Review: Fiio M9 Portable High-Resolution Audio Player


In September, we reviewed Fiio’s M3K, an ultra-budget digital audio player that we thought was a good value, despite its minimalist feature set. This week, Fiio continues its rapid-fire release streak with a new DAP on the opposite end of the spectrum — the more expensive but feature-packed M9. Though this player has some shortcomings that are, most likely, cost-saving measures, we think that the M9’s versatility and sound make it very compelling.

Review: Fiio M9 Portable High-Resolution Audio Player

The M9’s physical appearance is a pleasant evolution of the design language currently used by Fiio for its digital audio players. Simple, black aluminum housing, lots of 90-degree angles, a clean button-free face, and I/O hidden along the side and bottom. Rather than make a thinner player, Fiio made room for higher-end components by rounding out the left side of the player, but kept the overall size no larger than a deck of playing cards (slightly bulkier when wearing its included clear TPU case). At 133 grams, the M9 is light and pocketable, but feels substantial. The M9’s microSD port, power and track control buttons, and volume knob are aligned on its left side, and on the bottom are a 3.5mm multi-function jack (headphone out, line out, SPDIF coax out), 2.5mm balanced headphone output jack, and USB-C port. The M9 feels light, but substantial, though it’s clearly designed to be held in the left hand. Its buttons are clicky and easy to discern. The new gold-colored tactile volume knob is a very nice touch, but could use tweaks in either hardware or software. It takes about quarter turn to adjust the volume just one of the M9’s 120 volume steps (the knob rotates freely otherwise), which can be tedious — a software option for acceleration or new knob with more direct actuation would be helpful. Until then, large volume jumps can be achieved using the GUI that pops up.

Review: Fiio M9 Portable High-Resolution Audio Player

The front of the M9 is all glass and almost all screen. Positioned above Fiio’s now-signature multicolor LED logo is a 3.2-inch IPS touch display (includes pre-installed glass screen protector), with a resolution of 480×800 (292PPI) that is one of the best we’ve seen in a Fiio DAP — album art looks great, it’s bright enough to use in most conditions (still struggles in direct sunlight, however), and its touch response is very good. Under that display is an Exynos 7270 processor, dual AK4490 DAC chips, a 2350 mAh battery (charges in about two hours, good for about 10 hours of playback and 45 days standby), and support for Wi-Fi (2.4 Ghz only) and Bluetooth 4.2 (aptX, aptX-HD, LDAC, but not AAC). A microSD card is a must (theoretically up to 2TB is supported), as only 2GB of onboard storage is included. The M9 runs on a highly customized version of Android with very few apps pre-installed; we’re not familiar with KKBOX, NetEase Music, and MOOV, but users will be happy to see Tidal and Fiio Music on the home screen.

Review: Fiio M9 Portable High-Resolution Audio Player

As with its prior Android-based DAPs, Fiio has customized Android’s drop-down shade to include the most important features — toggles for Wi-Fi, Bluetooth, output mode, USB mode (storage/DAC), Gain, sound filter, and screen brightness, and allows its hardware buttons to be individually disabled in sleep mode. Over USB, the M9 interfaces with Windows & macOS using the MTP protocol, which is less than ideal — a separate driver install is included for file transfer on Windows, and Mac users must use the ancient Android File Transfer. We recommend transferring files to the microSD card directly.

Review: Fiio M9 Portable High-Resolution Audio Player

The M9’s audio chops are competitive with players at this price point and above. Just about every modern audio format is supported, including the main lossless codecs — DSD (64, 128), APE, FLAC, and ALAC. Important software features like fixed/variable line out setting, gapless playback, Bluetooth audio connection priority, and filter settings are all present. In DAC mode, after a driver install, the M9’s versatility really shines — in addition to headphone and line output, the M9 can also act as a digital transport (coaxial SPDIF output) and Bluetooth transmitter. Though users will likely find no problem with the M9’s audio hardware, the Exynos processor is undeniably a limiting factor. Originally designed for wearables, the 7270 is power efficient but not powerful enough to support many apps — Fiio has whitelisted just a few, which include Tidal and Spotify, but not Apple Music. There is good news, however — all of the M9’s USB DAC features work with iOS using just the standard ($29) Camera Connection Kit. We wouldn’t expect MFi Certification in a digital audio player, but it would have made this an even easier decision for iPhone users on the fence about adding a DAP to their everyday carry.

Review: Fiio M9 Portable High-Resolution Audio Player

We conducted most of our testing in the Fiio Music app. As far as we can tell, the app is the same on the M9 as it was in its previous residences. In some ways, that’s a good thing — Fiio Music remains a very good music player with a clean interface and lots of available sound tweaks, and it runs very well on the M9. On the other hand, it means that our gripes with the Fiio Music app are the same — managing large music libraries can be a chore. Playlist creation is still a drag and the search feature, while welcome, is half-baked — if you search for “Pearl Jam”, a result will appear for the band, but tapping won’t drill down into individual songs or albums — Fiio Music will just play them all. As a result, we fell back to old school folder diving. This type of navigation is a little awkward in the M9’s scaled-down interface; without a dedicated “home” button or gesture, we found ourselves swiping up to go “back” many, many times. We occasionally felt that track changes were slow, but microSD is likely the culprit there.

Review: Fiio M9 Portable High-Resolution Audio Player

The M9 is dead quiet and super clean (THD <.002%, SNR >113dB, noise floor <10uV), and has a frequency response of 5hz-80kHz. It puts out plenty of power for IEMs and low to medium-impedance headphones — 170mW into 32ohm single-ended and up to 220mW into 32ohm balanced. We tested all of the M9’s various input and output modes, and are happy to report that it sounds great. We heard great dynamics, realistic soundstage, and a sound that was transparent, if a touch warm.

Review: Fiio M9 Portable High-Resolution Audio Player

In hobby so full of absurdly expensive uni-tasker devices, it’s often easy to be impressed by a device that offers even a mildly convenient feature set. The M9, however, is so feature-packed that we struggle to include everything in this review. Though as we noted above there is room for improvement, it performed extremely well in our testing. Its most limiting spec — a processor designed for smartwatches — was circumvented easily enough using its unadvertised iOS compatibility. At $299 and truly “feature packed”, Fiio’s M9 is highly recommended.

Table of Contents

Our Rating


Company and Price

Company: FiiO

Model: M9

Price: $299

Photo of author

Guido Gabriele

Contributing Editor