HIDIZS MD4 – Review


| Quad Driver | 4x Tuning Switches |

HIDIZS MD4, the fresh new in-ear monitors from HIDIZS.

The HIDIZS MD4 is a quad driver earphone featuring an all-balanced armature driver configuration and 3D printed acoustic tubes.

Probably the most notable spec from the MD4 is a 4 position dual-switch that allows sound tuning on-the-fly with 4 sound profiles:

  1. Balanced
  2. Warm
  3. Treble
  4. Bass

You can see later below in this HIDIZS MD4 review, the corresponding switch position for each tuning and you will also see the frequency response curves declared by the manufacturer.

This IEM is part of the upper-tier models from HIDIZS and like all products from the brand, the HIDIZS MD4 presents an outstanding build and very nice aesthetics, with the use of metal for the main housing and a stylish space-grey metallic finish – yet, we noticed some unpolished details on the paint of the MD4 but it is fair to note that our MD4 is a pre-production unit (you can see them on our photos throughout this review)

Details such as connectors and cable quality, are mostly inherited from the HIDIZS Mermaid MM2, with nearly the same cable with metal details and angled bi-pin connectors.

FIND ALL: Headphones Scores Compared

MORE: Headphones Reviews

MORE: Best Headphones & Earphones Charts

SEE ALSO: Amazon Coupons & Deals

RECOMMENDED: Aliexpress Coupons


Tests & Scores


Accessories & Packaging

The HIDIZS MD4 comes with a plethora of accessories that include:

  • 3x vocal eartips
  • 3x bass eartips
  • 3x balanced eartips
  • 1x cleaning brush
  • 1x 2-pin cable
  • 1x leather case

We usually do not concentrate too much on the quality of the cases included with headphones but the case of the HIDIZS MD4 is one of the best looking and best built cases bundled for free with an IEM, even with better quality than cases included in other in-ear monitors with prices in the $400 tag.




HIDIZS MD4 weight in Ounces and HIDIZS MD4 weight in grams.

MORE:  Headphones Weight Comparison

SEE ALSO: Earphones Size Comparison


Bass & Sub Bass


Out of the box, bass on the HIDIZS MD4 while set to “balanced”, shows a nicely punchy bass with a fun effect that does not sound overly bloated as to “eat up” the whole sound signature.

On the other hand, some bounciness and loose issues were present.



The difference between “Balanced” and “Treble” by applying the switch toggles does not seem to show a drastic difference as to be worth mentioning.



Despite the “Bass” label, this switch setting does not apply any exponential bass-boosting effects neither over sub-bass, deepness nor reach. Yet, a bit of extra punchiness could be, arguably, perceived.



A nice punchy mid-bass is still present with, probably, a bit of loss over deepness and reach on sub-bass.


MORE: Earphones & Headphones Amplification Power Comparison

MORE: Best Basshead Earphones

SEE ALSO: Best Fun Sounding Earphones Chart



Mids & Vocals


According to our editor’s taste, the balance representation and tag might not be the best fit to the sound signature tuning with this switch position.

In general, lower mids showed a very full sound with deep male vocals but with noticeable mid-bass bleed that congested the lower midrange on bass-heavy moments.

Upper mids were noticeably more forward and cleaner than their lower mids, where female vocals and higher mid-pitched notes cut-through but risked to become a harshy and shouty at times.



This switch settings offer a way cleaner overall midrange, with a much improved placement of vocals that do not need to compete with a loose mid-bass.

Male vocals keep benefiting from a full and deep reaching sound but can exhibit a bit laid back presence and can tend to get overshadowed by female vocals.

Higher mids, unfortunately, get palpably hotter and substantially harsher.



Despite the label, this switch setting keeps showing a less bloated bass effect than the other switch settings, allowing their lower midrange to probably offer the best sounding tuning of all switches.

Lower mids and male vocals now sound a bit cleaner and exhibit even less bleed and congestion from mid-bass, while not sounding too laid back.

Upper mids, also, get a bit smoother presenting a lower chance of becoming harsh – yet, it still showed harshness on shouty vocals and hotter peaks.



The switch option showed a mixed effect in between “Bass” and “Balanced”



Highs & Treble


On this switch setting, the MD4 offers a good balance of brightness and detail.

On the other hand, the hot peaks seen on the MIDS & VOCALS section show similar tendency over the spikes related to piercing peaks.

Despite this, the MD4 does not suffer from too much sibilance.



A clear boosting of the upper highs and treble is noticed.

A perceivably freedom of a darkish layering is offered when using this switch but this will have a price to pay: stronger fatiguing peaks.



This mode shows some loss of brightness and detail but in return, their highs will sound noticeably more agreeable with piercing peaks and sibilance kept under control.



A much cleaner and ironically, less warm highs and overall sound signature is present with this switch setting.

To the benefit of their highs, their presence gets a lesser feel of congestion.

Nonetheless, highs keep sounding hot and fatiguing with frequent and intense piercing peaks.



Sound Leak

The sound leaking out of the HIDZS MD4 is slightly less hearable than most normal headphones, still this is not a model that could be rated as totally silent nor well-adapted for in-library usage – people thinking to daily commuting with the MD4 will not have issues.


MORE: Best Headphones for Libraries Chart

SEE ALSO: Best Earphones for Bed


Sound Isolation

With a deep and tight fit, the MD4 offers also a very good passive sound isolation with a performance noticeably better than most average earphones on the market.


RELATED TO THIS: Active Noise Cancelling Headphones Reviews




The earpieces of this HIDIZS model have a smooth design with gentle edges that never become pointy nor pain-inducing.

Overall, the team found the MD4 to be a very comfortable in-ear monitor that can be used for hours before introducing any fatigue.


RELATED: Best Earphones for Daily Commute

MORE: Most Comfortable In-Ear Headphones


Response to Equalization

With 4 tuning switches profiles and 9 pair of tuning eartips, the HIDIZ MD4 is hard to beat in the retuning department.

Showing palpable sound differences using the switches, the HIDIZS MD4 could be rated as “exempt of EQ needs” to retune the sound signature; still, trying to recover the hot highs was never an easy task by any EQ applied.


MORE: Editor’s Picks Earphones Chart

MORE: Best Bang for the Buck Earphones

Follow us:


Get the latest reviews on your favorite social network

Frequency Response (raw)

HIDIZS MD4 Frequency Response Curve


Blue= Balanced, Green= Treble, Orange= Bass, Red= Warm

RECOMMENDED FOR YOU: Headphones Frequency Response Curves

SEE ALSO: KZ Headphones Frequency Response Curves

HIDIZS MD4 Technical Specifications


TypeQuad driver
Driver Unit4x BA
Power Capacity3mW
Impedance8 ohms
Frequency Response20-40,000Hz
Tuning SwitchYes, 4
CordY-type, 2-pin
Cord Length1.2m
PlugStereo mini plug
WeightApprox. 14g
Supplied Accessories9x Earphone tips, brush, cable, case

MORE: Single Dynamic Driver Headphones Reviews

MORE: Amazon Coupons & Deals

SEE ALSO: Aliexpress Coupons – Discounts – Deals – Promo Codes – Sales Deals

Scores Scores


Buy it from:

SEE ALSO: Coupons – Discounts – Deals – Promo Codes – Sales Deals

SEE ALSO: Headphones Technical Specifications

FIND ALL OUR: Earphones Reviews / Headphones Reviews

MORE: Best Earphones Charts

SELECTED FOR YOU: Aliexpress 11.11 Shopping Festival Coupons

RELATED TO THIS PAGE: Aliexpress Anniversary Sale Coupons and Deals

SEE ALSO: Black Friday Coupons and Deals Black Friday Aliexpress, Gearbest, Banggood

MORE: Cyber Monday Coupons and Discounts


ALSO: Headphones Comparisons

MORE: Music Players / DAP / DAC / Amplificators Reviews




We hope you enjoyed this article. All the earphones reviews, keyboards reviews, power tools reviews, music players reviews, DAC reviews, amplifiers reviews, smartwatch reviews, gadget reviews, tech reviews, dashcam reviews, earbuds reviews, headsets reviews, in-ear monitors reviews (iem), in-ear headphones reviews are made as objective and thorough as possible to provide our readers a way to choose the best earphones, earbuds, iem, in-ear monitors, headsets and in-ear headphones. By providing exhaustive information we allow our readers to even fine-tune their choices to select among the best budget earphones, best earphones for sports, best basshead earphones, best fun sounding earphones, most balanced earphones, least fatiguing earphones, most comfortable earphones, best looking earphones or even for the best cheap earphones to buy.