M-Fidelity SA-43 Custom In Ear Monitors


500+ Head-Fier
Pros: Variable Sonic Adjustments, Great Soundstage, Featured-filled for this pricepoint
Cons: Limited Aesthetic Customisability, Need Good Amplification
It seems like as of now, custom in ear monitors or CIEMs for short are all the rage and being intrigued by them, I decided to give them a go. To those who are unfamiliar with CIEMs, they are essentially earphones that are made in the shape of your ears after you send the CIEM company a molding of your ear (usually made by an audiologist). I see many different CIEMs available on the market and the M Fidelity SA-43 isn't the creme da la crop, and at its competitive prices of $1199 (w/o Add-ons), I didn't expect it to be, but it's very unique in its on way.

(Purchasing Process)
This was my very first set of CIEMs and my fellow friend Calvin and fellow owner of Music Sanctuary, a place specializing in sale of CIEMs, recommended the M Fidelity SA-43 for its versatile nature which I would touch on later. Another special point about M-Fidelity's CIEMs is that the turnover time is 2-3 weeks while for most other companies they are usually 5-6 weeks and sometimes can even go up to months if there is a great back order. This by itself should be a major selling point for impatient customers and if you want it done even quicker, Rush order is at 1 week (at extra cost of course).

The SA-43 comes in a large rectangular case, about the size of an iPad Mini, in which houses a smaller clam shell case, that can fit the earphones snugly. The SA-43 comes fitted with earwax guard to prevent ear wax from entering the housing of the CIEMs, and the accessories include a canal cleaning kit as well as spare earwax guard.

Regarding the aesthetics, I opted my SA-43 to be silicon-filled as well as to have them in full opaque black that is rather sleek, however I do have to mention that I did send my SA-43 back after the first receival. Reason being is that the exterior and finish of the SA-43 was not up to standards but the guys at M Fidelity were more than willing to make me a new set as an apology and the surfaces were much smoother with a better polish as well the second time round. Photos published are a set of fully clear SA-43s that belongs to my friend because of a camera malfunction so as to show a more clear view of the earphones and its internals.

On to the ergonomics, I find that fitting is nearly perfect and why it is not completely perfect is because of the cables. Since I started owning earphones, I have never liked memory ear loops on my cables as I find it makes any earphone more difficult to achieve a perfect seal and my personal opinion is that earphone companies should just ditch the idea completely. However after much experimentation with countless twisting and turning of the ear loops, a perfect seal was finally obtained and now comes the great music.

That being said, I ought to cover the features this earphones have first and yes I did just use the word 'features'. I'm sure if you had seen the photos of the M Fidelity SA-43, you would have caught a glimpse of two switches on each faceplate of the SA-43 and you must be wondering what exactly do they do.

One of the switch apparently increases the impedance within the internal circuitry, let's call this the Impedance Switch (IS), while the other switch activates an additional bass driver and let's name this the Bass Driver (BD). To make it easier, I'll review the SA-43 in 4 portions, firstly with both IS and BD off, secondly with BD on, thirdly with IS on, fourthly with both IS and BD on.

(Sound with IS and BD off)
Using my iPod Touch 4 LOD into the TTVJ Slim, playing FLAC files, I can sense a hint of warmth, a punchy dynamic bass response, as well as a slightly shelved treble response and knowing that both my iPod and TTVJ are warm in nature, I find that the SA-43 managed to be neutral and present the sound characteristic of my amp and source. Changing to a simpler setup, my iPhone 6 streaming spotify, I was surprised to find that the SA-43 became even more neutral from the bass to the midrange but the muted highs still remained. Therefore with both IS and BD off, I find that the SA-43 is a neutral earphone with a slightly rolled off high frequency which could be a pro if you see it as being easy on the ears. To me this, this sounded like a slightly improved version of the Westone W4, which could be a useful reference for some.

(Sound with BD on, IS off)
With this configuration it feels like someone dropped a subwoofer into the system as it does provide a greater quantity in bass, however the impact remained the same and the quality seemed to dwindle, with the bass becoming less controlled and taut. The midrange was also affected by the activation of the bass driver, causing the sound to be slightly less clear and transparent. This is sort of reminiscence of my previous reference the Shure SE846 which in my opinion is a sound character that takes time getting used to. However with the more accurate signatures just a switch away, it's tough to be convinced this configuration is good enough.

(Sound with IS on, BD off)
Now this is where things get real interesting as I didn't expect an impedance change to cause such a drastic change to the sound. You would firstly notice how the soundstage just exploded into a gigantic sound sphere, almost as if like headphone standards. Along with that, a tad more treble and a recessed lower midrange. This difference was a technical wonder, but the sound signature became a little forced and artificial which makes you just wish to turn the switch off.

(Sound with IS on, BD on)
Here we have what I believe is the best sound signature that the SA-43 can offer as it managed to combine a full and natural tonality with an out of your head soundstage that is simply not found anywhere else in this price range of the in earphones world, be it custom or universal. Along with that, the bass increase of the extra bass driver seemed to sync well with the lower midrange dip of the impedance switch that it also manages to give a percival of neutrality, which is absolutely fantastic in my opinion.

(Minor Drawbacks)
Despite it being a wonderful product, no product is perfect or without drawback and the issue with the SA-43 is like a girl playing hard to get. It simply requires tons and tons of power to keep it going and the power required can be misleading. Simply because it is not difficult to get it loud being a earphone but to play more effortlessly and with finesse, it requires power headroom, so this earphone should be refrained from being paired with a smartphone or weaker-output audio players.

At the basic price of $1499, the SA-43 is simply a jack of many trades, and master of some in fact such as the phenomenal sound staging I cannot stress enough. The major selling point would be, to most people, still the configurable sonic signatures with the switches and with it having 4 types of sound packed into one in ear monitor, it is difficult for this earphone to disappoint.

View attachment
View attachment
View attachment


Reviewer at Headphone.Guru
Pros: Transparency, Spaciousness, Coherence, 4 Different Sound Signatures
Cons: Resolution When Switches Off, Long Canal May Be Disturbing, Needs a Powerful Source/Amp
M-Fidelity is a custom in ear monitor company located in south Norway. Alf Middelthon is its founder who was working with Starkey in the past. After leaving Starkey he founded M-Fidelity and brought his designs to the new company.
M-Fidelity has interesting designs including customs with switches and different acoustic hoses than the industry standard. Additionally, Alf offers plug-in earphones called ERM series with exchangeable filters. In my opinion, these earphones are really interesting in terms of getting different sounds from one single earmold.    
M-Fidelity also offers HF series hands free earphones as well as 7 different custom in ear monitors such as SA-33, SA-32 Live and entry level SA-12.
Alf is a very responsive and helpful person. I had no issue while getting SA-43. He usually replies to mails within 24 hours.
View attachment
Picture from M-Fidelity
Built Quality, Cable, Accessories and Internals:
The reviewed SA-43 has an acrylic shell filled with silicone. This is an option; you can get a silicone filled shell for a small additional fee. The silicone filling offers better protection against damages, surely I wouldn’t take the earphone into a test about damage protection. :) There are some bubbles in the shell due to filled silicone, but nothing major to complain about it, since it comes from the nature of the method.
The craftsmanship is quite good except a few minor mistakes, very little bulges on the surface. The faceplate is a bit thick but carefully placed on the earphone, there is no overflowing from the corners.
The sockets’ craftsmanship and placement is good, but I find them a bit too tight and it was a bit difficult to remove the cable at the beginning.  On the other hand, that tightness extends durability life and keeps sockets connected for a long time.
The wax filters seem to have high quality and they are replaceable with a tool included in the package. Thus, there are 8 replacement filters coming with the earphone and the diameter of the filters is wide enough to easily clean wax with a cleaning tool.
There are two switches on the faceplate of SA-43, blue one is for low frequency boosting and the red one is for mid frequency presence. The switches work quite well and their built quality is good. However, we need to be careful while inserting or removing the earphone, since these little things may be fragile.
The canal part of the SA-43 is a bit long, nearly past the second bend for a few millimeters. The canal is the longest one among my other custom in ear monitors. That length may disturb some listeners, but I have no complaints about the canal of the SA-43. In my opinion, silicone filled shell and long canal part offers a very good isolation. While jaw movements, I have no seal break and I can honestly say that SA43 has the best isolation among my other customs.
The SA-43 has 3-way crossover system with 4 balanced armatures.  Two of them are bigger than the others and there is an interesting coating material on the bigger armature drivers. Differently than the industry standard, the SA-43 has more rigid and non-transparent acoustic sound tubes. They remind me the material of PVC window.  
The stock cable of the SA-43 has standard quality and it is just like Westone or Unique Melody type of cable. There is no issue about the cable so far.
The SA-43 comes in a mid-sized outer box which seems like a carbon fiber coated. As accessories, there are cleaning tool, a small carrying case, replacement filters and their tools and owner manual. When we take the size of the carrying case into consideration, we can find it a bit small to protect the switches from damages. We may need a bigger place to put the earphones in for a better protection. Both outer box and carrying case gives a premium feeling, which has to be in a TOTL CIEM’s packaging.  
View attachment
Picture from M-Fidelity
The SA-43 offers 4 kind of sound signature from a single custom in ear monitor: Flatter, more dynamic, mid oriented and bass heavy. In general, the SA-43 has a sound which is very close to neutral when the switches off. When both switches off or on, it has great timbre and outstanding transparency.
Low Frequency:
When the bass switch off, low frequency has a presentation closer to being tight rather than being splay. The low frequency of the SA-43, especially mid-bass, has a bit warmer tone compared to neutrality of mids.
Sub-bass has quite fast and powerful attacks, hits from an area of impact between large and medium. Hitting to depth ability is very good and creates a good stage dimension. The tone is not the most natural among my other earphones, but it is quite good for a flagship and there is no armature kind of artificial or rough rumble. Mid bass, which is located in the middle of the stage, has a balanced presentation along with sub-bass; it doesn’t tighten the stage and the spaciousness remains the same when the switches off.   
When only the bass switch on, sub bass becomes more powerful and hits from a larger area on the stage with a bit more dynamism. However, mid-bass, which becomes quite prominent, gives a bit too warmth to the overall spectrum and the stage is filled with warm air and the spaciousness gets lost when bass switch on. Additionally, when only the bass switch on, the overall spectrum becomes a bit smoother, but at cost of loosing transparency and timbre ability. When both switches on and both bass and mids are more prominent, the overall presentation becomes balanced again and transparency gets back with a more dynamic and alive note recreation. 
The overall low frequency resolution and texture cannot reach to the level of my other flagship CIEMs, but we can find it quite good for a CIEM priced at 820 USD at the moment of this review posted.
Mid Frequency:
When the both switch off, mids are quite natural, full-bodied, and flatter. They also are quite balanced and controlled in terms of location on the stage. Even if mids aren’t cleanest one, they are neither laid back nor too forward. Some may find it a bit dry, but the overall tone of mids is close to neutral with great timbre ability. Instruments have an exceptional realism and it is almost impossible to talk about a veil on the presentation. Most of times, too much transparency may become fatiguing by thinning overall notes recreation. SA-43 represents both thick and thin notes quite good, especially when both switches off. It also has an outstanding transparency without brighten notes; and it doesn’t fatigue listener at all.
When only mid presence switch on, SA-43 becomes a mid-oriented earphone and instruments come a bit forward on the stage; the mid-bass presentation becomes laid back with a bit less dynamism overall. Due to less prominent low frequency and lack of smoothness which is normally added to the whole spectrum by mid-bass tone, mids may become unnatural and note creation becomes a bit thinner compared to other switching variations. Vocals and instruments come forward with a bit better resolution, but it tends to sibilance more.
When both switches on, mids are still exceptionally transparent and realistic, but depending on tracks, upper mids sometimes become a bit less controlled, and background details may become less clear.  On the other hand, when both switches on, the presentation becomes quite powerful, more resolved and dynamic.  Honestly, this is my favorite setup on the SA-43 with a more deeply enveloping sound.
When both switch on/off or only mid presence switch on, the detail level is quite good among my other CIEMs, but the resolution is not the best when the both switches off.
View attachment
Picture from M-Fidelity
High Frequency:
SA-43 represents highs with clean, transparent, thick and full-bodied notes. Highs are neither bright nor fatiguing; the detail level is good with a very true tone overall, but resolution and extension levels are not the best for a flagship. On the other hand, the overall speed of highs is good and it can overcome fast metal tracks as well as drums solos in fusion tracks.  
When both switches on or the only mid presence switch on, highs are more prominent and alive. Highs remain natural when the both switches on, but they are more natural and smooth when both switches off.
Soundstage and Instrument Separation:
The SA-43 uses the stage dimensions very good; it doesn’t have an overly wide or deep stage, it remains within the limits to present a great coherence and focus as well as a quite airy stage. It also has a quite spacious stage when the both switch off. When the both switches on, instruments becomes a bit closer to listener; even so, it remains spacious and creates a more enveloping sound with a better depth stage compared flatter response.
Instrument separation is very good within every single switch variation. Even if the background isn’t the blackest or the most stable one, instruments are very well positioned and separated with fairly effectual and enough distances to create a very realistic presentation.
Source Matching and Driving Issues:
The SA-43 is moderately hard to drive, so that we need a powerful source in order to reach to its full potential. I’ve tried it on several sources such as Fiio X3K, QLS QA360, HM901 with Minibox, IPhone 6 etc..
Pairing with a low quality or low powered source results in lack of transparency and spaciousness. If we have a powerful amplification/source, the SA-43 would become quite impressive.
View attachment
Final Words:
M-Fidelity SA-43 is one of the most transparent and true sounding custom in-ear monitors that I’ve ever heard. It brings a very realistic listening experience with its coherence and outstanding timbre. Surely, we need to accept that its midrange is not cleanest one and its overall resolution is not the best among my other CIEMs, especially when both switches off. Also and upper mids may come a bit too forward depends on tracks and reduce the detail level of the background when the mid presence switch is on.
Alf offers several options for faceplate and body colors as well as hardwire cords. Depends on current conversion, SA-43 with detachable cords is 6600 NOK/860 USD including shipping.
SA-43 Specs from M-Fidelity website:
* 4 balanced armature drivers, 3-way system, 2nd order (12dB/octave) hard-wired passive crossover (50 Hz and 5,3 kHz)
* Frequency response: 30-18000 Hz
* Sensitivity: 104 dB/mW
* Impedance: 50 ohms
* Cord: Twisted, hardwired or detachable, 125 cm (49″), goldplated stereo 3,5 mm (1/8″) jack
Website and Ordering Information:
Thank you my friend. Yes, I too think that the outer box has a premium look.
Excellent review ! Where did you buy them ? 
Thank you Victor. :) I got it directly from M-Fidelty.