HiBy R6PRO II 2025 Review – The First Player Featuring Cirrus Logic’s Flagship CS4308P DAC
The HiBy R6 Pro II has always stood as one of the most ambitious digital audio players in the mid-to-flagship segment, combining raw power, refined tuning, and the open flexibility of Android with audiophile sensibilities. The 2025 edition of the R6 Pro II represents the most significant evolution in the series yet. It is more than a facelift or incremental upgrade: this is a mature rethinking of how a high-end DAP should perform in a portable context. With stronger output, increased efficiency, upgraded internals, and a sound signature that feels both more resolving and more natural, HiBy has taken a confident step forward.
What’s New Compared to the Original R6 Pro II
The original R6 Pro II was already well-regarded for its dual AK4499EX + AK4191EQ DAC implementation, power output, and Class A/AB amplifier modes. However, it had a few limitations. Output power, while adequate, was not in desktop-amp territory. Its memory and storage were modest by modern Android standards. Efficiency and heat management in Class A left room for refinement. And while its sonic character was widely admired, some listeners felt it leaned toward being analytical rather than lush.
The 2025 edition addresses these points decisively. The move to dual Cirrus Logic CS4308P DACs shifts the tonality toward a more organic, musical presentation, while still preserving high resolution and decoding capabilities up to PCM 32-bit/768 kHz and native DSD512.
Output power has been significantly raised, especially through the 4.4 mm balanced jack, now reaching over 600 mW into 32 ohms. Memory has jumped to 6 GB with internal storage doubled to 128 GB, making the device snappier and more practical for large, high-resolution libraries. Battery life and thermal management are also improved, allowing longer listening sessions even in more demanding modes.
The sonic changes are not a departure but a refinement. Where the earlier R6 Pro II was sometimes described as slightly cool or technical, the 2025 version feels more balanced, with smoother upper mids and treble, firmer control of the low end, and an overall more mature presentation that encourages long listening sessions without fatigue.
Design
The 2025 R6 Pro II is arguably the most beautiful DAP design to date. HiBy has achieved a balance of minimalism and modernity that no rival player quite matches. The aluminum chassis is machined to fine tolerances, the glass panels are clean and seamless, and the tactile feedback of buttons and volume wheel is deliberate and precise. Even small design decisions, such as the gold-plated headphone jacks, the gentle curvature of the body, and the included leather case, speak to a vision of functional elegance.
The screen deserves praise. At nearly six inches and Full HD+ resolution, it delivers crisp text, vibrant artwork, and smooth responsiveness. Navigating through libraries, streaming apps, or settings feels closer to a modern smartphone than a traditional DAP. Yet unlike a smartphone, the R6 Pro II 2025 remains focused on audio first, with bit-perfect playback and audio-centric hardware that preserves signal integrity.
This is not a pocket-slip player in the strictest sense. At nearly 300 grams, it has presence. But in the hand, it feels balanced, solid, and unmistakably premium.
Software
HiBy utilizes a highly customized Android 12 operating system that globally bypasses Sample Rate Conversion (SRC), enabling bit-perfect decoding for any apps running on the device.
The icons and drop-down menu are tailored specifically for audio playback optimization, while the overall interface remains familiar to users of Android phones.
Although Android 12 is not the latest version, it is more than adequate for an audio-focused device, as many advanced system features are irrelevant for this use case, and it is not designed for graphics-intensive gaming.
The fast CPU ensures smooth processing of DSP enhancements, and users can easily adjust the output tonality using the built-in MSEB panel on HiBy’s device.
The MSEB panel is frequently highlighted as one of the most practical features of the HiBy DAP series. It allows users to address minor audio issues, such as treble harshness or muddy lows, through intuitive sliders labeled in user-friendly terms.
These adjustments apply globally across all applications, ensuring consistent sound quality whether using Qobuz, Tidal, YouTube, or even playing mini games.
For more advanced users, the device offers additional features like Convolution, Fixed Sample Rate, and Sound Field adjustments.
HiBy is a leader in this area, and experimenting with various DSP options or exploring presets shared by other users online can be both enjoyable and rewarding.
Class A/AB
As with the original, the Class A/AB mode switch allows for sound customization. In Class A mode, the mid-bass feels fuller and denser, with smoother treble.
This is particularly noticeable with dynamic drivers, higher-impedance gear, or larger ensembles with fast basslines, where Class A mode provides greater agility and power in the lower frequencies.
In Class AB mode, the sound is cleaner and cooler, making it well-suited for instrumental tracks and background music for work.
USB-DAC
The R6Pro II 2025 can be connected to laptops and PCs to function as a sound card. The decoding quality via USB connection significantly surpasses the typical audio output of a computer.
However, it would be beneficial if HiBy included a toggle to enable or disable charging from the USB source, as well as quick access to DSP features when operating in USB-DAC mode.
Consistent with the previous generation, the USB-C port supports coaxial digital output, connectivity to external USB storage devices, and PD2.0 18W fast charging. This allows the device to recharge to over 50% capacity in just over an hour.
Wireless
The Bluetooth functionality of the R6Pro II 2025 is largely identical to that of the original R6Pro II, allowing it to serve as either a transmitter or receiver for devices like the Steam Deck.
It supports mainstream codecs, including SBC, aptX-HD, and LDAC, with the flexibility to switch between them to prioritize latency, range, or audio quality.
In a brief test, the connection stability performed as expected, matching the reliability of the previous generation. It remained consistent in both a living room setting and on a moving train.
An increasing number of users are turning to streaming, and in addition to AirPlay, the R6Pro II 2025 supports DLNA. It also offers HiByLink for control via smartphones and the HiByCast application for remote operation from phones and tablets.
These features are particularly valuable for those who use their DAP as the central hub for their home music system. The Wi-Fi signal strength is comparable to the previous generation, performing reliably. In a living room setting, the signal strength is excellent, and even when moving the device into a room separated by walls and doors, the connection remains stable.
Browsing the internet and using online services on the R6Pro II 2025 is quick and efficient. The high-resolution display also makes it suitable for tasks like watching Netflix.
Specifications
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Operating System: Android 12 with HiByOS integration, bit-perfect playback
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Processor: Qualcomm Snapdragon 665, octa-core
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RAM: 6 GB
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Internal Storage: 128 GB, expandable via microSD
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Display: 5.9-inch IPS, Full HD+ (1080 × 2160)
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DACs: Dual Cirrus Logic CS4308P
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Decoding Support: PCM 32-bit/768 kHz, native DSD512
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Clocking: Dual femtosecond oscillators (45.1584 MHz, 49.152 MHz)
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Amplifier: Switchable Class A / Class AB
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Outputs: 3.5 mm single-ended, 4.4 mm balanced, line-out options
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Output Power (32 Ω): 165 mW single-ended, 632 mW balanced
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Connectivity: USB-C, coaxial digital out, Bluetooth 5.0 (LDAC, aptX HD, two-way), WiFi dual band
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Battery: Approx. 5000 mAh, USB-C PD fast charging (~18 W)
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Battery Life: up to 13 hours SE AB mode, ~10 hours balanced AB mode, lower in Class A
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Dimensions: 147.5 × 75.2 × 15 mm
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Weight: ~285 g
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Build: Aluminum chassis, glass front and rear, premium leather case included
- Price: $699
Disclaimer: The R6 Pro II 2025 was kindly provided by HiBy for review.
In The Box
Sound
HiBy aimed to create a DAP with dynamic, detailed, and well-separated sound, and the R6 Pro II 2025 delivers on these promises. It offers a dynamic and complete sound profile with controlled, impactful bass, crisp mids, capable tonality, and well-extended treble, making it a versatile choice for various music genres.
This model represents a meaningful upgrade over the R6 Pro II, with a bolder and more powerful presentation. HiBy has significantly refined its sound performance, now offering a mature and well-rounded audio experience across its range. The R6 Pro II 2025 stands as a testament to this evolution.
The R6Pro II 2025 delivers improved resolution, denser mid-bass, better contrast, and a heightened sense of dynamics. It provides a clearer outlining of vocals and instruments, with greater emphasis on transients, increased bass intensity, and faster bass decay.
Vocal transparency and presence are more pronounced in this version, despite its fuller body, making the original R6Pro II sound calmer and smoother in the mids by comparison. The 2025 model feels more vivid and stresses the two ends overall.
The increased output power is noticeable in the volume, as it sounds louder at the same volume step compared to the previous generation.
Bass
The bass of the R6 Pro II 2025 is authoritative without exaggeration. Sub-bass extension is deep, with a tactile presence that underpins electronic music, cinematic soundtracks, or modern pop. The difference compared to the earlier model is one of refinement: bass notes now land with greater precision, with quicker attack and more controlled decay.
Instead of bloom or overhang, bass is tightly articulated, yet carries a natural body that feels organic rather than clinical. Double bass in jazz recordings is rendered with wood and string resonance intact, while kick drums in rock retain both impact and air movement. The jump in amplifier power translates directly into a sense of grip and drive, particularly when paired with full-size headphones.
Mids
The midrange is the crown jewel of this player. Vocals emerge with a richness that feels lifelike, neither pushed forward nor recessed, but perfectly centered within the stage. Male vocals are warm and grounded, female vocals open and fluid, never piercing. Acoustic instruments carry their natural timbres faithfully: the resonance of a guitar’s body, the transient bite of a saxophone, the decay of a piano chord.
Compared to the previous R6 Pro II, the new model leans slightly warmer in the upper mids, reducing any hint of sharpness while preserving detail. This makes it particularly satisfying for vocal-centric music, chamber ensembles, and live recordings where the nuance of presence is critical.
Treble
The treble presentation strikes a balance between extension and smoothness. High frequencies extend gracefully, capturing cymbal shimmer, string harmonics, and ambient air without tipping into harshness. The earlier model could, in some pairings, edge toward brightness; the 2025 edition has smoothed those edges without dulling the sparkle.
There is an ease to the treble that encourages long listening sessions, yet micro-details remain fully present. Reverb tails, subtle hi-hat patterns, and delicate percussion textures are all audible, layered, and realistic. Its treble is tuned not to impress in the first thirty seconds, but to satisfy for hours of listening.
Genre-by-Genre Listening
Classical
Symphonic works reveal just how balanced and spacious the R6 Pro II 2025 can sound. Strings have warmth and fluidity, brass sections punch with clarity without glare, and the layering of orchestral instruments is well separated. Large-scale works such as Mahler’s symphonies benefit from the device’s dynamic swing, where quiet passages emerge from an inky black background and crescendos build with drama. Chamber ensembles highlight their midrange purity: the interplay between violins, viola, and cello sounds natural and cohesive, with each instrument occupying its own place in the hall.
Jazz
Jazz thrives on nuance and timing, and here the R6 Pro II is superb. Upright bass plucks resonate with woodiness, cymbal rides shimmer with the right metallic edge, and brass instruments bite without harshness. The timbre of a saxophone solo feels almost tactile, while piano chords bloom naturally across the soundstage. The slight warmth of the upper mids makes older recordings, often brighter or thinner, more enjoyable, while modern jazz benefits from the detail and air. Live recordings capture room ambience vividly, pulling the listener into the performance space.
Rock and Metal
With electric guitars, bass, and drums competing for dominance, rock and metal can challenge a player’s ability to maintain separation. The R6 Pro II 2025 handles these genres with aplomb. Distorted guitars are crunchy without becoming smeared, bass guitar lines remain distinct, and drums punch with visceral energy. Vocals sit securely in the mix, cutting through without strain. On denser metal arrangements, the added amplifier power of the 2025 edition shows its worth, driving demanding headphones with authority and keeping pace with double-kick patterns and layered guitar riffs.
Electronic and EDM
Electronic music demands both sub-bass depth and treble sparkle, and this DAP delivers both—synth basslines hit with conviction, extending deep into the sub registers without distortion. Fast transients, like hi-hats and claps, remain crisp, ensuring that rhythm-driven music feels engaging and alive. The soundstage has enough width to handle the spatial playfulness of electronic production, where panning effects and layered textures create immersive environments. For long EDM sessions, the smooth treble ensures fatigue-free listening, while the bass impact keeps the energy high.
Vocal and Acoustic
For those who prioritize voices, the R6 Pro II 2025 is a standout. Singer-songwriter tracks reveal the intimacy of close-miked vocals, with breath, phrasing, and emotional nuance fully intact. Acoustic guitars sound resonant and detailed, fingerpicking rendered with texture and clarity. Folk and world music, where traditional instruments blend with vocals, show the player’s ability to present tonal authenticity — sitars, ouds, or hand percussion all retain their natural character. Compared to the earlier model, the new DAC implementation adds a touch more warmth and naturalness, making voices in particular sound more human and less clinical.
Technicalities
The technical performance of the R6 Pro II 2025 is superb. Dynamics are bold, with both micro-dynamics and large-scale swings convincingly portrayed. The rise and fall of orchestral crescendos, the punch of rock choruses, the quiet subtleties of acoustic interludes — all are rendered with agility and poise. The soundstage is wide and convincingly three-dimensional, with instruments placed clearly across width and depth. Imaging is stable and precise; vocals lock into center, instruments occupy a defined space, and nothing collapses under busy mixes.
Noise floor is impressively low, even with highly sensitive IEMs. In balanced mode, the player maintains a black background, letting quiet details emerge. Transient response is excellent, with crisp attack and clean decay, preserving the character of fast percussive music and complex arrangements alike. In Class A mode, the sound thickens slightly, adding warmth and density, while Class AB brings a leaner, more neutral transparency. This versatility allows the listener to tune the presentation to mood, genre, or headphone pairing.
Everyday Experience
Living with the R6 Pro II 2025 is as much about usability as sound. The extra memory and storage make the Android interface fluid and responsive, whether switching between offline FLAC files or streaming apps. The larger battery and improved efficiency extend listening time in the modes most people will use daily. Fast charging makes top-ups practical, even before a commute or a studio session.
Connectivity is comprehensive. Two-way Bluetooth with LDAC and aptX HD ensures it can act as both a transmitter to wireless headphones and a high-end Bluetooth DAC/amp when paired with a smartphone. USB-C output doubles it as a desktop DAC when connected to a computer. Coaxial digital output allows integration into larger home systems. This versatility gives the R6 Pro II a role beyond just a portable player: it is a hub, able to adapt to multiple use cases.
Heat is still present in Class A mode, particularly when driving headphones through the balanced jack at high gain. The battery drains faster in that scenario as well. But these are conscious trade-offs for the sonic gains that Class A provides, and in Class AB, the device runs cooler and longer.
Sum-Up
The HiBy R6 Pro II (2025) is the most complete and mature portable player HiBy has built to date. It takes everything that made the original R6 Pro II appealing — the hybrid amplifier architecture, high-resolution decoding, open Android environment — and elevates it with stronger output, refined tuning, smoother treble, fuller mids, deeper bass control, greater memory, and improved efficiency.
It is also the most beautiful DAP design available, marrying function with form in a way few competitors can match. The sound is balanced, engaging, and detailed, yet forgiving enough for long sessions. The power is sufficient to drive a wide range of headphones with authority. The interface is fluid, the features plentiful, and the build impeccable.
This is not just an incremental revision. It is a confident stride into the future of high-end portable audio for anyone seeking a digital audio player that balances musicality, power, and elegance. For the asking price, the HiBy R6 Pro II 2025 stands as one of the finest options on the market today.