FiiO FD7

FiiO FD7 Review

The FiiO FD7 is a flagship IEM featuring a 12mm pure beryllium diaphragm dynamic driver and a semi-open acoustic design. It is priced at $599.99

Disclaimer: The FiiO FD7 sent to us is a sample in exchange for our honest opinion in this review. We thank FiiO for this opportunity. 

To learn more about FiiO reviews on Headfonics you can click here.

Note, this 2-page review follows our new scoring guidelines for 2021 which you can read up on here.

FiiO FD7
FiiO FD7
My first listen was enough to convince me that the FiiO FD7 is a special IEM indeed with a clean true to life tonality that is revealing with an almost absolute pitch tonality and great staging. For me, these are the best FiiO IEMs so far and are worthy of their flagship title.
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There are a few pure Beryllium single dynamic driver IEMs out there on the market today but not a huge amount with the rest being beryllium plated rather than pure.

There’s the Final A8000 which is a rather popular pure Beryllium driver model. DUNU has their LUNA, ADV has their M5-1D, and Periodic Audio has their Beryllium IEM just to name a few models out there that.

Most models have not hit the general mainstream and I bet your average next-door neighbor never heard of any of them. I’m sure if people heard them they will seek them out more often and this last statement is a spoiler alert, to say the least.

FiiO just released their pure Beryllium 12mm single dynamic driver IEM version which model number is labeled the FD7 and is similarly fashioned to the FD5 in many ways except for the sound signature.

FiiO FD7
Copyright FiiO 2021

Tech Highlights

I believe this is FiiO’s first attempt at a single dynamic pure Beryllium driver IEM. Their recently released single dynamic driver IEM was the FD5 and it has a Beryllium coated DLC driver but not a pure Beryllium driver.

Actually, besides that, most of the tech implemented in the FD7 was bought over from the FD5 including the volcanic field system which controls internal sound waves. Another carry-over tech is the front acoustic prism system which is also implemented here which addresses issues with sound wave time delays.

I bet the driver itself in the FD7 employs the same type of Tesla 1.5 N52 magnets which thanks to them made it very hard to photograph both IEMs close together due to them repelling away from each other because of their very strong magnetic fields.

There is no mention of this either but I bet similar Daikoku voice coils were used on the FD7 and even uses the same or a similar moving coil design type as the FD5 did.

FiiO FD7


The same body style, the cylindrical-shaped body style was also used on the FD7 same as the FD5 but FiiO upscaled its looks by going with black gold and yellow gold color scheme and are in fact quite gorgeous to look at. To me, they look better compared to their relative the FD5.

They give off this boutique jewelry quality essence and a nice visual appeal. The gold ink brushstrokes, as FiiO calls them are not there just for looks either but have purpose and form part of an open back shell design that vents off the prism and volcanic systems.

At 11 grams each earbud, the FD7 buds feel substantially heavier but that is a mental illusion created by the robustness of their construction. Imagine holding a similarly sized polished solid steel ball-bearing and you’ll get the picture somewhat.

Connectivity is made possible via MMCX connectors which are red and blue color-coded plus the cable connectors have left and right indicators making it easy to identify left and right sides.

FiiO FD7

Comfort & Isolation

For a semi-open back IEM design the FiiO FD7 does block out lots of noise and I think it has to do with the shell design itself and the way it slips itself into the ear canal.

The output ports are mounted at an angle which makes these IEMs anchor in place. Comfort however is not compromised by that and the angle of entry was carefully calculated and took to my ears particularly well.

This cylinder shape is one of my preferred designs because it barely touches the Concha or the Antitragus and just barely rests itself on the Tragus. Those parts of the inner ear are usually sources of discomfort while wearing IEMs.

So that being said, they do wear comfortably and I rarely ever had to remove them to for example massage my ears like with uncomfortable models that create pressure points and discomfort.

FiiO FD7

Stock Cable

I said it once and I will say it again. I like what FiiO did here far as their stock cable. This cable design is one of my favorite designs mostly because of the tip design.

The high purity Mono Crystalline pure silver wire in a LITZ braid has a 4-wire main with a total of 224 strands and is wrapped in medical-grade TPU sheath. All the hardware is metal, color-keyed to match the assembly and FiiO branded except for the tip system which was licensed from a company called FABRILOUS.

The tip system is the same as the FiiO FD5 stock cable had which consists of a type of channeled micro 4 pin XLR type connector that no matter what plug is used it keeps a stock look with none of that dongle wire excess or long lever like extension crap.

You get three tips total. There’s a common sized 3.5mm TRS tip of course but you also get two balanced plugs. One is 2.5mm and the other is a 4.4mm Pentaconn. The only plug missing here is the 3.5mm TRRS balanced connector and a 6.35mm adapter but the included three will suffice for most situations.

Packaging & Accessories

Well, I got a Déjà vu feeling unpacking the FiiO FD7. The storage case seems to be the same as the one included with the FD5. In fact, the box and packaging are nearly the same. What changed were some of the included accessories.

A cleaning brush, an MMCX removal tool, 3 set total of sound tubes, 2 come mounted on a metal plate and 3 sets of plugs for the stock wire come in the box plus the cable assembly.

Tip selection is fairly ample and FiiO includes 16 sets of all sorts including two foam tips, rubber, silicone, and spinners plus two which are the triple flange type tips that are specifically for the thin bass tubes.

Another accessory that comes in the box is a FiiO branded magnetic wire clip which will probably stay in the box because it just adds extra weight to the wire. Personally, I never use cable clips.

Sound Impressions


Pure Beryllium to me has this almost absolute or perfect pitch and to me, that is what the pure Beryllium driver does best. That sound intro fits the FD7 well. I think it has to do with the driver’s cone stiffness and weight which is ultra-light and rigid giving it the ability, therefore, to respond quickly with zero amount of cone flexing.

Anyone who has heard for example the Focal Utopia might recognize the tonality, which is best described as wide, midrange centric with an excellent top-end while bass output remains somewhat cool and clinically clean with a generally fast transient response. Well, that same tonality is here.

I mostly used the medium balanced tubes for all my listening tests because I felt they had the best balance and tonality overall and I used the tips that came preinstalled which I also found to be the best for my ears but of course, you might have to play around to find what works best for you.

The simple sound signature breakdown here is an apparent midrange first in quality, in second place the treble, and last but not so least the bass response with very good harmonic content and a very realistic pitch.


Bass response on the FiiO FD7 is fast, clinical, precise in tone but the very bottom octave seems recessed a few decibels compared to the rest of the bass spectrum and I confirmed an early roll-off on a tone sweep test which starts to drop at 24Hz and drops sharply below that frequency.

There is a character of coolness added due to that early drop in bass frequency response which drops output in those very low frequencies removing a bit of emotion those fundamental harmonics deliver in music. There is some good impactfulness in the bass area but mostly in the mid-bass area and not much at that bottom octave.

If there were a few more decibels at those very bottom frequencies this set would have perfect bass because of its speed, fast attack and decay, and great dynamics. It distinctly reproduces every note faithfully and in a graceful manner. With a few decibels of gain below 50Hz, they become closer to perfect and they certainly can handle some amount of boosting well.


This area is the highlight of the FiiO FD7 because of its smoothness and the amount of detail you get from the entire wide middle range. Tonality seems just about right and sounds are reproduced very realistic in tone and pitch.

I love the way for example choruses sound on the FD7 because of their resolve capabilities. Every sound seems in its place, all sounds are in their own space, and things never sound conglomerated. Veil and opaqueness are kept at a minimum.

Forwardness is kept at bay also and the midrange seems well balanced with the rest of the frequency bands and constantly kept very listenable. I did notice some small peaks around 2 and 5 kHz in the tone sweep test but they were not major peaks and nothing to worry about.


If you go back and read my review on the FD5 the one thing I complained about was some harshness in the upper frequencies and an early high-frequency roll-off. It seems FiiO was listening in.

The high frequencies were not only cleaned up on the FD7 but the extension is way better. The highs have a very good level of definition and clarity. They never become hurtful or fatiguing; remain sharp and airy unless you get a bad recording.


A wide-open soundstage is always preferred but I personally feel sometimes that width can be overcooked making a particular headphone or IEM sound unrealistic and too spacious.

The FiiO FD7 has a very realistic soundstage and a very precise one at that. This IEM actually excels with complexity and manages to keep all elements within a recording in their place with very good 3D localization.

The whole of the 3D panorama is painted well using a good amount of height, width, and depth. Panning or imaging is very accurate, smooth, and precise.


The FD7 is not genre-specific and can do all types of music well, from Hip Hop, EDM, and other music that depends on a good clean bass response especially if you boost those lower frequencies. Actually, these are good for Hip Hop especially for the lyrics because you can easily hear what they say with the FD7.

But what surprised me the most was the amount of detail you get with complex pieces, such as in Classical music where you sometimes have dozens of musicians all on one stage. This IEM does well in reproducing background nuances and micro-detail also.

The Howard Shore LOTR Fellowship soundtrack has a track called “The doors of Durin” where at the end it seems the director commands and all out, all aboard and all engines on command and every musician goes on a euphoric rampage.

Long story short as they say, I lost count of how many separate elements I heard in there and felt euphoric. Inferior IEMs would probably melt reproducing that piece but the FD7 never lost its cool and remained faithful reproducing that piece very well indeed.

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