Review: HiBy R6 Pro II

Sound impressions

I’ve lately come to appreciate the subtle effects different DAPs have on the sound of my favourite IEMs, enough to say that choosing the right DAP is critical to maximising the performance of your drivers. I’ve been very fortunate to experience most of HiBy’s DAPs over the past two years, and so it makes it easier to pick out the differences between them (which I’ll do below).

On its own terms, R6 Pro II represents a different approach to the other HiBy DAPs in that it goes all in to maximise DAC performance over almost every other aspect of the sound, including amplification power output and battery life. The end result is a technically impressive DAP that overshoots its price bracket by quite some margin, at least in RAW performance. That doesn’t necessarily translate into a subjectively ‘better’ experience, though, as I’ll explain below. 

As mentioned earlier, battery life takes a massive hit when R6 Pro II is set to Class A mode with a balanced driver, but that’s really the optimal configuration for this player. That said, the sound differences between Class A and AB with IEMs is subtle at best, and so switching to the less resource-intensive mode will make sense for most people. Also, the back of the DAP tends to get quite warm with Class A streaming WiFi music to thirsty IEMs, though it doesn’t get hot enough to cause discomfort in a shirt pocket, at least not for me.  

Tonally I hear R6 Pro II as neutral and balanced, with a hint of warmth from its well-defined bass tuning, a hint of midrange clarity boost, and nicely extended and resolving treble region. It’s not a DAP that’s going to colour your drivers with its own sound, so you’re not going to get added warmth or brightness in any meaningful measure, but it will definitely elevate the qualities inherent in your drivers.

Bass control is very good, getting a decent grip on most drivers I’ve tried with it so far. This is a good indicator that the power output, while not the most impressive on paper, is more than enough to give you top performance, with adequate headroom, with most if not all IEMs. There’s no skew towards sub-bass or midbass, the tuning staying mostly linear throughout the lower frequencies.

Midrange resolution and clarity are both above average. Vocals, both female and male, are well-defined and properly imaged, with perhaps a touch of emphasis in the upper mids for some added clarity, but nothing I’d be able to pick out definitively without A/B comparisons with other DAPs. 

Treble is sweet, mostly smooth, with good extension and air where called for. It’s not a relaxed treble tuning, more in line with HiBy’s recent switch to a livelier house sound from some of its more traditionally laid-back tunings (including that of the original R6 Pro, if memory serves). 

If there are any flies in the ointment, I hear them in the upper midrange-to-treble transition, where the edges of some notes are ‘harder’ than I’d like when compared with more refined flagships. There’s also a very faint grain in the trailing edges of some female vocals and cymbal splashes, though this is rare and very, very slight, again only noticeable with direct comparisons with higher-end DAPs. 

Overall I’m impressed with the tonal performance and tuning of this DAP, more so than I was with HiBy’s recent ESS Sabre DAPs, R6 III and R5 II. This is the first time I’ve heard AKM’s new flagship DACs in action, and the fact that they’re being used in a lightweight portable DAP like R6 Pro II is impressive in and of itself. 

The sound isn’t quite as velvety-smooth and relaxed as AKM’s previous flagship, the now-discontinued AK4499EQ, or the even-smoother AK4497, opting instead for a more technical-but-not-analytical sound that shoots for minimal distortion and noise. But in doing so, this DAP is likely to appeal to a more sophisticated audience that may have shirked at shopping at this ‘lowly’ end of the market in years gone by. 

Technically then, R6 Pro II is a new benchmark for sub-$1,000 DAPs, in my opinion. The first thing I noticed was an ink-black background and absolutely no hiss with any IEMs, even at higher volumes in high gain. While this is no doubt related to the lower than usual power output, it must also have at least something to do with the high-spec DACs under the hood.

With such an impressively-dark background, imaging is notably very accurate, enhancing the imaging qualities of IEMs with already-accomplished technical chops. Vocals and instruments are precisely placed on the stage, which I must say is not quite as wide or tall as I expected it to be, but isn’t intimate or closed-in either. If you have wide-sounding IEMs, R6 Pro won’t cramp their style, but you’re not going to get a magical expansion of stage as you might with some of the powerful flagships I’ve used of late. 

Interestingly, R6 Pro II lacks a bit in terms of dynamics, something I think is directly related to its ‘under-specked’ output power. It’s not audibly blunted, but I feel like the sound is slightly flatter and volume swing not quite as extreme as I hear them with some IEMs on higher-end DAPs with significantly more amplification headroom.  

Overall, I think R6 Pro II sets a new bar for technical performance for DAPs at this price point. It’s technically as adept as DAPs that cost twice as much, and out-DACs most DAPs at even higher price points than those. Where it falls short is the ‘last few percent’ of refinement. There’s nothing wrong with a harder, more ‘etched’ sound, and indeed this is a preference for many, but I feel R6 Pro II is occasionally over-etched. 

It’s a minor quibble that, in truth, a few tweaks in MSEB should be able to easily sort out. But it’s fair to say that while I’d happily pit the new Pro against many other DAPs on pure performance, it’s not quite good enough to match today’s top-tier flagship DAPs. On the flipside, it offers exceptional price-performance value, so much so that the hard wall of diminishing returns for DAPs now starts at $750, whereas before it was well over $1,000. 

Continue to select pairings…      



Picture of Guy Lerner

Guy Lerner

An avid photographer and writer 'in real life', Guy's passion for music and technology created the perfect storm for his love of portable audio. When he's not playing with the latest and greatest head-fi gear, he prefers to spend time away from the hobby with his two (almost) grown kids and wife in the breathtaking city of Cape Town, and traveling around his native South Africa.


2 Responses

  1. Fabulous review! With so much detail and thought.

    Any view on how these compare to the shanling m6 ultra? And would pairing the R6P2 with an amp like the Topping NX7, be able to drive full sized headphones like say Sennheiser HD650s?

    1. Thank you. I have not used the Shanling so can’t say, but yes, connecting the R6 Pro II via line-out to an external amp will easily power full-size headphones.

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