FiiO M23 Portable Digital Audio Player Review

Introduction:

The M23 is FiiO’s latest portable mid-to-high-end music player, the successor to the M11 Plus. The device boasts a Qualcomm Snapdragon 660 SoC for smooth performance. At its heart lies a top-tier audio solution: the AKM AK4191EQ and AK4499EX DAC combination. This duo meticulously processes audio up to 32-bit/384kHz PCM, DSD256, and even lossy MQA formats, guaranteeing pristine sound reproduction. Further elevating the experience is the dual THX AAA-78+ amplifier configuration, delivering a powerful, transparent soundscape.

For integration with various sources, the M23 offers versatile connectivity options including USB ports, Bluetooth, and WiFi. The 10.5-hour battery life promises extended listening enjoyment. When connected to USB power, the M23 unlocks a desktop mode with increased power output, making it a compelling choice for audiophiles seeking a versatile and powerful portable, or even desktop, audio experience.

Disclaimer:

I would like to thank FiiO for providing me the M23 as review sample. I am not affiliated with FiiO beyond this review and these words reflect my true and unaltered, opinions about the product.

Price & Availability:

The FiiO M23 is available in two different options: the one with the aluminum housing is priced at $699.99, while the second model with a stainless-steel housing is $899.99. More information can be found at the link below.

• FiiO M23 Portable Digital Audio Player

Package & Accessories:

The FiiO M23 arrives in a black box adorned with FiiO branding. It’s enveloped by a white cardboard sleeve showcasing the product image and relevant branding details.

Inside the box are the following items/accessories;

• 1 x FiiO M23 Digital Audio Player
• 1 x USB 3.0 Type-C to Type A Charging/Data Cable
• 1 x MicroSD card tray Eject Tool
• 1 x USB A male to USB Type-C female adapter
• 1 x Silicone
• 1 x Quick Start Guide
• 1 x Warranty Card

Design & Build Quality:

The FiiO M23 closely resembles the M11 Plus model in terms of appearance. I quite like the design, which features hexagonal elements and modern lines. The device is available in two color options: dark blue with an aluminum outer casing and the silver one with a stainless-steel casing.

The device measures 136.5 x 75.7 x 18.1 mm. Its weight varies depending on the material chosen: approximately 299 grams for the aluminum alloy version and approximately 392.3 grams for the stainless-steel version. Regardless of material, the device feels solid and high-quality in your hands.

The front of the device is dominated by a large screen. The M23 boasts a stunning 5.5-inch display with an 18:9 aspect ratio and a resolution of 720 x 1440 pixels. The screen offers a good screen-to-body ratio and comes with a pre-installed, edge-to-edge (2.5D) tempered glass screen protector for added protection.

On the top of the device, you’ll find the 3.5mm headphone jack that functions as both a headphone output and a line output, alongside a coaxial output. There’s also a 4.4mm balanced headphone jack that can double as a line output port.

The bottom features two USB Type-C ports. The first is a USB 3.0 port for data transfer and charging, while the second is dedicated solely to power supply and charging. You’ll also find a MicroSD card slot here.

The left side of the device houses a hexagonal-shaped power button with a nice LED status indicator around the edges, along with a multifunctional button that also features the same hexagonal design.

FiiO’s unique 2nd Gen Intelligent Volume Adjustment System takes the form of an “all-in-one volume button + touch panel” located on the left side. It boasts a beautiful carbon fiber surface.

The volume can be adjusted using the slider, which is both mechanical and touch-sensitive. The improved carbon fiber surface enhances the aesthetics. This interface supports both touch and mechanical actions for precise volume adjustments up and down.

The right side of the M23 features a hold switch, a desktop mode switch, and three buttons dedicated to playback controls: play/pause, next track, and previous track.

The rear surface of the boasts a glass panel with a beautiful textured surface that exhibits multicolor effects depending on the viewing angle.

Exuding top-notch craftsmanship, the M23 boasts a robust build quality. The device feels incredibly solid in hand, with no imperfections like gaps, burrs, or any signs of looseness.

Some Technical Specifications:

Hardware & Software Features:

FiiO’s latest mid-to-high-end portable music player, the M23, positions itself as the successor to the M11 Plus. Let’s take a closer look at the hardware and software features of the M23.

1) Hardware Features:

DAC & USB DAC Functionality:

The M23 employs a high-end digital-to-analog converter (DAC) from Asahi Kasei Microdevices (AKM). This formidable duo, the AK4191EQ and AK4499EX, utilizes AKM’s Velvet Sound technology for meticulous decoding of digital audio formats up to 32-bit/384kHz PCM, DSD256, and even lossy MQA. This translates to an exceptionally clean and accurate sound with a high signal-to-noise ratio (SNR) of at least 125dB and incredibly low distortion (THD+N) of less than 0.00038% (measured at 1kHz with -12dB input at 32Ω).

A special design isolates the digital and analog sections, minimizing interference. Additionally, it incorporates “DWA ROUTING technology” for an improved signal-to-noise ratio. These features contribute to a clean audio foundation capable of handling high-resolution audio and delivering a smooth, natural listening experience.

The FiiO M23 offers USB DAC support that is compatible with MAC’s, Windows PC’s, Android and iOS devices. Windows PC’s do need the installation of an USB DAC driver that is available on FiiO’s website, while Android, iOS and MAC computers do not need any driver installation. The USB DAC mode of the M23 supports up to 384 kHz – 32bit/DSD256.

Qualcomm Snapdragon 660 SoC & Storage Options:

The FiiO M23 features a Qualcomm Snapdragon 660 SoC with a capable Adreno 512 GPU, ensuring a smooth and responsive user interface akin to a smartphone. The device comes with 4GB of RAM and 64GB of internal storage, while the M23 Plus version offers additional storage expandability through a single microSD card slot supporting up to a theoretical 2TB capacity.

THX AAA-78+ / Amplification / Other Hardware Features:

The FiiO M23 comes with a unique dual-Type-C port setup. One port caters solely to power input (“POWER IN”), allowing for external power connection and enabling the “Super High Gain Mode.” This mode unlocks the potential of the M23’s dual, high-performance AKM AK4191EQ and AK4499EX DAC chips, boosting power output to a staggering 1000mW per channel (with Super High Gain Mode) This increased power makes the M23 ideal for driving demanding, high-impedance headphones that typically require more power to achieve optimal sound levels. While in Super High Gain Mode, the other Type-C port functions independently for data transfer, such as connecting the M23 to a phone for use as a USB DAC.

The M23 upgrades the well-regarded THX AAA amplifier technology used in previous FiiO models with the all-new THX AAA-78+ amplifier architecture. This improved design utilizes a fully discrete, balanced 8-way parallel amplification circuit for exceptional power delivery and minimal distortion.

The M23 come with a pretty robust audio architecture that has dedicated operational amplifiers (op-amps) for each stage of the signal processing chain. The I/V and LPF stages are handled by two low-noise and high-precision OPA1612 op-amps, while voltage amplification is entrusted to two low-noise and high-bandwidth OPA1662 op-amps. Together, these high-quality op-amps ensure audio signals are accurately reproduced at ample power outputs. The audio circuit further benefits from a significant number of high-precision film resistors, ensuring consistent signal processing.

The LPF section specifically employs 8x Panasonic film capacitors. These capacitors play a crucial role in maintaining a highly detailed and stable sound by minimizing phase shifts and ensuring consistent output across left and right channels, as well as across different frequency bands.

Moreover, the M23 has a 4-stage, 20-rail power supply, which is a design that offers a pretty clean and consistent power source for both the digital and analog sections of the audio circuit. Furthermore, the M23 features independent digital and analog power supplies to minimize interference and ensure optimal performance for both aspects of audio processing. Notably, the analog power supply incorporates multiple stages of voltage regulation and filtering, including OVP (over-voltage protection), adaptive voltage stabilization, high-efficiency voltage boosting, π filtering, and LDOO voltage stabilization. This multi-stage approach provides the M23 with a power supply design comparable to those found in desktop type audio equipment.

Patented Desktop Mode:

For the first time on FiiO players, the M23 features a switch specifically to toggle desktop mode (D.MODE). When engaged, the M23 draws power solely from an external source, bypassing the internal battery. This can be beneficial for extended use at a desk setup, as the battery remains uncharged and avoids potential wear from frequent charging cycles.

Wireless Connectivity:

A) Wi-Fi: 

The FiiO M23 features a built-in Wi-Fi antenna supporting both 2.4GHz and 5GHz frequencies. It offers compatibility with the 802.11 b/g/n/ac protocols, providing a smooth and stable connection. In my experience, the download speed, connectivity range, and stability are superior to any other digital audio player I’ve used, coming very close to modern smartphones.

B) Bluetooth & Bluetooth Range:  

The M23 utilizes a Bluetooth SoC (no model information), enabling high-resolution two-way Bluetooth with the BT 5.0 standard. This SoC can transmit SBC, AAC, and LDAC codecs while receiving AAC, SBC, and LDAC codecs for playback.

The M23 can function as a Bluetooth DAC/amplifier when connected to Bluetooth transmitting devices like smartphones.

During my testing, the M23 maintained a stable Bluetooth connection for approximately 12 meters when paired with Bluetooth earphones like the FiiO FW5.

Battery Duration & Charging:

The FiiO M23 features a 5500mAh Li-Polymer battery, slightly smaller than the M11 Plus and supports fast charging protocols like QC3.0, QC4.0, PD2.0, and PD3.0 PPS. The device employs a dual-mode fast-charging system that utilizes rapid fast-charging + normal fast charging. At a lower battery state of charge, extreme fast-charging is used to safely allow for up to 30W charging speeds. When the battery gets close to a full state of charge, the M23 switches to slightly slower normal fast-charging, which allows for greatly improved charging times while still maintaining battery health. The battery taking about 2.5 hours for a full charge.

My testing revealed a playback time of approximately 10-10.5 hours using the 3.5mm single-ended output. Using the 4.4mm balanced output reduces battery life to around 9 hours.

Here are my testing conditions:

• Volume: 50%
• Gain: High
• File Format: MP3, 44.1 kHz / 16-bit
• Display: Off
• EQ: Off

DAPS (Digital Audio Purification System)

The DAPS (Digital Audio Purification System) featured on the M23 combines two key components: a FIIO-developed HiFi audio core that bypasses the standard Android system and a low-jitter clock co-processor. Working together, this system offers a unified high-precision, low-jitter clock source. It also ensures the original sampling rate of the audio stream (both PCM and DSD) is maintained regardless of whether you’re using FIIO Music, third-party apps, USB DAC mode, or other options.

2) Software Experience:

The FiiO M23 Plus combines Android 10 (currently Android12 is being optimized) with a capable Snapdragon 600 SoC and 4GB of RAM, resulting in a smooth and responsive user interface (UI). The M23 features a customized Android OS with pre-installed apps like Google Play Store, Chrome browser, Gallery, Clock, and a Technical Support app, alongside FiiO’s own application store.

The Google Play Store pre-installation allows access to various streaming services like Spotify, Tidal, Qobuz, Deezer, and even Apple Music. You can even install entertainment apps like Netflix, Amazon Prime, or YouTube to enjoy your favorite shows, videos, and movies.

FiiO provides also its own app store dedicated to music and radio streaming services.

Another highlight is the FiiO Music Player, boasting a rich feature set, extensive settings, and a user-friendly GUI including a 10 Band PEQ.

The M23 offers 6 operating modes: Roon Ready, Android, Pure Music, Bluetooth, AirPlay, DLNA all easily switchable. The default Android mode can be changed to other modes via the drop-down menu or settings.

Overall, the M23 delivers a user-friendly and familiar UI that receives regular updates. A valuable addition is the Technical Support Menu, providing quick access to firmware updates (both over-the-air and local), a quick start guide, online feedback options, and more.

Equipment’s used for this review:

• DAP’s             : FiiO M23, FiiO M11 Plus
• IEM’s              : Campfire Audio Supermoon, Oriveti OH700VB, Meze RAI Penta
• Headphones  : FiiO FT5

Key Features: 

• High-fidelity audio processing with AKM AK4191EQ and AK4499EX DACs
• Dual THX AAA-78+ amplifiers for clear and powerful sound
• Versatile connectivity options including USB, Bluetooth, and WiFi
• 10.5-hour battery life with fast charging support
• Desktop mode for extended use at a desk setup
• Runs a customized Android 10 OS (upgradable to Android 12) with access to streaming services and music apps
• FiiO Music Player app with extensive features and user-friendly interface
• Digital Audio Purification System

Albums & tracks used for this review:

• Norah Jones – Come Away With Me (Flac 24bit/96kHz)
• Adele – My Little Love (Deezer HiFi)
• Sarah McLachlan – Angel (Flac 24bit/48kHz)
• Sertap Erener – Aşk (Flac 16bit/44.1kHz)
• Edith Piaf – Non Je Ne Regrette Rien (Flac 16bit/44.1kHz)
• Diana Krall – So Wonderful (DSF)
• Aretha Franklin – I Say A Little Payer (Flac 24bit/96kHz)
• Michael Jackson – Billie Jean (Flac 24bit/96kHz)
• George Michael – Don’t Let the Sun Go Down on Me (Flac 24bit/192kHz)
• David Bowie – Heroes (Flac 24bit/192kHz)
• Elton John – Rocket Man ((Flac 24bit/96kHz)
• Barry White – Just The Way You Are (Flac 24bit/48kHz)
• Isaac Hayes – Walk On By (Flac 16bit/44.1kHz)
• Sting – Englishman in New York – (Flac 24bit/48kHz)
• Eric Clapton – Wonderful Tonight (Flac 24bit/96kHz)
• Dave Gahan – Kingdom (Tidal Hi-Fi)
• Radiohead – Live in Berlin “ Album” (Deezer HiFi)
• U2 – Sunday Bloody Sunday (Flac 16bit/44.1kHz)
• Muse – Hysteria (Flac 24bit/96kHz)
• Red Hot Chili Peppers – Nobody Weird Like Me (Flac 24bit/48kHz)
• Michael Jackson – Billie Jean (Flac 24bit/96kHz)
• Bear McCreary’s – Valkyries (Deezer HiFi)
• Bro Safari, UFO! – Drama (Deezer HiFi)
• Armin Van Buuren – Vini Vici (Flac 16bit/44.1kHz)
• Daft Punk – Doin’ it Right (Flac 24bit/96kHz)
• Lorde – Royals (Flac 24bit/48kHz)
• Massive Attack – Angel (Flac 24bit/48kHz)
• Toutant – Rebirth (Deezer HiFi)
• Gogo Penguin – Raven (Flac 24bit/192kHz)
• Gogo Penguin – Murmuration (Flac 24bit/192kHz)
• Portishead – It Could Be Sweet (Spotify)
• Max Richter – On the Nature of Daylight (Flac 24bit/96kHz)
• Charly Antolini – Duwadjuwandadu (Flac 24bit/192kHz)
• Tchaikovsky – Symphony No. 5 (Flac 16bit/44.1kHz)
• Ferit Odman – Look, Stop & Listen (Flac 24bit/192kHz)
• Chopin – Nocturn No. 20 In C-Sharp Minor (Flac 16bit/44.1kHz)
• Clair de Lune – Claude Debussy (Spotify)
• Fazıl Say – Nazım Oratoryosu (Live) (Flac 16bit/44.1kHz)
• Vivaldi – Le QuarttroStagioni “The Four Season” (Deezer HiFi)
• Otto Liebert& Luna Negra – The River (Flac 24bit/192kHz)
• Lunatic Soul – The Passage (Flac 16bit/44.1kHz)
• Deftones – My Own Summer (Shove it) (Flac 16bit/44.1kHz)
• Metallica – Dyers Eve (Flac 24bit/96kHz)
• Metallica – Sad but True (Flac 24bit/96kHz)
• Opeth – Windowpane (Flac 16bit/44.1kHz)
• Megadeth – Sweating Bullets (Tidal Hi-Fi)
• Rush’s – Tom Sawyer (Flac 16bit/44.1kHz)
• Slayer – Angel of Death (Spotify)
• Liquid Tension Experiment 2 – Acid Rain (Spotify)
• Yosi Horikawa – Bubbles (Spotify)

The Sound:

The FiiO M23 shines in its balanced and natural sound reproduction, particularly in the critical midrange. It excels at capturing detail, weight, and a smooth character, ensuring all instruments and vocals are conveyed with accuracy. Bass is well-controlled and impactful, extending deep without muddying the midrange. Treble is clear and crisp, revealing intricate details without becoming harsh, even with energetic headphones. This creates a spacious soundstage with well-separated instruments, perfect for enjoying complex musical arrangements.

This review is based on listening impressions after a burn-in period of approximately 120 hours. The following sonic evaluations primarily focus on the device’s performance through the 4.4mm balanced output, paired with IEMs such as the Campfire Audio Supermoon, Oriveti OH700VB, and Meze RAI Penta, as well as headphones like the FiiO FT5.

Bass:

The FiiO M23 prioritizes controlled and extended low-frequency response. It delivers deep, impactful sub-bass without compromising the clarity of the midrange in your IEMs or headphones. This is particularly evident in genres like electronic music and hip-hop, which rely heavily on a strong low-end presence. When paired with IEMs like the Oriveti OH700VB and Campfire Audio Supermoon, or headphones like the FiiO FT5, the M23 accurately reproduces the sub-bass foundation in Massive Attack’s “Angel” without muddying the midrange. Lorde’s “Royals” serves as another example where the M23 maintains a clean and defined sound across the frequency spectrum.

The midbass region, which is responsible for the body and punch of instruments like bass guitars and cellos is produced in a quite natural manner. This is evident in well-mastered rock recordings where the bass guitar lays a solid foundation for the music. Regardless of the electronic or traditional origin of the prominent bass line, the M23 renders it with control, detail and precision, contributing to a well-rounded sonic presentation. This is a great ability for the clarity of other instruments in the mix.

The FiiO M23’s control extends to complex bass passages. In intricate pieces like Gogo Penguin’s “Murmuration,” the bass line remains clear and defined, even during sections with fast and frequent bass notes. This allows the listener to easily follow the intricacies of the bass part. This is also a great feature for the clarity of other instruments in the mix.

Midrange:

The FiiO M23 revealed a particular strength in its midrange reproduction, a critical aspect for most musical genres. The FiiO M23 prioritizes a balanced and natural presentation, particularly in the midrange. It achieves a remarkable combination of detail, weight, and a relaxed character, ensuring that every instrument and vocal is conveyed with remarkable accuracy and musicality

In the case of nuanced musical performances, such as Norah Jones’ “Don’t Know Why” featuring delicate jazz vocals, the M23 is capable of reproducing a wide range of sonic details. The M23 portrays both subtle emotional inflections and the full dynamic range of the singer’s voice. This level of detail and clarity extends throughout the midrange frequencies, as demonstrated by its faithful reproduction of the warmth of a cello and the sharp attack of an electric guitar in David Bowie’s “Heroes” that was audible while listen to the Oriveti OH700VB.

The M23 exhibits a pronounced emphasis on the lower midrange frequencies. This characteristic results in a full and robust presentation of the instrumental body, enhancing the perceived realism of the music. Listeners may experience a heightened sense of the physical presence of the instruments, particularly those that occupy the lower midrange, such as cellos, bass guitars, and baritone vocals.

The upper midrange remains well-controlled, ensuring that vocals and lead instruments retain their clarity and definition without becoming harsh or piercing. This allows for intricate details like breath control in vocals or the attack of plucked strings to shine through without becoming fatiguing during extended listening sessions, perfectly capturing the emotional delivery in George Michael’s “Don’t Let the Sun Go Down on Me.”

Treble:

The treble range of the FiiO M23 offers a delightful balance of detail and smoothness, perfect for diving into the intricate guitar work of Metallica’s “Dyers Eve” or the soaring vocals of Opeth’s “Windowpane.” The highs are clear and crisp, revealing small nuances of cymbals, wind instruments, and shimmering vocals when paired with IEM’s like the Campfire Audio Supermoon and Meze RAI Penta. This extended response creates a sense of airiness and spaciousness, allowing you to appreciate the full sonic tapestry of the music, whether it’s the complex layers of Rush’s “Tom Sawyer” or the instrumental wizardry of Liquid Tension Experiment 2.

Furthermore, the M23’s treble presentation goes beyond just detail retrieval. It excels at capturing the natural decay of notes, particularly in cymbals and other percussive instruments. In Metallica’s “Dyers Eve,” for instance, you can hear the subtle fade of a cymbal strike rather than just a one-dimensional crash, adding a layer of realism to the listening experience. This ability to faithfully reproduce transient details is often a hallmark of much more expensive audio equipment, making the M23 a compelling option for budget-conscious audiophiles seeking high-fidelity sound.

The M23 keeps the treble smooth and clear, even with energetic headphones. FiiO’s engineers hit the sweet spot – detailed highs without any remarkable harshness or sibilance, which was audible with headphones and IEM’s with energetic top end like the FiiO FT5 and Oriveti OH700VB. This means you can listen for hours without getting fatigued, ensuring a comfortable and enjoyable listening experience across a wide range of musical genres.

Soundstage & Imaging:

The FiiO M23 delivers an expansive soundstage that feels open and spacious. This means your music will seem to come from a wide and deep space, creating a well-rendered layering effect, which is one of the best in its price class. Instruments and vocals are well-separated, thanks to the clean background, making it easy to distinguish individual elements within even complex recordings. This wide and airy presentation is ideal for listeners who enjoy music with a lot of instruments and intricate passages.

Comparison:

FiiO M23 versus FiiO M11 Plus ESS:

Both players deliver impactful bass, with the M23 offering an audible advantage in detail and control. The M23’s subbass delves deep, extending the low-frequency response while maintaining remarkable clarity. The M11 Plus ESS, while offering a pretty natural and dynamic subbass response with good depth, lacks the extended reach and precision of the M23. The M23 excels with its natural and controlled midbass presentation. The M11 Plus ESS, while offering a smooth and powerful midbass, it is slightly missing the same level of micro detail and separation. Instruments do sound a bit less defined, and complex passages do lose some nuance.

The midrange is a battleground where both DAPs excel, but the M23’s slightly more balanced and organic presentation offers a compelling combination of detail, weight, and a relaxed character. The M23 reproduces vocals and instruments, with a touch more mature lower midrange emphasis that adds richness to cellos and bass guitars, while the controlled upper midrange ensures vocals instruments remain clear and free of harshness. The M11 Plus ESS leans towards a transparent and airy midrange with a touch of additional warmth. It delivers good clarity and resolution for instruments and vocals, with a slight emphasis on female vocals in the upper midrange. While the M11 Plus ESS exhibits a touch of grain, it’s subtle and doesn’t significantly detract from the overall listening experience. The M23, on the other hand, remains free from any noticeable grain.

The M23 separates itself from the M11 Plus ESS in the treble region. The M23 offers a delightful balance of detail and smoothness, revealing intricate nuances in cymbals, wind instruments, and vocals. This extended response creates a spacious and airy soundscape, allowing listeners to appreciate the full tapestry of complex recordings. The M11 Plus ESS, while featuring a bright and energetic treble with good clarity, is missing some definition compared to the M23. It delivers a controlled performance that meets expectations for its price range, but the M23 has the upper hand in terms of micro detail retrieval and naturalness.

Both the M23 and M11 Plus ESS do show an expansive soundstages. The M23 delivers a truly open and spacious soundstage, separating instruments and vocals with excellent clarity thanks to its clean background. While the M11 Plus ESS also offers a realistic and expansive soundstage with decent separation, the M23’s slightly cleaner background grants it a slight edge in resolving complex passages.

Conclusion:

The FiiO M23 shines as a HiFi player with superb sound. It delivers natural detail, especially in mids, with accurate instruments and vocals. Powerful yet controlled bass avoids muddiness, while crisp treble unveils subtle details without harshness. This translates to a spacious soundstage for complex music.

Packed with powerful features, the M23 offers an AKM DAC combo for high-fidelity processing and dual THX amplifiers for clear, powerful sound. It offers versatile connectivity with USB, Bluetooth, and WiFi, along with a 10.5-hour battery with fast charging. Desktop mode allows home integration, while the FiiO Music Player app and upgradable Android OS provide extensive music management and streaming access. All these abilities make the M23 a perfect choice for those who want a versatile device below the 1000 USD price range.

Pros & Cons:

• + Well-Balanced and Natural Sound Reproduction
• + Transparency and Detail
• + Clean & Powerful Output (Desktop Mode)
• + Versatile & Feature-Rich
• + Mature & Fast UI
• + Hardware Specs (SD660 CPU, THX AAA-78+, AK4191EQ + AK4499EX DAC, etc.)
• + Above Average Battery Life
• + Dedicated Desktop Mode (D.MODE) extends player life by bypassing the battery
• + Excellent Value

• – Similar design with the M11 Plus
• – Minimalist Packaging in order to reduce cost
• – Silicone case instead of leather case included with the M11 Plus

Thank you for the Read!