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Moondrop Chu II IEM Review

Rate this IEM:

  • 1. Poor (headless panther)

    Votes: 2 1.0%
  • 2. Not terrible (postman panther)

    Votes: 3 1.5%
  • 3. Fine (happy panther)

    Votes: 31 15.7%
  • 4. Great (golfing panther)

    Votes: 162 81.8%

  • Total voters
    198

amirm

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This is a review, listening tests, EQ and detailed measurements of the Moondrop Chu II In-Ear Monitor. It is on kind loan from a member and costs just $19.
Moondrop Chu II IEM Harman target review.jpg

Compared to some other IEMs I have tested, these are lighter weight due to lack of extra metallic parts. They are also a bit smaller which makes them more comfortable to wear. Three sets of silicone tips came with it. The nozzle is quite large so mounting the tips was a bit of a chore but not as bad as some other IEMs.

IEMs can be finnicky to mount on my GRAS 45CA and the Chu II was that. I think I got 90% there in the measurements you see below.

Moondrop Chu II Measurements
As usual, we start with our IEM frequency response measurement and comparison to target:
Moondrop Chu II IEM Harman frequency response Measurement.png

Wow, this is quite good! The gaps between its response and our target is very small. Since the target is not high resolution anyway, this may just as well be as good as the target with just some overshoot around 14 kHz.

Creating filters by eye/hand may be a bit tricky though due to the shape of the deviations:
Moondrop Chu II IEM Harman relative frequency response Measurement.png


What I was really impressed by was the low distortion:
Moondrop Chu II IEM Harman Distortion Measurement.png

Moondrop Chu II IEM Harman Distortion THD Measurement.png

Considering that we don't need to boost bass, this is extremely good results though shy of the best we have seen.

Group delay is uneventful as it typically is for IEMs:
Moondrop Chu II IEM Harman Group Delay Measurement.png


Impedance is low:
Moondrop Chu II IEM Harman Impedance Measurement.png

Sensitivity is also low for an IEM but still better than just about any standard headphone:
Most sensitive IEM review 2024.png

Comfortable listening on my RME ADI-2 Pro is about -40 dB so should not be a hard load for just about any source.

Moondrop Chu II Listening Tests and Equalization
First impression was very good although I thought the bass was not quite there. It felt like a fitment issue although pushing them into my ear made no difference. I wanted to EQ it anyway so here we are:
Moondrop Chu II IEM Harman Equalization.png

I took the midbass down and boosted the treble. This naturally made things worse as I lost more bass response. So I put in the Band 1 filter and that added the warmth back it. I usually don't EQ above 8 kHz but here, that peak around 14 kHz was quite wide so I went after it. Can't swear it is not placebo but the effect was softening the highs and reducing their sharpness.

Playing my reference tracks with or without EQ showed very subtle difference despite the plurality of the filters. With the filters in place, the clarity improved with better ability hear fine detail like strings and vibration in voices. On the Nathaniel Rateliff track above, the result was absolutely stunning! It felt like his head was fully inside my head singing! I have listened to this track many times with my standard headphone where the experience was not this good.

The response with EQ was so good that I had to put them back on and keep listening as I type this review! Absolutely reference quality sound reproduction.

Conclusions
The last 12 months or so has definitely been the era of budget IEMs that produce level of fidelity that is jaw dropping. The Moondrop Chu II joins that crew producing very good out of box response with very low distortion. A bit of EQ adds lipstick to an already beautiful woman, producing a level of fidelity that amazes on any well recorded music. Fitment in my ears is better than some other IEMs due to lighter weight and smaller size. And the look is more conservative which is nice.

It is my pleasure to recommend Moondrop Chu II IEM. For the price of fast food for one and half people, you can have an IEM that can transform our audio experience!

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As always, questions, comments, recommendations, etc. are welcome.

Any donations are much appreciated using: https://www.audiosciencereview.com/forum/index.php?threads/how-to-support-audio-science-review.8150/
 

Attachments

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Yes, the difference in weight is significant vs zeros & co. And very comfortable. And can be get even cheaper on occasion. A no brainer imo.
I wonder if there is any other difference with the I (even cheaper) besides the detachable cable.
 
Once China starts to apply Chinese audio performance to speakers that outperform Genelec, Neumann, KEF, Revel with lower prices, then it's going to get wild. Imagine performance of a Genelec 8361 for 1/3 of the price.
 
Here are Harman and ... the one I never remember the name graphs from GizAudio (others have measured it and result are almost the same). IMO the same result as other cheap iems tried to be tuned to Harman. If you are sensitive to highs like me the 12.5khz peak is gonna kill you, and even if you eq it it is still going to be partially there. Boosted mid lows (as always) and the resonance at 8khz which is partially a result of the measurement system and ear canal. 19€ here in Europe ... if you are going to eq it or use Moondrop Spring Tips (which tame the 8khz and 12.5khz peaks) it could be recommended.

A10.png


Harman.png
 
I have them. Dont know why but bass feels a bit muddy bloated or just distorted...

Im not sure why. Bass from Zero2 or Sonus feels better. Also rest of the FR seems not as clear.
 
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Maybe I’m getting old but the iem market seems insane to me. Looking at the sound quality I can get for around 20-30$ vs the one I encounter over the so-called flagships…and I’m left scratching my head.
I come across this phenomenon in headphones as well only with iems it seems exaggerated beyond belief.
 
Here are Harman and ... the one I never remember the name graphs from GizAudio (others have measured it and result are almost the same). IMO the same result as other cheap iems tried to be tuned to Harman. If you are sensitive to highs like me the 12.5khz peak is gonna kill you, and even if you eq it it is still going to be partially there. Boosted mid lows (as always) and the resonance at 8khz which is partially a result of the measurement system and ear canal. 19€ here in Europe ... if you are going to eq it or use Moondrop Spring Tips (which tame the 8khz and 12.5khz peaks) it could be recommended.
Not sure if why I don't use my Chu2 much boils down to exactly those frequencies, measurements are not exact in that range, but I agree. The Chu2 sounds very sibilant out of the box to me, which is a shame since I like them a lot otherwise. Great fit and comfort for a bargain price, only shame is that they don't come with the same tips as the original Chu.

Thanks for the measurements Amir!
 
Wow, IEM's are getting ridiculous now with the price/performance ratio, just insane!
 
The Chu2 was actually okay, but I remember the fit being a little weird. The unit is small, but something about the shape of the shell didn't fit my ears, resulting in an awkward insertion depth.
The Zero:2's feel differently angled, but other than that, I remember them fitting properly.
It's so affordable, it's very responsive to EQ, and it worked great even when topped with L70+HighGain+BRIR.
Pretty good!
 
@amirm ...By any chance did you get the Moondrop Chu II DSP ? As I found the little DSP tweaks and the 3 slightly different 'tuning' available Moondrop App worked well with the Chu II DSP.
This USB-C w/DAC + DSP Parametric EQ/App version is interesting. For $24 U.S. you can try Amir's tweak built right into the iem. Technology is amazing.
 
Vast improvement over the OG Chu.

Top tip, if you take the ear loop plastic off you can wear these upside down. With wide enough tips these seal well that way and easier to pop out in a communal setting.
 
Treble can be tamed very easily if you unscrew the cap of the nozzle and place a small piece of napkin or paper to act as a filter
 
IEMs are a solved problem and the solution requires just one simple dynamic driver. There is no reason to pay more than $20ish for an IEM, unless you want an actually useful special feature like the crazy isolation of my ER2XR (and I can't really think of any other case). Otherwise you're paying for jewelry, and I don't know about you but I don't watch myself in the mirror while I listen to music. Cheapness also means that if you try one that you can't get to fit you well, no great loss.
 
IEMs are a solved problem and the solution requires just one simple dynamic driver. There is no reason to pay more than $20ish for an IEM, unless you want an actually useful special feature like the crazy isolation of my ER2XR (and I can't really think of any other case). Otherwise you're paying for jewelry, and I don't know about you but I don't watch myself in the mirror while I listen to music. Cheapness also means that if you try one that you can't get to fit you well, no great loss.
It does seem that way! In a way it's sad, because there's probably less to strive for, but in reality as you say "solved problem" which is a bit like DACS being a solved problem. Although re Headphones & IEM's there's still the element of spatial audio to be implemented effectively & easily - something as good as Smyth Realiser, because otherwise speakers can't be totally faithfully reproduced.....but this will require somehow an easy and effective measurement of your individual HRTF and then that to be processed with DSP through the headphones & IEM's, but IEM's in the conventional "fixed frequency curve" sense seem like a solved problem to me - just like you say.

EDIT: but Amir should continue to measure IEM's because we still need to know which ones are good, there's still gonna be some bad IEM's out there, and absolutely the same with headphones, and speakers indeed!
 
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