ryanjsoo, I rarely comment in reviews. You did a great job. The consumers need all manner of views and critical input to balance out the hype which I am a part of   Good stuff. I hope folks give you a thumb to assure a well balanced review gets the lots of views  it should

Is there still WIFI signal interfere as what happened on X7?

Excellent review. I'm loving the X5 3 so far.

Agree, very well written review. Hope to get my pre-order within a couple of weeks. There's certainly nothing you've mentioned that's put me off. Is sensitivity in db more critical than impedance with regard to background hiss? Its my only concern, getting too much hiss with my SE846's, but I do have an ifi iEMatch to fix that if necessary. 

Very informative and nicely documented review, thanks. This will be my first DAP, it should arrive in 10 days now. Can't wait to (at last) test what's a DAP vs. a iPhone 6S is able of... Ok, I likely already know the answer...

Nice review, @ryanjsoo  !!! 

@Benjamin Ruan I'm assuming you mean the X7 produced noise through the headphone output when WiFi is active? In that case, I didn't experience any noise with the X5 III, I had WiFi enabled during the entire review period and frequently used Spotify to stream music.
 
@psikey Both impedance and sensitivity affect an earphone's susceptibility to hiss though sensitivity will have a bigger effect. I know they aren't really comparable, but my Shure SE215's didn't produce too much hiss and I'm usually pretty sensitive to that kind of thing.
 
And thanks for the kind comments everyone else!

Excellent review! I particularly appreciated the comparisons to the Oppo HA-2 as I own that device.  Thanks for posting.

I really liked that fact that you put a "About Me – Some background, Gear of choice, Preferences and Biases" section. Gives everyone  an idea of where you are coming from. Wish all reviewers did that.

@punit Thanks! You can thank Brooko most of all, he suggested I write that up. I definitely think it helps my readers to understand my preferences and reasons for some priorities, hope you enjoyed the review.
 
@erich6 Thanks! The HA-2 is my main benchmark for portable sources, I did a LOT of research and testing before settling on that model. One of my friends that owns an audio store ranks it within the top few sources under $1000, of course few since the Mojo and such exist. From my testing, and apart from the outstanding but more expensive Mojo, I think the HA-2 is really great. I find it to suit my bright preferences perfectly while bringing nice quality too, so I hope people can understand why I find it superior overall to the X5 III. 

I purchased an Onkyo DP-X1 about a year ago for $800, it's now $600. I wanted a DAP with 400+GB capacity and the ability to browse by composer, something essential for classical music fans and that is overlooked by almost every DAP maker other than Apple and Onkyo/Pioneer, including, unfortunately, Fiio.

@majid The Onkyo is a really nice player but the Fiio does support the same amount of storage with 2 micro sd slots and 32GB internal as well. Since they both run android, you can just use Poweramp, which I guarantee is better than the manufacturer's music app. Poweramp has the ability to browse by composer as well as a plethora of other features, well worth the $0.20 asking price when on sale . Neutron is also a top music app though I personally prefer the interface of Poweramp.

How's playing EDM with fiio x5 iii? Is there a lot of differences in terms by boosting its sound quality?

@Snowball0906 You'll hear a difference with any type of music so long as you are familiar with the material. The X5 III has a really nice, extended and textured bass response so I think it's a very good choice for EDM. The separated sound and size of the soundstage also aids during complex passages in EDM. I find it less fatiguing than my HA-2 for EDM, it's a solid choice overall.

May I know if you had try Final Audio Design's IEM? Do u think it will be compatible with Fiio x5 iii ? I've tried iFi black label stack with my iphone and connected to my final audio design 8, and the result was terrible because black label is too powerful for my heaven 8. Now im worried that my heaven 8 is not compatible with x5 iii..

@Snowball0906 I've briefly tried the Heaven VI and F7200, I found them to be relatively balanced with the VI being the bassier earphone. Both had a kind of mid forward presentation, so the X5 III should be a great pairing. I did prefer to use my mid-forward Oriveti New Primacy's with the X5 III over my HA-2 which was a little too thin. Ultimately, sources only vary by so much and the X5 III is pretty neutral which means it won't be as polarising with more sculpted earphones. Given that most Japanese earphones are on the brighter side, a slightly dark/neutral and full source like the X5 III is a good idea. If you are worried about power, the X5 III can go to very low volumes on low gain, it is a great companion for iems and background hiss is on the quieter side of the sources I've heard.

Seems you like this unit yet the Oppo and Mojo may offer higher SQ. I'm in the market and have been looking at all three of these plus the Sony M1a. I struggle with the idea that to run an Amp/ Dac  with my smart phone has some limitations mainly storage and battery time. In your opinion are there any other products that bridge that gap better??

Thank you so much Ryan! I've been looking for someone who tried with FAD IEMs that could give me some comment on fiio x5 iii. May I know if you've encounter any problem with Spotify/ Tidal?

@Jedclampet That's tough to say, the X5 III is definitely the most flexible as an all-in-one solution (and it can be used as a USB DAC for your phone/laptop). All have pretty decent playtimes, the X5 III probably has the best battery life followed by the HA-2 and then the Mojo. None will drain your smartphone's battery since they run off of their own batteries, I had a few issues with the HA-2 charging off my phone, but with the right cable, it functions normally. I would recommend all 3 on a SQ basis, the Mojo is the winner for me, but the form factor is kind of awkward for portable use, the HA-2 is easily one of the most stackable DAC/AMPs out there with perfect dimensions for smartphone use. As far as storage goes, you would have to look at a DAP that has expandable storage, the DAC/AMPs obviously won't address that issue.
 
@Snowball0906 No problem mate, hope my very brief impression have helped you out! I only used Spotify on the X5 III and didn't encounter any issues, quality was similar to the Fiio music player as was volume. For some reason, Poweramp was much quieter than the other players though I didn't try the alpha version due to stability issues (I did adjust the preamp, etc). 

@ryanjsoo how do you think it will fare when paired with se846? They are quite sensitive so i am worried about the background hiss. I am currently using iPhone 6s+ and hifiman hm-650 with minibox amp and didn't notice any hiss so what are the odds? Will i hear hiss on fiio 5x iii?