General Information

A revelation in balance and details, space and dynamics.
The SA-50 has some of the greatest speakers available today, all of which are tuned and tweaked with pride and passion to deliver the most true and real-life sound reproduction from M-Fidelity to this date.

We call it The Essence of Sound.


* 5 balanced armature drivers, 4-way system, Highest quality hard-wired passive crossovers
* Frequency response: 22-24000 Hz
* Sensitivity: 102 dB/mW
* Impedance: 30 ohms
* Cord: Twisted, hardwired or detachable, 125 cm (49″), goldplated stereo 3,5 mm (1/8″) jack

– The SA-50 loves to be fed great recordings in lossless and hi-res, and deserves a dedicated dac and amp!


Latest reviews


Headphoneus Supremus
Pros: Bass impact & control
Transparency & resolution
Good accessory bundle
Cons: Needs a proper source to shine

M-Fidelity SA-50 introduction

Hi there PA fam, and welcome to another review. Today I'm looking at the M-Fidelity SA-50 custom in-ear monitor. This custom in-ear monitor has an organic, smooth sound that is still resolving and detailed. The SA-50 was released recently and is the newest flagship offering from M-Fidelity.

These monitors contain 5 high-quality balanced armature drivers and a 4 way, hard-wired, passive crossover system. The SA-50 is one of the more affordable TOTL customs available but is definitely still competitive with pricier alternatives.

M-Fidelity is a company based in the picturesque town of Jørpeland in Rogaland county, on the western coast of Norway. They make a variety of custom in-ear monitors for musicians and audiophiles alike, providing noise isolation and hearing protection. There are even CEP (Communication Ear Protection) options for pilots and ground crew available.

Disclaimer: This sample was provided for the purpose of an honest review. All observations and opinions here are my own, based on my experience with the product.

* 5 balanced armature drivers, 4-way system, Highest quality hard-wired passive crossovers
* Frequency response: 22-24000 Hz
* Sensitivity: 102 dB/mW
* Impedance: 30 ohms
* Cord: Twisted, hardwired or detachable, 125 cm (49″), gold-plated stereo 3,5 mm (1/8″) jack
Price: $1032

Package and accessories


M-Fidelity's CIEMs come in a high-quality large, black travel case with a carbon fibre pattern and the company's branding stamped on the front in gold lettering. The case is too large for a pocket but perfect for keeping in your bag. Fortunately, there's also another smaller carrying case inside but I'll get to that in a moment. Let's take a look at everything inside.

  • SA-50 CIEM
  • Detachable 3-wire OFC, 2-pin cable
  • 8 x spare wax filters
  • Wax cleaning tool & brush
  • Shirt clip
  • Semi-rigid carrying case
  • User manual
  • Instructions for replacing wax filters
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As you can see, that's a pretty decent kit and includes everything you need. It's great to see the addition of the pocket-sized carrying case as well. All the components are high-quality and the overall unboxing experience is a good one.

Build, customization & comfort


Build & customization
There are several shell colours and faceplate options to choose from, all of which you can see on the website. While not as extensive as what some other companies offer, you should be able to find something that suits your personal tastes.

The model I have is decked out with clear shells and carbon fibre faceplates. Build quality is very good. There are no bubbles visible in the shells and the faceplates are joined to them seamlessly.

Unlike a lot of other CIEMs, the SA-50 has only 2 tubes leading into the ear canal. The top one carries the lows and mids, while the bottom one is for the mids and highs. Partway down each tube is an acoustic filter and at the end of each tube is a removable/replaceable wax filter.


Comfort & isolation
Comfort will depend a lot on sending a good set of ear impressions. So make sure that if you're ordering CIEMs, that you visit a good audiologist and let them know the exact requirements needed from the manufacturer.

It's always a good idea to read the information regarding impressions on the website because sometimes the requirements for ear impressions can vary between different manufacturers.

When I first received my SA-50 there was an issue with the left earpiece that was causing some discomfort. After speaking with Alf (the man in charge of operations), I decided to send them back in for some modifications. Within a very short time, the adjustments had been made and the monitors were on their way back to me. I should mention here that Alf was very responsive and helpful throughout the process. Overall, I found the customer service to be excellent.

Now, onto the comfort: Once the adjustments had been made to the left side, I had no issues with the fit and I find the SA-50 to be extremely comfortable. I can easily wear these for hours on end, which turns out to be a good thing because it's hard to stop listening, but more on that later.

The seal with these is very good and is maintained while talking or singing along to the music (yes, these will make you do that too!) Like most custom in-ear monitors, if the fit is good then so is the noise isolation.

Put the SA-50 in your ears and you can easily get lost in your own little universe as all but the loudest of external noises are cut off.


The M-Fidelity SA-50 is smooth yet resolving in nature. It immediately strikes you with its clarity, which it manages to maintain regardless of its warm nature. Its warmth lies in the lower frequencies, which add body without any noticeable colourization or bloat.

The SA-50 sounds very natural and organic; coherency is one of its mainstays. Its 5 BA drivers and their passive crossovers create a perfectly unified blend. Although the SA-50 is not neutral, it is linear and balanced. The way it can render sounds with such clarity and detail without ruining the upper midrange or lower treble is another thing I like about this CIEM.

Sources used for testing
The SA-50's bass is slightly boosted, giving the overall signature its warmth and fullness. The mid and sub-bass are fairly linear, with neither being given preference over the other. While the quantity is ample, it's the quality that gives SA-50's bass life.

It's authoritative; given the right tracks it can come out to play in force but in a way that is considerate of the overall sound. It never becomes overbearing or intrusive but at times has the impact and punch similar to a dynamic driver.

Playing Katatonia's Dead End Kings album with its heavy kick drums you could be forgiven for thinking you were listening to a large dynamic transducer. The sub-bass doesn't have quite the same authority as the mid-bass but it never sounds lacking.

The attack is reasonably fast, as is the decay, so it avoids coming across as lethargic or clumsy. Instead, it's lithe and extremely well-controlled. Sub-bass notes reach deep but the quantity is quite reserved and coupled with the fast decay it maintains that sense of control.

Fairly neutral and transparent with a hint of extra body, the SA-50's midrange really complements the weight of the bass. Vocals and instruments alike are presented with clarity and layering. With its generously sized soundstage, it adds space in between the elements to give that desired separation.

Electric guitars have a good crunch to them, making albums like It All Starts From Pieces by Distant Dream sound exceptionally good from start to finish. The SA-50 strives for natural tonality, rather than absolute accuracy; the extra body and smooth presentation means it is on the musical side of the scale (just where I like it).

Vocals are presented just slightly forward, with a small increase in the upper midrange. In "ARIEL" from Anathema's Distant Satellites, the haunting vocals at the beginning of the track are reproduced equally as well as the energetic ones towards the end of the track. The SA-50 conveys the raw emotion of the recording and simply draws you in.

A track I often use for testing is "Embers" by Helen Jane Long. The combination of piano, plus the violins and cellos are great for checking tonality and resonance, and here the SA-50 again flexes its muscles. With its mixture of natural tones and touch of warmth, the SA-50 overall has an above average midrange.

The SA-50 stays true to its linear and accurate presentation in the treble. There's a slight peak in the lower treble at around 6KHz to add some bite and then it's attenuated to keep things on the smooth side. This is followed up by another peak at 11KHz to increase the harmonics.

Just like the rest of the spectrum, the treble is crisp and clear. The definition is very good, as is the extension, lending an airiness that defies its sometimes deceptively relaxed nature. The 11KHz peak though, can at times, sound a little abrasive, for me personally.

Portraying an average width in its presentation, the SA-50 has a well-defined soundstage that finds strength in its depth and imagery. Vocals take up a space that's fairly intimate while instruments are positioned behind and to the sides, adding to the overall dimensions.

Due to the midrange's mostly neutral nature, space between elements is easy to determine. The well-controlled bass also adds to the openness of the SA-50's signature. Positional cues are good, accurately pointing out the location of separate elements. Add to that the peak around 11KHz which adds an additional airiness and you have a very competent soundstage.

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Sources & compatibility
Even though the M-Fidelity SA-50 has a fairly low impedance (30 ohms) and high sensitivity (102 dB/mW) I found it needs some solid power behind it to sound its best. While it can be driven easily by my Galaxy Note 5, it lacks some body and definition.

For best results, this CIEM deserves a solid DAP or DAC/amp. While it sounds good with the Topping DX7, I found the treble to be a little on the thin side.

The ATC HDA-DP20 proved to be a really good partner for the SA-50 with a wide soundstage and punchy bass. Transparency and resolution are fantastic. The treble also sounds superb with this combo.

Pairing with the Acoustic Research AR-M20 resulted in a bit more warmth and body overall. The soundstage is wide with good depth. Treble is energetic but smoother than the DX7.

Inearz Audio Fusion ($725 USD)
The Inearz Fusion has six BA driver per side and is characterized by its mid-bass hump and smooth treble. It aims at a more fun and coloured tuning, in contrast to the SA-50s accuracy and linearity.

The Fusion has more body in the sub and mid-bass. Its mid-bass is more hollow sounding in comparison to the SA-50's tighter and more impactful mid-bass. It's the sub-bass where the Fusion excels, having more quantity than the SA-50, but with the same fast decay and control.

In the midrange, the Fusion is more diffuse, which results in less defined imaging and a tendency to sound more congested; not in the sense of a closed-in soundstage but instead, more of the elements melding together into a single mass of sound and lacking separation.

Both have a similar treble, which is closer to neutral and a shade relaxed. This results in a smooth and non-fatiguing experience and one that rewards you for turning up the volume, without fear of it becoming strident. The SA-50, however, is more accurate in its decay and has the greater extension.

Inearz' Fusion has a similarly wide soundstage but can't compete with the SA-50's stronger imaging. It doesn't have the clean slate that the SA-50 presents or the same amount of transparency, although the detail is there.

Custom Art FIBAE 2 ($557 USD)
The FIBAE 2 is a cracker of a CIEM and possibly one of the best value entry-level monitor currently available. With its forward midrange, weighted bass and lively treble it's a real blast to listen to. The FIBAE 2 is more coloured than the SA-50, which has a more linear and mature tuning.

Surprisingly, the 2-driver FIBAE 2 has a hint more oomph in the sub-bass region. It tends to let the bass shake and rumble a bit more where the SA-50 has a faster decay and more control. When it comes to the mid-bass, these 2 monitors are closer in quantity but again the SA-50 keeps a tighter rein on things which keeps the overall presentation sounding cleaner.

The FIBAE 2 has less resolution and layering in the midrange, caused by its more W-shaped signature. Vocals are more forward and have more body which can lessen the definition of some other midrange elements. The SA-50, in contrast, is more linear in its approach allowing those extra details to be heard. Additionally, the SA-50 has more tonal accuracy in the mids while the FIBAE 2 goes for a more "fun" tuning.

Both of these in-ear monitors have great treble. The FIBAE 2's treble, however, is more upfront and energetic. It has an addictive liveliness and sparkle, while the SA-50 has a smoother and more relaxed treble. Once more, the SA-50 is more tonally accurate and controlled with natural sounding harmonics and sheen.


The M-Fidelity SA-50 is a CIEM that sounds impressive from the start but doesn't reveal all its cards on the first listen. Initially, I was struck by its clarity, followed by its meaty, full-bodied but controlled bass. As I continued listening I found that not only is the sound clear, but it's also very resolving, yet still musical.

Thankfully the clarity and detail are not achieved by simply boosting the upper midrange or lower treble and that's one of the things that separates this monitor from some of the more mediocre ones out there. The fact that there's enough warmth to give the midrange body and musicality, yet still have that resolution and balance is a testament to its technical prowess.

M-Fidelity website

*This review was originally posted on my blog at Prime Audio. Drop by anytime to see more like this.


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