The Superdongles: Cayin RU7 and L&P W4

Track notes

To put my overall sound impressions and comparisons into context, I subjected both dongles to the ultimate test: real music. Using my ‘reference’ IEM, FiR Audio’s exceptional Rn6 (reviewed here), I set about taking notes about the subtle (and not-so-subtle) differences I was hearing with the same music from the same sources (MacBook Pro 15” and LG V60 smartphone). 

Rachel Bobbit – More (indie pop/female vocal). RU7 renders Rachel’s delicate vocals perfectly, blending neatly with the surrounding instruments, and coming off slightly warmer and fuller than they do with W4. There’s some overlap between instruments and vocals, especially in DSD64 mode, and layering, while tight, is not too compressed. Guitars are nice and crunchy, and drums have a solid kick to them. 

W4 adds even more delicacy and air to the vocals, with the guitar strums in the intro appearing from a blacker background. Subtle sounds are more clear in the mix too. Both drums and guitars are less explosive, with W4 sounding a touch less dynamic compared to the Cayin, but in exchange it ups the resolution and improves on layering and separation, with more space between instruments and vocals. 

Max Richter – On the Nature of Daylight (modern classical). Switching W4 to Tune 02 to take advantage of its more incisive personality, this timeless melody rewards with a rich, lustrous musicality. The timbre of the bow strings and violins is so sweet, it’s like being in the same room as the performers. Upright bass adds a gravitas to the sound without ever dominating the mix, while the violins cut through without ever sounding too sharp or one-toned. Stage is natural, not sounding too wide, with a fair amount of depth. A seemingly professional and faithful reproduction of the music as mastered. 

With RU7, I’m hearing more reflections of the walls, as if I’m at a live performance in a small Italian square. There’s a warmth to the sound that fills the spaces between the strings, and when the first bass notes appear, they do so with a weight and resonance that I can almost feel. That midbass lift softens the strings slightly, giving the violins a smoother sound with less bite. Unlike W4, RU7 does less to separate the different elements, and instead lets them blend and feed off each other, creating a more musical tapestry, an ebb and flow of notes. 

MrKitty – After Dark (synth pop/male vocal). The intro synths have a slight warm haze to them with RU7, followed by the thumping, thunderous punch of the synth drums that make this one of my all-time favourite bass tracks. While the bass hits cut through the mix, as they should, they never distort, and the lead vocals are clear and well separated. Fading echoes and effects reveal a sizeable stage, with good depth and natural width. This track really gets my head bobbing, sounding absolutely exceptional with the Cayin.

W4 cuts back on the reverbs in the intro synths, and pulls back the slam of the bass hits compared to RU7. Everything sounds more balanced, but also less exciting. I can hear more texture in the synths and more depth to the reverbs, but I find myself picking out elements rather than losing myself in the sexy energy of the music (cue iconic video below). The imagery in the video is more RU7 than W4, in this case, so take that as you may.     

Def Leppard – Pour Some Sugar One Me (rock/male vocal). Love this track, brings high school memories flooding back. But I’ve used it here for a different reason: the recording is a hot mess. It’s sounding a little too sharp with W4, I must say. The drum hits are ever so slightly piercing, and W4 doesn’t seem keen to soften the blows. While there’s no sibilance as there sometimes tends to be, it comes off as just a bit too crunchy for my liking. 

Switching to RU7, and things aren’t much better. The snares are still too hot, but the overall tone is smoother, and guitars aren’t quite as crunchy, which makes this whole lumpy porridge of a track easier to swallow. If you’re looking to take the edge off, RU7 is the better option. W4 will give it to as is, and makes no concessions for bad recordings.

Dead Can Dance – The Host of Seraphim (ethereal/female vocal). Slowing things right down, with one of the most emotionally transcendent pieces of music I’ve heard in my lifetime. Lisa Gerrard’s haunting vocals are on full display with RU7 and Rn6, evoking a mixture of sadness and hope, and when she starts to chant, I can’t help but close my eyes and let the tears well up. The detailed warmth of the RU7 works so well here, and synergises perfectly with the drivers too.

W4 casts a different light on this track. The vocals are more defined, with the male backing vocals more apparent and more forward than they were with RU7. There’s more detail here, more space on the stage. Lisa sounds more ‘correct’, but possibly a touch less emotive too. The warmth I heard in her vocals has been replaced by a more neutral, slightly cleaner tone, not dry, but nowhere near as organic as it was with the Cayin. RU7 had me lost in the emotion of the music, W4 has me walking curiously through the soundscape, looking at all the different elements it reveals. 

Side note: This track has been used in many different movie soundtracks, typically to add gravitas to poignant moments in the story. Below is a clip of perhaps the most famous of these, the heart-breaking, soul crushing sequence in the visual documentary Baraka

Ilan Bluestone – Will We Remain (EDM/female vocal). This track can be quite tough on IEMs and sources that can’t handle its extremities of bass and treble. Add to that a standout vocal performance by EL Waves and you have the potential for something really special – or really fatiguing. 

I already knew that the Rn6 aces this track with most of my sources, so it was reassuring to know just how well it did with both W4 and RU7. Starting with W4, the bass on this track is intense – deep, powerful, textured; it feels like the air is sucked out the room whenever that bass hits, which is just how I want it. Then, the vocals, so rich, smooth, clear, with a feminine delicacy. Rarely have I heard it presented so well. The trebly parts are my least favourite in general,  but W4 did well to control the bite and expose the airier parts of the mix. 

I was excited to hear what RU7 would do with the bass on this track, and I wasn’t disappointed. It added a touch of warmth, but at the same time, exposed some of the higher frequency detail that gave the bass a different dimension. The same warmth was lent to the vocals, which sound even more organic here. I also found the stage really opening up, with more depth than I heard with W4, and there’s something about the dynamics of the RU7 that brings out the rhythm of this track. Lastly, I like how RU7 smooths over the harsher edges of the upper midrange and treble, which makes it a better choice for those who like their treble more pillowy than sharp. 

Laufey – Beautiful Stranger (vocal jazz). I’ve only started exploring the music of this up a coming artist, but I really like what I’m hearing. She has a soulful voice, full of control, and this track is very well recorded from what I can tell. It’s full of warmth and bassy reverb with the RU7, but the bassy undertones don’t infringe on the vocals at all, which are placed front and forward on the stage. Instrument timbre is very good, but maybe a little too coloured, the pianos in particular sounding more cushioned than I’d expect. 

From the opening guitar strings I could immediately hear the W4 was tightening the sound, moving Laufey from a smoky bar with noisy patrons to a cool, air conditioned recording studio. Every note stands out, and the vocals are even clearer and more detailed. Piano timbre is also back on point, and the smaller details in the track are easier to pick out. I don’t want to say the W4 version is any less musical, it’s just a different musical presentation, technically more assured, with a darker background and more distinct placement of elements on the stage.

Continue to closing thoughts



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.


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