(Last Updated On: September 25, 2019)

In the crowded land of IEMs, is the MEE Audio MX4 Pro just another case of me too?

Header image. The MEE Audio MX4 PRO.
The MEE Audio MX4 PRO.

Founded in 2005, MEE Audio, a subsidiary of S2E, Inc. is located in City of Industry, California. They proudly proclaim “we are MEE, and we deliver Music Enjoyment for Everyone.”

Although somewhat under the radar (at least for me), it turns out that they have been producing headphones and earphones for 14 years, focused primarily on sports and wireless designs.

In 2009, they launched their first few IEM models, the M9 and M6. Based on reviews and customer feedback, MEE Audio IEMs have evolved to included detachable cables and wireless options. In 2018, the MEE Professional division was created, with products intended for audio pros and musicians, rather than the general consumer market.

MEE Professional has adopted a fairly unique product approach, with a simple standardized design but offering many configuration options. There are user selectable upgrades such as different driver designs, engraved artwork faceplates and custom-fit 3D-printed silicone ear tips (made to order at their Los Angeles manufacturing facility.)

The clear housing on the MX4 PRO.
The clear housing on the MX4 PRO.

MEE Audio MX4 PRO

“I think the MX4 PRO is a very capable IEM. For my musical tastes, this requires the use of the Comply foam ear tips to achieve adequate bass presence. However, the MX4 PRO doesn’t exist in a vacuum, and we must remember that there are other great-sounding, hybrid, multi-driver IEMs available at a third (or less) of the price.”

Pros:

  • »Clear and resolving sound, with a relatively neutral signature.
  • »Decent included accessories.
  • »Comply foam tips improve bass response dramatically.
  • »The small size will fit most folks.
  • »IPX5 moisture resistance.

Cons:

  • »Standardized accessories and build quality across the entire MX PRO lineup. While very impressive at the MX1 $60 price point, it’s less impressive for the $200 MX4.
  • »Lacks bass response with the silicone ear tips.
  • »Clear housing too transparent and doesn’t leave enough to the imagination.
  • »Unusual detachable cable connectors will make finding non-MEE Audio replacements difficult.

Purchasers can choose to upgrade their in-ear monitors at the time of acquisition or in the future as budgets and requirements change. With this approach, MEE Professional hopes to blur the line between universal and custom in-ear monitors (CIEMs) and to promote their “vision of delivering great audio performance and on-stage hearing protection for musicians on any budget”.

The MX PRO Line

The current MX PRO lineup consists of 4 models: The MX1 ($60), MX2 ($100), MX3 ($150) and yup, you guessed it, the flagship MX4 ($200). To make things even easier, unlike the ultra-confusing and impenetrable naming systems employed by some IEM manufacturers (I’m looking at you KZ), the MX1 employs a single driver, the MX2 has 2 drivers and so forth.

Comparison of the MX PRO lineup from meeaudio.com.
Comparison of the MX PRO lineup from meeaudio.com.

Today we will be looking at the MX 4 Pro, which as we discussed, is the top of the MX PRO line. This model features a 4-driver design, with a single dynamic driver (they call it a “moving coil subwoofer”) for bass frequencies, and 3 balanced armatures to deliver “precisely detailed mid-range and treble frequencies”.

Although it appears that MEE Audio has not published any detailed frequency graphs, it is possible to intuit the intended sound signature from the (albeit basic) bass/mids/highs charts, the “sound characteristics” and the “tuned for” descriptions for each model.

The MX1 and MX2 have more pronounced low end, as often is the case with consumer products, with the MX2 featuring “enhanced bass” and a “dedicated subwoofer”. The MX3 touts a “crisp, focused midrange”, while the MX4 is far more balanced with extended highs and is described as having “high-fidelity reference sound” for “stage and studio monitoring”.

From all this, the clear intent is for the MX4 to shy away from the popular ‘fun’ sounding v-shaped sound signature and strive for something more neutral, analytical and accurate. Let’s find out if MEE Audio accomplished these intentions with the MX4 PRO.

Close up of the left monitor. Red and blue wires, and green circuit board visible inside.
Close up of the left monitor. Red and blue wires, and green circuit board visible inside.
Cables, connectors and ear tips visible.
Cables, connectors and ear tips visible.

The Challenge of In-Ear Monitor Reviews

This section is a standard inclusion in my IEM reviews.

I’d like to add a caveat. IEMs are notoriously difficult to review and compared to full-size headphones, it is problematic to trust review findings will be applicable to all readers.

While the size of one’s ear may impact the comfort or sound of a full-size headphone, small details like the inner shape of a reviewer’s ear and the fit of an IEM greatly impacts not just the listener’s comfort but dramatically changes the perceived performance of an IEM.

This is compounded by the plethora of ear tip sizes, materials, and shapes (which may or may not be included with the IEM) all of which uniquely fit different people. Most significantly, the quality of the ear tip seal within the ear changes the sound. So, beware dear reader, what suits one reviewer may not be applicable to you.

MX4 PRO Technical Specifications

  • Driver Type: Triple balanced armature + moving coil dynamic hybrid
  • Frequency Response: 20 Hz – 20 kHz
  • Impedance: 12 Ohm at 1 kHz
  • Sensitivity: 103±3 dB (1 mW @ 1 kHz)
  • Maximum Power Input: 30mW
  • Cable Length: 1.3 m detachable
  • Cable Connector: 3.5mm, right-angle plug
  • Water Resistance Rating: IPX5 – Can resist a sustained, low-pressure water jet spray.
  • Microphone Specifications: Omnidirectional, 100 Hz – 10 kHz, -42Db± 3dB
  • Warranty: Lifetime replacement. New pair at ½ price.
The in-line microphone.
The in-line microphone.

MX4 PRO Packaging and Accessories

The packaging is fairly standard black and white cardboard. A plain black box embossed with the MEE Audio logo is slid into a white box covered with product details and pictures. Inside the black box, you will find:

  • MX4 PRO In-Ear Monitors
  • Stereo audio cable
  • Stereo headset cable
  • Carrying case with carabiner
  • Comply™ memory foam ear tips
  • Silicone ear tips (4 pairs: small, medium, large and flanged)
  • Shirt clip
  • ¼” (6.3mm) adapter
  • User Manual
The included accessories.
The included accessories.

I’m getting pretty used to the standard meager included offerings from Chi-Fi IEM manufacturers. A roomy zippered case with internal pockets and bagged Comply memory foam ear tips are very welcome surprises in the MX4 PRO box. The silicone ear tips are pretty standard fare (small, medium and large), but it is nice to receive a 2-flanged pair of silicone ear tips and a ¼” gold plated adapter as well.

A rather nice zippered case holds all the accessories and the MX4 PRO.
A rather nice zippered case holds all the accessories and the MX4 PRO.

Cable

This review pair of MX4 PRO IEMs are the white/clear color, rather than the black/smoke color combination. On one hand, this is a nice change from the army of black IEMs out there, and it provides a nice compliment to the white and silver Apple aesthetic. On the other hand, the colors really don’t speak to me.

My wife quite likes the look of the MX4 PRO, so perhaps the non-black colorway and smaller size of the MX PRO lineup will be appealing to someone other than the stereotypical male portable audio electronics purchaser, who traditionally likes any color as long as it is black.
2 mm DC connectors, clip, 3.5 mm jack and Y-connector on the cable.
2 mm DC connectors, clip, 3.5 mm jack and Y-connector on the cable.

There are two 1.3 m cables included in the package, one with a microphone and one without. They are constructed of clear rubber wrapped around a single silver braid. Cables are terminated with a matching 3.5 mm jack on one end and a removable 2mm DC connector on each monitor end.

This 2 mm DC connector is a new one for me and eschews the typical 2-pin or MMCX connector found on many other IEMs. This not-the-norm decision was a deliberate one by MEE Audio, and they claim that their research shows that it is more reliable than the MMCX connector (primarily because the connector is not allowed to rotate in the socket) and that it is simpler and thus less expensive to produce.

Of course, the unusual connector also pretty much locks you into purchasing aftermarket or replacement cables from MEE Audio themselves.

Love it or hate it, each cable contains a stiff memory wire to route the cable over the ear and help it stay in place. I’m a fan of this sort of cable routing as it helps fit and stability and it tends to decrease cable microphonics. Speaking of which, the slippery rubber coating on the cable is reasonably free of annoying transmitted noise from clothing, helped in part by a small clip mounted below the Y-connector.

Also included is a small slider that can snug up the two thin cables headed to each DC connector. Due to the MX PRO series modular scheme, the cable and accessories are the same as the $60 MX1 model. This would be an above-average accessory kit for that price range but feels a bit economy fare for a $200 model.

MX4 PRO Build Quality and Design

Transparent designs work best when you have something impressive to show off, but unfortunately, there’s not much to see here. You can clearly examine the internals of each IEM through the clear plastic housing, as well as the microphone electronics. Again, fine for the MX1 or 2, but it just doesn’t feel premium enough for me at the MX4 PRO’s level.

The clear housing and visible internals.
The clear housing and visible internals.
As I alluded to above, I’m not a huge fan of the colorway of these IEMs. The shiny wires, crystal clear coverings, and plastics used actually reveal too much. Being able to plainly see the tiny wires and circuit boards inside hurts the impression of intrinsic worth. I think the darker translucent black smoke color looks more upscale.

Customizable Options

The intent of the MX PRO line is to blur the line between universal and custom IEMs. The modular design allows all parts, customizations, and accessories to be changed, replaced, or upgraded independently between all four MX PRO models. Ordering from the MEE Audio website walks you through the customization process step-by-step.

The externally identical MX1 PRO, MX2 PRO, MX3 PRO, and MX4 PRO in black smoke color from meeaudio.com.
The externally identical MX1 PRO, MX2 PRO, MX3 PRO, and MX4 PRO in black smoke color from meeaudio.com.

After you select your desired sound signature (and starting price point) between the 4 models, and then either the clear or smoke color, you have the option to add custom faceplates. Faceplate choices include 5 default designs ($10), custom text ($15) or custom artwork ($20) on metal faceplates. I think the custom faceplates have the potential to improve the overall look of the product.

When not in use, the monitors stick together due to the magnetized faceplates.
When not in use, the monitors stick together due to the magnetized faceplates.
The faceplates are held on very securely with magnets. This leads to an interesting default state as the flat faceplates magnetically join together when not in use.
Custom faceplates and silicone ear tips from meeaudio.com.
Custom faceplates and silicone ear tips from meeaudio.com.

For $150, you can order custom silicone ear tips to approximate CIEMs. These tips require ear impressions and take approximately 3-4 weeks to manufacture. All custom ear tip orders include a cleaning tool and a 0.15 oz bottle of Oto-gel.

To get the optimal audio quality from any set of In-Ear Monitors (IEMs), an airtight seal with your ears is absolutely imperative. The shape of your ears is as unique as a fingerprint, however, which can make it difficult to get a perfect seal with conventional silicone or foam ear tips, not to mention maintain that seal as you move about.

Custom in-ear monitors and earplugs avoid issues with fit and seal by contouring your ears exactly for a perfect fit that never falls out. Our in-ear monitors use custom molded eartips made out of soft, medical-grade silicone in order to provide a more consistent seal for improved audio performance and maximum noise isolation without discomfort. – MEE Audio

Blue silicone custom ear tip from meeaudio.com.
Blue silicone custom ear tip from meeaudio.com.

MEE Audio first requires a 3D model of your ears in order to manufacture custom ear tips. This can be done based upon digital or physical ear impressions and there are 4 options to obtain an impression:

  1. Bring the MEE Audio Audiologist Instruction Sheet to a local audiologist to make a physical cast and mail the impressions to MEE Audio in California.
  2. Visit MEE Audio office in person and have it done for free.
  3. Get scanned by MEE Audio at a musician or audiophile tradeshow or event.
  4. Use existing ear impressions that you previously had made.

Finally, you get to select cables. Beyond the two standard included cables, you can choose between mono or stereo cables. The standard cables can be upgraded for $2 to be longer (1.8 meters) or the longer cables can be additionally added for $12 each. A Bluetooth adapter cable ($60) is also available.

MX4 PRO Sound Quality

As we discussed earlier, the MX4 PRO is proposed to deliver a balanced sound with extended highs. MEE Audio describes it as “high-fidelity reference sound” for “stage and studio monitoring”. In practice, I think they’ve done a decent job tuning this IEM for its intended purpose.

The included literature may be vague but does indicate suggested usage and sound signature.
The included literature may be vague but does indicate suggested usage and sound signature.
I’ve been really enjoying this new wave of affordable hybrid, multi-armature, multi-driver IEMs. Nothing seems to beat the low-frequency extension of a traditional moving coil driver and proper pairing with midrange and high frequency balanced armatures can create a shockingly good sounding budget IEM.

Going into listening, I was expecting a high-end bias, but with a relatively balanced mid and low range. In other words, in order to match the literature, my expectations were for a near neutral-sounding monitor, with a bit of zing in the upper frequencies.

As with most IEMs I review, I tested the MX4 PRO with a variety of sources ranging from directly from my Apple iPhone X dongle, to using the JDS Labs C5D and from the Hagerman Audio Tuba desktop amplifier. The MX4 PRO are efficient enough to vary little in performance due to amplification, and as IEMs are all about portability, the bulk of my listening was directly from my phone.

Because it is just my way, music choices varied widely in quality and genre.
Close up side view.
Close up side view.

Bass

I tried the medium, large and flanged silicone ear tips initially with the MX4 PRO. Compared directly with the new $50 KZ ZSX (Terminator) hybrid IEMs that also arrived this week, one thing jumped out as lacking in the MEE Audio offering: low-frequency presence.

I wouldn’t consider myself a bass head per se, but when the music calls for it, I-like-a-dat-boom. The MX4 were really not doing it for me. Music felt flat and unengaging. “But Trav!” you protest, “these are for mastering purposes and are supposed to have a flat frequency response.”

But where’s the fun in that?

I played around with audio frequency generators and the audible low frequency drop off was especially noticeable under 30 Hz with the MX4 PRO.

I could hear the almost subsonic rumble of 20 Hz through the KZ IEMs (think of what it sounds/feels like when a huge machine drives by your house – you don’t hear the rumble so much as feel it in your core). However, with the MX4 PRO, I couldn’t perceive anything under 24-25 Hz and the overall low bass frequencies were recessed across the board.

I’m unabashedly a Prince fan. Prince was the embodiment of funk, and in order to properly groove to his music, headphones have to be able to deliver a tight and deep bassline. The MX4 PRO felt like someone had dialed back the bass tone control a few notches. It was there, but unfortunately, really not engaging.

That was until I ripped open the Comply foam ear tips bag and tried them out. Huge improvement. Impact and slam increased noticeably, and the entire listening experience is far more enjoyable. In no way does bass dominate the sound signature, but it feels like a well-tuned subwoofer properly added to a home theatre. Extra low-end oomph when it is called for.

The comply ear tips dramatically improve bass performance.
The comply ear tips dramatically improve bass performance.

Midrange

Vocals seem accentuated by the MX4 PRO. Timbre and body seem to be reasonably natural, but the details feel like they are dialed up. While I wouldn’t use the common descriptor “lush” to describe the midrange, things generally sound full and maintain a decent body and weight.

The crisp and clear sound yields a listening experience where it is easy to pick out individual notes and to notice small details in the music.

Clad in silicone ear tips.
Clad in silicone ear tips.

Treble

Certainly, there is a bit of an emphasis on high-frequency response. The MX4 PRO can rightfully be described and bright and revealing, although I don’t find them harsh or especially sibilant. They definitely lean towards a more analytical sound, but thankfully with the use of the foam tips, the overall sound signature is reasonably balanced and not so lean as I feared when trying the silicone tips.

Upper frequencies stand out, but not to the point of unnaturalness. I don’t find them fatiguing, but rather I enjoy the spotlight they shine on the details of the music.

I cannot recommend the comply foam ear tips enough.
I cannot recommend the comply foam ear tips enough.

Conclusion

Due to their small size, and a growing to-do list around my home, I used the MX4 PRO for many hours as I worked outside.

They provided the soundtrack for the building of a new back step, a deck railing for my father and for a number of general fall maintenance chores.

Their small size proved to be very comfortable for long listening sessions and the cords proved robust enough to survive innumerable snags and pulls (I really should try the bluetooth cord).

I think the MX4 PRO is a very capable IEM. For my musical tastes, this requires the use of the Comply foam ear tips to achieve adequate bass presence. However, the MX4 PRO doesn’t exist in a vacuum, and we must remember that there are other great-sounding, hybrid, multi-driver IEMs available at a third (or less) of the price.

So, to justify the price tag, the MX4 PRO has to bring something else to the table. In my opinion, the build quality, aesthetics, and intrinsic impression of worth do not set it apart. The included accessories are better than the Chi-Fi bare bone offerings, and the customizable options (faceplates, custom personalized ear tips, and cables) are interesting, albeit at additional cost.

Comparing the MX4 PRO with hybrid offerings from KZ.
Comparing the MX4 PRO with hybrid offerings from KZ.

Ultimately it is up to you to decide if the MEE Audio MX4 PRO offers enough value for the money. At $100, I’d not hesitate to recommend it, but with the KZ ZSX and ZS10 Pro sitting beside the MX4 PRO in front of me, each at a fraction of the price, they highlight what incredibly tough competition exists in the budget IEM market.

Yet for the right person, the MX4 PRO may be the spot-on choice. Smaller size and more gender-neutral aesthetics. Sweat-resistant IPX5 water repellant rating for the gym or for performing on stage. Enhanced focus on clarity and details in music playback.

For someone out there, the MX4 PRO is what they’ve been waiting for.