 that are superb and have an optimal curve

There are a lot of different preferences in IEM curves; it's not like a single one is "correct" (and even the understanding of what most people prefer changes every year). The IEM I use is intended to be used with EQ (Moondrop Dusk), and that’s not really a problem — it comes with a usb dac dsp cable, and tablets and phones nowadays tend to have usb-only outputs anyway. I get your point, but having an EQ isn’t really a hassle, it actually gives you many possibilities

 

[audioholic63]

Given the bar set below $20USD by the Truthear GATE what does an IEM need to do be worth 10x the price?

 

[solawind]

Given the bar set below $20USD by the Truthear GATE what does an IEM need to do be worth 10x the price?

You very likely may prefer different FR than Gate has (thus, having abitity to EQ is important to get best results). Personal preference is the reason why there are so many IEMs with different frequency tunings around. It’s very likely that the Gate won’t fit your ears — especially for long listening sessions. Unlike loudspeakers, fit is very important for IEMs, and only with a perfect fit do they feel like nothing in your ears. So in practice it is much more complicated than "the $20 one matches Amir’s selected target better, so nothing else needs to exist"

 

[phoenixdogfan]

The tuning is maybe good for EDM? It looks likes something Kirk would pull out of the ear of the dead captain of a vanquished Klingon War Bird after beaming onto its bridge to rescue survivors. Tuning would prolly work for his music too.

Great review, Amir.

 

[Somafunk]

The tuning is maybe good for EDM?

Be pretty guff for electronic music, not enough bass/sub bass, too much vocal shout and severe roll off in treble.

 

[muza_1]

It looks like a Klingon forehead, there are better options for less with pretty similar tuning(s), a lot of interchangeable nozzle offerings have the same tuning trend, personally I rather have switches (or nozzles) that only adjust the bass or treble levels without changing the overall shape of the curve.

 

[Robin L]

Considering how close the 7Hz x Crinacle Zero:2 IEMs get to the curve and how low their distortion, these earbuds appear to be surplus to requirements.

 

[renaudrenaud]

I want to add my voice about it. 20$ IEM with excellent measurements are here. Why choose x20 time more expansive and hideous IEM with strong EQ required?

 

[audioholic63]

You very likely may prefer different FR than Gate has (thus, having abitity to EQ is important to get best results). Personal preference is the reason why there are so many IEMs with different frequency tunings around. It’s very likely that the Gate won’t fit your ears — especially for long listening sessions. Unlike loudspeakers, fit is very important for IEMs, and only with a perfect fit do they feel like nothing in your ears. So in practice it is much more complicated than "the $20 one matches Amir’s selected target better, so nothing else needs to exist"

I wasn't speaking from the perspective of hitting a target. I bought the Gate and once I got the right tips for my ears I was shocked at the sq. I can use them flat although I like a little eq. They are comfortable. They have a pretty much non-microphonic cable, which I cannot say for most IEMs I have bought and some headphones. All for a landed cost of ~$13 USD. So if that can be accomplished at that price point I just scratch my head over a $200 price point.

 

[Maiky76]

This is a review, listening tests, detailed measurements and equalization of HIDIZS MK12 IEM. It was sent to me by the company. I only see the "Turris" version on their site which goes for US $179.
View attachment 489103
The metal shell resembling mask of an alien in science fiction, gives the unit fair amount of heft. While it felt cold when first put in my ear, I quickly acclimated to it and found it comfortable.

MK12 comes with three different types of screw on filters and selection of three types of silicone tip in different sizes. For all of my testing, I used the "balanced" silicone tip. I tested another one and the variation in mount/remounting was larger than any difference it would show. I did test all the filters (see next section).

Company provides some measurements but on a fixture that doesn't comply with research:
View attachment 489104
Let's see how it measures on my GRAS 45CA.

HIDIZS MK12 IEM Measurements
I started the measurements using the default filters. Seeing fair amount of deviation from target, I tested the other two as well:
View attachment 489105
The red seemed the most behaved to me although it has shortfall in both bass and high treble, in addition to too much energy from 100 to 400 Hz. So for the rest of the tests, that is what you see.

Deviations from target are not too bad and should be reasonably easy to correct due to their broad nature:
View attachment 489106
As noted, you may be able to use less filters if you moved the levels higher. I can't do that as it would mess with the distortion measurements. Speaking of which, the performance is superb, sans one region at high playback levels:
View attachment 489107
It is essentially distortion-less at 94 dBSPL in most of the range!

View attachment 489108

Group delay is not revealing in IEMs and such is the case here:
View attachment 489109

Impedance is on the low but reasonable side:
View attachment 489110

Combined with good sensitivity, it should be easy to drive with most sources:
View attachment 489111

HIDIZS MK12 Listening Tests and EQ
Going from my everyday headphone to MK12, I immediately noticed the extra energy above bass. It gave it a warmer but what I call "wooly" response. That is, too much of a good thing. Next to that I noticed the brilliance gone from high frequency notes. Both characteristics follow the measurements so out came the EQ filters:
View attachment 489113

I had to pull down the filter at 6300 Hz to taste. I also had to reduce levels fair bit to avoid clipping.

Once there, I was shocked with the fidelity. Sub-bass was deep and tight. Sound was now much more open with high clarity treble. I sat there enjoying track after track. So at least to my ears, the target the company is using is not correct.

Conclusions
The MK12 seems like a high quality unit with many options for tonality. Alas, they did not use a standardized fixture and target, resulting in tuning that has too much upper bass and too little treble. I am unclear how this would be a preferred tuning unless someone listens to bright music all the time. I wish at least one of the filter/tip combinations would provide something close to our target.

Fortunately, distortion is kept to near minimum, making it a breeze to equalize resulting in delightful response. Even with my eyeballed filters, the transformation was massive resulting in superb fidelity.

I can't recommend the HIDIZS MK12 IEM as is. If you can EQ it though, it turns into a wonderful butterfly with excellent response.

------------
As always, questions, comments, recommendations, etc. are welcome.

Appreciate any donations using: https://www.audiosciencereview.com/forum/index.php?threads/how-to-support-audio-science-review.8150/

Here are some thoughts about the EQ.
Please report your findings, positive or negative!

Notes about the EQ design:

• The average L/R is used to calculate the score.
• The resolution is 12 points per octave interpolated from the raw data (provided by @amirm)
• A Genetic Algorithm is used to optimize the EQ.
• The EQ Score is designed to MAXIMIZE the Score WHILE fitting the Harman target curve (and other constraints) with a fixed complexity.
  This will avoid weird results if one only optimizes for the Score, start your journey here or there.
  There is a presentation by S. Olive here.
  It will probably flatten the Error regression doing so, the tonal balance should be therefore more neutral.
• The EQs are starting point and may require tuning (certainly at LF and maybe at HF).
• The range around and above 10kHz is usually not EQed unless smooth enough to do so.
• I am using PEQ (PK) as from my experience the definition is more consistent across different DSP/platform implementations than shelves.
• With some HP/amp combo, the boosts and preamp gain (loss of Dynamic range) need to be carefully considered to avoid issues with, amongst other things, too low a Max SPL or damaging your device. You have beed warned.
• Not all units of the same product are made equal. The EQ is based on the measurements of a single unit. YMMV with regard to the very unit you are trying this EQ on.
• I sometimes use variations of the Harman curve for some reasons. See rational here and here
• NOTE: the score then calculated is not comparable to the scores derived from the default Harman target curve if not otherwise noted.
• Occluding IE devices generally must have very good fitting/seal in the user's ear canal for best performance.
  please spend a few minutes to pick up the best ear tip... Be sure to perform this step otherwise the FR/Score/EQ presented here are just worthless.
• 1. more bass = better seal
  2. More isolation from the outside world = better fit
  3. Comfort

EDIT:
I used a wrong script to design the EQ.
Hereafter is the correct design.
@delta76 thanks for pointing out the unbelievably high score...

Great L/R match.

I have generated one EQ, the APO config file is attached.

Score no EQ: 64.1%
Score Amirm: 81.5%
Score with EQ: 96.7%

HIDIZS MK12 Red Nozzle Harman Full EQ
November112025-110619

Preamp: -10.40 dB

Filter 1: ON PK Fc 28.5 Hz Gain 2.81 dB Q 0.49
Filter 2: ON PK Fc 199.5 Hz Gain -2.96 dB Q 0.75
Filter 3: ON PK Fc 694.4 Hz Gain 1.92 dB Q 1.31
Filter 4: ON PK Fc 3520.2 Hz Gain 1.74 dB Q 1.55
Filter 5: ON PK Fc 7619.9 Hz Gain 5.00 dB Q 1.15
Filter 6: ON PK Fc 6280.9 Hz Gain 6.11 dB Q 3.24

 

[delta76]

Here are some thoughts about the EQ.
Please report your findings, positive or negative!

Notes about the EQ design:

• The average L/R is used to calculate the score.
• The resolution is 12 points per octave interpolated from the raw data (provided by @amirm)
• A Genetic Algorithm is used to optimize the EQ.
• The EQ Score is designed to MAXIMIZE the Score WHILE fitting the Harman target curve (and other constraints) with a fixed complexity.
  This will avoid weird results if one only optimizes for the Score, start your journey here or there.
  There is a presentation by S. Olive here.
  It will probably flatten the Error regression doing so, the tonal balance should be therefore more neutral.
• The EQs are starting point and may require tuning (certainly at LF and maybe at HF).
• The range around and above 10kHz is usually not EQed unless smooth enough to do so.
• I am using PEQ (PK) as from my experience the definition is more consistent across different DSP/platform implementations than shelves.
• With some HP/amp combo, the boosts and preamp gain (loss of Dynamic range) need to be carefully considered to avoid issues with, amongst other things, too low a Max SPL or damaging your device. You have beed warned.
• Not all units of the same product are made equal. The EQ is based on the measurements of a single unit. YMMV with regard to the very unit you are trying this EQ on.
• I sometimes use variations of the Harman curve for some reasons. See rational here and here
• NOTE: the score then calculated is not comparable to the scores derived from the default Harman target curve if not otherwise noted.
• Occluding IE devices generally must have very good fitting/seal in the user's ear canal for best performance.
  please spend a few minutes to pick up the best ear tip... Be sure to perform this step otherwise the FR/Score/EQ presented here are just worthless.
• 1. more bass = better seal
  2. More isolation from the outside world = better fit
  3. Comfort

Good L/R match.

I have generated one EQ, the APO config file is attached.

Score no EQ: 51.5
Score Amirm: 85.8
Score with EQ: 108.3

HIDIZS MK12 Red Nozzle APO EQ Score Flat@HF 96000Hz
November102025-135708

Preamp: -6.67 dB

Filter 1: ON PK Fc 174.8 Hz Gain -3.34 dB Q 0.51
Filter 2: ON PK Fc 610.2 Hz Gain 3.28 dB Q 1.00
Filter 3: ON PK Fc 3785.2 Hz Gain 1.44 dB Q 3.17
Filter 4: ON PK Fc 6388.8 Hz Gain 4.13 dB Q 2.89
Filter 5: ON PK Fc 7810.8 Hz Gain 4.58 dB Q 0.93

View attachment 489281

wow isn't it one of highest score calculated for a IEM?

 

[Curupira]

Hidizs seems to insist on unorthodox tuning even when their R&D team has access to the research and "meta" tuning, which makes me think they stay clear from Harman and IEF/JM on purpose in order to distinguish themselves.

All their iems I've seen and heard seem like pulled straight from 2018's KZ lineup. Therefore, while their specs and post EQ performance are commendable, I voted Poor: there are no excuses for those 2.5\4.5khz résonances that were commonplace in the past, nor for the severe treble roll off on the best filter.

since they generally use amplifiers or DAPs that are easy to equalize with, but I can't stand it in earbuds

And yet iems are the most prone to HTRF deviation due to the way the project sound into the eardrum, bypassing the ears' pinna region altogether; so EQ can have the most impact.

 

[Talisman]

And yet iems are the most prone to HTRF deviation due to the way the project sound into the eardrum, bypassing the ears' pinna region altogether; so EQ can have the most impact.

This doesn't matter to me because they need to be a plug-and-play product. I don't care how good the results are, because I simply don't want to EQ my earphones; I want to plug them in and listen.
If there are €20 products that sound divine without any adjustments, why should I pay five times as much and have to adjust the response on top of that?

 

[solawind]

If there are €20 products that sound divine without any adjustments, why should I pay five times as much and have to adjust the response on top of that?

But it does not sound divine. All you can say is that it is well correlated to Amir's selected target. Nothing more. Personal HRTF varies between individuals (and for IEMs to a great extent) so it is not the same. Thus having ability to EQ is important to really make any IEM "sound divine".