Sudio Fem
Jarvin Cassidy Co 2021

Sudio Fem TWS Review

The Sudio Fem is a True Wireless System featuring IPX5, touch controls, Bluetooth 5.0, and up to 20 hours of battery life. It is priced at $139.00.

Disclaimer: The Sudio Fem sent to us is a sample in exchange for our honest opinion. We thank Sudio for this opportunity.

To learn more about Sudio reviews on Headfonics you can click here.

Note, this review follows our new scoring guidelines for 2021 which you can read up on here.

Sudio Fem
Sudio Fem
Listening to the Fem, I found it to be controlled, but appropriately accentuated at the right spots in terms of painting a soundscape. Overall, the Fem is a product that has incorporated Swedish design principles to both the audio and the aesthetics, resulting in a coherent and elegant product.  
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Although we have reviewed Sudio before with a feature done by Marcus last year on their TOLV TWS, this is my first encounter with their wireless products and Sudio as a company.

According to the company, Sudio is a combination of the words “Swedish” and “audio”. What this means is that they are integrating the elegant Swedish design language into their audio products, to spark a moment where you get lost in the music and time stands still.

The product portfolio of Sudio includes Bluetooth devices, ranging from speakers, over-ear headphones, Bluetooth IEMs, and of course some TWS earbuds. The Fem is positioned just below their top of the line ETT earbuds and priced at $139.

Sudio Fem
Copyright Sudio 2021


The Sudio Fem comes equipped with a single graphene-coated dynamic driver, with a Realtek Bluetooth SoC inside.

The Realtek SoC features Real Clear Voice technology with the use of the 4 microphone system to filter out noise. Each earbud is also equipped with fast charging technology that can give 1 hour of listening with just 15 minutes of charging in the case.

The Fem doesn’t offer top of the line codecs such as aptX and instead, you get a max SBC as well as AAC for Apple users.

Though this might seem like a downside to not using a Qualcomm chipset. But considering the performance of the Sony flagship TWS which also tops out at SBC, there is more to a good-sounding TWS than simply its decoding capability. 

Sudio Fem


The earbuds that come with the Sudio Fem have a rounded form factor and connected to a protruding rectangular piece that seems to house the mic.

The outer coating of the Fem is rubberized, with a smooth matte black finish which seems durable enough to resist scratches and bumps from daily use. Each earbud is equipped with a magnet that will help in precise placement when returning the earbuds into the case.

The Fem also has an IPX5 certification. This certification guarantees that the Fem TWS can withstand light jets of water from all directions. So bringing them along to the gym or your morning run will not be a problem.

Comfort & Isolation

The Fem comes with 5 pairs of ear tips in different sizes, however, they are not a regular full-sized silicone tip design and more of a ‘half-cut’.

This might mean tip rolling with traditional IEM tips will not be as easy but these are designed in this shallow manner to allow the charging case to close properly. Larger tips might prevent them from fitting into the case.

The earbuds nozzles are shaped to follow the contour of the ears, so as long as your ears are not particularly small, the Fem will not introduce any comfort issues. The level of passive isolation is average for me with the stock tips. 

Sudio Fem

Charging Case

The case of the Sudio Fem is also coated in the same black rubberized material that is used on their earbuds. It is attached to a waxed leather strap to accentuate the minimalist aesthetic of the Fem’s charging case, much like the TOLV had.  

This is a clamshell design with a magnetic closing mechanism, so mechanical wear and tear wouldn’t be too much of a concern down the road. Sudio also decided to put 4 LEDs inside the charging case that indicate the battery level, which is a nice touch as it gives me a better picture of when I should be charging the case again.

Battery life

I read in the box that the Fem can give around 5 hours of listening time on each full charge of the earbud. I was expecting to get a bit less than 5 hours, based on my previous experiences with most TWS earbuds. I was surprised to see that the Fem is surpassing that 5-hour promise that they have on the box, as I was able to get almost 6 hours on each charge from the earbuds.  

The charging case on the other hand was able to charge the earbuds around 2 times and some change. This would put the total playtime of the Fem at around 20 hours. It’s nice to see what’s listed on the box translate to real-life experience.

With the implementation of a fast-charging system, battery recycling is fast. When I had the case at just 25%, I was able to get it back to full capacity in less than an hour. This makes me worry less about forgetting to charge the Fem, as getting power back into the earbuds wouldn’t take too long anyway.

Touch Controls

Since the Fem uses a Realtek Bluetooth SoC, touch controls are a bit different on the Fem. A single tap on either earbud for play/pause, double-tap on the left earbud for the previous track, on the right for the next track.

What was a bit difficult for me though was having to triple tap on the left earbud to lower the volume and on the right to increase the volume. This turns out to be a bit cumbersome for me, and it sometimes even ends up changing the track.

Voice assistant can be accessed by pressing and holding on to either earbud, but it was not the most reliable way of accessing Google Assistant for me.

Also, when I return one of the earbuds into the charging case, all controls on the other earbud are still active. This forces me to get my phone or get the other earbud again if I want to reverse any accidental track changes or volume adjustments.

Most of the common touch controls found on the Fem are fairly intuitive to use, however, the slightly more intricate touch controls might need a bit of work.

Sudio Fem

Packaging & Accessories

When the Fem arrived, I was curious, because it came in a plain black box that just said Sudio across the front. There was nothing else written on it, and there was a pull tab that would allow me to open the box. Inside the outer box there you will find black gift wrapping tissue that covers the real packaging of the Sudio Fem.

The box of the Fem is a thick cardboard box that articulates much like a drawer. Inside, there are the earbuds themselves, a manual, a guarantee card, a short USB C cable, and 4 additional pairs of ear tips of different sizes.

It’s interesting how the Fem was packaged so mysteriously, and at the same time, while the box itself seems to be more well protected than usual. There isn’t even a single dent on the real box, because of the protective outer box.

Sound Impressions


With the less than ideal seal of the design of the Fem, I was expecting to have lethargic bass from the Fem, however, it did exceed those expectations.

The bass seems to be pulled back slightly compared to the other parts of the frequency spectrum, but it can pack a punch once it is called to do so. While being able to pack a punch, it remains clear and doesn’t bleed into the midrange. 

Bass on the Fem doesn’t call attention to itself too much, but it lingers there to compliment the rest of the frequency spectrum. It seems that bass on the Fem seasons the other frequencies well, while not taking over the whole show.

The bass line played through the Fem is articulate and distinct. Each note played by the bass guitar sounds distinct and full-bodied.

When I hear drum beats, the beats are distinct and the transients from drums beats are there. I would have wanted to hear the decay just a pinch longer to give drum beats a more natural timbre. However, being able to present this much quality in the bass region at this price point is already a win in my book. 


Compared to the mid-bass region, the lower midrange is slightly recessed, which pushes back male and female vocals slightly. When the track is vocal-centric though, the vocal range comes out as clear and textured.

When the track becomes busier with drums, cymbals, and other instruments, some vocal information might end up getting lost. Listening to Gotta be Patient by Michael Buble, I found that vocal texturization seems to have been lost. I ended up having to strain a bit to find the vocal texture information from Michael Buble’s voice.

In contrast to the lower mids, the upper mids is a bit more emphasized. Piano and guitars come out as forward, and the tinkling of piano keys comes out as realistic. Guitar plucks have the correct timbre to them. This leads to good instrument separation so that even if each instrument might be playing the same note, they will still sound distinct and uncongested.  


As the upper midrange goes into the treble region, the Fem starts to be more relaxed compared to the rest of the spectrum. I like how the lower treble is clear and can present cymbals well. However, when it comes to headroom beyond, the Fem tends to lack a little bit of that.

I can hear that the Fem’s upper treble regions tend to roll off a bit. This will ensure that the Fem would never become sibilant or fatiguing, but I would have wanted a bit more energy in the upper treble range for some of that sparkle. I’m glad it’s a bit too little, rather than a bit too much though.

This kind of treble presentation makes for an overall more relaxed listen, which might make the Fem a good choice for long casual listening sessions.  


The Fem’s ear tips have a shallower flange, which makes for a looser seal around the ears. I believe that this gives the Fem a slight advantage in staging. Despite not having much in terms of air, the Fem can cast a decent soundstage. The sound stage that the Fem creates is less than an inch out of my head, but it makes use of it quite well.

One of the strengths of the Fem is the ability to create images within the soundscape. I like how the Fem can create an image in each part of the sound stage. I found this enjoyable when I watched movies with the Fem, as each of the sound elements was placed accurately.

The image of each sound element might not be the sharpest, but at least they are correctly placed albeit in a blob. And I think we need to give credit to Sudio for being able to achieve that.  

Sudio Fem

Wireless Performance


Connecting to the Fem is not too difficult, it just takes the normal process of searching for the earbuds, and pairing them to your phone.

Subsequent pairing requests between the Fem and your phone should not cause issues, but once in a while, pairing between my phone and the Fem fails. I would then need to put them back in the case and let them initiate pairing again to successfully pair with my phone.

I wasn’t able to perceive too much latency on the Fem, so watching videos and playing games on the Fem doesn’t seem to be a problem. Measured latency is at around 2mS, which is typical for a lot of TWS.

Call quality

I was able to use the Fem on calls, and I think that the noise-canceling microphones and Realtek’s Real Clear Voice system does their job well. Even when I deliberately go beside a fan running on high, the fan’s sound didn’t go across to the other end of the line.

My voice came across as clear on the Fem, however, once in a while, my voice seems to drop off then comes back shortly. My voice came across clearly in general though.

Audiofly AFT2

Select Comparisons

Audiofly AFT 2


Sudio and Audiofly came with different approaches to creating their TWS IEMSs. Sudio went for a more minimalist design, while Audiofly looks a bit more industrial.

With the bigger form factor and slightly larger earbuds, the AFT2 offers about double the battery life when compared to the Fem. However, both earbuds would be able to withstand a whole day of use without any issues.

Both earbuds also have 4 LED indicators on the case that indicate battery level. So in terms of battery life and usage, I think it would be a matter of choosing a smaller form factor with the Fem or longer battery life with the AFT2.


I believe that the AFT2 was able to implement a more seamless touch control experience especially with volume controls, and automatically disabling certain controls when only 1 earbud is in my ear.

Both earbuds also implement noise canceling through their built-in microphones, and both are able to filter out noise from an electric fan directly beside the earbuds during calls. I noted some momentary drops when I’m in the middle of a call with the Fem though.

The Fem tends to stay connected to my phone despite being an extra 2 meters away from my phone compared to the AFT2. However, the Fem is less consistent in automatically connecting to my phone when compared to the AFT2.

The Fem did not implement any advanced Bluetooth codec, but the loss in resolution is not as evident as I would like to believe. So the Fem not having the AFT2’s aptX capability is not that much of a loss in general.


The sound signature of the 2 earbuds are a bit different. Where the AFT2 tends to be more vocal-centric, the Fem has more of an upper midrange bump emphasizing instruments quite a bit more. For sub-bass and power, I found the Fem is slightly elevated compared to the AFT2.

In terms of width and breadth of the soundstage, the Fem has a slightly wider stage compared to the AFT2, however, imaging was a bit more tangible on the AFT2 though.

The 2 earbuds simply have different priorities, and I can see that their design choices necessitate prioritizing certain features over others. And it will be up to the user which trade-offs they are willing to make when choosing between the 2 TWS earbuds.

Sudio Fem

Coumi ANC-860


The first impression that I had of the Coumi ANC-860 is that the charging cases of the 2 TWS earbuds are very similar. They both have the waxed leather strap, and they’re both black. At about half the price of the Sudio Fem, the Coumi might seem like a good alternative to the Fem based on the looks.


At first glance, Coumi was able to cram a few extra features with their ANC-860, like having the ability to turn-on or turn-off ANC, having transparency mode, and claims of longer battery life. These might make the Coumi seem like a better deal, but that’s not the entire story.

Opening up the charging case of the 2 TWS earbuds, the Sudio has 4 battery indicator LEDs, where the Coumi only has 1. Also, the ear tips on the Coumi is proprietary, and the shape of the earbuds are similar to the OG AirPods. This makes the ANC-860 a bit harder to get a perfect fit with.


When I put on the ANC-860 though, I immediately missed quite a few things from the Fem. The first is the control over the mid-bass region. While the ANC-860 has a lot more in terms of bass quantity, the Fem can present a much clearer bass region.

The lower midrange is about the same on both earbuds, but the Fem has a more enhanced upper midrange region. Though the treble on the Fem is a bit lacking, the treble on the ANC-860 is even more relaxed sounding.

While the 2 TWS earbuds might give a similar first impression due to how close their cases look, the ANC-860 has a very different sonic presentation when compared to the Fem. 

Sudio Fem
Copyright Sudio 2021

Our Verdict

The Fem immediately shows its Swedish roots, as the design language is minimalist but functional. From the case to the earbuds themselves, the aesthetic is well thought out with a simple elegance to the whole aesthetic.

The Realtek Bluetooth SoC might implement some features differently from its Qualcomm counterparts, but the Fem can integrate them well into its system.

Listening to the Fem, I found it to be controlled, but appropriately accentuated at the right spots in terms of painting a soundscape. It is not audiophile-level but suitably tuned for a non-fatiguing casual listening experience.

Overall, the Fem is a product that incorporates Swedish design principles and an above-average consumer-orientated listening experience.

Sudio Fem Technical Specifications

  • Compatibility: Android, iOS
  • Playtime: Up to 20h total
  • Built-in microphone: Yes
  • Range: 10m
  • Bluetooth version: 5.0
  • Voice Assisted (Siri and Google Assistant): Yes
  • Codec: SBC, AAC
  • Water-resistant IPX5, sweat resistant
  • Wireless: Yes

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