Fit and Comfort

Seen above is the FiiO FT3 placed on a mannequin head, to help show how these headphones would look on the human head. Note that the head is slightly under average sized, so account for the discrepancies accordingly. As with all headphones, getting a good fit and seal is crucial, so make sure to properly use the available height adjustability of the headband and the swivel/rotation of the ear cups themselves. This section is mostly a summary of the points expanded upon in more detail on the previous page and I will mention here that the FT3 is relatively heavy (for dynamic driver headphones) at ~390 g, but does not feel like it. It wears its mass quite well owing to good weight distribution with the metal parts used throughout, and the wide self-adjusting suspension band also helps spread out the mass more along the top of your head. There are caveats associated with this for those with larger or smaller heads though, as pointed out on the previous page. The ear cups also come spring-loaded so this can be good or bad depending on how much clamp you feel on the side of your head. Lastly, the ear pads are not the largest out there and do not have any contouring or an oval/D-shaped design, so there remains room for improvement. On the other hand, my average sized head and ears had no issues with these constraints. We get two types of ear pads and the stock suede pads were my preference for comfort. I also appreciated the pad install mechanism as well as the foam gasket to prevent any sound leakage between the ear pads and the ear cups themselves, and both sets of pads were also malleable enough to fit over my ears without leaving a gap anywhere. Part of this also has to do with the clamping pressure which I would describe as being on the correct side of average for me. Do note that the cable connectors come straight down from the ear cups, so a replacement cable with longer connector housings could be a potential issue in hitting your neck/shoulders—the stock cable should be fine in this regard. Lastly, keep in mind that the FiiO FT3 is an open-back set and thus will be best used in a quiet environment without others in the vicinity.

Audio Performance

Audio Hardware

FiiO mentions it spent ~1.5 years developing the FT3 which, given it has one of the largest R&D teams in the audio industry, means a lot of cumulative time. This is supported by the use of highly uncommon and large 60 mm dynamic drivers in the FT3 given pretty much everything else goes the 30-50 mm route. The larger driver should be theoretically capable of producing deeper bass and at lower distortion throughout, which is one of the reasons planar magnetic drivers have become popular and also are much larger than the average dynamic driver. The diaphragm uses a DLC (diamond-like carbon) coating which is again new to me given these DLC drivers have only been popping up in IEMs based on my experience. The surround gets beryllium-plated to add to the overall lighter aspect of the driver as well as making for a more rigid and responsive driver going back and forth in the magnetic field generated by an asymmetrically positioned neodymium N52 magnet cluster that FiiO says helps adjust for any larger movements of the diaphragm and the associated voice coil. Rounding off the acoustic design is the 350 Ω impedance voice coil made of Japanese copper-clad aluminium wire (CCAW) that is 35 µm thin. The increased impedance should allow for a better signal-to-noise ratio when powered off a capable source and the rated sensitivity of 105 dB/Vrms (100.44 dB/mW) at 1 kHz means the FiiO FT3 is only slightly more demanding than your average set of over-ear dynamic driver headphones asking for ~10 mW to hit 110 dB transient peaks. So while I would not recommend a basic dongle necessarily, a decent portable DAC/amp should be fine. Indeed, the FiiO BTR7 pictured in the previous page met my needs even off the 3.5 mm output, and the likes of the FiiO Q7, K5 Pro ESS, K7, K9 Pro ESS, and R7 are all more than fine and pair nicely with the FT3. If you are more in the DAP game, I do have the new FiiO M15S here being tested and it provides plenty of juice too.

Frequency Response Measurement and Listening

I will mention that I have a general preference for a warm-neutral signature emphasizing a slightly elevated bass and smooth treble range with detailed mids and good tonal separation. I also generally prefer instrumental music over vocals, with favored genres including jazz and classical music.


Our current headphones test setup uses a set of two custom in-ear microphones for the two channels. These microphones closely adhere to the IEC711 class, but have been tweaked to be more reliable in the >10 kHz frequency range, the precise issue with my previous setup, that is otherwise still very good and will continue to be used for IEMs and earphones. Two soft silicone pinnae are installed on the sides, separated by a distance matching my head, and multiple "height" adapters have been 3D-printed for further customization, based on fit, head size and shape. Each set of microphones has an XLR output I separately adapted to 3.5 mm. I used a transparent source—the FiiO R7 in USB mode—for measurements after confirming it was not a bottleneck in any way. This artificial head simulator feeds the microphone lines into a reference USB sound card, which in turn goes to a laptop that has ARTA and REW running. I begin with an impulse measurement to test for signal fidelity, calibrate the sound card and channel output, account for floor noise, and finally test the frequency response of each channel separately. Octave smoothing is at the 1/12th setting, netting a good balance of detail and signal to noise ratio. The default tuning was used for testing, and no app or program-based EQ settings were chosen, unless specifically mentioned. Each sample of interest is measured at least thrice with separate mounts to account for any fit issues, and an average is taken of the individual measurements for statistical accuracy.


As per usual, you can find my headphone frequency response measurements on VSG.squig.link, along with all the earphone measurements. Scroll to the bottom and choose different targets there, including two from Harman Kardon, developed after years of R&D. The Harman 2018 over-ear target in particular is a reference curve many headphone makers aim for now, but I find it too bass-boosted. As such, I am opting for the Harman 2018 curve with the bass target from the Harman 2013 curve, which is what is being referred to as the "Harman Combined" target there. Before we get talking about the sound signature of the FiiO FT3, I want to first talk about the channel balance achieved here. You will notice how the left and right channels are pretty much identical all the way from 20 Hz to 20 kHz, which is the region of interest for human hearing even if FiiO mentions a 7 Hz to 40 kHz response. Indeed, knowing this was a randomly picked retail unit makes it all the more impressive given companies have difficulties getting this level of channel matching even with much more expensive headphones! There was no channel imbalance perceived thus and I will also mention that using the headphones for ~75 hours didn't change anything either for those who would undoubtedly be curious about burn-in. So far so good!


We've seen how the FiiO FT3 comes with two different sets of ear pads in the form of the pre-installed suede pads and the partially fenestrated protein leather pads in the box. Seen above are the average frequency response measurements for my sample of these headphones with both sets of pads and we see there are clearly two different sound signatures. I typically find suede pads to result in more bass leakage resulting a dip in the sub-bass, although here things are quite different. Some of this can be attributed to the dampening in place in the ear cups and credit is due for the use of the foam gaskets between the pads and the ear cups. We end up with a warm neutral sound with the suede pads thus, almost a mild V-shape sound signature even. This bass shelf from an open-back set (semi-open, really) is already making the FiiO FT3 different from what it is competing against for your money. Overall bass extension is quite good all the way down to 20 Hz, if not below. The dampened drivers do make it feel less bassy on the ears than the graphs suggest though, and I will point out that the sub-bass punch was milder than what I expected. Instead I had a more mid-bass emphasis with good impact and detail coupled with excellent separation and appreciation of both leading and trailing ends of tones. The replacement pads result in a lowered bass response to be firmly warm-neutral although, given the same dampening in place, I thought the suede pads fared better here and I agree with the choice of using them as the default pads for the FT3. The protein leather pads made for a slightly grainier sound hurting detail retrieval and also reduced the dynamism of the large dynamic driver.

The FiiO FT3 feels like a set people would appreciate to just place on their head and have something playing in the background. As such, if you are working on the PC and want to have background sound where you aren't exactly going to use it for an analytical examination of said music, the FT3 with suede pads would be a great contender. The overall tonality is highly agreeable with me and just two simple EQ filters can get this combination to be spot-on with the target curve too if that is to your liking. Indeed, the lower distortion of the FT3 drivers came to the forefront when I played around with EQ and I did not notice any issues to where you can possibly push the set to have more bass or even make it have cleaner mids. Vocals are otherwise already clear and prominent to make this good for general media consumption too. Imaging is slightly hazy with brass instruments but precise enough overall to not be a concern. I did find the soundstage to be on the more compact side to where you won't forget this is still a set of headphones. Timbre is a strength of the FiiO FT3 wherein everything sounds so good and natural be it kick drums or guitars. Some of this no doubt is from the tonality employed here wherein you see a smooth ear gain leading to an even smoother upper mids and treble reproduction. I am not sure how much those dampening triangles are going to help with standing waves in the higher frequencies but something sure is working here. Once more we get a dampened response resulting in a more relaxed presentation over an analytical one. This is not to say it's boring or less engaging though, more that I did not want to take the set off my head listening to varied music genres including jazz and classical. The protein leather pads tilted things towards a brighter, arguably shouty sound even after a few hours of just using them to where I probably would not use them with the FT3 at all unless all you cared about was cleaner bass and lower mids.


Unfortunately I don't have a lot of open-back headphones here in the price range the FiiO FT3 operates in. There's the planar HIFIMAN Sundara, which I will be getting in shortly, which is one of the most recommended headphones ever. There are a few other dynamic driver sets from Audio-Technica, Beyerdynamic etc. too which would have been nice to talk about here. But really the first thing that came to mind was the Sivga Phoenix, which also aims to go for a warmer sound but ends up far worse tuned and closer to the grainier FT3/pleather pads combo to where the default sound signature with the FiiO FT3 makes it much more amenable to most. The Phoenix may well be more comfortable though and the wooden ear cups are a safer choice than the more aggressive design used on the FiiO FT3, but I'd pick the latter every single day of the week! I thought of the Philips Fidelio X3 but really the Sennheiser HD 6XX is a much better take on that same formula. Indeed, the HD 6XX costs less than the FT3 for those in the USA whereas others elsewhere will need to pay even more than the FT3 for the HD 650. This is more traditional for open-back sets in having bass roll-off but gives you some of the best mids reproduction of any set of headphones at any price point. The tonality is also pleasant here but can be dark for some to where the FT3 with its improved extension on either side strongly merits a consideration, if not a purchase to pair with the HD 6XX for a highly compelling two-set headphones collection!