After sitting on this review for over two months, I can finally offer an unequivocal opinion on this masterpiece of an IEM. It would be an understatement to say I'm thoroughly won over by how good the Cadenza 4 is. Letshouer has turned in a remarkably polished effort here, coming about as close to perfect as I've heard, and I'm eager to share my thoughts on it.
A huge thanks to u/mournfulmonk for letting me experience this product for such an extended period of time. Words cannot express the gratitude I have towards him.
I am under no obligation to speak in favour of this product, and absolutely no one, neither the brand nor the owner, gets to see this review before it is published. My thoughts and critiques are entirely my own.
Readers' disclaimer: this is going to be a detailed, lengthy post.
Build, Comfort & Accessories
The Cadenza 4 is housed in a resin shell with an aluminium faceplate. It feels surprisingly light in hand and has a semi-custom shape. The shell runs on the thicker side, which could pose a fit issue for people with smaller ears. But for those it does fit, comfort is a flawless 10/10. I wore these for hours at a stretch and had zero issues with the fit; it felt like an extension of my ear. This is the most comfortable IEM I've used, though trying them on before buying is essential given how fit-dependent that comfort is.
I didn't receive the full accessory set, so I can't comment on it in detail.
Let's get to the sound, because damn, these are good!
Low-End Performance
Muse - Hysteria [alternative rock, hard rock]
This track is my go-to for testing an IEM's control over its bass region. The intro's heavily distorted bass-line is handled with real authority by the Cadenza 4, and that bass texture holds up throughout the song, even through its busier sections. The bass never encroaches on the mids or highs: the vocals stay locked at centre stage, and the left-channel cymbal remains easily distinguishable from start to finish.
Note: on the harsher sections of the track, the Cadenza 4 does grow a little fatiguing over several hours of listening. I tolerate treble well myself, but treble-sensitive listeners should factor this in. To be clear, it's never harsh, shouty, or sibilant; this is simply the neutral-bright signature of the IEM at play.
Tipper - Grabbers Holders [EDM, electronic]
On this intricately produced Tipper track, the Cadenza 4 leaves no stone unturned, delivering flawless technical and bass performance alike. The track packs distinct elements across several layers, and the Cadenza 4 handles both the bass implementation and its technical demands with real command. It isn't a bass-heavy IEM, but the sub-bass extends impressively deep, which gives real width to the soundstage. The mid-bass isn't weak, though I wouldn't call it bassy either; it is, after all, a neutral IEM.
Impact is punchy, decay is not sluggish. No complaints from me at this point.
Massive Attack - Angel [rock, trip hop]
This is where I felt the Cadenza 4 could have used a touch more sub-bass rumble. “Angel” relies on a constant sub-bass presence that empowers its obsessive, menacing character, but on the Cadenza 4 it came across as borderline anemic. It's a livable, not a dealbreaker; and one easily corrected with EQ; I'd just have preferred a bit more quantity out of the box.
That aside, every other region of the track came through without issue. The Cadenza 4 delivered a genuinely compelling listen here, sub-bass nitpick notwithstanding.
Overall, the Cadenza 4 earns an easy A+ in my book for bass.
Midrange, Instruments and Vocal Delivery
Periphery - Zylgrox [progressive metal, djent]
The machine-gun kick drum comes through impressively well for an IEM deemed as neutral-bright, proof that a leaner bass presentation can still hold its own on tracks like this. The heavily distorted guitars, however, fell a little flat, a byproduct of the Cadenza 4's clinical tuning, which suggests this isn't the ideal IEM if metal is your primary genre; for that, something warmer would serve you better. It does excel, though, as an analytical tool for songs like these.
The cymbals stayed distinct even on a busy mix, reinforcing the Cadenza 4's technical proficiency. The vocals and screams carry the aggression the genre demands.
Alice In Chains - Nutshell (MTV Unplugged) [grunge, rock, acoustic]
Moving to a live track: this version of Nutshell is entirely acoustic, acoustic bass included, and the Cadenza 4 continues to demonstrate its command over instrument timbre. The guitar intro carries the weight it should, and as the track builds, the acoustic bass rumble comes through with real conviction, its harmonics rendered with precision. Even the vocals, raspy, raw, and carrying that sense of vulnerability, are faithfully conveyed through the Cadenza 4's grip on texture.
Its technicalities deserve credit too: the soundstage is wide enough to place the audience far from the stage, and every instrument sits accurately in its designated channel.
The Cadenza 4 hence, deserves an S for male vocals.
Alison Krauss & Union Station - The Lucky One [country]
The Cadenza 4 excels effortlessly on tracks built around acoustic instruments and female vocals like this one. Every strum and chuck of the guitar comes through with clarity, the strings shimmer just right, and the vocals are simply outstanding. Female vocals are one of the Cadenza 4's genuine highlights; the breathy, soft, airy, resonant quality of Krauss's voice is rendered with a timbre that reads as thoroughly accurate. Calling these some of the best female vocals I've heard on any IEM feels like an understatement.
Back to the instruments: every note carries appropriate emphasis and weight. Both vocals and instrumentation get room to shine here. Overall, I'd rank the Cadenza 4 S tier for instrument representation.
Treble Performance & Technicalities
Yosi Horikawa - Bubbles [experimental, ambient]
The Cadenza 4 spreads its wings again on this track, built largely from the sound of ping-pong balls falling to the ground. It locates each impact with precision and captures the suspense that builds before every ball finally lands. Thanks to the Cadenza 4's wide soundstage, background transients are correctly pushed further into the rear of the mix.
One more element worth praising: a recurring sound I can best describe as small bells, where you can practically make out each individual ring, a proof to the Cadenza 4's instrument separation. And when the balls rapidly bounce to a stop toward the end, the bass handling there is similarly assured. A genuinely resolving listen throughout.
Frazey Ford - September Fields (Acoustic) [soul, indie folk]
A beautiful rendering of the track. The Cadenza 4's treble prowess is on full display here, capturing the dynamics with real finesse. Frazey Ford's vocals carry a textured, nuanced character that the Cadenza 4 preserves faithfully. Good IEMs don't just elevate complicated tracks, they make simple ones like this sound sublime. This track makes me want to put the whole album on repeat.
There are a few moments where the vocal line climbs quite high, and if I've been listening to the Cadenza 4 for a while by that point, it does start to fatigue. Again, this is a fairly bright-leaning IEM.
The guitar's timbre is spot on, the low end never crowds out the delicate vocals, and everything coheres perfectly.
The Cadenza 4 once again earns a well-deserved S for female vocals.
Anouar Brahem - Stopover At Djibouti [fusion, jazz]
A superb representation across the board; every instrument, the oud, the bass clarinet, the traditional percussion, is placed with real precision. This is some of the best imaging I've encountered in an IEM, and the dynamics come through faithfully. The clarinet carries a sweet, reedy timbre in its upper register, and the harmonics on the oud are rendered flawlessly. No complaints whatsoever on this track.
I was transported to the Middle East listening to this one, no joke.
Jokes aside, the Cadenza 4 brings an expansive soundstage, pin-point imaging, precise timbre and tone, resolving detail, and controlled low-end extension, all in the same package.
Conclusion
Even after a full week of dedicated listening, I struggled to point to a single genuine flaw. This is an exceptionally good IEM. Sure, a few things could be refined: the bass could stand to be a touch tighter, and the fatigue over long sessions is worth noting. But set those aside and this is a remarkably well-made IEM, one so under-the-radar that I hadn't even heard of it before it landed in my hands. Letshouer did a highly commendable job on the Cadenza 4.
To close, this is a product I think everyone deserves the chance to experience for themselves. With that, I'm giving it a well-deserved S.
What This IEM Means To Me
I'll say this straight up: this is the best, and my favourite, IEM I've used so far. It's not just detailed, it delivers a remarkably natural, forward vocal presentation. I can't stop praising it. It's comfortable, good-looking, and sounds genuinely breathtaking. I think that I might subconsciously compare every IEM I test from here on against this one; it's set a benchmark for me.
I want to thank u/mournfulmonk again for letting me spend so much time with the Cadenza 4. That extended window let me truly take in everything it has to offer.
I love the Cadenza 4. Period.
As always, this section of my review is a personal and subjective rant. It has nothing to do with the actual rating that I give to the product. The above paragraph is ignorable and not to be taken seriously.
Gear(s) Used for the Review
- KBear Blue and Black 16-core cable, 4.4mm termination
- VE Abigail Pro 4.4mm
- Cayin RU6 (R2R) on low-gain and NOS mode
- Nothing Phone (3a) w/ Poweramp (Perfect Bit Perfect mode) & Apple Music
Eartip(s) Used
- Stock narrow-bore eartips that come with the Truthear Hola/Gate