Originally posted on Reddit but sharing here because I love these IEMs.
These are currently my favorite IEMs, but please take everything here with a grain of salt. Your preferences are likely to differ from mine–personally, I value tuning above resolution, though I do think these are pretty resolving. I’ll list some of the other IEMs I’ve tried in order of preference at the bottom of the post so you can have an idea of how our tastes might match up.
Sound first! Fuck talking about build quality at the beginning of a review!
The tuning on these, to my ear, is close to perfectly neutral. What I mean by that is that nearly everything–vocals, drums, most instruments–sounds accurately represented. Where the Chu deviates from my understanding of neutrality is in the bass and in the treble.
Bass:
The bass region as a whole is about 1-2db below what I consider neutral, though it is still executed extremely well in my opinion. Sub and mid-bass and proportioned perfectly for my tastes–kicks have impact yet don’t overstay their welcome, mid-bass sounds are able to punch but don’t bleed into the mids, bass guitars are properly articulated and are audible even in dense mixes. The only bass sounds that suffer on these are those found in Hip Hop and EDM. 808s are a little weak, and electronic basslines or bass-heavy sounds like dubstep growls lack some of the body that gives them authority.
That being said, I believe the slight treble emphasis provides a lot of these sounds the texture that they would otherwise lack on many other sets. For example, the bassline by little-known electronic artist Skrillex in “Summertime Blood” is satisfyingly rendered on the Chu with a rich, ASMR-like quality. By comparison, the same sound comes across loose and weirdly meaty on the Ikko OH10 and hollow-sounding on the Yume: Midnight. It seems to me that some of the harmonics that give a lot of electronic bass sounds their crunchiness or distinct texture reside in this treble region, and so, while it might seem counterintuitive, the Chu’s brightness helps in making its bass sound more “full.”
Treble:
They’re slightly bright! Just a little bright. And it’s the kind of bright I really, really like. There’s no peakiness going on here as far as I can tell, so I only find these fatiguing at high volumes or over long periods of time (longer than it took for the Dusk to become fatiguing). Drums and vocals sparkle just enough to be interesting. The brightness also makes these sound more open. I don’t know if this quality exists thanks to the treble (and I’ll talk more about it in a following section), but it seems to me that the emphasis in the 4-8k region in combination with the good upper treble extension really helps with layering and imaging.
Mids:
What can I say about the mids? They measure perfectly. Though it doesn’t bother me, I’d note that they are slightly on the thinner side. Only slightly, and that’s when compared to more full-sounding IEMs with either more lower-mid emphasis or less treble. The only potential criticism that I personally might have is that the mids don’t have as much depth as they do on more technically capable sets like the Kato. The harmonics are all correct though. Every instrument I throw at these sounds not just accurate, but convincing.
Which brings me to why I truly love this set: they’re CONVINCING! Above all, when I wear IEMs I want to be convinced. I want to feel like there are guitars and drums and singers present, even if they happen to be performing inside my head. For this, I need instruments to sound full and true, I need different sounds to be separated, and I need some measure of detail/resolution. The Chu passes all these tests with flying colors.
Build
The build is good. They fit reasonably well as they’re fairly small and ergonomic. I have a harder time than most fitting IEMs, and found that the Aria and Starfield were both too weighty and imbalanced to stay in my ears reliably. Not the case with the Chu, especially when I use the rubber earhook attachments. I’m not a huge fan of this system–I really didn’t like it on Final Audio’s E5000–as the cable is prone to pulling its way out of the casing + it’s hard not to get a bit of extra wire bunched up in between the hook and the IEM that might put some unhelpful pressure on the IEM. Thankfully, this system is not a necessity on the Chu, so I don’t fault Moondrop for including them. Rather, it’s a nice option for those who want it. While the downward-pointing cable is unusual, it also means people who prefer not to wear cables over the ear (a.k.a. all my normie friends) won’t be required to.
The metal feels solid. I’m 99% sure it’s the exact same zinc alloy used on the more “premium” Aria, but even if it’s a cheaper material, it certainly doesn’t feel budget. A lot of people have complained about the cable, but I honestly think it’s pretty decent. Maybe my standards are particularly low… anything that isn’t as wildly tangly as the Blon BL03 cable or as cheap and stiff feeling as KZ’s clear cables is fine as far as I’m concerned. It’s more tangly and less durable feeling than the SSR’s cable, though I think the SSR has a standout cable for the sub-$100 range (very low memory, and the smooth plastic sheath is both durable and makes them easy to untangle).
My only complaint with the build is entirely subjective, and it’s that I don’t really like the aesthetics of the Chu. It has an odd shape, it pokes out of my ear a bit, and I feel like the leaf-like design is pointing the wrong direction. The colors are fine, but not really my style. Still, it’s way better looking than the tacky Blon BL05, the boring CCA CRA, the nerdy ER2SE, the gaudy Tripowin Mele… need I go on? Have I pissed enough people off yet?
Some Test Tracks and Comparisons for Reference
All these tests are using Spring tips… a lot of these nitpicks are solved by using other tips, but I wanted to give some more insight for people who wouldn’t plan on tip rolling with these.
Testing these with a bright track – The Chain by Fleetwood Mac: Everything is present, but almost nothing is overemphasized… the snare is a little forward, but not so much that it’s distracting.
Faust by Gorillaz: Texture!!! The texture of the bass is just right. Sizzly, but not too sizzly. Again, snare has just a bit too much ride… on sets like the Midnight, they fade more naturally and aren’t quite as forward to begin with. Vocals are also a liiiittle sibilant/airy, to where, if I focus on them, it almost sounds like the top register of their voices are detached from the lower registers. Almost a ghostly quality. Again, it’s very faint and doesn’t meaningfully detract from my enjoyment of the song.
cheap flowers by Lexi Jayde: The bass and kick together are full and punchy here, whereas they’re simultaneously limp and bloated on the Aria. Vocals and instruments are equally forward and easy to discern, and they’re represented properly. Though the bass is FULL sounding, it lacks some richness that would be achieved with a slight bump to the bass as a whole or with some more mid-bass.
Dubstep - Junkyard by SpaceYeti: here’s where that lack of richness really shows its face. Satisfying sub bass, but the heft that I expect from this genre isn’t really there with the Spring tips. It is definitely enough to get by, and I much prefer this well-proportioned but lower quantity approach to the OH10’s “big” but loose and unsatisfying bass.
Final Thoughts
Even after receiving the Kato (which I really like), I still prefer the Chu’s tuning. Unlike with nearly every other IEM I’ve owned, I don’t really have a favorite set of tips for these–with Spring tips, the reverb/room information these convey is kind of unbelievable for a $20 set. With more standard silicone tips, the bass sounds a little more full and the harmonics from the lower mids all the way to the upper mids are PERFECT. On other sets, Drifting Circles by Attacca Quartet is a good song–with silicone tips on the Chu, it brings me to tears. The dynamic range is so believable; sounds swell and fade exactly as they’re supposed to, which I’ve come to realize is hugely important for music in this vein (a lot of the emotion from strings relies on volume control).
This is hella incoherent so if you’ve made it this far thanks for reading!!!
Some IEMs I’ve tried in order of preference:
Chu = Kato > Yume > OH10 > Hana 2021 > Dusk > Timeless > Midnight > Olina
