Sound Impressions


On the first X5 we had a very big break from the old FiiO house sound and the Wolfson WM8740 DAC chip. I remarked that I felt it to be much more neutral, far less colored and far more expansive to the DX50 and far more resolving and precise than the musical X3 Gen 1. Overall it was a winning DAP and represented, along with the E18, the way FiiO wanted to go with their house sound; a serious, more accurate and true to life sound.

Gen 1 ‘Metal’ qualities

Now what I also noted on the old X5 Gen 1 was a slight preponderance to display sibilance especially in comparison to the Ibasso DX90 which had the upper midrange and treble under far better control. I didn’t go into it as much as I should have but that impression over the months and years since then is rather less complimentary and you could argue that the whole top end of the X5 Gen 1 just sounded way too metallic in comparison to other mid-range DAP’s such as the AP100 from Hidizs, M3 from Shanling and of course the DX90. Increasingly the more dynamic and natural sounding DX90 became the go to DAP and the slightly more staid, neutral and metallic sounding X5 lay by the side unused.

The Changes

Well now the X5 Gen 2, tonally speaking, has corrected a lot of those concerns and then some. On a more general level the new X5 displays a similar tonality overall to the first gen X5, albeit for me slightly drier than the warmer gen 1. Those looking for a night and day difference between the two will be left somewhat disappointed but it’s the subtle changes and the general tweaking with the frequency response that makes the new X5 a far better proposition and should give the DX90 a good run for its money.


The most fundamental change for me has been the upper midrange and lower treble in the new Gen 2 which is a lot more even and in the case of the midrange a bit more forward sounding. Gone is that harsh metallic aftertaste that often marred whispering vocals such as Chris James’s velvety emo like voice on the Veldt from Deadmau5 and in comes a far more controlled tonal quality. Voicing now displays far less sibilance and sounds cleaner and more natural than before. This was the one aspect of the original X5 that made me put it down in favor of the DX90 in the long run and the first thing I looked for on the new gen to be remedied and thank goodness they did. It’s like a brand new DAP in that respect.

Bass Tweaking

The second major tweak FiiO brought about on the new Gen X5 was the bass tuning. On the first gen X5 the bass response was fairly weighted and warm but focused more on a mid-bass hump than any deep sub-bass response which gave the edge to the DX90 superior extension and snap. Dynamics and detail felt a bit lacking in the original X5 making it sound a bit uneven and one dimensional down below. On the new Gen 2 X5 FiiO have flattened out that mid bass hump and greatly improved the sub bass response making the bass that bit more extended but much more linear and coherent. This is also a more dynamic and snappier bass response that conveys a more convincing level of detail and texture than the old gen 1 slightly blander low end qualities.

The Top End

With that slight harshness done away with as well as the metallic edge to the attack, the X5 Gen 2 top end sounds far more engaging. It also sounds more detailed and articulate though not quite on the same level and extension as say the Cayin N6 or even the DX90 but it’s a lot closer than the older X5 Gen 1. Percussion was snappy and clear without being tizzy or harsh and just like the bass response I found the clarity to be much more present than before. You could argue that the X5 gen 2 overall is the brighter sounding of the two with a slightly more forward focus on the treble response but personally I find the treble on the X5 Gen 2 to be just right in terms of balance between detail and energy.




Power wise the X5ii is rated at 16-150ohms and with a high and low gain its ideal for matching with most portable headphones. Rejoice planar users because the X5ii matches very well indeed with the He400s, particularly with female vocals and does more than a decent job indeed of filling in that very wide soundstage on the HE400s. It does require a bit more juice, up to 70-75 on high gain to really kick off compared to just 45-50 on the Noble 4 Classic but that’s still well within the capable range of the X5ii. You can go a few steps higher on low gain and still get a good response with a slightly lower noise floor with the HE400s.

The Oppo PM-3 performs at very similar levels as the He 400s with volume matching on high gain also around 75 on the X5ii. Tonally it’s also a strong match but with a slightly thicker sound, heavier bass line and a more intimate sound stage than the HE400s. Although both drove pretty well out of the X5ii I did find myself gravitating more to hard rock and modern pop genres with the bassier PM-3 and sticking to the classics and vocals with the airier HE400s.


For IEM matching I actually found the X5ii to be very flexible indeed for matching. Power wise noise levels were very low indeed, certainly much lower than the Alien and the X3ii when set to low gain. Volume sat naturally around 40-50 depending on sensitivity with the T10i from RHA going quite a bit higher at over 60. The neutral and slightly dry tonality suited my more liquid and rich IEMs such as the Heir Audio 8.0 but it also paired very well indeed with the Noble 4 Classic which I actually ended up using for most of my sound impressions given its flattish response. Normally if I have a very uneven treble the Noble 4c will chew it up, sounding bright and thin but not with the X5ii which kept on the right side of bright with little or no distracting treble peaks.



All tested straight out of the jack using the Noble 4 Classic, picked for its flattish and neutral signature.

X5 Gen 2 vs X3 Gen 2

Whilst both display far more neutral signatures than FiiO of yesteryear the X5 Gen 2 provides a far more resolving and detailed response than the new X3 Gen 2. I also much preferred the voicing on the X5 2nd Gen to the new X3. By contrast the X3ii sounded far more distant, less engaging and less detailed. The X5ii’s treble extension and detail is also more noticeable than the X3’s less resolving top end. The X5ii also displayed a better level of imaging and dynamics than the X3ii which by contrast sounded a bit more closed in and flatter sounding. So sound wise the X5ii is a convincing step up.

However functionality wise the X3ii is still a compelling package coming in at $150 cheaper, displaying much the same level of functionality including native DSD decoding and it is very much the more portable of the two size wise. With the X5ii you are really buying into a superior, more resolving and controlled sound, with increased memory capacity and additional amping power for higher end cans.

X5 Gen 2 vs DX90

The Dx90 is the slightly smaller of the two and still has the best mix of touchscreen and physical control buttons at this price range. It does lack the same level of storage capacity with only one memory card slot as opposed to the X5ii’s dual microSD slots and both now have OTG so the playing field there is quite even. Both have line out and digital output features and both have DAC functionality. The Dx90 has been around a few years now so the fact the X5 is edging closer with revision 2 in 2015 is both good and bad news. Bad because honestly it should have been there competing ages ago and good in that the DX90 is no longer officially for sale, as in discontinued. In a few quick months though this discussion is going to be DX80 vs X7 – tech moves fast these days in DAP-land.

Sound wise things though are a heck of a lot closer and honestly it will come down to pure preference in the type of tonality you want. The DX90 for me still has the better sub bass and treble dynamics and with superior depth and height to its soundstage. But I like the mids a little better on the X5 and the level of control on the vocal presence on both DAPs makes the choice a little harder than before. Both show good control on sibilance, both have a slightly more natural flow to the treble but I still give that very slight edge to the DX90 in terms of openness and extension. If you prefer your bass a little bit more linear and the tonality a bit drier but crave a slightly more forward midrange then the X5ii might be your preference.

X5 Gen 2 vs Cayin N6

If you thought the X5ii was a little on the large side then the Cayin N6 is not for you. Cayin, along with Shanling should be given credit for crafting memorable designs but the aesthetics and usability of both the UI and the whole form factor is just plain weird. The N6 is big, too big, the X3ii looks like a modern masterpiece of svelte design side by side. It’s about 20% shorter, 10% thinner and 25% less in height.

Now for me the N6 bulk is neither here nor there. You should have seen my Ferguson portable cassette deck in the early 80’s to get the meaning of big. To be fair also to Cayin the N6’s left side jog wheel is easy to use and the physical materials are a very high standard. Both the X5ii and the N6 share the same LCD screen specs which is a 2.4 inch 400×360 IPS but the UI color scheme used by Cayin is dull compared to the X5ii which looks bright, saturated with plenty of pop.

The X5ii UI is also far more mature and developed than the N6 UI and combined with the new hardware button layout I would say it also has the edge in ease of use. The N6, on the other hand, has a speedy on-board 8GB of memory which is always helpful but held back by the X5ii dual memory card slot and OTG functionality which gives it the edge in total overall capacity. The X5ii also has a slightly longer rated battery life at 10 hours to the N6 8 hours, or less. As a portable media player or DAP the X5ii is just far superior physically.

Sound wise the N6 sounds that bit better and that is where the extra money is ploughed into. The timbre is just that bit more flowing and natural sounding on the N6 making the X5ii sound just a little bit too dry and unnatural sounding in comparison. Whilst the vocal presence on the X5ii is far superior to the older X5 and very close to the DX90’s level of performance I just found that compared to the N6 it didn’t quite have such a fluid feel. The N6 also benefitted from a slightly deeper and smoother bass extension and a wider soundstage with slightly improved dynamics over the X5ii. If you want a neutral sound that is has a level up in terms of refinement, resolution and voicing the N6 for me has the edge. If you need to keep it tidy and have a bigger music collection with longer on the go trips the X5ii is the better option.

X5 Gen 2 vs Shozy Alien

Apples and oranges here in terms of physical appearance and functionality. The Alien is a mechanical conduit for a killer sound but it’s as awkward looking as bumping into Ernie the Giant Chicken dressed in a Peter Griffin suit. Those working the Apple UI get ready because here is the big secret – the Alien has no UI, it has no screen either. Shuffle guys understand this timeless battle with the unknown and will most suit them. For everyone else the FiiO X5ii is streets ahead with an actual LCD screen, an actual UI, better memory capacity, DAC functionality, line out and superior battery longevity. Also I am pretty sure if you sit funny with the Alien in your pocket you could quite well die from sudden puncture wounds. Good to know then that the Alien flies off the shelves for less than $200 just to keep things in perspective.

Sound wise though I think the Alien holds its own against the X5ii considering the price difference. It’s not as neutral as the X5ii, it has a fair bit more noise, especially with IEMs so if an absolute black background is what you want then the X5ii is the superior choice. Tonally though I prefer the free flowing natural and more upfront signature of the Alien to the slightly more controlled and probably the more technically accurate X5ii.

If you want digital excellence the X5ii is the better of the two; a bigger soundstage, deeper extending sub bass and a more articulate and resolving treble response. If you want something more intimate, yet more musical with a very pleasing and energetic timbre, especially in the mids then the Alien is going to be a lot more suited and at half the price. It’s an audiophile battle only though, that lack of physical screen and UI on the Alien will always hold it back.

Final Thoughts

The FiiO X5ii is a solid evolution and update on the original X5 and brings harmony to the complete range of hardware controlled non touch DAPs in the FiiO range from the X1 to the X5. If this came out at the same time as the DX90 I would have a bit of a tough decision on which one I would stick with but given that it is 2015 and the X7 is just about to hit the market the X5ii may have a shorter than normal shelf life. The X7 is modern, sleek and desirable looking, the X5ii is for old school guys who like great sound disguised in a ‘Sherman’. I am really glad they didn’t up the price on the new gen and as of now the old gen is discontinued as per the normal FiiO life cycle product development.

I do commend FiiO for really pushing hard on this and keeping everything as up to date as they can, unlike some other firms which just let their device die in favor of something brand new. This latest gen X5 does indeed sound really competitive now and it is knocking hard on the door of the DX90 for the mantle as one of the best sounding mid range DAPs out there.

In the long run I do hope this will be the last revision with this form factor. I do not think there is much more to be done here save adding a big HDD or SDD on-board and keeping the codec range and UI as optimal as possible with strong firmware updates. Given the X7 is projected to be double the price right now there is still a window for the X5ii but it is closing fast with the AK Jnr and the new XDP-100R from Pioneer all in the same price bracket. FiiO hard-core fans won’t care, this will sell regardless but for the rest we could move on reasonably quickly. Just enjoy it while you can.

Technical Specifications

Model/Number – X5 (X5 2nd gen)
Headphone Port – Standard 3.5mm Headphone Port
Color – Titanium
Drive Ability – 16~150 Ω
Dimensions – 109 mm× 63.5 mm× 15.3 mm
Volume Control – 120 steps digital potentiometer
Weight – 165 g
Equalizer – 10-band equalizer (±6dB)
Display Screen – 2.4″, 262,144 color HD IPS screen with 400×360 pixels
Line Out – Standard 3.5mm Port (Shared line out / S/PDIF coaxial out)
Digital Out (Coaxial) – Standard 3.5mm Port (Shared line out / S/PDIF coaxial out)
Balance – 10 dB
USB DAC – Supporting up to 24bit / 192kHz and DSD (driver installation required)
Gain – 3.6dB(Gain=L) // 9.1dB(Gain=H

Partial Performance Parameters for Line Output

THD+N – <0.001% (1 kHz)
SNR – ≥114 dB (A-weight)
Frequency Response – 20 Hz~20 kHz
Dynamic Range – >110 dB
Crosstalk – >115 dB (10 KΩ/1 kHz)
Line Output Level – 1.53 Vrms (10 KΩ/1 kHz)

Partial Performance Parameters for Headphone Output:

Output Power 1 – >245 mW(32Ω//THD+N<1%)
Output Power 2 – >436 mW(16Ω/THD+N<1%)
Output Power 3 – >27 mW(300Ω/THD+N<1%)
Output Impedance – <0.2 Ω(32Ω)
Crosstalk – >75 dB (1 kHz)
THD+N – <0.001% (1 kHz)
Frequency Response – 20 Hz~20 kHz
MAX Output Voltage – >8.2 Vp-p
SNR – ≥117 dB (A-weighted)
MAX Output Current – >250 mA(For reference)

Power and Battery:

Power – DC5V 2A recommended
Battery Capacity – 3300 mAh
Charge Display – Red light indicates , green light turns on after fully charged
Battery Life – >10 h (32Ω; normal volume with display off )
Battery Display – Yes (Accurate battery % readings))
Charging Time – <4h (DC5V 2A)

Audio Formats Supported:

DSD: DSD64, DSD128 (.iso&.dsf & .dff);
APE(Fast): 192 kHz/24 bit;
APE(Normal): 96 kHz/24 bit;
APE (High): 96 kHz/24 bit;
AIFF: 192 kHz/24 bit;
FLAC: 192 kHz/24 bit;
WAV: 192 kHz/64 bit;
WMA Lossless: 96 kHz/24 bit;
Apple Lossless: 192 kHz/24 bit;
Lossy compression: MP2、MP3、AAC、ALAC、WMA、OGG…

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18 Responses

  1. Review Man

    Hi all,

    Before considering buying a product of Fiio you better first have a look at their own forums. Their devices do not come cheap but service is very bad. There is no follow up on reported issues and no solution are provided for issues that are simply not acceptable fro devices in this price-range.

    The Fiio X5II has serious stuttering issues when using cards that aren’t fast as you can read here:

    Do not forget that a lot of people encountering failure do not take the time to report or post this in fora so one can imagine that a lot of people have problems with the Fiio X5II.

    Reviewers basically just take a snapshot of a new product and do not have the time to find out that some of their reviewed products actually do not deliver what the client should expect for the price. Therefore I urge everybody encountering problems with the relatively expensive Fiio X5II to report this in their forum and force them to deliver a solution.

    • headfonics

      That’s odd because apart from the review I have been using the X5ii for well over a year and 2 months prior to the review (including referencing it in a number of comparitive reviews thereafter) and never encountered the problems you are speaking off. So that begs the question, are you generalizing or have you engaged reviewers and found the majority never touch their unit after posting a review?

      • Review Man

        Hi, you might want to follow the link in my post or run a search on google for “stuttering fiio x5” I’m not here to trash a product. I just think it is fair to inform people about malfunctioning of an expensive product that should have NO technical problems (even though the review can be all 5 stars).

        Did you read their forum, did you check the several threads about the glitches in playback? Did you read the comments form genuine users that are trying to get the issues solved, Did you notice that Fiio did not reply in any off the cases?!

        If you using it over 2 years without a problem you are lucky. Did it cross your mind that you are using the right memorycards, probably the good ones that work. It might be therefor you didn’t encounter any problem?

        Sorry if I get the impression you doubt my honesty. I would not refer to Fiio’s own forum only if I was about to trash them. I would have found myself some sites that only post negative comments. I didn’t as I want the problem (that many owners encounter) solved so they and I can enjoy this device too.

      • headfonics

        I don’t doubt your honesty, just the casual link between reviewing and knowing a product is slightly erroneous. My 64gd sansdisk cards cost $20 each, never had an issue with the x5. Not sure if FiiO would be re-engineering their DAP for this. Have you tried faster cards for $20? I have also had a quite a few cheaper throwaway cards. Perhaps this is anecdotal on the forums rather than, as they say in ICT helpdesks a “known issue”.

      • Review Man

        The link between “reviewing and knowing” is not erroneous and to be complete does not apply in any way to headfonics. But for sure you agree that most of the reviewers make their review when a product comes out and then “hop on” to the next new product. Nothing wrong with that. But it just might be that problems appear afterwards, On longer use or with different fabrication dates. How many products from reputable companies are being called back now-a-days because of technical errors only appearing after more and more customers being confronted with it.

        Your statement that the stuttering might be just anecdotal instead instead of a known issue I can’t take serious. Many owner have serious issue with the Fiio X5II. Stuttering is just a word used in one thread but there are more people experiencing glitches, stuck music, skips, rattling sound etc.

        Anyway I regret this is ending up in a yes/no discussion. All I wanted is to report a know issue after trying to solve it myself for a whole year in silence. I did my best and gave Fiio the advantage of the doubt but this is a joke and needs to be solved.

        As for your personal use, I’m happy for you but you can’t be serious that trying faster cards is a solution. There are tons of cards out there does one need to try them all and hope to find one that works?! Besides that, when the Fiio X5II first came out it should work and cards that were the fastest on release date not on the ones that are out now.

        I’ve been reading headfonics with pleasure from the beginning and learned a lot. But when reporting the malfunctioning of a product turns into a discussion like this I better move on. Have great fun with your Fiio X5II and enjoy the music.

      • headfonics

        Its your call buddy but that’s my experience and I have been using the X5ii happily for 18 months so its not a known issue, if it was it would be happening to all of us and not a select few. If you choose to bypass us because I dont necessarily agree with a few of your points then that’s your call but surely you must consider that not everyone will experience what you are experiencing.

        A known issue is whereby the X5ii is guaranteed to stutter etc and in this case it simply is not. That doesn’t mean I dont have empathy for your situation it just means its not absolute and required extensive documentation.

        I notice you have done that but again the numbers on that thread amount to less than 20 people. A manufacturing recall requires a parameter of 1-3%, a known issue perhaps 0.5% with a written workaround from the manufacturer. I know because I actually been in the manufacturing business for a long time. Now you could argue that FiiO have not tended to your needs in a satisfactory manner. I grant you that and on a CS level that is worth considering in terms of reporting on forums.

        Put it this way, and like you this is entirely from a personal perspective, every card I have works with the X5ii, cheap, fast, slow doesn’t matter, never a conscious decision for me to pick a certain card because it might not work simply because I have yet to encounter that. As a reviewer and a user, I cannot report what has not happened to me in the same way you you must report what has happened to you. Both are personal perspectives and I can drum up 20 people also from the various local groups who will have the same experience. It thus creates a challenging picture to validate.

        And yes reviewing and knowing can be erroneous because it is a blanket statement to say all reviewers do not know and that is not a factual reality. Some do and some don’t and for those that do know and use all the time they will challenge you as is their right. I am sure if you have been reading our reviews from day one you will see the X5ii referenced quite a lot in testing of earphones, headphones etc. As also a number of other credible reviewing websites.

      • 24bit

        Going to have to agree with Marcus here on this. My X5 has never had any problems. But, when I use a junk, no name micro sd card in any of my portables, the experience lags like no tomorrow. SD cards of an off brand variety will stutter and lag out when you track skip, play and pause too frequently. Those issues vanish when I drop in a proper Sandisk sd.

      • 24bit

        Logical argument would be that non firmware and non hardware related stuttering in a portable player would be directly related to bad SD cards. Combine that with improper or corrupted formatting, which I deal with all the time when I help Android firmware developers code and patch firmware and that is a severe problem. These potential hazards make up the majority of the very small percent of users complaining about the Stutter. SDformatter v4 fixed the formatting problem users were having with their micro sd cards when used with the X5.

        Now for giggles, take your sd card and drop that in a Cowon, or a Calyx M. Let the Library update and then drop some songs on it. Enjoy. Then take it out and stick it into the Fiio X5 and witness your stuttering problem caused directly by format incompatibility issues. A problem made even worse if you use a 3rd party, off brand SD card and if you use the wrong SD format tool. My being the only one in the conversation (outside of Marcus who first brought up SD cards) is irrelevant.

      • Review Man

        Hey thanks for the additonal info, it helps.

        As for you being the only one mentioning SD cards I was explicitly referring to the qualification you used, “junk and no name” cards. Furthermore you mention they don’t work whilst Markus mentiones he uses all kind of cards. So that are two completley different opions form experts. Besides this discussion you can read on the Fiio form that quality of cards is not a guarantee. My Samsung was their top of the range and the fastest (not saying it is a good one) back then. Costed €50 so one might expect 100% functionality.

        Last but not least, some reflection on my own initial post. Maybe it would have been better to warn people that some cards could have trouble playing FLAC files when using the X5II instead of stating the device itself has a problem. My bad. Nevertheless I do feel that Fiio support should improve big time we are not talking $10 stuff here.

  2. Andy

    Sound-wise you sound very convinced that X3II is in fact inferior to X5II. Apart from likely biased subjective opinions, do you have some sort of objective evidence to back up the claim that X5II is “a convincing step up” and that X3II is “far more distant, less engaging and less detailed. The X5ii’s treble
    extension and detail is also more noticeable than the X3’s less
    resolving top end”?
    For example spectrum analysis based on null-test?

    • 24bit

      There really aren’t any credible means to measure a portable music player in the manner you are asking. Just as there are no measuring gears available to tell you how large and spacious the sound stage in an HD800 is compared to Apple iBuds, or how much physical impact the bass slam has, how soft it is compared to something else and so on. There are a ton of potential sound qualities right now that cannot be measured by anything, yet we can still hear all of them and talk about them freely. Hopefully, in the future new technology will be invented to help out here and accurately measure things like placement of sounds, distance between instruments and so many other qualities like that, that we have no clue how to actually test in a lab. :)

      • Andy

        Null-test is an industry standard that objectively proves transparency. It’s also fairly easy to do, although in X5II vs X3II it’s a bit more difficult as both players suffer from higher latency. All what’s needed is a stereo recorder and then playing back mono track with one of the channels inverted. Should both players exhibit same signature, the result would be 0 or very low-level noise.

        “There are a ton of potential sound qualities right now that cannot be
        measured by anything”

        Headphones are always subjective matter, but this statement doesn’t hold weight for me.
        Actually yes, all of that can be measured. And by doing so, you’ll eliminate personal bias. Listening is always subjective, thereby using it to objectively asess sound properties is inappropriate at best.
        Even when you and those believe their ears are perfect and pristine, ABX is also an option. Switching gear with maximum of 0.2 second gap is preferred.

        Suddenly, expectation bias disappears.

        Why I brought this up you ask?
        I actually did an ABX with 3 independent listeners, and none of them could safely say which is which (X5II vs X3II). Just for lulz I repeated the test with SL-SX480 (€15) and X5II (€400) and yet again, no statistically relevant result.

      • Andy

        Glad you could add something respectable and relevant to this year-old discussion. Bravo!

      • Andy

        Applying the same logic would be like comparing 192kHz 24bit recording with 44.1kHz 16bit one – recording captured with LF on 22k and 90dB of dynamic range due to microphone hiss.
        Both recordings would be nearly identical, save for minuscule difference in rounding and SRC, and both recording would be indistinguishable in ABX.
        Yet in sighted listening, 192/24 would win for most audiophiles. Why? Because it’s higher number, so it MUST be audible, right?

        Going way too much into boutique region has very noticeable drawbacks – not only price of such gear but also down-to-earth parameters like power consumption.
        Only 0.14W is needed for audibly transparent DAP with balanced out and 3.6Vrms amplitude (9Vp-p). But X5II draws 1.22W, due to its unnecessary discrete layout, that achieves better figures, but those numbers are not practical and the price might be too high. X7 is even worse in that aspect.

  3. Emrah Yıldırım

    I have a Bose QC25, and I’m stuck between X5ii and DX80. Which do you reckon will be the best match?

    • headfonics

      X5ii for me. I always found the dx80 to be too warm for the QC25 which needs something more neutral and clean given its a veiled can.


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