Fearless Audio S6 Rui

Before starting this review, I would like to share technical aspects and package details.

Also, I would like to thanks to Penon Audio for this great opportunity. Here is the link of the S6 Rui;




Driver: 6 balanced armature (1 Sonion compound low frequency, 1 Sonion compound middle frequency,2 Knowles independent high frequency)

Impedance: 20 ohm

Sensitivity: 116dB/MW

Passive noise reduction: 26dB

Frequency response range: 20Hz-20kHz

Connector:2pin 0.78mm



Package Details:

Fearless S6RUI earphone

Eartips 4 Foam, 3 (SML) SpinFits and 3(SML) Black silicone.

Leather Carrying Case

2-pin SPC 8 Core cable

Shirt clip

Cleaning tool

Metal plaque with information pertaining to the model


Test Equipment:

Lotoo Paw Gold

Astell & Kern AK120

Opus #1


Package, Design & Isolation;

I think Fearless Audio has changed their package design recently. Old package was simple yellow box but now, S6 Rui comes with white designed cartoon box. Inside the box, there are leather cover case, tips, warranty card, and cleaning tools. The carrying case is really fantastic. It reminds me the Anole VX leather case both as design and color. Case has nice touch and its size is pretty enough to keep S6 Rui inside of the box. This is pretty impressive because most of the earphones come with simple carrying case at this price range. It is nice to see that Fearless Audio improves their products and package quality day by day. Cable is another great thing of S6 Rui. Its stock cable is really great and I don’t think I will upgrade it.


My S6 Rui has K9 faceplate with translucent A5 shell design, but there are many other customization options for it, and you can select different designs. And also, you can make your own design as well. This is my second Fearless Audio product and I’m familiar with its shell design and quality. Earphone itself has ergonomic shape which provides good fit and isolation. Built quality is fantastic. No blemish, quality defect or QC issue on it. Like other Fearless products, it has also industry standard 0.78mm 2 pin socket so you can use aftermarket cables with S6 Rui. Isolation is great, no complaint here. I got pretty good seal with the silicon tips. S6 Rui’s body design makes a great comfort and isolation in ears.



S6 Rui is pretty well known iem in the audio community and I guess almost every person who buys it loves at the very first sight. Its sound like a dynamic driver, it has nice energy with dynamism and also provides nice detail in every frequency. S6 Rui is some of few earphones that I heard like this kind of bass performance. It is pretty impressive for a balanced armature driver; it hits hard and sub bass goes pretty deep. Mid frequencies are laid back but vocal sound is slightly forward. High frequencies have nice sparkle and extension and it’s prominent on the overall sound.



The upper frequencies are slightly bright, airy and well-extended. A tremendous feature is that the trebles do not loose their control too much. In general, the S6 Rui has a V-shape sound structure, so I can say that the trebles are quite prominent. The fact that the prominent presentation does not make it sound perfect or good by itself, but it is important how it is tuned. In general, I like the tonality of the upper frequencies as well as its control. There is no metallization in the treble, and it has a natural presentation. I did lots of tests with my favorite Le Trio Jeoubran album, and treble does a really good job on stringed instruments. The separation of the instruments and the airy presentation on stage are pretty impressive.



Mid frequencies are smooth, easy to listen and overall presentation is soft and does not pressurize the stage in any way. Mids are smooth and its detail and resolution level are quite impressive. It is not shy to give many details in music. Mid frequencies are generally laid back than the other frequencies. Tonality is slightly colored and warm. You feel this coloration especially in the instrument’s sounds, the instruments play a little thick and meaty. In fact, lower mid has a big role in here. Vocals seem to be centered on the stage, and it doesn’t seem like you hear it all over the scene. Detail level is good to hear every single detail in the music.



Basses are at top of the area where the S6 Rui is the most successful. Basses are really strong, bulky and they don’t have any problems about reaching deep. Another thing that surprised me is the beats of the bass are reminiscent of the dynamic driver. Both hits and tonality are very similar to the dynamic driver. Sub basses can go deep very well. I said it was like a dynamic driver, but let me emphasize that you can’t get close to a powerful dynamic driver. I love the sound performance of the armature drives, but I think they are a little weak in generating sub-frequencies. Most armature driver headphones are dry and dull with lower frequencies, of course there are some very well tune earphones out there, they are exception. At S6 Rui, I think I can say that it is included in this class. Not dry, not weak or slow, it is very dynamic and natural beats in this regard. Although the bass is strong, it is extremely fast and controlled. It’s not the fastest armature driver I’ve listened to, but in that sense it’s definitely good. Overall the bass performance is quite pleasant to listen to and the prat feeling is quite high.



I can say that the soundstage is wide and deep enough to create room for vocals and instruments. But there is no exception here. It is not the best in its class, but it is better than the average I believe. The instruments and vocals can play from pretty wide area and it is easy to listen. Background is black and clean. It provides clean and clear presentation.



S6 Rui vs Atlantis:

These are two different earphones both as sound characters and technical details. S6 Rui has 6 balanced armature drivers while Atlantis has 4 balanced drivers. Both earphones’ material and built quality are fantastic. S6 Rui’s sound is dynamic and rich, it has nice bass slam with extended trebles. S6 Rui takes its power from the low frequencies and it adds body on the overall sound. Atlantis is slightly warmer and it sounds is reference like. Of course, not exactly reference but its neutral and balanced sound signature bring it closer in that sense. S6 Rui is much more enjoyable earphone. Bass is more powerful and pronounced with S6 Rui. Its bass hits almost like dynamic driver, actually its bass performance is better than some dynamic drivers. Atlantis is less authoritative and when it’s compared to S6 Rui, it feels bass light. Roll off on the bass becomes more apparent. Atlantis bass is tighter and faster, but not a big margin. Mid frequencies are bolder and thicker with S6 Rui while Atlantis has airier and more neutral. Instruments sounds are more realistic on Atlantis. S6 Rui is playing instruments bold and chubby way. Soundstage is wider and airier on Atlantis. S6 Rui has also wide soundstage but Atlantis’ gives better feeling. At the end, both earphones are pretty good for sound but it depends on your preferences. If you are looking for a fun signature, powerful bass with dynamic earphone, go for S6 Rui. Atlantis sound is totally opposite. Neutral, balanced sound makes Atlantis almost reference earphone, and if you are looking for that, go for it. But Atlantis’ price is almost double on S6 Rui.


S6 Rui vs Audiosense T800:

Lately Audiosense T800 is one of my favorite iem under 500$ which its sound is really impressive. It has 8 Knowles drivers per inside and configuration is like; 2 dual drivers for high, 4 mid drivers for mid, and 2 drivers for low frequencies. Both earphones’ material and build quality are top notch, no complaints here. Sound wise, they are sharing some similarities in sound. Both S6 Rui and T800 have extended and sparkling trebles. S6 Rui is little bit more extended and it has more energy than the T800. T800 is more relaxed and smoother without effort. S6 mid frequencies are more laid back and it’s like dominating with low and upper frequencies. T800 mids are more pronounced and more upfront than the S6 Rui. Vocal is also forward on T800. But earphone has nice details and timbre on mids but T800 is just a bit better for my taste. It is more romantic and natural feeling. Bass quantity is similar in quantity but S6 Rui hits a little harder. Soundstage is wider and deeper on T800 but that doesn’t mean S6 Rui is narrower. It is also wide and pretty deep but T800 puts more air and space between instruments.



Fearless is a very fresh company but they already made many amazing earphones, and a lot of people using their iems with pleasure. S6 Rui is one of them, and great iem which deserves its popularity in the community. Dynamic and engaging sound with easy to love tuning make S6 Rui as a all rounder. Its powerful bass performance accompanied with smooth and detail mid and prominent clear treble.

All the body and material quality are fantastic. Stock cable doesn’t need to upgrade, it is already good looking and sounds beautiful as well. Leather carrying case is not a usual thing to see in this price range which is great. Overall if you are looking for balanced armature earphone with warm and detailed sound, S6 Rui is a great option for its price.


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