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Fiio FD15 Review (Love’s Take)

FD15

Fiio FD15 Review 

Intro 

Hello, this is my full written review and feature of the Fiio FD15 ($149) from the audio brand Fiio. The FD15 is a gorgeous single dynamic driver earphone which acts as the predecessor to the legendary Fiio FD5 (originally $300) from years past. Folks, the FD5 still holds up, even today. Truly a special iem and one that I’ve enjoyed since its inception. Such a fun sound, musical, heavy bass, sparkly highs and a build and design which is to die for. I’m telling you, the FD5 is still one of the best built and best looking iems anywhere near its price point (Subjectively speaking of course). I actually purchased the FD15 for right around $147 off of Amazon US as I absolutely needed to hear this set! Also, the price is so low as opposed to the older FD5 that… I couldn’t resist. 

Fiio

Fiio is one of those brands that absolutely stole my attention for years. I’ve been a fan ever since some of their older sets like the Fiio F9 and F9 Pro. I’ve only actually reviewed a handful of their products over the years. Those include the Fiio FH5 (FH5 Review), the Fiio FH15 (FH15 Review), the Fiio JD7 (JD7 Review), the Fiio FH9 (FH9 Review), their wonderful true wireless set, the Fiio FW5 (FW5 Review) and finally one of my favorite amp/dacs under $500, the Fiio Q15 (Q15 Review). Each product I gave solid marks. In fact, the FH9 is still one of the best iems that my ears have heard under $1k. Truly a special set. The JD7 I still regard in my top five under $100 for a single DD. It’s an absolute beast which flew way under the radar. Even their tws set, the FW5, I challenge you to find a better “sounding” tws anywhere near its price. It has an AK dac chip inside of it for crying out loud. Just awesome products. Beyond those I’ve reviewed, I’ve purchased so many that I’m sure I’ve paid for someone’s college at Fiio. 

Staying Power

This is a brand which has been around since 2007 when they were heavily into dac/amps and portable audio products. Obviously, their catalog has evolved to darn near every type of audio product on the market. I feel that price to performance, good build quality, and always a focus to use the best materials ie: dac chips, drivers, amping etc. Have they had some bombs? Of course they have. Sure, they’ve had some duds over the years. However, for the most part Fiio has been a huge player in the audio game with just about every product that they bring to market. Also, they have some serious staying power. Ask yourself how many brands have been around since 2007 while staying relevant the entire way through. I can actually answer for you… there aren’t many. 

Competition 

Now, as always, the one huge dilemma for any product in darn-near every price segment is “competition”. No doubt the FD15 is up against some heavy hitters. Think about it, the Simgot SuperMix 4 (SM4 Review), QOA Adonis New (Adonis New Review), Hidizs MP145 (MP145 Review), Hidizs MP143 (MP143 Review), Juzear 41T, CCA Hydro (Hydro Review), Aful MagicOne (MagicOne Review), Sliivo SL41 MK2, QOA Aviation (Aviation Review), and remember there are a multitude of iems hovering around $200 that are absolute killers. Also, I only named a few there. Tack in about fifty more to that total of iems that seriously compete for your dollar. So, the FD15 is not without an uphill climb, and it definitely needs to stand out in one way or another. I certainly have an idea of where I feel that it stands and possibly who the FD15 is for, and I’ll try my best to explain my thoughts as you go along in this review. Also, just a side note; when I rate the FD15 later in this review it will not be against all driver configurations, but instead against single DD sets within its price point. Anyways, I’m definitely ready to get into this. So without further ado, the Fiio FD15 everyone…

What a nice looking iem. The stainless steel hits the spot perfectly.

FD15 Pros

-Build Quality is really impressive (just as good as the FD5, FD7) 

-I absolutely love the design of this set, it’s striking

-As per usual Fiio gives a great unboxing experience

-Wonderful Furukawa modular cable (slick looking) 

-13.8 massive dynamic driver

-Some of the best organic timbre anywhere near its price point

-The bass is great, well-defined, clean, textured, punchy

-Midrange is very musical, clean, clear, and tuneful, great for vocals

-Treble comes across sparkly enough yet never offensive to my ears

-Well layered, great imaging

-Open and expansive stage with good depth of field

-Really a well-tuned iem 

FD15 Cons

-Fit may not be wonderful for everyone 

-Carrying case cannot actually be carried. What do you call this thing? 

-The FD15 is going to get cold in the winter outside (is this a con?) 

-Could use some dynamism as the FD15 is a smoother, calmer approach

-The FD15 isn’t for bass-bois, not a bass heavy set (not really a con, per se) 

-Not the world’s most detailed set. Certainly, aimed at musicality first. 

Gear used for testing

Ifi Go Blu 

EPZ TP50 

EPZ TP35

Aful SnowyNight

Shanling H0 

Fiio Q15 

iBasso DX240 with Amp8 MK2 

Shanling M6 Ultra

Packaging / Accessories 

Unboxing 

A few things in life are “givens”. It’s a given that the sky is above our heads, that the ground is under our feet, and that peanut butter and jelly sandwiches are always better with crunchy peanut butter. Okay, I may have slid that last one in there. Now, there is one other “given” … that is… Fiio will always provide a nice unboxing experience. The question isn’t whether it will be good, but rather, how good? So, the FD15 arrived at my home fairly large white box with a picture of the FD15 on the cover and some specs on the back. It’s a harder style of cardboard, feels nice, opens from the top. Once opened you’ll see the FD15 looking all stellar with the cable attached tucked nicely inside some foam cut-outs. Next to the FD15’s is a smaller box which houses the carrying case (if you want to call it that). Inside of the case is all of the accessories. Right away you’ll see many little baggies (the worst baggies ever) which carry all of the different styles of eartips, the cleaning tool, the extra tuning nozzle, as well as the mmcx tool. Really a grand packaging and accessory haul for a $149 iem. 

For $149 the overall package that Fiio provides is very good.

Eartips 

As Fiio does, they added in five different styles of eartips and eleven pairs of eartips into the packaging. In case anyone hasn’t informed you… that’s a lot. The first set of tips are the “Balanced” tips (S, M, L) which are gray in color and come with a semi-wide bore, rigid flange and fairly rigid stem. Next Fiio provides the “Vocal” tips (S, M, L) which are a white flange & red stem wider bore eartips which have a slightly flimsy flange and a shallower fit. The next set is the “Bass” tips which have a light gray flange with a red stem which have a semi-wide bore, rigid stem and firm flange. These tips are very much like KBear 07 eartips. Great eartips that I seriously wonder why in the world they call them “Bass” tips. Anyways, next we have Fiio’s special “HS18” tips which are a white semi-wide bore eartip with a flimsy flange, flimsy stem too. I do not like these tips and have zero idea how they seal in anyone’s ears. Lastly, Fiio provides two sets of medium sized slow rise foam tips. Decent foamies but I never use foam unless I absolutely have to. Anyways, this is an awesome array of tips for a $149 set. I did use the “Bass” tips as they literally are the KBear 07’s yet just colored differently. Great tips for this set too as they enhance the upper mids by a small degree and add some crispness to the bass, maybe a hair more punch too. 

Carrying Case

So, the “carrying” case that comes equipped with the Fiio FD15 is the same case that came with the Fiio JH5. Ya know what, I have to change direction here because folks, this isn’t actually a carrying case at all. This is a drawer. But wait, there’s more. Not only is it a drawer, but it also has Lego pegs on it? I know, it’s confusing and an odd decision on Fiio’s part. Especially since they’ve literally used this exact drawer with many of their sets now. I don’t “not” like it. I actually don’t know what to think. Anyways, the case/drawer is a fully transparent rectangle that comes with a slide-out drawer. It’s of a decent size. Meaning, you could fit the earphones and cable as well as the rest of the accessories if you are talented at packing things. I think the benefit of these drawers is that you can put one on top of the other as you purchase Fiio gear. At least I think that was the vision. Now, I don’t know if it’s the best vision either. I know one thing is 100% true though, at least some of you will absolutely adore these case/drawers. 

Cable

Now we get to a truly positive aspect of the FD15, that is the cable. Fiio provides a very nice looking wire with this set. It’s nicely plump, substantial, nice to look at and best of all, it’s modular. The cable is actually a Furukawa monocrystalline copper and Furukawa monocrystalline silver-plated copper cable. As pure as it gets. This cable is comprised of four large strands and each strand has 100 copper wires as well as 20 silver-plated copper wires. That makes a total of 480 wires with a total size of 22AWG. Fiio states that they heat treat all alloys to their melting point, up to 1050 degrees Celsius for around 744 hours. The cable is an mmcx cable with an almost metallic brown insulation. Truly a gorgeous cable folks. In fact, Fiio promotes this cable to be identical to their Fiio LC RC 2024 cable. Like I said, the FD15’s cable is a modular design, in that it comes with both 3.5 single ended and 4.4 balanced terminations. Very easy to swap too. All you do is align the termination with the cable, push it on, pull the cover back over it and thread it on. In my opinion the cable is a bright spot of this set and perfectly contrasts the stainless-steel design of the FD15. I love the color choice, the materials, as well as the modular aspect of this cable. 

One of the best stock cables in the price point. Furukawa copper & SPC, modular, slick looking!

Build / Design / Internals / Fit 

Build Quality 

So, do I even have to write this section out? I mean, this set is an absolute tank! So, the FD15 is made entirely out of 316L stainless steel. Really one of the hardiest steels out there, completely resistant to any corrosion. Also, stainless steel will give you some of the most gorgeous mirror polished designs. Especially 316 stainless. I know because I worked with 316 for many years. Fiio went through the painstaking process of electro-plating and hand polishing each unit, so they are striking to look at. Also, fingerprints love stainless. But I digress, back to the good stuff. Folks this set is so hardy, and ridiculously durable. The style is the same body of the Fiio JD7, FD5, FA7S, FD3 etc. Same mold, or at least very similar. It’s awesome. The only complaint back in the day was fitment for some folks. Fiio states that they remedied this problem by raising the y-axis of the nozzle 7.6-degrees. I never really had a fit issue in the past (so long as my tips were right) but this newer FD15 fits like a glove. Anyways, the nozzle really isn’t very deep for insertion and not what I’d consider shallow either, maybe medium length and with the tuning nozzles attached they are exactly 6mm in width. Pretty standard. You have three tiny vents right in a row at the back of the unit and one small vent near the nozzle. Not much more to say other than to reiterate that the FD15 is built very well. Oh, and it has two sets of tuning nozzles. 

Tuning Nozzles 

Like I said, the Fiio FD15 comes equipped with two sets of tuning nozzles. I like these types of tuning nozzles the best. These are the longer style where the male threads are on the nozzle adapters and the female threads are on the shell body. They are longer and less easy to lose. I have to be totally honest; they don’t change or alter the sound a whole lot. You have the Black nozzle, which is supposed to enhance the highs, make them more detailed, a bit more levity to the sound. Next you have the Red Nozzle, which is supposed to be a bit lusher sounding, more low-end weight, more of an emotional organic sound. To be perfectly honest, yes there is a discernible difference, but it isn’t world changing. You won’t all of a sudden have a completely different set of earphones by changing the nozzles. Which, by the way is about par for the course as far as tuning nozzles goes. What you will have is a slightly altered version of the same tuning. Like, using the red nozzle I still hear a neutral sounding set. Perhaps the low-end is a hint more emphasized, but not by much. The treble is slightly less energetic which gives the perception that the bass has a hair more oomph. The black nozzle provides a hint more extension into the upper frequencies (it seems) while the bass perhaps doesn’t sound as well defined. I suppose I’d consider the black nozzle as the more likely approach with a better balance by the tiniest of margins. For review purposes I did use the black nozzle. Yet I honestly still enjoy the red. 

Design

Folks, I absolutely love the design. Of course, I’ve loved the design of every set from Fiio with this body style. You’ll notice a groove on the faceplate area which houses the Tesla Valve underneath which runs to the three small vent holes. Anyways, it creates a dope look. Again, fully stainless steel with a high polish makes the FD15 look very handsome, regal, and simply gorgeous. The FD15 comes in two colorways. Those being the silver set that you see in my pictures, and they also come in black, which is sweet looking in its own right. I don’t have a whole lot to say but I really am impressed. The FD15 looks slightly similar to the FD5 and really does rival it in the looks department. For me anyways. 

Internals

Now we get to one of the more loaded sections. Friends, this set has so much physical technology within. Like I stated, the FD15 comes equipped with a massive 1.5T tesla 13.8mm Magnalium Diaphragm DLC Dynamic Driver. Magnalium is a cute name to call it, but the material is actually a blending of magnesium and aluminum. Just by saying that you know that it is a very strong and efficient material with high rigidity and strength. Next, it’s the gasket which is made using the DLC material and now comes in a w-shape. Basically, the driver effectively provides an uptick in vibrational area by around 30% from the FD5. Which is very substantial. Next, the voice coil is actually 1.38 times longer resulting in what Fiio says is a 70% in driving power. Lastly, Fiio added what they refer to as a “Tesla Valve” which sits just under the faceplate and vents to the atmosphere through the three small vent holes on the rear of the unit. This Tesla Valve is really a channel with what appears to be restricted cavities as the pressure builds it’ll lower the resonant frequency and balance the pressure very well. External air flow into the FD15 passes unrestricted while internal air flows to the outer cavities along the tesla valve. Okay, I did a horrible job explaining that, but you get the gist. The tech is great as Fiio is quite literally always trying new things. I could go on and on with acoustic tech that they’ve employed in their past earphones. They are one of the few budget-oriented brands doing actual R&D and trying new things. Other than Aful and a few others. However, Fiio has so many patents. True engineers.

Fit / Comfort 

Like I said, the fit for me is pretty nice. I have to fiddle for a second or two but once they are seated and sealed, they are comfortable. I would suggest that you get a few different types of tips to try out just in case the FD15 doesn’t fit perfect right away. However, the FD15 is an extremely comfortable set once you get them where you want them. Their weight really isn’t an issue either because of the fact that they sit inside of your outer ear. 

The Ifi Go Blu, EPZ TP50, Shanling M6 Ultra, & Fiio Q15 are only a handful of the sources which work wonderfully with the Fiio FD15.

Drivability / Pairings 

Output Power 

The Fiio FD15 is rated with an impedance of right around 32 ohms as well as a sensitivity of about 112 db’s. What this means is that the FD15 is a very sensitive iem. I have used everything from those super cheap no-name Amazon dongle dacs on 3.5 to my iPad and I have gotten good fidelity and plenty of headroom volume. Without question the FD15 can be used with smartphones, and weak dongle dacs. However, like most iems the FD15 is helped quite a lot with more juice. It has a huge 13.8 mm Dynamic Driver which seems to yearn to be pushed. In fact, the best I’ve heard from the FD15 is when I set high gain on my dongle dacs (too many to name) or medium gain on my 1w daps and dac/amps. Trust me, the FD15 will scale. However, there is a plateau where there is no further benefit with more power. I’d say that ideally you should try to give this driver a good 50-100 mw @32 if possible (best guess, don’t take my word for that). Just to push the driver a little bit. I noticed the bass region tightens up, becomes punchier, more contrast in the sound, better defined too. The treble seems to extend a hair further as well but that may be me dreaming that up, although… I really don’t think so. So, more juice helps but at the end of the day the FD15 can be driven from most any source with no issue whatsoever. 

Source Tonality

As far as pairing the FD15 I’d say that you can use pretty much any source tonality and be perfectly fine. I don’t think the neutrality of the FD15 sounds worse or better with a cooler or warmer source device. Just make sure you enjoy the sound of your source. Really, I think the neutral sound of the FD15 kind of goes with any source tonality. For instance, I used the neutral iBasso DX240 and I’m in love, sounds wonderful. Also, I used the warmer and more velvet Shanling M6 Ultra which also is a very nice listening experience. I don’t think it matters. The tuning of the FD15 is such that there’s no real peaks to be exaggerated by a source. For instance, it has no real spiky treble peaks where a colder source would push them to sharpness. Vice-versa, the FD15 isn’t veiled or “bassy” either and so a warmer source isn’t going to exaggerate the warmth. The world of sources is your oyster with the FD15. Pick one and have fun. 

What do you need? 

I’ll be honest with you, the Fiio FD15 is one of those sets which honestly works and sounds good on… anything. It just does. It’s not neutral/bright, or warm/neutral, it’s neutral. Also, it is very sensitive so using a less powerful source really isn’t an issue. Like I said, pick a source and have fun. Of course, a bit more power does tighten things up a bit, but I don’t think that more power is “needed”. Pick one and have fun. 

What a nice pairing between the iBasso DX240 and the Fiio FD15.

Sound Impressions 

Note: before I get into the sound portion of this review I should first state that I most certainly burned this set in. Folks, the FD15 has a 13.8 mm driver and I feel that it does help to burn-in this larger DD. I had them on the burn-in rig for right around two full days, maybe two and a half. Also, I listen primarily to flac or better files stored on my devices. Mostly I use UAPP (USB Audio Player Pro) and for some dongle dacs I use Hiby Music Player as well. 

How does it sound? 

The Fiio FD15 is what I would consider an almost dead neutral iem. Timbre is about as natural as it gets. Very clean-organic sounding. I hear a very good balance across the mix in what I would refer to as a U-shaped sound signature. Almost mid-centric yet with a subtle low-end elevation as well as a boost in the upper regions. Still, it has a wonderful balance dynamically. Just a sweet sounding iem folks. As the predecessor to the Fiio FD5 you’d think the bass would play a much larger part in the tuning, but I find the bass (which is very good) to be more of a supporting role. Instead, I feel the main focus rests in the mids to upper mids. I keep thinking of words to describe this set and I keep coming back to… Sweet. How do I describe something which is simply pleasant? Across the board too. Nothing about this set is shrill, peaky, veiled, artificial, sibilant. I’m telling you all right now it is a timbre-first, neutral-musicality focused iem with nothing fatiguing. Let’s go with five words, top of the head to describe the FD15. Again, sweet, balanced, tuneful, stainless (both in build and in sound), natural. Those are my first five folks, and I stand by them. A wonderful sounding set which still holds good energy, decent dynamism, and even nice extension both ways, yet it never seeks to offend. Nothing about this set goes too far. It has linear dynamics, and it’s great. 

Mellifluent 

I’ve had a wonderful time getting to know the FD15 much in the same exact way that I enjoy the Kiwi Ears Orchestra Lite. In fact, the FD15 could be considered the dynamic driver version of the Orchestra Lite, to my ears anyways. The reason I know this is because the Orchestra Lite is one of my absolute most favorite iems at any price point. Subtle differences but very close. Timbre like the Aful MagicOne, or like the Aful Explorer 5 yet with slightly less bass. Just a musical sound that oozes mellifluousness. Similar to the Dunu Kima/Kima 2, yet more refined across the board. It’s in the same vein as those sets though. The FD15 won’t highlight every last micro-detail or tiny little subtlety within your music. It isn’t analytical at all. Yet it is ridiculously clean sounding. Great clarity, black background, smoother than it is crisp, with a rhythmic style of sound. It’s a set that flows, like waves in the sea. Vocals for days! It trades hard right angles for curved surfaces, nothing jagged, nothing abrasive, nothing edgy. This set is glass-lined through-and-through. It’s honeyed and dulcet with a euphonic style. Truly a special single DD at its price. That’s if you enjoy this type of sound. 

Graph courtesy of Gizaudio, Thank You!

Bass Region 

The low-end of the Fiio FD15 is a high-quality bass. You won’t see any bassheads seeking out the FD15 either. This is not a set for bass-bois. So no, you won’t want to pursue the FD15 if you are into heavy bass. Those who will enjoy this bass are those who enjoy “good” Bass. That said, I also don’t feel the FD15 lacks at all. It’s a nice and marginally meaty bass. This is also a high quality low-end which really does a good job at defining the lower portions of the mix. I hear nice speed as transients move along swiftly yet retain enough harmonic lag to come across slightly atmospheric. This is a low end which can take on slightly speedier tracks down low as well. I wouldn’t put them in the same conversation as planar sets or some BA sets, but the speed is great. Couple that with the fact that the bass sounds very naturally authentic and what you have is a winner in my opinion. The low-end never overstays its welcome and doesn’t infringe on other areas of the mix to any detrimental degree. I’d say its slightly sub-bass focused but that is easily debatable. Very well textured too and does so with decent note density. I hear a solid note surface, nothing pillowy, nothing fuzzy. Basically, the low-end is clean. 

Sub-bass 

I haven’t completely agreed with myself that the FD15 is “sub-bass focused”. Different tracks tell me different truths about the low-end. However, one constant is that the sub-bass is very clean. Perhaps it could use a hint more guttural emphasis down low, but I haven’t heard any track where I feel the FD15 lacks. In fact, extension into the lowest of the lows is deep. Not lacking. No sir, this is a nicely robust sub-bass, yet it isn’t emphasized to the point that it steals focus. It’s balanced so well with the rest of the mix. No offense at all. That is an important detail about the sound. However, this is a sub-bass which will show up in tracks that present a lot of sub-level info. For instance, “Tell Me What’s on Your Mind” by The Decemberists is a track which will rattle and reverb in the back of most eyelids. The FD15 replays this track’s bassline with solid haptic feedback and vibratory goodness. Enough to “feel” the bassline as well as come across deep pitched and dense. Just not overtly lifted like so many sets.

Good supporting actor?

It’s natural to my ears. That’s what the sub-bass is on the FD15. It shows up when it’s needed and doesn’t needlessly affect other areas of the mix when it isn’t needed. Again, there’s a very nice balance here. However, the sub-bass is very clean. It’s clean at attack, quicker in decay, no real dragged-out resonant harmonics and extra fat to the sound. Notes are well defined, textured, and compact with a solid note structure. Fiio also did a nice job of giving the FD15 a quality bass down low which isn’t at all one-noted, flabby, sloppy, muddy, or too bulbous. Trim but rigid, shows up when it’s called upon and a good supporting actor. 

Mid-Bass 

I would venture to say that the mid-bass somewhat plays second fiddle to the sub-bass but it’s really not cut-n-dry. Once again, the mid-bass is the type which can come across full enough and meaty enough when called upon. I hear a slightly softened attack yet with a quick decay. Certainly not pillowy either. More like solid note density wrapped in a thin layer of cotton. Okay that was a terrible example, but I think you get it. It’s a very pristine bass which hangs its hat on quality, texture, resolution, speed and good timbre with a nice slam to it. For instance, songs like “2040” by Lil Durk carry a fairly heavy bass drop in which I found the FD15 is able to show up in a satisfying way. Really a clean drop, no fuzz at the edges, precise, and doesn’t tend to mask other frequencies. The mid-bass is also pretty nice for bass guitar, kick drums too, yet it doesn’t have the most authoritative hollow boom that I’ve ever heard. “Billie Jean” by Weezer is a track I always use for testing because the kick drums hit right away, no waiting around, and they are one after the other. What I like about the FD15 is that the notes are very concise. I hear a sticky leading edge on attack and a moderately heavy boom. The kick drums are quickly trailed by a sharp and snappy snare drum. It’s nice for sure, though some folks may want a heavier and more weighted sound that the FD15 wasn’t really tuned to provide in full. 

Mid-bass cont… 

That all said, the good thing about this bass region is the fact that it’s got very nice note definition, and it can take on some fairly speedy bass tracks, timbre is great, and the whole presentation is clean. Again, nothing muddy at all and nothing sloppy. What I hear is clean precision with enough weight and density to satisfy most genres just fine. Finally, I don’t hear the bass encroaching on the midrange very much. The mid-bass has great resolution, tight notes, not overwhelming, and it is very nice to hear at this price. 

Downsides to the Bass Region 

I think the biggest issue with this bass would be a subjective matter for those who simply enjoy more amplitude from this part of the frequency. Those who want a more earth rumbling weight and a darker and heavier drone will likely want to keep looking. Like I said, definitely not for true bass heads. However, this bass is for those who enjoy very good and quality bass. I’m sure some people may want a bit more excitement and fun out of their low-end, and I totally understand that. It just means that the FD15 probably isn’t for you. Bass is so very important, well, every area is important, but the bass is the foundation and getting it right will dictate a lot about the rest of the mix. The FD15 is wonderfully balanced, never over the top, timbre is great, note structure is great, note definition is solid. There’s a hint of softness on attack on some tracks but overall density is good and transient decay/sustain is on the faster side of the aisle. 

Photogenic, what a beaut!

Midrange

If you ask me, the Fiio FD15 is a mid-forward iem. Certainly not recessed to my ears. The FD15’s midrange has a very musically engaging sound in which vocalists are put on a pedestal. I hear a very smooth sound that doesn’t exclude some crispness when needed. Note weight is lean-lush, semi-rich, or any other mix of words describing notes which aren’t too heavy, yet not too thin. The mids are energetic yet without the glare, lively yet without the sharpness like so many midrange boosted sets. It’s really a sweet-sounding midrange. On top of that, timbre is very natural. The engagement factor is high as the FD15 has a certain elegance in its cadence, an unforced symphonic quality which is always fluid, graceful, and rhythmic. Can you tell that I enjoy the FD15? Just a little. Very much like the Kiwi Ears Orchestra Lite in its effortless ability to convey my music. Again, it’s smooth across the board while also coming across with a very precise and accurate rendering of midrange notes. Always moist, supple, and never dry or clinical sounding. 

Charming 

Now, it’s true that you won’t get the most pinpoint and detailed listen from the FD15 as its fluid and melodic nature leans heavily towards the musicality end of the spectrum. Yet you also don’t really miss out on details either as transients are still rather quick, notes are still well defined, clarity is still… crystal clear. I’d say the FD15 has a clean way of expressing macro-details and about average in the micro. The FD15 simply doesn’t have those hard etched fine lines drawing distinction between each note in a “detail-beast” fashion. It isn’t dry, papery, or artificially boosted either. In my opinion a natural type of sound… probably isn’t the most “detailed” way to listen to music. I think authenticity of timbre is more musical than analytical anyways. Real life doesn’t provide high-resolution, zeroed-in, thin, and etched-out notes. Also, I would hate for this set to lose any of its engaging qualities just for a few easier to discern details. No way! All in all, the FD15’s midrange is charming to the core. From the low mids to the upper mids you won’t get shout, glare, sibilance (to any great degree), or any metallic tinge at the crest of notes either. Really a high-quality midrange which begs me to listen to vocalist heavy tracks. Having said all of that, it goes without saying that this type of replay obviously won’t be everyone’s favorite. You do have to enjoy a more mid-forward style earphone. This isn’t a V-shaped type of sound. It isn’t just exciting at the edges. 

Lower-Midrange

The low-mids definitely come across neutral in tonal color. This isn’t a situation where the bass is feathered-into the mids adding copious amounts of warmth and weight. However, I don’t consider the low-mids to sound lean at all. They have good presence and good clarity which makes up for not having the fullness of a warmer note. My opinion of course. The low mids have a very vivid style, up front, centered, and not so far forward that they sound unnatural or boxy. Actually, male vocals sound very good. Take The Red Clay Strays in the track, “I’m Still Fine”. The lead’s voice has an edginess to it, almost raspy, and it’s so easy for some sets to portray his vocals unauthentic. Especially when he uses more breath and begins to belt out. I love the smoothness and chiseled-out way that the FD15 centers his vocals as the focal point and not in an aggressive way. Or Chris Stapleton in “Sometimes I Cry”. Another voice that sounds wonderful with the FD15 in my ears. His is an even more raspy, edgy, and even sharper voice. I enjoy when Chris reaches those high notes that the FD15 has a way of sanding them down. Never too abrasive. While the rest of the time his voice is full, clean, not grainy, and sounds effortless with the FD15. 

Upper-Midrange 

The upper portions of the midrange are so well laid out. I really mean that. Females eclipse male singers with this set by a slight margin for me. I just feel the FD15 is tuned in such a way that females can come across completely dulcet and alluring due to the great energy in the upper-mids which never seems to offend. Something not many sets are able to accomplish. Instruments are very natural to the ear too. Percussion has some snap and some edge to them without sounding coarse. Strings sound great with the smooth yet clean sound in this region. Just enough crispness, yet forward too. It’s a nice mix. At any rate, instruments generally sound great. Of course, that can change from track to track, recording to recording. Now, the upper-mids are a hair closer to the listener, but not by much. I still hear a more neutral sound, slightly brighter, a little more vibrant, even shimmery while never coming across dry. Female notes tend to have some body to them, some sugared richness. Not rich in the sense that they’re weighted, warm or thick. More like milky, clean note outlines, organic, moist. I hate the word “moist” but it serves its purpose here. Females sound great. Like Adele in “Hello”. She sounds fully emotional, wholly engaging, and very well highlighted against the rest of the mix. Almost haunting. I get this from many females, but this was the song playing in my ears at the moment. The point is the upper-mids seem made to replay female vocalists in a very sonorous, almost euphonious and liquid way. 

Downsides to the Midrange 

I would first probably say that those folks who only dig warm, weighted, and an even fuller sounding midrange probably won’t like the neutral canvas of the FD15. Detail-heads will not be impressed either. The FD15 is not going to impress those who love to pick apart every last detail in their music. Not that the FD15 lacks in detail retrieval, but it won’t blow your mind with its resolving abilities. Folks, it takes all kinds in this hobby and no two are exactly alike. I could sit here for hours exploring different types of listeners and how the FD15 may or may not fall short for them. To be honest, I have a very hard time saying anything negative at all about the midrange on this set. It is awesome to me. I’ve had so many listening sessions, late at night, in bed, eyes closed and just swimming in the way the FD15 captures certain inflections. The way it smoothly, yet so vividly replays certain instruments. Also, I realize I went pretty hard for the FD15 in this section. For all intents and purposes, I’d do it again and again. Really a nice sounding midrange. One of the better in the price point in my humble opinion. That all said, is the midrange enough? 

Treble Region 

The highs on the FD15 generally runs smooth. Have you noticed a common theme? Once again this is another region where I don’t hear anything offensive to the ear. As though Fiio took this tuning right to the brink of my comfort and capped the brightness there. The treble region actually has solid energy as it isn’t a rolled off treble. Not by any stretch. However, it isn’t an ultra-brilliant/bright type of treble either. Not a treble head’s paradise. Like the rest of the mix, the timbre is also very nice up top and also like the rest of the mix the treble isn’t the most detailed or analytical. You don’t have any of that forced resolution by boosting the treble to illuminate the minutiae. There’s nothing even remotely artificial sounding. Very nice timbre, very natural to the ear. A real “even keel” type of treble. In fact, between 2k-8k there is a substantial dip, almost a linear dip too until some energy pops back into focus after the presence region. Roughly anyways. What this does is bring upon a very easy to handle treble region that doesn’t sound harsh, sibilant, or splashy. 

Pretty darn nice

Despite that, the treble has plenty of sparkle, plenty of controlled brightness and very nice extension into the upper treble. I don’t miss any energy in this region and to me the treble fits the overall tuning very nicely. I’d say there’s enough actual emphasis to lift the overall tonal color of the spectrum while not washing out treble notes in a mishmash of treble tizz and splash either. Again, not a treble head’s dream, but fantastic for those who love a treble which promotes an overall musical sound. However, with that musical sound you also have enough emphasis up top to bring on some presence of air and openness to the sound. Certainly not rolled-off, dark, or congested sounding. There’s an effervescent and open “feel” to the sound. To an extent anyways. This helps with stuff like instrument separation, layering, and helps to simply hear each note somewhat distinctly. I’m not saying it’s some enormously vast breadth of open space, but for a smoother sound which is mostly non-glaring, non-offensive, and non-analytical, it’s pretty darn nice. 

Not the best, but good

I just said that detail retrieval up top is not going to amaze the listener, but in the exact same breath I also don’t feel that you will necessarily miss out on very much. Once again, we have a smoother presentation, not as much crunch, or treble bite as some other sets. There’s some lack in that regard. If you consider that “lack”. Basically, there are many other sets which perform much better in the treble if “better” (to you) means analytically refined, transparent, crisp, ultra well defined and some sets have more of a haptic “feel” to each treble note. The FD15 is a milky ride along easy moving wave. Obviously, there are plenty of hybrid sets, planar sets, or multi-driver sets which have greater capabilities in this region to separate instruments, define notes, form contrasts, stuff like that. What the FD15 does so well in this region, and every region, is that they come across natural, timbre-correct, coherent, and extremely musical without any damning sharpness. So no, detail retrieval isn’t going to be top-class and those who yearn for a more precise note body and crispness won’t exactly find that here. Still, you have very good extension, cymbals don’t sound splashy, have solid note body, and they are distinct. Also, details are still pretty nice simply due to the cleanliness of the sound as a whole. Again, you aren’t missing much. 

Downsides to the Treble Region 

This is very much a preferential downside, but I’d say that anyone who really desires an edgy, highly precise and brilliant treble region will likely not be very impressed. Again, the FD15 presents the treble in a smooth manner, semi-bright yet non-offensive. So many folks that I know love just a sprinkling of offense. They like that hard, crisp, defined, and biting note edge. The type of treble that you feel as much as hear. Those types love a treble which comes across bodied, but also with solid density and treble punch. The FD15 isn’t quite that. It is very clean, timbre is great, fits the overall tuning well, and the extension is very nice. Yet it doesn’t have that type of demeanor where every last micro-dynamic and subtle detail sounds perfectly evident. Smooth and easy doesn’t really give you that. Still great for what it is and for the style of the tuning but of course it won’t be for everyone. 

The Fiio FD15 is quite literally a picture in any moment.

Technicalities 

Soundstage 

This is another bright spot for the FD15 as the soundstage actually comes across pretty vast. The FD5 was the exact same way. Something about Fiio’s acoustic cavity really helps the sound to come across in a larger sense. You also have good extension both ways and a fairly dynamic sound as a whole. Whatever the contributing factors are, the FD15 certainly has an above average stage and a more holographic presentation too. I’d say width is above average, height is too, and depth is pretty nice as well. In fact, I find that the depth is great for layering of instruments which helps with imaging as well, but I’ll get into that in a minute. As far as the stage is concerned, it is closer to the listener. So, while the stage is very full, with good width, height, and depth, it’s also more up front. You don’t get that stadium feel. We see so many iems lately with a more forward and closer, more intimate setting. Still, in my book the soundstage is a bright spot for the FD15. 

Separation / Imaging 

Instrument separation throughout is actually quite good, even with a smoother take on my music. The FD15 is very clean folks. That cleanliness, black background, and transparent type of replay helps even a smoother set to sound decently well separated. I honestly don’t have an issue hearing instruments in a relatively well contoured manner. There is some space between. Of course, I have to mention that the FD15 won’t fare as well against more complicated and congested music. Ultra bass-heavy songs may pose a problem as well (who’s listening for separation in Ultra bass heavy songs?), and obviously poorly recorded jams won’t help the FD15. So, while it isn’t class leading, the FD15 performs well for what it is (single DD) and for how it was tuned. Imaging follows the exact same line of thinking and really follows suit with its instrument separating ability. Actually, scratch that, Imaging is great. The FD15 is able to create some layers to my music. Some front to back depth of field which helps to hear those drums further back, kick drum dead center, the acoustic guitar at the front right, the cymbals spread wide for example. Of course, not every track follows that spread. That was just an example. Anyhow, if you have a nicely recorded track which isn’t too chaotic then the FD15 will perform very well and images the stage nicely. 

Detail Retrieval 

Like I’ve said this entire review, the detail retrieval on the FD15 from Fiio is certainly, at the least… average. That’s the worst it’ll be. Which is actually quite good. No, the FD15 won’t create perfectly contoured and intricate fine line and concrete-discreet note outlines as it isn’t a dry, ultra transient tight and clinical type sound. It isn’t forced bright or boosted to try to illuminate all of the little data points and intricate sound info which some sets are unkindly tuned with (we all know the downsides there). Also, the FD15 is smooth, it glows rather than illuminates, it’s moist in body, very clean but not edgy. Again, it’s all rounded corners and wavy lines rather than right angles and straight lines. Basically, the FD15 won’t be considered the best technical set in its price point, but it may surprise some folks even with its penchant for musicality. About average in some tracks and above average in others. 

Comparison

Fiio FD5 / Fiio FD15

Fiio FD5   ($300) 

I felt this comparison was necessary, albeit, maybe not very helpful, is with the FD15 and it’s predecessor, the Fiio FD5. The FD5 is a legend set folks. I mean it was and still is a banger of an iem. Truly a special set which still holds up in my humble opinion. Maybe not at $300, but it holds up for sure (by the way, the FD5 can be found for cheaper nowadays). Now, the FD5 is another single DD and happens to be the predecessor of the set I’m reviewing today. In fact, Fiio states as much in eir promotional material. The FD15 is basically “part 2” of the series. So, the FD5 has one rather large 12mm Beryllium Coated DLC Dynamic Driver and has a semi-open build to it. The FD5 also has a ton of acoustic physical tech going on inside of its cavities, just like the FD15. It too has tuning nozzles and is also accessorized quite well. Friends, I’ve owned this set since its beginning, and I have enjoyed it the whole way through. It has been a constant in my collection and one that I still reach for every now and again. Always reminded why it’s so special. That said, there are a number of differences between these two sets, even with all of their similarities. I’ll try to help those words makes sense. Lol. 

Differences / Similarities 

Both sets have darn near the exact same housing size, shape, and somewhat similar designs. Now, the newer FD15 is a hair heavier at 12 grams to the FD15’s 11 grams. So basically, the same. Both are fairly heavy relative to their size. Yet also, they are both made out of stainless steel and both superbly sharp looking. I do consider the FD5 the better looking iem but I truly enjoy both of them. I just like the FD5’s brushed metal faceplate and semi open design. It looks beyond dope. Now, the FD15 fits me much better, and I chock that up to the fact that Fiio changed the insertion angle of the nozzle. That additional 7.6-degrees really helps for me. Of course, the FD5 has a semi-open faceplate to the closed-back FD15. The FD15 has a substantially larger driver with a 13.8mm DD compared to the FD5’s 12mm DD. The FD5 uses a Beryllium Coated DLC to the FD15’s Magnalium (magnesium/aluminum) and DLC DD. Also, while the FD15 has a great unboxing and probably the better modular cable, I find the FD5 to have an even better accessory stack. It’s got a better unboxing and is more premium by a slight margin. Most certainly a better carrying case. Actually, the FD15 doesn’t even have a case, it has a drawer, with Lego pegs on it. Weird I know. Honestly, the FD5 just feels and looks a hair more premium, more stately, higher end. But it is only by the tiniest of margins folks. Remember, the FD5 came in with an MSRP of +$300 whereas the FD15 costs half of that. Which is wild. So, I guess that explains the presentation difference. 

Sound Differences 

I’d say the FD5 is quite a bit more V-shaped sounding to the U-shaped and mid-forward sound of the FD15. They are actually two completely different tunings. Good compliments to each other. The bass is thicker, fuller, and more authoritative on the FD5. However, the bass on the FD15 is cleaner, better defined, more agile, better layered, less one-noted. However, the FD5 is simply boosted more in this region, yet very clean in its own right and much more haptic and guttural. The midrange of the FD15 is more musically gifted, melodic, even slightly cleaner sounding. Now the FD5 actually sounds more detailed in this range yet with a greater emphasis in the pinna rise which can sound shouty at times. The FD15 doesn’t do that, it’s balanced, forward, easy, and probably the better midrange (for me at least). Next, the treble on the FD5 is brighter, better extended, more intricately defined, better detail retrieval, more bite, and simply more brilliant. While the FD15 is less offensive, smoother across the range and still very clean. Technically, the FD5 “probably” has the upper hand, as it’s just more detailed, better instrument separation. However, I find imaging abilities if both sets are on part with each other, especially in less intense tracks. The soundstage of the FD5 is more open, airier, and probably a hint grander in size. Yet I do find the FD15 to be every bit as deep and just as well layered. So, the FD5 is more energetic as a whole, while the FD15 is better balanced. Two very different styles of listening. 

Final thoughts on this comparison 

I would certainly call these brothers a preference battle. If you like an energetic V-shaped sound then the FD5 would likely suit you, but if you enjoy an even sounding, much more tuneful and balanced sound with a forward vocal-centric take on your music then maybe the FD15 is a bit better for you. In truth, these are two sets that I really enjoy, for different reasons of course. Both are fantastic sets which shows off Fiio’s abilities to engineer and design. I personally enjoy the newer FD15 a bit more and feel that it is better suited to my taste at the moment, but I will always like the FD5 quite a lot. 

**I could not find a comparison graph between the FD15 and the FD5, so I added the next best thing. That’s a graph of only the FD5 below.**

Fiio FD5 Frequency Response Graph.

Is it worth the asking price? 

I will answer this question quickly and very decisively… absolutely the Fiio FD15 is worth the price of $149! Of course it is! I would pay that price again and again. Of course, this answers this question for me and my personal taste and doesn’t account for everyone. To one it’s well worth the $149, and to another the FD15 may not be. That’s the nature of this subjective hobby. However, for this guy I truly enjoy what the FD15 brings to the table and how it portrays my music. Again, very similar in almost all ways to the Kiwi Ears Orchestra Lite. Just a fine-tuned and very impressive tuning that never causes fatigue. If you enjoy just putting a set in your ears, closing your eyes and getting lost in your music then I would certainly advise you to check out the FD15. I will say that there are some genres better suited for other sets and there’s different sound signatures that I enjoy “at times” a bit more. I actually enjoy all sound signatures folks and so some days I might want something warmer or heavier in the low-end. Maybe even brighter, more detailed and analytical too. I bounce around a lot. Still, for $149 I feel this is a steal at that price. 

The Why… 

Because this set is built like an absolute tank. Made entirely out of beautiful stainless steel and polished to a mirror finish. Just beautiful! Wavy lines capture the faceplates looking more like jewelry than anything else. Also, it’s cylindrical body fits my ears very well, very comfortable for me. Next, the unboxing is fantastic for a $149 set. Other than the weird case (you may love it, so I’m sorry), I love the modular Furukawa SPC modular cable as it looks amazing with the FD15 attached, a ton of tips and a premium presentation. Good job all-around for Fiio on this one. With all that said it’ll always come down to the tuning and sound. As always. Folks, I think this is one of the most pleasant sounding iems to come out in a while. Musical through and through. Not the kind of musical that’s rich, warm, and engaging, but engaging in its perfect timbre, symphonic and mellifluent lean, and its ability to never seem to cause undue sharpness. Just a wonderfully clean and balanced sound from the sub-bass to the upper treble. Bass is quick, textured, tight, and well defined. The midrange is an instant classic with wonderful vocals across the board and very pristine. Wonderfully melodic. The treble is non-fatiguing, still brilliant and open sounding but not overtly so. The soundstage is wide, tall and deep with great imaging and layering capabilities. I think this set is easily worth the cost of ownership and I am happy to own them. 

Ratings  (0-10)

*Note: all ratings are based upon my subjective judgment. These ratings are garnered against either similarly priced sets or with similar driver implementations or styles with the unique parameters of my choosing. In the case of the Fiio FD15 ratings below, that would be $100-$199 single dynamic driver earphones. Please remember that “ratings” don’t tell the whole story. This leaves out nuance and a number of other qualities which make an iem what it is. A “5-6” is roughly average and please take into consideration the “lot” of iems these ratings are gathered against. $100-$200 is not a very large sized scope of iems. So, It should be fairly easy to see a rating above a “9.0”. My ratings are never the same and each set of ratings tells a different story. Each time you read one of my ratings will be unique to that review. Basically, I create a Rating that makes sense to me. 

Aesthetic 

Build Quality:     9.9     Wonderfully built.         

Look:                      9.8     Love the look of this set. 

Fit/Comfort:         9.0    Fit and comfort is very good for me. 

Accessories:          9.6    Nice unboxing, far above average. 

Overall:                 9.6🔥🔥                                 

Sound Rating     

Timbre:                  9.9    Completely natural, great timbre!

Bass:                       9.3    Speedy, well defined, textured. 

Midrange:            9.8    100% melodic, vocals are top notch. 

Treble:                     8.9   Well extended, non-offensive, clean. 

Technicalities:      9.1    Mostly great for what it is.    

Musicality:             9.8    Musicality is its life blood.                                                     

Overall:                    9.5🔥🔥🔥

Ratings Summary:

Okay, before you go any further, I need to preface a couple things because so many of you message me about these “things”. First, please read the note under the header for this section. I outline “what” I’m comparing the FD15 against, as well as “what price range” I’m comparing the FD15 against. In the above note I said that I’m comparing this set against all “SINGLE DD” iems between $100 and $199. I don’t do across the board ratings, mostly because those are too broad, even less nuanced, and they only hold up for about six months tops. I do ratings according to the consumer. I’m not saying mine are perfect, but they make more sense to me and hopefully to prospective buyers. Each rating on every review is different. These are on the spot comparisons with every earphone I have in my arsenal, and I rate them on the fly. It takes some time to do. At least a two-hour rating/comparing period for every review depending on how many I actually have on hand. Very few times have I rated something against a set that I didn’t have in my hands, physically. I rate using songs which pertain to each rating. Maybe one day I’ll begin sharing those songs. Sorry for this explanation by the way but I feel I needed to speak on that.

READ

Anyways, please don’t message me saying that I gave the Fiio FD15 a “9.5” against every set on planet earth! READ. I gave it a “9.5” overall sound rating against single DD iems in the price range of $100 to $199. You do the math. Think of the single DD sets in that range. Sorry if this comes across coarse. I really don’t want to. However, I get at least 10-15 (sometimes more, sometimes less) messages about these ratings and I have to re explain myself. Maybe I need to do away with ratings altogether. You guys all know how I feel about them. 

Explain Yourself! 

The one rating which jumps out at me and is usually the subject of most messages and complaints is the “Bass” rating. I gave the Fiio FD15 a “9.3”. I think that’s fair. It’s tight, very clean, of very high quality, and nicely textured, nicely layered. In truth, I wanted to give it a higher rating but held back only because it could use some a few more db’s. That’s it. It is a wonderful bass. Now, bassheads wouldn’t give this set a “5.0”, mainly because they like… heavy bass. This isn’t that. Next, how in the world could I give the FD15 a supremely lofty rating of a “9.8” in the midrange, it isn’t even the most detailed? So, this is where subjective preference comes into play. I think it’s easily the best midrange out of all single DD’s between $199 and $200. That’s it. It’s the best and so it gets the highest score. Same goes for the “9.9” I gave the FD15 for timbre. Because against single DD’s within the specified range, it’s the best. Again, for me. You may feel differently, and I wouldn’t ever dream of arguing with you about it. Because you are you and I am me. The rest of the ratings I don’t think need very much explaining. One more thing, now that you’ve read my little rant, please pay these ratings no mind. Don’t let them hold water. Grains of salt folks. Unless you really trust every word that I write and know what I enjoy, I’d just keep scrolling. 

Final thoughts on the Fiio FD15 before I conclude 

What a set. What a fine set. Is it perfect? Absolutely not. No way is it perfect, it has many little issues. It isn’t the most fun sounding, sub-bass isn’t the deepest, doesn’t slam with the most impact. The mids aren’t the most detailed, separated, and aren’t the most technically inclined as a whole. Of course, the treble region isn’t the most brilliant, crisp, biting or most contoured. There’s a lot of subjective gripes that some could have. The beauty of this set is that it isn’t supposed to be all of those things. The FD15 is supposed to be exactly what it is, mid-forward, vocally gifted, very musical, and easy in the ears. In that vein, it’s a wonder of a set. Truly a special single DD. Without question it will not be everyone’s favorite, and I really hope my words have helped you to decide if it works for you, or not. I think Fiio absolutely nailed this set and did a very fine job crafting a gorgeous iem that stands out aesthetically within its price point and is built to last. I am more than happy to own it and happy to be able to listen and get lost in its sound. With that said, I most certainly recommend the Fiio FD15, if, you enjoy that mid-centric, mid-focused sound, musicality first, with a great balance across the mix. If that aligns with you than it’s an easy REC. 

Conclusion 

To conclude my full written review and feature of the Fiio FD15, I want to thank each and every one of you for taking the time out of your day to click the link and spend some time here. I highly doubt there are many of you still reading this, but for those who are, I cannot thank you enough. Writing these reviews is an absolute joy for me, and I do so first because it is a crucial creative release for me. I love it. However, a close second is that I do this for you. Those are the reasons. Hearing that any word I wrote made your listening experience better will always be like joy washing over me. That’s the truth. On top of that, mobileaudiophile.com thanks you as well. It is because of you that we are able to continue to write reviews and publish to this awesome website. So, thank you very much. 

Other perspectives 

Now that I’ve thanked you for checking out my review, I also hope that you’d check some other reviewers’ thoughts about the FD15 out. There are so many good reviewers out there folks. Just solid people who really do a good job breaking down these products. Many of them are my friends, and many of them have fantastic takes personal to them. I hope you’ll listen to, watch, or read other reviews and perspectives so that you can gain an even better understanding of what you are getting with the Fiio FD15. Folks, we are all very much different. The guy sitting right next to me may have a completely different opinion than I do. I think you know that I really like the FD15, but the next guy may not. He may hate this set, who knows. Or maybe he loves it too. The point is, it’s just more info to help you make an informed purchasing decision. I am not the last word on audio, and I do have my own subjective likes and dislikes, so does the next guy. So please click on some more links. Okay, with that all said I think I’ve covered it all. Please take good care, each and every one of you. Stay as safe as possible and always… God Bless!

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