FiiO FD5 Review

FiiO FD5 Review

1 February 2021 0 By Petros Laskis

Less is more…

Pros: – Natural and high musical tuning
– Great bass extension and quality
– Wide soundstage
– Precise imagining
– Interchangeable sound tube in two sizes
– Excellent build quality
– Stainless steel construction
– High end cable with interchangeable plugs
– Luxury carrying case
– Five different kinds of ear tips

Cons: – A bit heavy
– May not fit well small ear cavities
– Medium noise attenuation
– Not as comfortable as anatomically shaped iems

The FD5 was kindly provided by FiiO and is still under their ownership.
This is my honest and subjective evaluation of it.

The retail price is €300 and you can get it from


After a long and adventurous journey into multi driver iems – hybrid or not – including the much acclaimed FH3 , FH7 and FA9 , FiiO is back to where it all began.
Six years ago the EX1 was their first iem , a single dynamic driver design as is the case with their brand new flagship the FD5



Technology inside

Say hello to FD5, a single dynamic driver iem with a large 12mm diameter.
Size is not all that matters and this big boy packs some heavy technology and innovation inside.

The diaphragm is beryllium coated combined with diamond like carbon coating (DLC) in order to make full use of the physical rigidity and flexibility of the materials to reduce unneeded vibration and properly damp the sound for improved quality.

In order to address the issues that come with time delay between different sound waves , an acoustic prism was specifically developed for the FD5.
This was inspired by technology used into high end tweeters.

By installing a conical device close to the front end of the diaphragm the designers were able to control how sound waves travel into the tube and eliminate standing waves plus enhancing sound diffusion.

A “volcanic field” was added to the rear of the FD5 in order to reduce low frequency standing waves and distortion.
The FD5 also adopts semi open design which relieves air pressure inside the ear leading to longer listening sessions.

As we can see FiiO used high end technology in order to fully exploit the single drivers most important feature which is the one point source radiation of the sound waves.

Build quality and comfort

The shells are well made from robust stainless steel that not only looks striking and beautiful but additionally helps to reduce the harmonic distortion of sound inside the FD5.
The overall impression is that they definitely feel and look more premium than the price would suggest.


The curved cylindrical design was cleverly adopted in order to enhance fit and to greatly reduce unwanted resonances and reflection of the sound waves inside the body.

But steel as we know is a heavy material and as that each ear piece weighs a whole 11gr.
According to this the FD5 is quite heavy especially when compared to aluminium or 3D printed iem like the FA9 and can become a little fatiguing after a prolonged time of use.
Anyway this wasn’t a deal breaker for us because we always take small breaks after an hour or so of continuous use in order to protect our hearing.


Overall fit is good and comfortable but don’t expect custom like anatomical fit.
Due to the generic cylindrical shape some users may experience difficulty to properly fit them especially if they have a deep cavity or a smallish inner ear.

Although the FD5 is a semi open design passive noise control was above average and we have successfully used in noisy environments.
Still it will not isolate like some custom like closed back iems do.

The FD5 features interchangeable sound tubes in small and large sizes to best fit our ears.
The large one will fit most ears and results into a balanced sound signature while the small one can be combined with the triple flange ear tips in order to fit smaller ears and additionally enhance the bass reproduction.



The cable is of very high quality and if it was branded it would probably sell more or less at the FD5 asking price.

We are very grateful that FiiO is paying attention to reviewers and customer feedback.
This is quite like the cable that was used with the EM5 earbud and back then when we reviewed it we wished that FiiO would adopt it in all future flagship earphones.


Our wish was granted and the FD5 is equipped with such a cable in a slightly different form.
It is detachable with an expanded MMCX connector at the earpiece end and an interchangeable audio straight plug at the other end.
The plug is easily swapped and we get 3.5mm , 2.5mm and 4.4mm variants to fit all use cases without the need of an adapter.



High purity monocrystalline silver plated copper is used in eight strands with 19 wires per strand.
Litz type 2 structure is adopted where each wire is individually insulated.


Cable length is 1.20m and the handling experience is very satisfying with low microphonics and tangle free use.


FiiO is always generous when it comes with the supplied accessories so except the cable and the extra sound tubes we get bass , vocal and balanced ear tips in three sizes each.


Additionally we will find extra foam and triple flange ear tips in two sizes plus the Final Audio MMCX extraction tool and a small cleaning brush.
The brand new premium and high quality HB5 carrying case is included.


Sound impressions

The FD5 with an impedance of 32Ω and a high sensitivity of 109dB/mW is very easy to drive but it will not pick up internal noise.

We have tested the FD5 with various devices such as the FiiO BTR3K , BTR5 , Q3 , Q5S TC , M11PRO , the EarMen Sparrow and Eagle , SoundMAGIC A30 and Zoorlo Ztella among others.
The burn in process is beneficial to the FD5 and we would suggest at least 80-100 hours in order to reach the intended sound signature.

The FD5 while it is very enjoyable from entry level sources it scales incredibly well and can do justice even to high end partners so we wouldn’t be hesitant to use our best gear with it.
We have greatly enjoyed it with the FiiO Q5s TC and EarMen Sparrow.

Sound impressions to follow are with the balanced ear tips and the large sound tube.

The overall sound signature is very balanced with excellent timbre and an even , natural and very musical tonality.
One striking aspect is in the sound projection and the way that it feels integrated and homogenized.
Music sounds as a true whole and it doesn’t feel like split into several frequency bands as is the case with a lot of multi driver iems.
The FD5 feels very clear and undistorted even when pressed hard to very loud listening volumes.


Bass is the star of the show not because it is accentuated or emphasized but rather for the high quality characteristics.
Low notes are extended down to the sub bass region without any significant roll off.

Quantity is of equal loudness to the rest of the frequencies and as natural as it can get.
Many people that are not used to proper bass levels may initially perceive it as too much but in the long run they will discover that this is the correct bass amount that an earphone should have in order to be balanced according to the equal loudness curves.
If we would like to criticize the bass quantity from a puristic point of view then yes it could be toned just a touch lower to be perfect and of better proportion to the lower mids.

The large and rigid driver can move plenty of air and still recover very fast.
As a result we get an impactful , full bodied bass response that is speedy with great dynamics and excellent control.
Texture is vibrant and visceral with great detail and ample layering.
We can distinguish every drum beat and hammer stroke, even the kind of string bowing or the most silent pizzicato.
Reverberation and echo are very well reproduced and add greatly to the overall sense of reality.
In other words this is one striking performer and among the best we have ever tested.

Transition to the mids is linear without significant mid bass bloat but some times upper bass can feel a little foggy compared for example to the FH3.

The middle section is slightly restrained but not recessed.
The tuning follows the Harman Target response curve but it does not sound overly V shaped or hollow.
Voices and other instruments are centered on the mix without being highlighted or drawn far away.
Timbre is correct and everything sounds lively and engaging with a well rounded and full body.
Clarity is amazing and we can hear every single breath of the singers or their lips whispering the notes.

Higher frequencies are well extended and crispy without being fatiguing or sibilant and timbre is retained very natural.
The presentation is clear and vibrant with very satisfying micro detail levels.
The FD5 is not an analytical or overly detailed earphone but is not lacking in this department.
It is just not oriented in monitoring duties and the fine nuances are presented as an integrated part of the whole musical experience rather than being solely highlighted.
The best part is that the high frequency notes are equally full bodied as the rest of the spectrum and never sound lean or light.
Transient response is moderately fast and time decay is spot on timing with all the notes naturally fading into the recording space that is persuasively recreated.

Talking about space the FD5 can draw a wide and large soundscape which is projected just a little outside our head.
There is enough room for all the instruments to shine with good accuracy across the left to the right axis but depth layering is restrained and unfortunately we don’t get that three dimensional effect.


Minor sound tweaking can be done with the supplied ear tips and the small sound tube.
We haven’t experimented extendenly because the small tube must be used with the triple flange ear tips that we find them very uncomfortable.
Anyway the few times we tested we felt that the large size tube was much more to our liking.
The various other ear tips are worth testing because they really offer some fine tuning without altering the general character of the sound signature.

At the end

Well what an irony.
FiiO have managed to exceed our expectations and beat their own multi driver flagships with a single dynamic driver iem.
It is obvious that for our individual tastes and hearing perception the FiiO FD5 is not only the best tuned and more mature FiiO iem till now but one of the best we have ever tested.
The FiiO FD5 is the definition of the proverbial phrase “less is more” and a lesson in design and proper implementation.
You don’t need to have a dozen of various drivers and complex uber high tech crossovers as long as you are able to be innovative and carefully design around a single quality component.
And FiiO R&D team have managed exactly that elevating simplicity to a whole next level.
The FD5 is a thoughtfully created and tuned iem which is highly enjoyable with all kinds of music without drawing attention to itself.
So to sum up if you value very natural timbre and tonality and you prefer listening rather than analyzing to your music then the FD5 is made for you.
Sit back and enjoy , satisfaction guaranteed.

Test playlist –

Copyright – Laskis Petros 2021.