Fiio FD11 Review

Established in 2007 in Guangzhou, China, Fiio produces and develops high-resolution digital audio players, portable headphone amplifiers, DACs and earphones. The brand name is a combination of Fi (as in HiFi) and iO (number 1 & 0) the binary symbols representing the convenience of digital coding. 

FiiO focuses on product quality, style and service and places great importance on users’ needs, ceaselessly pursuing perfection in product design and manufacturing. The FD11 is the newest earphone from the company and is the first in a series featuring the “bionic conch” design inspired by the Nautilus shell. It retails for around £/$36.

fiio fd11

The Packaging

The FD11 comes in a compact rectangular box with a white slip cover adorned with teal and silver accents. There is a large illustration of the product and a “Hi-Res Audio” logo in the top right corner. Removing the slip cover reveals a black container with a clear plastic lid containing:

● Fiio FD11 IEMs
● 2 pin OFC cable with 3.5mm plug
● 3 pairs white silicone eartips
● Documentation

Compared to earlier models such as the FD3, this is a rather sparse set of accessories, but it appears that Fiio has prioritised the cost for the IEMs and the cable.

Build and Design

The FD11 has a zinc alloy shell with a faceplate decorated with an array of diamond shapes resembling a flower. It is shaped like a Nautilus shell and the finish is shiny and smooth. The earpieces feel solid and well made and have some weight to them. 

The 2-pin sockets are circular and recessed and are colour-coded for channel identification. The fit was very secure. Although the design is neat and stylish it does preclude the use of aftermarket cables since the recessed area will not accept standard connectors. I tried cables from Yinyoo, KBEAR and Hifi Hear with no success. 

There is a small vent for the dynamic driver on the top surface opposite the 2 pin socket and there is another similar vent at the base of the flared nozzle, which has a silver-coloured metal grille.The stock cable is a 4-core OFC type with 2 pin 0.78mm plugs and a 3.5mm gold plated TRS termination. There are coloured rings matching the inner part of the 2-pin plugs. The cable appears well made and is quite flexible but light in weight and very comfortable around the ear.

Cable noise was very minimal with no noticeable microphony in use. There only criticism I have is the lack of a chin slider as the cable proved somewhat prone to tangling. 

Internally, there is a dynamic driver with a 10mm “carbon-based” diaphragm (presumably DLC or Graphene), an asymmetric dual magnet array and a dual cavity construction. The shell also features a “C-shaped acoustic flute” which employs an extended path for the bass frequencies similar to a transmission line speaker. This is similar to Smabat’s “coiled up acoustic” Maze design and is intended to improve the sub bass quality.

Fit and Isolation

Straight out of the box with the pre-fitted tips, I was unable to get a secure fit or acceptable isolation. The shiny metal shells and their weight distribution made the earpieces unstable although this was partly due to my ear anatomy. I swapped the stock tips for medium KZ Starlines which have a longer cross section and the fit was snug and comfortable, isolation was adequate and the earpieces remained stable in the ear at all times.

Sound Impressions


The FD11 was initially tested using an Xduoo X20 DAP. However, the cool/neutral tonality of the X20 did not match well with the IEMs.  Switching to the Hifi Walker H2 with its warmer profile had the desired effect. During testing, a Samsung smartphone and Ruark digital radio were also employed and a 100 hour burn-in was performed before evaluation. 

The FD11 proved to be V- shaped, lively and colourful in character with a weighty sub bass providing a solid foundation, an open midrange less recessed than some similar profiles and sparkling upper frequencies with copious detail.

The profile might be described as a mild Harman curve with a touch of extra energy in the upper midrange and a more than usually extended treble. The soundstage was notable for its width and a good depiction of height endowing the staging with an “airy” feeling. The depth, however, varied according to the material being played, becoming less extensive or flatter with volume and with more energetic content.


The “C-shaped acoustic flute” certainly seemed to be effective and delivered a powerful, “breathy”, detailed low end with accurate timbre. Sub bass rumbled healthily, mid bass provided an entertaining kick with good speed and the texture of bass notes was well-defined and musical. The reproduction of recorded ambience was well presented.

This low frequency performance was demonstrated effectively in Liquid Mind’s “Soft Focus” from the album “Liquid Mind X”. Chuck Wild’s floating atmospheres, pentatonic melodies and suspended chords were solidly underpinned by a weighty, well-extended sub bass displaying both texture and detail. The attractive resonant timbre blended perfectly with the lead melody producing a calming, meditative feeling.

The opening to Britten’s “Sinfonia da Requiem” came over powerfully on the FD11. Powerful timpani strikes introduce the piece and they were reproduced cleanly and precisely with excellent speed and impact. Later in the movement the bass drum displayed accurate timbre and authentic decay. Andre Previn’s superb recording with the LSO, produced by Christopher Bishop and Christopher Parker, is a classic and the FD11 certainly did it justice with a fine depiction of the ambience in the hall.


The midrange possessed an attractive lively quality with plenty of detail, allowing the listener to appreciate the layering and imaging in the music. The lower part of the range derived some warmth from the bass region, whereas the middle range was a little recessed while still remaining articulate. There was an emphasis in the upper midrange leading into the lower treble which produced a more forward presentation. This resulted in some “glare” which resulted in an unnatural tonality similar to “BA timbre”, but this only occurred on certain material and in busy passages.

The detailed figuring of the solo instrument in Walter Leigh’s “Concertino for Harpsichord and Strings” was accurately portrayed by the FD11.  In the wonderful Lyrita recording by the New Philharmonia under Nicholas Braithwaite, the resonance of the harpsichord and its overtones lent a sense of realism taking the listener direct to the performance. Towards the end of the second movement the keyboard plays delicate arpeggios while the string section takes over the main theme. Here the balance between the lead instrument and the orchestra was perfectly judged.

The FD11 also excelled with vocals. Jeff Wayne’s “War of the Worlds” features a cameo by Richard Burton. He introduces the track “The Eve of the War” and further parts of his narration appear throughout the piece. His rich and characterful voice was reproduced authentically and it contrasted well with Justin Hayward’s lead vocals in the chorus. The synth melodies and electronic sound effects later in the track displayed good movement and precise imaging.


Following on from an elevated upper midrange, the treble continued somewhat emphasised, and was a little brighter than neutral. There was a slight dip in the middle range and further peaks in the high section which delivered some sparkle and good extension. Detail retrieval and separation was notable with fine elements standing out well and only some occasional hardness on certain material, especially at high volumes. 

Clannad’s “Magical Ring” is perhaps their finest album. “The Fairy Queen” is an instrumental showcasing the Celtic Harp supported by guitar and traditional woodwind. The fine detail of the fingering was highlighted due to the emphasis in the lower treble and it enabled the skill of the player to be appreciated. Being a simpler piece, the FD11 captured the separation and space in the recording realistically.Reynaldo Hahn’s “A Chloris” performed by John Lenehan and Julian Lloyd Webber is a meditative transcription for cello and piano.

Similarly to the Clannad piece above, details of the playing were well reproduced and in this case, the ambience of the studio came over very convincingly. The timbre of the cello was clean and crisp, with the “rosin” of the bowing particularly clearly presented. At the same time, the piano accompaniment was in perfect balance.

Soundstage and Imaging

Exhibiting excellent width and a good impression of height, the FD11 gave a good account of itself here. It was only in the depth of staging where things could be improved.

In smaller and intimate settings, there was a good sense of space but in more complex tracks there was a flattening of perspective which impacted on the layering and separation causing a congested effect.

At the beginning of Holst’s beautiful “Somerset Rhapsody” a solo cor anglais presents the first theme followed by the string section. This worked really well with the woodwind clearly defined above the accompaniment. After timpani announce the second melody, the full orchestra joins in and the FD11 found it hard to separate the various sections of the orchestra resulting in a merging of the different instruments. 

Supertramp’s”Logical Song” displayed the same character. At the start there was a spacious quality with ample width and good layering with Roger Hodgson’s distinctive vocals standing out well but later when the full band was supporting the solo saxophone, things quickly became somewhat busy, making it hard to follow individual elements. This was mainly due to the elevated upper midrange and lower treble which tended to dominate the presentation and reduce the depth. 


HZ Sound Heart Mirror ($39)

The Heart Mirror has been praised for its neutrality and accurate timbre and is often included in earphone enthusiasts’ lists of favourite IEMs. Like the FD11, it employs a 10mm dynamic driver with a carbon diaphragm (described as “nanometer”) and the well-constructed full metal shell has a shiny silver finish. The Heart Mirror has a neutral/bright profile with superb transparency and clarity and excellent detail retrieval which derives from low distortion and a lack of colouration. 

Compared with the FD11 the bass is more neutral with a higher resolution although not as extended and with a cooler tonality. The midrange is more transparent and the treble is cleaner and smoother. It does not have such a bold character but is more measured and neutral in nature. Timbre is very natural and there is more detail on offer than the Fiio. The staging is more open and it displays more depth than the FD11. However if you are a bass lover then the FD11 will be more suitable as it has more depth and impact.

Fiio FD3 ($109)

Fiio’s own FD3 is a single dynamic driver model with a 12mm “Flagship-level” DLC (diamond-like carbon) diaphragm, a Neodymium magnet with a flux density of 1.5 Tesla, a front acoustic prism and semi-open acoustic design. There are two sets of “sound tubes”, “bass” and “vocal”. Its profile displays a prominent bass and a clear detailed treble with a slightly recessed midrange. The overall tonality is on the warm side.

The FD3 improves on the FD11 by dint of its more focused bass which excels in texture and power. The midrange is more even than its sibling, and does not suffer from any harshness and the high frequencies are more refined with a more spacious quality. The overall character is “cinematic” with a bold presentation and although somewhat V-shaped the midrange never gives the impression of being recessed.

The semi-open design produces a much more three-dimensional staging. Of course the FD3 is in a higher tier but it is a useful comparison.

Smabat NCO ($92)

The NCO is a “bullet” style IEM with a full metal construction, MMCX interface worn cable down and an 8mm “HD” drive unit with a graphene diaphragm. Its USP is the “Maze” bass enhancement system which utilises an extended path for the low frequencies similar to a transmission line speaker. 

Like the FD3 above it has a bold, colourful presentation with fast transients and the profile is mildly V-shaped. There is copious detail and excellent imaging and the soundstage is very spacious. The bass is superb in extension, resolution and detail. It surpasses the FD11 in the midrange, which is slightly warmer in tone and more even in level throughout. Treble is extended, detailed and smooth with no discernible peaks, and is also preferable to that of the FD11.


Fiio have made use of “trickle down” technology in the FD11 with a high quality dynamic driver, modern diaphragm material and an innovative bass design. This philosophy certainly worked well in the FD3 and is also successful in the FD11 but perhaps to a lesser extent.

The bass region is certainly worthy of praise with a powerful and extended range with a natural timbre. I found the midrange to be emphasised at the treble boundary and the lower treble at times displaying a similar quality, but the lively and entertaining delivery generally focused on musical enjoyment and at the price, the FD11 acquitted itself very well.

I found the IEMs performed best with a powerful source and in this case, due to the recessed sockets, I was unable to test the FD11 with a balanced cable. This would have provided extra power and perhaps revealed how it scaled up. I also found it to be very sensitive to the source, so finding a good synergy was important.

The fit may also be a problem for some, with the smooth weighty shells affording little grip and some tip rolling was necessary to obtain a good seal. Of course this will depend on individual ear anatomy and it may not be the case for everyone.The FD11 is well built and a solid performer, above average for the price.

Compared to the sumptuous packages of other Fiio products there is a basic accessory set and the proprietary cable does limit options. However, these are minor issues and do not detract from the overall performance which is admirable and the FD11 should be in your shortlist if you are in the market for an IEM in this price range.

About Post Author

Author: Lynn Gray

Lynn has been interested in audio since the 70s when his brother brought him his first ever Hi-Fi system. Since then, he has developed an interest in portable audio when the first Walkman came out. He has been testing products for a number of years and enjoys experiencing new technology.

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