FiiO FF3S Review featured image

FiiO FF3S Review

In this feature, Meldrick reviews the FiiO FF3S, which is a new set of 14.2mm dynamic driver earbuds with a detachable SPC cable and interchangeable plugs. It is priced at $89.99.

Disclaimer: This was sent to me as a sample in exchange for my honest opinion. Headfonics is an independent website with no affiliate links or services. I thank FiiO for its support.

You can click here to learn more about the FiiO audio products we have previously assessed on Headfonics.

Note, that this post follows our current scoring guidelines which you can read in more detail here.

FiiO FF3S Review featured image
FiiO FF3S Review
Despite making use of the same driver on paper, the FiiO FF3S earbuds offer a more neutral-warm U-shaped tonality compared to the warm leaning V-shaped tonality of the original FF3. It also improves on the comfort and usability of the previous generation with a lighter build and a new detachable cable.
Sound Quality
Slide here to add your score on the gear!66 Votes
Inoffensive warm sound signature
Removable cable
Comfortable for long hours
Lacks high end detail
Lacks a bit of punch
Award Score

Even for most well-known Chi-Fi brands, the earbud segment doesn’t receive as much attention as the IEMs or full-sized headphones. Despite this, FiiO has been steadily updating its lineup of audiophile earbuds.

Today I will be assessing the FiiO FF3s, an updated take on the brand’s well-received FF3 dynamic driver earbuds priced at $89.99. Sporting a new detachable cable and a bass-focused sound signature, does the FF3S have what it takes to stand out?

FiiO FF3S Technical Highlights

Tech Highlights

The FiiO FF3S is an updated pair of “earbud” style single dynamic driver earphones that come with a removable cable with interchangeable terminations.

Unlike its predecessor the FF3, the FF3S stock cable does not only come with a detachable 3.5mm unbalanced and a 4.4mm balanced alternative plug but also the individual buds themselves are now detachable via the same 2-pin 0.78mm connector seen in the FiiO FF1.

Up until recently, it was quite rare for earbuds to come with a detachable cable, making FiiO’s new direction with their earbud lineup quite refreshing. 

Similarly to FiiO’s other earbud offerings, the FF3S makes use of a comparatively large beryllium-plated PU dynamic driver. According to FiiO, this choice of driver construction plays a large part in the improved bass response that they speak highly of when compared to most earbuds.

Lastly, the FF3S makes use of an upgraded aluminum shell and design that not only gives it a more subdued appearance but also greatly improves comfort over the original FF3 by decreasing the weight of each earbud by 52%.

FiiO FF3S front design


As previously mentioned in our review of the Fiio FF1, the original FF3’s more premium build and construction did come with some compromises.

After testing and comparing all three earbuds it is obvious that FiiO has taken the design highlights of the original FF3 and FF1 and fused them to design the superior FF3S.

The stem and body of each earbud are constructed out of aluminum with a sleek anodized black finish with slight hints of green. The appearance and hand feel of the aluminum shell do not particularly stand out, but in daily use, I appreciated their durability and how resistant they were to wear and tear.

The backplate of the FF3S is identical to the one used in the original FF3, making use of an ornate geometric pattern with a tasteful bronze color. The graphic is sealed under what appears to be some sort of sapphire, giving the otherwise utilitarian shell of the FF3s some flare.

By the backplate, a pair of vents are expertly machined onto the shell to improve airflow and contribute to the improved bass response. This machining of the vent is quite nice and I did not feel any sharp edges or gaps even when I ran my finger across the circumference of each bud.

The FF3S exchanges the tube-type stem of its predecessor for a more rectangular flat-type stem seen in the more affordable FiiO FF1. At first glance, this flat stem may appear to be less premium, but as we will mention below, this new stem design comes with much-appreciated improvements to comfort.

FiiO FF3S back design


The FF3S is very comfortable to wear, especially compared to the original FF3, thanks to its improved ergonomic shape and lightweight. The earbud sits securely in the ear, without causing any pressure or fatigue.

Despite seeming counterintuitive, I found that the wider flat stem of the FF3S was more comfortable than the cylindrical tube-shaped stem of the original FF3.

From my testing, the original FF3 sits at an angle within the ear that causes its stem to rub against the ear, while the FF3S fits snugly in the ear canal without rubbing against the outside of my ear at all.

I found that the FF3S was more comfortable than the FF1 as well because of its narrower stem. The Venture Electronics ZEN LL is more comfortable, but the FF3S is a close second even compared to the rest of FiiO’s lineup and more common MX500-style earbuds.

In my testing, I found that using either the included silicone rings or foam covers was a must in ensuring a good fit, especially for on-the-go usage.

FiiO FF3S paired with ddHiFi tc35 Pro 2

Stock Cable

The stock cable of the FF3S is one of its main selling points, as it is very well-made and versatile. The cable is composed of 152 wires of high-purity silver-plated monocrystalline copper, covered with German-made TPU material.

Aside from the 0.78mm terminations on the left and right side of the cable, the FF3S stock cable is identical to that of the original FF3.

I was excited to try the FF3S out with my collection of IEM cables. However, the narrow 2-pin connector on the buds themselves made them incompatible with my other cables, aside from the stock cable of the FiiO FF1.

According to the FiiO website, they are currently developing a “FiiO-designed headphone cable” that will be compatible with the FF1 and FF3S. This would be great in ensuring that the buds do not become useless in case of cable damage.

The stock cable has a modular plug system, which lets you switch between a 3.5mm and a 4.4mm termination, depending on your source device. The plugs are easy to swap, as you just need to screw them on and off the cable. The plugs have a dot and a groove to help you align them correctly.

Throughout my day-to-day testing, I never experienced any microphonics in my mixed on-the-go and desktop listening. Additionally, I appreciated how the rubber coating material around the cable prevented any cable memory or cable tangling, making it convenient to listen to the FF3S after taking it out of my case.

FiiO FF3S accessories

Packaging & Accessories

The FF3S comes in a simple and elegant white box, with a picture of the earbud some specifications on the front, and some manufacturer information at the back.

Inside the box, you get the earbuds, the cable, 2 plugs,  six pairs of donut foams, six pairs of full foams, six pairs of silicone rings, and a pair of silicone wing hooks.

The donut foams have a hole in the center, which reduces the bass and increases the treble. The full foams have no hole, which increases the bass and reduces the treble.

The silicone rings can be used to improve the seal and stability of the earbud and come in two sizes: large and medium. The wing hooks can be used to provide extra support and grip for the earbud and are made of soft and flexible silicone.

There are decent inclusions given the price range, letting users experiment with these accessories to find their optimal combination.

Sound Impressions


Similarly to the FF3 and FF1, FiiO has done a very good job in crafting earbuds that have a bass response that makes them competitive with the more common IEMs.

The bass of the FF3S is warm and authoritative though the sub-bass performance does not hit deep until you start playing back drum-heavy tracks. The bass is not muddy, nor does it bleed into the mid-range, but rather well-controlled and textured.

I never found myself wanting more bass. I always found that the quantity and quality of bass that the FF3S was providing was sufficient for what the track needed.

The mid-bass emphasis accentuates bass guitars, giving them an atmospheric feel that envelopes the listener. Bass lines in funk and soul tracks are lush and decently textured.

It is by no means a powerhouse at detail retrieval or playing back with texture, it is very laid-back and relaxing, adding weight and warmth to the sound. The bass is suitable for genres that require rumble and deep atmospheric synths.


The mids of the FF3S are smooth, natural, and very slightly recessed, compared to the mid-bass. The mids are not very forward or detailed, but they are clear and pleasant.

Compared to more V-shaped buds such as the original FF3, the FF3S’ vocal and string instrument presentation was much clearer.

The lower mids are not very thick or congested, despite the warmth presented by the bass, and the upper mids are not very harsh or sibilant at all. The vocals are well-placed and have a good timbre, but they are not very intimate or emotional.

They instead maintain a relaxing presentation, placing no unnatural emphasis on the vocals. The instruments are decently separated and have a good tonality, but they are not very realistic or expressive. The mids are suitable for genres that emphasize a natural and relaxing timber over hyper-detail and resolution.


The treble of the FF3S is airy and even crispy at times. Compared to the mids, it is slightly recessed. The treble is not very detailed or refined, but it is smooth and easy to listen to.

Similarly to the FF1, I found myself craving a bit more detail retrieval and resolving capabilities on the top end. Wind instruments and cymbals all sounded flat with the same tonality.

It is important to note however that I did not experience any fatigue or discomfort even in tracks I specifically listen to for sibilance. This just adds to the relaxing and laid-back tonality that I keep on coming back to while listening to the FF3S.


The imaging of the FF3S is decent and coherent, but not very precise or accurate.

The earbud has a good sense of direction and positioning, but not a lot of depth and layering. The earbud can handle simple tracks, but it can struggle with busy tracks, with complex mixes merging into a solid wall of sound.

The soundstage, on the other hand, was quite good, even compared to other earbuds. Compared to the IEMs that I usually listen to, earbuds such as the FF3S and FF1 are in their own class altogether. Their staging performance is closer to my semi-open Koss KPH30i instead of IEMs.

Click on page 2 below for my recommended pairings and selected comparisons.

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