Review: FiiO X5 (loaned by FiiO)

Disclaimer: this article is not an example of native advertising.

I wasn´t paid by FiiO to write this review, nor did I receive any compensation.
The unit to be reviewed was loaned to me for several days after which I sent it
to the British Isles to another reviewer. To me, it´s important to tell you this,
because there are places out there not telling you that they´re writing
reviews where the result has been predefined by the manufacturer.

1. PROLOGUE

Sometimes life is indeed like a box of chocolates, you never know what you´re gonna get. But nobody ever tells you that you might not like the things you´re getting. In my case, the 14 months since my last article were Hell. Taxing for both my boyfriend and me, he now calls it his "Annus horribilis" - and nothing else could be a more fitting expression. I won´t dwelve into details, I´ll only say that the last year involved the passing of a family member. In light of this, every appeal some gear aimed at music reproduction has, has paled. But before I digress into a discussion about what's important in life, I´ll say that for you, dear Constant Reader, the only important thing is: I'm back!

Considering the fact that the successor of the FiiO X5 (2nd gen) has just been released two days ago, it is ironic that I should review the FiiO X5 (1st gen) before the older FiiO X3 (succeeded as well by the X3 (2nd gen)). I´ve owned the latter since October 2013 and, I have to admit, haven´t been that happy with it. Why? I expected a gadget without firmware crashes, featuring pristine decoding of lossy formats, fast reaction times and neutral sound. Instead I received the opposite. In December 2013 FiiO announced on Head-fi, that several X5-preview-models were to be delivered to willing reviewers all over the world. Though my initial application was rejected, I nonetheless did receive the European preview model a few months later. I was supposed to test its newest beta-firmware to measure its performance with lossy codecs, a task I gladly accepted. After all, it was me who in November of the same year started a lengthy and tiresome discussion concerning the quality of lossy decoding on both FiiOs. For convenience reasons, this article is seperated into several chapters, that way you can scroll to the part interesting you the most:

1. Prologue
2. X5 Competition
3. HiRes DAP - why?
4. Specs & features
5. The importance of firmware
6. Listening test
7. Conclusion
8. Fancy graphs (measurements)

Is it a bird? Is it a plane? Is it a 1st-generation iPod? No, it is a FiiO X5!

2. X5 Competition

Just like the models from Astell&Kern, Sony and others like iBasso, or even the laughable Pono (righteous my ass), the FiiO X5 is a HiRes-capable DAP. In comparison to most of these models though, it isn´t as ridiculously expensive nor is it loaded with marketing hype. The Sony NWZ-ZX2 costs a whopping 1199,- Euros, the AK 240: 2.400,- Euros. And yet they´re still incapable of powering lots of cans: the expensive Sony for example achieves so little gain that it can´t power 75 % of all headphones out there. The Sennheiser HD-600 on the Astell&Kerns? Impossible. You could spend much less money and buy the FiiO X5 for 399,- Euros.
It cannot play videos, isn´t able to connect to devices via Bluetooth / NFC or act as a DLNA streamer, it also doesn´t feature a touchscreen like all the other players. Instead, you´d get a sort of oldfashioned click-wheel on the X5 (hello, iPod 1st gen), buttons and even more important: a powerful headphone output. All of this doesn´t change the fact that the most dangerous competitor for the X5 are FiiO's own X3 and X1: both were/are cheaper (219,- / 99,- Euros) and offer - with the exception of the X1 - exactly the same features (the X3 lacks OTG). Instead of a clickwheel, the X3 sports buttons, a really crappy LCD display, a different audio path using less ICs and one MicroSD card slot instead of two. The X1 looks like a smaller X5 and lacks a second MicroSD card slot, a digital out, a line-out and the Hi-Gain option for high-impdance headphones.

Very competitive rival to the X5: FiiO's very own X3

3. HiRes DAP - why?

Good question. Why should a DAP dedicated to music playback only be an option when every smartphone can do the same... and contains a camera, the ability to add apps, surf the web, etc. And I won´t even mention that the expression "HiRes" is thoroughly misleading (extended frequency response and lower noisefloor would be the correct designations). Easy answer: portable HiRes DAPs are equipped with well engineered and powerful headphone outputs. At least when it comes to FiiO. But the X5 (the same goes for the X3 and, partly, for the X1) is much more than a simple player. Because FiiO likes to equip their players with features otherwise only found on the more expensive competition, the X5 can do many things you´d normally need several, individual devices for. It´s a portable DAP, USB-DAC, USB-to-S/PDIF converter and it acts as a stationary HiRes player via its line-out. Compared to the smartphones people usually use, the X5 will be able to drive many headphones - even difficult ones like my Sennheiser HD-600 - without problems, impedance-related frequency errors or low gain are absent. On smartphones you have weak headphone outputs, furthermore, they aren´t able to play often-used formats like FLAC (the iPhone, just to name one), you´d need an extra app for them. All of this is solved by the purchase of the FiiO X5.

FiiO X5, backside fashioned out of aluminum

4. Specs & Features

The heart of the FiiO X5 is a somewhat older SoC, the Ingenics 4760B ('XBurst'), launched in 2010. It´s a low-cost MIPS design, aimed at smartphones and the like. It features two cores (the second core serves the GPU) and includes an FPU (floating point unit). This SoC is responsible for everything, ranging from decoding media formats to drawing display elements. The D/A-converter is a Burr-Brown PCM1792A, an IC usually found in stationary digital devices of the more expensive kind. Headphones are amplified by two OPA1612 and two LMH6643. All chips inside the X5 dealing with audio reproduction are supplied by Texas Instruments, a fact the company likes to gloat over. As for the rest of its specifactions, please refer to the following itemization:

General specs

Dimensions: 64.6x114x15.6 (WxLxH, mm)

Weight: 122g

Display: 2.4" 260,000 colors HD IPS Screen at 400x360

CPU: Ingenics 4760B 600MHz Dual Core

DAC: PCM1792A, supports 192KHz/24Bit

Outputs: 3.5mm Headphone jack, 3.5mm Line-output, 3.5mm Digital Coax output

Storage: 2 x microSD slots (currently max supported 128GB x 2)

Battery: 3700mAh Li-Polymer Battery, up to 15 hours playback time

Headphones impedance range: 16~300Ω

Gain selection: 0/6 dB 

Line output Level: > 1.5 Vrms

Headphone output power 1: > 460 mW@16Ω

Headphone output power 2: > 255 mW@32Ω

Headphone output power 3: > 28 mW@300Ω

Headphone output impedance: <0.26Ω

Headphone output crosstalk: >75 dB@1KHz

Headphone out THD+N: < 0.003%@1KHz

Frequency response: 20Hz~20KHz（+/-0.1)

MAX output voltage: > 8 Vp-p

SNR: > 115 dB

MAX output current: > 150 mA

Supported formats

Lossless: APE(fast:): 192K/24B; APE(normal): 96K/24B;

APE(high): 96K/24B; FLAC: 192k/24B;
WAV: 192k/24B; WMA 9.1 LOSSLESS: 96k/24B;
Apple Lossless 192K/24B; DSD 2.8224;

Lossy compression: MP2, MP3, AAC, ALAC, WMA, OGG

FiiO X5 size comparison against the Sony MZ-R 909, an ancient MD recorder

But what about manufacturing quality? Let me put it this way: should you encounter an intruder in your house you can use the X5 to knock him/her unconscious. It is heavy and feels like a portable tank. It is neither small nor fragile (the MZ-R 909 pictured above looks & feels flimsy in comparison), once you grab it it conveys the haptic of something engineered for military use. This impression doesn´t extend to the clickwheel though (see the image below), it feels like a plate made out of cheap plastic (which it is, only covered by a sheet of rubber). It turns too easily for my taste, it should have offered more resistance upon moving it. My criticism continues with the aluminum 'enter' button in the middle which wobbles the moment you press it. Everything concerning the clickwheel feels a bit tacky. Compared to the rest it is quite the difference, if you ask me.

FiiO X5 clickwheel: rubber-coated plastic with aluminum button in the middle

Every jack, whether it´s the digital output, headphone out or the USB port, is manufactured well, gripping plugs tightly. The display shows good contrast and decent colour temperature from every angle. All in all, it is exceptionally manufactured... but I would have loved to have another colour option. Maybe white, gold or silver, you know; something fancy that would be pleasing to the eye (guess what: I acquired the X1 in gold). The design and haptic of the X5 carry a strong technical vibe, people looking for smoothness or elegance should look elsewhere. In part, this can be rectified somewhat by several accessories FiiO and others are offering. Just have a look at the image below listing several possible additions.

FiiO X5: selection of accessories

5. The importance of firmware

Since releasing firmware 2.0, FiiO likes to brag about the 32 bit floating point decoding of some lossy formats, namely MP3 & OGG. They describe their decoding as industry leading; that is the truth and I´m partly responsible for this as I started a discussion in November 2013 in the X3-thread on Head-fi. I literally bombarded FiiO with emails regarding their then botched decoding of lossy formats, when that didn´t prove successful, I wrote the post I linked above. Shortly after, others started to chime in while I continued providing measurement data revealing how bad the X3 was decoding MP3, OGG and WMA. To make a long story short, FiiO started to work on revamping their decoding engine. It took them half a year to pull it off, the results are stellar and well beyond my expectations. The X5 and X3 now decode MP3, OGG and WMA as pristine as foobar2000. Which is in fact industry leading; I don´t know any other company producing portable players that decode these lossy formats the way the devices from FiiO do. So what I called 'bragging' at the start of this paragraph is completely justified. I have to mention Head-fi member JoeBloggs, who works for FiiO and was incredibly helpful in getting it done (he will read this article and he will know what I´m talking about).

On the other hand, the opportunity to play around with so many different firmwares poses a problem. You see, many of them cause the FiiO X-players to sound different. Yup, I know what I just wrote and believe me, I feel ridiculous. I really don´t know how FiiO is able to slightly alter the sound of some player just by changing a tiny piece of software. I measured several different firmwares on the X3 and on the X5 and couldn´t find significant differences. I did some listening tests, sighted and double-blind, and was always able to confirm differences. I would love to be contacted by someone who could explain to me how this can be possible. Anyway, I will come back to why it poses a problem after I have finished my listening test.

Outputs on the FiiO X5: digital output, line-out and headphone out

6. Listening test

Headphone out

I reviewed the X5 using firmwares 0.01a, 1.17, 1.20 and 1.21b... which makes the description of the sound somewhat difficult as the FiiO kept changing its sound with different firmwares. I reviewed it using FLAC (24/96, 16/44.1), WMA Professional (24/48), AAC (48 kHz) & MP3 (48 kHz), finally settling on firmware 0.01a - which was the first and - in March 2014 at least - the only one that got the decoding of most lossy codecs right.

Using that firmware and a combination of double-blind and sighted listening, the X5 wasn´t a bad player. It also wasn´t a good player. Yet you can read several reviews all over the web where reviewers allocate almost magical properties to its sound - which isn't true. The overall perceived EQ was balanced, only missing a bit of treble and bass. From all the three FiiO X-players I´ve heard (X1, X3 & X5) it certainly is the most balanced. But: dynamics weren´t up to snuff. This player sounded 'little' and timid when it came to rendering transients, exploding bass drums or crisp cymbal crashes. The staging suffered, too: soloists transformed into cardboard characters; while my reference files were holographic and three-dimensional, the X5 sounded flat, wide and two-dimensional. The lacking dynamics wouldn´t have been too bad in the long run... but the missing spatiality made me sad. I reviewed it using several headphones: Sennheiser HD-448, HD-558 & HD-600, I could observe this 'cardboard'-stage with each one of them. Despite these shortcomings, it was very capable of retaining the character of the music it was playing.

And now I´m coming back to the problem of different sounding firmwares. When I received my FiiO X3 in October 2013, well, I hated its sound. In the beginning, it badly lacked at spatiality, just like the X5. It took FiiO almost a year to come up with a sound one could listen to without missing anything (FW 3.00). Before that I listened with the Sony MZ-R 50 or the Sony NW-HD5; both amped by the FiiO E07K, they were clearly superior. In December 2014 I bought the FiiO X1; when FW 1.40 was released a few weeks ago, I again noticed a change in spatiality. Every FiiO X-player so far has matured long after sales had started (Philips calls this principle "banana"; they ripen while they´re at the buyers home). Very problematic for first impressions, I think. So it´s very possible, even likely, that the X5 sounds different at the time of writing. After all, in April FiiO released FW 2.50 for the X5 (and the next beta is already underway) but, since I don´t have it anymore, I cannot re-test it in order to determine if it really sounds different. For that reason I have to rate it like this:

Sonic Balance:

Dynamics:

Resolution:

Stage / Ambiance:

Character:

Line-out

It sounded much better through its line-out. Why? No idea. But the same thing applies to the X3, too. Via its line-out, the X5 sounded almost like my reference files, lacking only a tiny bit of treble and bass. Detail retrievance was on par with my reference, only differentiation suffered slightly. Dynamics? No problem anymore. Surprised? Yeah, me too. Spatiality? The same. Holographic, three-dimensional, just like my reference files.

Sonic Balance:

Dynamics:

Resolution:

Stage / Ambiance:

Character:

USB port, two MicroSD card slots for (right now) 256 Gb of storage space

7. Conclusion

Built like a tank, looking like a tank, sounding, to me, like a little cat at the time it was staying with me. How to conclude a review for a device everyone else seems to love but I don´t? Especially when the company engineering it has been so incredibly forthcoming and friendly to me and others? Let's sum up the obvious stuff: the FiiO X5 looks good, it can do a lot of things that may come in handy. It not only is a portable DAP, it can also be used as a DAC for your PC. It can play almost any codec you throw at it: FLAC, MP3, APE, WMA (including the rare Professional variant), OGG, even the unnecessary DSD. The display looks good from every angle, using its interface was wonderful. Less good are the clickwheel and the size and weight of the whole unit. Wrapping up, it´s a robust, feature-rich DAP. On the other hand, the sound issue remains. It wasn´t sounding well through its headphone out, at least when I was reviewing it using an alpha-firmware more than a year ago. I´m confident that FiiO rectified most of the sound issues I described. Of course, I cannot be sure so in the end it´s up to you, dear Constant Reader, if you want to purchase it or if you spend a little less money and get either the X3, the X3 (2nd gen), or even the X1 instead.

A beautiful, big and robust booty, don't you think?

8. Fancy graphs (Measurements)

Headphone out

RMAA-generated spreadsheet, showing results for three headphones

Frequency response

Noise level

Dynamic range

THD + Noise

Intermodulation distortion

Stereo crosstalk

Phase delay, Sennheiser HD-558

Phase response, Sennheiser HD-558

Jitter, 24/96, headphone out

This must be the best headphone output I´ve ever measured. Never before have I seen an output lacking phase distortion of any kind; remarkable. The noisefloor is at -114 dB, this is professional level. Total harmonic distortions are low, intermodulation distortions show that the Sennheiser HD-558 is a headphone that is difficult to drive. Have a look at the weird looking noisefloor and the low-frequency IMD when the X5 is amping it. I don´t know how audible those distortions are, though. The most interesting thing however is the graph showing jitter: while it is pretty low, it´s different from the amount of jitter found on the line-out. Have a look at the next graph:

Line-out

Jitter, 24/96, line-out

RMAA quality assessment, 24/96

Frequency response, 24/96

Noise level, 24/96

Total harmonic distortion, 24/96

Intermodulation distortion, 24/96

Intermodulation distortion, sweep, 24/96

Phase delay, 24/96

Phase Response, 24/96

Impulse, 24/96

Odd, isn´t it? Jitter is lower on the line-out even though both outputs use the very same DAC. But instead of having no phase distortion on the headphone out, you have plenty on the line-out. IMD is a bit lower, total harmonic distortion is much higher. On other portable gear I´ve measured, it´s usually the other way around. And, of course, there is a very, very slight channel imbalance which is probably insignificant. Absolute phase is retained - always good. One thing is for sure however: for a portable device, it measures very well.

Last update: 19.06.15