HiBy RS8: The New Portable R2R Summit

Sound impressions

While I always say that sources don’t have an actual ‘sound’, they do affect the IEMs and headphones you plug into them in different ways, so you could say they have their own sound characteristics. RS8 is no different. 

Going back and forth between other DAPs I have on hand, like HiBy’s RS6 and the original Sony WM1Z (see select comparisons below), sounds appear to be coming at me from a darker background, and I can hear my own tinnitus during quiet passages more so than any perceptible noise from the amplifier (of which I’m convinced there is none). 

Listen to anything binaural by David Chesky, like Amber Rubarth’s seminal Sessions From The 17th Ward LP, and you’ll be treated with instruments splayed across the room with nothing but blackness between them. Likewise, the exceptionally well-recorded La Luna by Ottmar Liebert and Luna Negra will have you looking over your shoulder at where some of the sounds are coming from. 

Speaking of black backgrounds, and to answer the question on many people’s minds, there’s no perceptible hiss from any of my IEMs, even in high gain Turbo mode (which I rarely use), but then I never heard hiss with the R8 and many others did. This will be one of the YMMV metrics, methinks. 


There’s a certain sweetness to RS8’s sound that’s perceptibly warmer than neutral, but I don’t feel it strays too far from a reference tuning to my ears. While bass definitely digs deeper than I’ve heard with any other DAP, with more sub-bass weight, it’s also tighter and, importantly, more textured. But it’s not hard-edged, like an iron skillet. 

Listen to the opening salvos of A Fine Frenzy’s Elements, and the big drum hits are deliciously bouncy and palpably life-like. Whether that’s because of better amplification, a more refined DAC section, or a slightly lifted bass shelf, I can’t say, but it’s probably a combination of the three. I’m not really hearing bass to be overly elevated, just better controlled and weighted. A bass-light IEM will still be bass light, but the sub-bass weight and midbass punch from IEMs like Z1R suggest RS8 has a firm grip in the bass department.  

Vocals are unmistakably R2R, which is to say they don’t sound digital or processed at all. There’s a natural, realistic smoothness to female vocals and just the right amount of chestiness in male vocals that puts a smile on my face every time. 

If vocals sound hard or harsh with RS8, point a finger at the IEM or recording. Even Ethel Cain’s sometimes metallic-sounding vocal recordings on A House In Nebraska and Thoroughfare, from her brilliant Preacher’s Daughter LP, are mostly dialed-back to normality here, stripping back the grain and revealing the deep emotion in her performance with almost any IEM I used.

I’m also not hearing upper midrange vocals being pushed too far forward. Rather, RS8 places them more in line with other elements in the music. This does mean recessed vocals in a track or with a V-shaped IEM will still sound recessed, especially with IEMs that produce genuine bass impact or treble emphasis. A good example here is Meiko’s Crush, from her binaural LP Playing Favorites. When she strays too far from the mic, I sometimes have to strain to hear what she’s singing, especially with IEMs that naturally recess the upper midrange.    

On the whole, I’m hearing the midrange as perceptibly more resolving, clear and transparent than I’ve heard it with several other DAPs, without any significant emphasis in the lower, centre or upper midrange. Note weight is solid but not thick, and mids generally don’t come off as overly warm as RS6 or as smooth as WM1Z.

Treble is likewise not overly forward but still well extended. There’s genuine clarity here, but I’m also hearing treble to be on the slightly relaxed side, which might concern those who pine for high-energy brightness and dollops of added air from their treble. I do think the treble presentation is what gives RS8 its sense of refinement, because it’s certainly not overplaying the treble to create false details. If there is any treble lift it’s more likely in the mid-to-upper treble, but at no point does it cross over to sibilance. 

My go-to treble tests include Missy Higgins’ Shark Fin Blues and Lana Del Rey’s Lust For Life duet with The Weeknd. In each case, female (Missy) and male (Weeknd) sibilants can be harsh with the wrong source or IEMs, like with Supermoon on a brighter source for example, but RS8 has no issues calming the esses down to tolerable levels. 

Overall, I hear the RS8’s tonal profile as one of natural balance, both in its R2R-derived organic voicing and its analogue presentation. It has excellent extension at both ends, and mids that don’t try to be flashy or overly forward. 


Despite its pleasant tonality, RS8 also has genuinely high-end technical chops that give it a sense of effortless power in the way it presents the sound from my favourite IEMs. 

I’m particularly enjoying RS8’s expansive staging. Interestingly, some of the early mumblings on the Interweb suggested RS8’s staging was less than impressive, but in my experience, nothing is further from the truth.  Combined with the pitch-black background, tiny sounds feel farther away at the extremes, giving the effect of a wide and deep stage, with natural vertical height as well (this will, of course, be IEM-dependent to a large degree). Al Di Meola’s Traces of a Tear mesmerises with its wide-panned effects, and tiny flecks of detail at perceptible depth on the stage, for example. 

On some tracks with some IEMs the staging is impressively holographic, sounds emanating beyond my head on all axes. Listen to Limehouse Blues, the opening track of Arne Domnerus’s iconic masterpiece, Jazz at the Pawnshop, and it’s as if you’re inside the small, intimate jazz club where the performace was recorded, complete with smoky atmosphere and clinking beer mugs. On a much larger scale, the crowd ambiance in the Eagle’s live recording of Hotel California actually makes you feel like part of the crowd, with an out-of-head staging that’s genuinely holographic.  

I’m also hearing more nuance in the music when comparing back and forth with other DAPs. Not only is the background quieter and stage larger, but it feels like I’m actually hearing more of the actual music. Just the other day I was listening to Beyries’ Alone, one of my all-time favourite acoustic vocal tracks, and I was delighted to hear a faint cymbal strike perfectly imaged behind a louder guitar riff, something I heard for the first time on a track I’ve heard dozens of times before. As such I’d say RS8 is at least two or three notches more resolving than RS6, and possibly even more than the WM1Z, which itself is already a very detailed performer. 

Tiny microdetails also seem easier to discern, but more than that, the placement and movement of tiny details on the stage is easier to follow. In Pink Floyd’s seminal Time, I listen for a small segment in the clocks intro where you can faintly hear the gears of a mechanical clock whirring back and forth in the left channel, something RS8 makes easy to discern.

I’d say the larger staging, even more than the quiet background and resolving power, is the easiest audible difference I hear when switching between DAPs, and I’m curious as to how RS8 compares in this regard to the other top-end players from Cayin, Sony and A&K. It’s an overused adage to say that I’m hearing new parts of the music with [insert product name here], but in this case it’s true; RS8 is at least presenting music in a different way, but I also feel it’s doing so by virtue of superior technical performance, not tuning tricks.  

Overall, RS8’s is an expressive, expansive, nuanced and refined technical presentation. There’s also a vibrancy to the sound that engages you almost immediately, not as an overwhelming ‘shock to the senses’, but rather it just sounds genuinely large, life-like, and dynamic. 

Select pairings 

Sony IER-Z1R. Until RS8 came along, Sony’s WM1Z DAP (see select comparisons below) was the undisputed synergy king for the IER-Z1R. While in some ways this is till the case, RS8 makes a compelling challenge for top spot with my favourite IEM. The most immediate quality it imparts on Sony’s flagship IEM is an even greater sense of expansiveness, adding to Z1R’s already cathedral-like stage with added depth and width, and better separation of the elements. It also imparts Z1R’s bass drivers with more power and control than the WM1Z can muster, and I haven’t heard Z1R’s bass sounding this good with anything other than Sony’s desktop TA-ZH1ES.

Z1R likes power, but doesn’t need crazy amounts of power to shine (WM1Z’s modest power output is more than enough for it, in my opinion). RS8 drives it loud, with great authority, at 60 on the volume dial, in low gain Class AB mode without Turbo. Higher gain modes with Turbo kick performance up a notch, but not enough to justify the extra battery drain.  

Campfire Audio Supermoon. With a lively, spritely tonality, Supermoon is best paired with warmer, analogue sources, and RS8 couldn’t be a better match in that regard. I hear Campfire’s flagship planar to have a smoother, less grating treble response, and any semblance of upper midrange glare is mostly muted too. This leaves Supermoon free to deliver its combination of exceptionally-technical musicality, and I hear it as nicely balanced overall with some of the best bass quality (and quantity) in the business, a clear and resolving midrange, and a smooth, non-fatiguing but still very lively treble. 

Planar drivers are notoriously power hungry, but I find Supermoon relatively easy to drive. It still demands some traction on the volume dial, 60-65 in low gain is more than loud enough for me, and I’ve started experimenting with lowering the volume while activating Class A and Turbo, which seems to give Supermoon some added fullness and smoothness, both of which are welcome.  

Oriolus Traillii. The Bird is one of those IEMs that sounds great from just about any source, and RS8 is no different. It doesn’t need much power to shine, with 35-40 clicks in low gain, AB, no Turbo, more than enough to get it singing sweetly. While RS8 does impart some of its analogue voicing to Trailli’s already-musical delivery, there’s no diminishing any of Traillii’s technical traits here. Stage is super wide and fairly deep, trailing outward in an arc that puts you in the 10th row of a large live performance. 

RS8 doesn’t overexaggerate bass notes, though that would have benefitted Traillii in my opinion, but it puts the Bird’s impeccable timbre and slightly forward vocals front and centre unhindered. It also has plenty of air to complement Traillii’s already-airy presentation, so if you’re not a fan of too much upper treble energy, keep this in mind. Overall I’d say the synergy between the two is excellent.   

Sony MDR-Z1R. This was a last-minute test just to see how well RS8 drives full size headphones, though to be honest, Sony’s flagship full size cans are fairly easy to drive. What’s more impressive is how much control I’m hearing, especially in the bass and upper treble, every bit as good – and in some ways even better – than paired with the desktop TA-ZH1ES. This is no small feat, considering ‘Taz’ and Z1R were literally designed to work together.

RS8’s dark noise floor and sweet tonality perfectly complements MDR’s natural voicing, with a wide, deep stage and excellent layering and separation. MDR is known for its lively yet easy-going presentation, and RS8 adds a richness that makes it even more engaging to my ears. While I don’t need to turn the volume past 65 on low gain for most tracks, I do prefer it with Class A Turbo, where volume is dialled down to 40, but with plenty of power and control. 

Select comparisons

HiBy R8 ($1,999). 

R8 is the original HiBy 8-series flagship on which RS8 is based, and the two share more similarities than differences physically. It’s crazy that R8 was considered a ‘heavy’ DAP when it was first released, with the heftier and notably heavier RS8 boldly taking over that mantle now. Performance-wise the two are also very similar, with R8 being slightly snappier, whereas RS8 has the potential to be snappier still with some further tweaking from HiBy. Dials and controls are decent on R8, excellent on RS8, epitomised by R8’s loose and inaccurate volume wheel compared to RS8’s firmer, more precise implementation.    

Tonally, I hear RS8 as warmer, slightly thicker and more organic than R8. Bass sounds harder on R8, with RS8 more natural and slightly warmer. Mids are drier on R8, with harder edges to the vocals, where RS8 is smoother and more natural. I find R8 has more lower treble energy, where RS8 has a more relaxed lower treble and a slight bump in upper treble air. R8 has drier, sharper transients, and slightly more sibilants where they’re present in a track. 

Technically, details might at first seem easier to hear on R8, but that’s more a factor of the drier, more analytic-leaning tonality. This is mostly obvious in isolated strings and tapping sounds (like finger clicks), where R8 is drier and more prominent and RS8 silkier and less forward. Even though it sounds fuller, RS8 has better control technically, so music is more layered, with better separation between vocals and instruments. Stage is also slightly wider and deeper, giving sounds more room to breathe. 

Overall, I’d say R8 has a tendency to sound more technical, more tonally neutral and learning towards a slightly analytical presentation relative to RS8, whereas RS8 sounds more naturally analogue, with a hint of warmth and a more cohesive sound, while matching R8 in technical elements like layering and separation.  

HiBy RS6 ($1,400).

RS6 is the original Darwin DAP, and as such represents the foundation of HiBy’s R2R tuning and sound design. RS8, to me, is a more refined and elegant progression of that sound, with a generous bump in technical performance. Physically, while sharing design traits, RS8 is significantly bigger, thicker and heavier, and its matte titanium finish is also more luxurious to the touch than RS6’s plated copper. I also find RS8’s buttons to be more tactile, and its volume wheel is significantly better made and easier to operate than RS6’s undersized effort.  

Tonally the two are more similar than different. RS8 has tighter control of the bass, which results in less looseness and bloom that I occasionally hear with RS6. Mids are a touch less warm on RS8, with vocals more resolved and also airier in the upper registers, while RS6 tends to warm up the vocals and push them more forward too, but with less resolution. Treble is more relaxed on RS6, but still with excellent definition and enough sparkle. RS8 is more neutral, and also extends further into upper treble, giving the sound more air than the thicker-sounding RS6.

Technically RS8 has a wider, deeper stage, with more space around instruments and vocals. RS6’s warmer tonality shrinks the stage a touch more compared to RS8, and also robs it of some depth, although I wouldn’t call RS6’s stage intimate either. RS8 clearly out-resolves RS6, and also sounds more dynamic and refined by comparison. 

Overall, both DAPs share the same Darwin R2R DNA, but RS8 is a more refined, resolving, hi-fi version. RS8 is better technically, and while some might prefer RS6’s thicker, warmer sound, both have the same unmistakable analogue flavour that works so well with so many different IEMs. 

Sony WM1Z ($3,200).

Very few audio devices compete with the elegant, luxurious design of the Sony WM1Z, with its solid copper frame and real gold plating. It’s a marvel of industrial design, naturally fitting in hand, with easy one-touch operation and a build quality that approaches perfection. RS8 has a bolder, more masculine, more eye-catching design, with an understated titanium finish that feels every bit as premium as the Sony. 

WMZ1 is considerably smaller, but not that much thinner, and while it weighs at least 100g less than RS8, it feels equally stocky and solid. It’s starting to show its age technically, with a proprietary connector and SD-resolution screen not quite up to today’s full HD and USB-C hardware, and a relatively sluggish UI compared to RS8. That said, as a non-Android, non-streaming DAP, WM1Z is designed with a different type of user in mind. 

Tonally I find WM1Z to have less bass presence than RS8, dialing down the midbass and presenting a more even-keeled, though still nicely boosted low-end. RS8 is bigger, punchier, but also tighter and more textured. RS8 has more midrange contrast and detail, while WM1Z is still very detailed but slightly smoother and more in line with the bass. Treble emphasis is lower treble-focused on WM1Z, but very clean and silky, while RS8 has equally silky treble but with more sparkle and more mid-to-upper treble emphasis. 

Technically the WM1Z has resolution in spades, but I hear RS8’s stage to be wider and deeper, even though WM1Z is renowned for its spaciousness. Layering and separation are also slightly more pronounced on RS8, but possibly because of WM1Z’s relaxed nature and smoother delivery. RS8 is more dynamic too, with WM1Z sacrificing some dynamic contrast for a more relaxed, even-handed listen.  

Overall, I find both of these DAPs to be very close to the top of their game, tonally and technically. RS8 is livelier and more dynamic while remaining analogue and musical in nature, while WM1Z has the unique combination of easy-listening smoothness with excellent resolution and technical performance that epitomises the ‘Sony sound’. I do prefer RS8’s synergy with more IEMs, including Z1R, which is something to consider when deciding on which DAP pairing is best for your own use case. 

Continue to closing thoughts…



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.


One Response

  1. Redefines the term “fully comprehensive” when it comes to gear reviews!
    Quite outstanding (again) in every respect.

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