Moondrop Chu II IEM Review

[b7676]

Diffuse field

 

[heraldo_jones]

The reason why the peak is still there after you try to eq is that the peak might not be at the same frequency in your ears. You might try a tone generator and see where the peak actually is, in your ears.

I know about that, but it doesn't matter whether you EQ or not, or if the frequency positions change slightly due to the insert depth. It's a resonance and can't be removed without affecting the natural representation of the sound.

 

[Sombreuil]

I have purchased 3 pairs of the original Chu in the past. Each time from the online superstore. Taking anywhere from 1 to 3 months for arrival. As far as sound quality goes I liked them a lot.

None of them lasted very long. The first pair I used them as I would any IEM. I'd walk around with them attached to my phone while I did all types of things around the house. They lasted maybe a month before one side died. I figured maybe it was a bad batch and ordered another. I believe there was a sale going on so even cheaper than the listed $19. That pair lasted 2 months.

Even though I told myself I'm done with this certain model I ended up buying another pair a few months later. I babied this pair. I was very delicate with the wires & only listened to them when I was seated in one spot with the headphone amp. 3 months until the left driver went out & I was barely even using them. It was the left driver each time that went out first.

That is my experience with the original Chu. Pretty good sounding IEM but not even worth $19 in my opinion. Hopefully, for others sake, the Chu II Is of better quality.

2 months isn't bad, I received mine yesterday and the right side is already broken. I used them twice...
Well, let's hope their support is good.

 

[yofi]

I just got the Chu II DSP in last night. I spent two hours doing some extra work yesterday evening with them in my ears. Comfort is good for me. The Shure SE215 is my point of reference here. They don’t wedge themselves as deeply into my ear as the Shure does, however they are just as unobtrusive for me.

I can’t believe the sound I’m getting for $23USD. The last time I messed around with couch-money-priced IEMs was 7-8 years ago when the VE Monk+ was all the rage. I still have a limited edition one of those in brown and bring it out from time to time for fun. However sets like the KZ ATE and ZST didn’t have any staying power for me. Hard to recall the sound anymore, but it wasn’t enough to overcome bad fit and noisy cables, that’s for sure.

I’ve had the Shure SE215 this whole time. The squigs tell part of the story:

The Chu II is definitely brighter than the 215, I can tell that by ear easily. For me, that’s a pretty big plus. The 215 is slightly elevated in the mid bass, but it sounds so much muddier than the Chu II. I’d had that complaint with the 215 for a little while anyway. Whether or not the Chu II can last a decade though like my SE215 has, that’s the question isn’t it? I hope it does, because it sounds great. I want to pick up an analog cable to try it without DSP.

Speaking of the DSP I tried it on the regular tuning, then less bass, then back to regular. I was afraid the bass would bleed up into the mids, but it doesn’t. I won’t be trying the bass head tune, that’s not my flavor.

Hard to say to not try this. I don’t have a lot of money, but it’s not hard to come up with $20 bucks.

 

[WickedInsignia]

Got these recently, they're a great easy buy.
The tuning is eminently listenable, no peaks and just enough bass. Sounds "correct" and fun but not "lush" in the way that something like the HD600 is. Maybe a little plasticky in some areas but I would say only noticeable if you've ever been treated to the uncanny HD600 timbre.
I also felt the technicalities were middling, imaging/soundstage have nothing all that special going on. Not sure why that is. I find the treble/upper mids to be very unoffensive and maybe it has something to do with that. They're not blunted, but the Truthear Zero is slightly more forward here and has better technicalities to my ear. There's a keener sense of space and direction with those, but there's also less upper bass to cool things off. I like the Zero more for critical listening but less as a daily driver where I'm not focusing on the music.
The Chu II is so easily a daily driver, just wonderfully easygoing and "right" tonality. I wish more headphones sounded like this, it would make recommendations so simple.

Some problems to be aware of from reviews online are that the brass nozzle is meant to be susceptible to corrosion, and moisture buildup in the nozzle might create imbalance. They are quite comfortable for me though and the nozzle size is less bothersome than the Zero.

 

[Doltonius]

Soundstage...the perception or illusion of space/location/depth is certainly real. I can understand how live performances and recordings can vary in soundstage.

Speakers depending on spread pattern and positioning also differ. I have difficulty understanding how IEMs can have soundstage. That is, if they have better/worse soundstage how exactly do they accomplish it. This post by JAE lays the issue out well. The clues our ears/brains use to localize sound are not available to IEMs. I am open to learning more.

Do you think cognitive bias is real?
We cannot be "confident that I can distinguish it in any blind test" until we do a blind test.

You know that the MP145 and Chu II for example differ greatly in frequency response. And frequency response is something that enough difference is definitely detectable in blind tests. They don't just differ in abstract subjective terms. That some people prefer MP145 over more Harman-compliant IEMs like the Chu II is evidence that the Harman target is not the endgame target for everyone. I don't think this is controversial at all.

 

[Doltonius]

I know about that, but it doesn't matter whether you EQ or not, or if the frequency positions change slightly due to the insert depth. It's a resonance and can't be removed without affecting the natural representation of the sound.

if the resulting FR that reaches your eardrum is natural, it is natural. there is nothing in theory preventing this from happening.

 

[somebodyelse]

You know that the MP145 and Chu II for example differ greatly in frequency response. And frequency response is something that enough difference is definitely detectable in blind tests. They don't just differ in abstract subjective terms. That some people prefer MP145 over more Harman-compliant IEMs like the Chu II is evidence that the Harman target is not the endgame target for everyone. I don't think this is controversial at all.

It's not controversial partly because actual response in ear depends on the user's physiology, as does the HRTF. No target can be right for everybody. The Harman target is an evidence based average, so works well for people close to the average physiology. For a manufacturer that makes sense because it has the best chance of sounding good to the largest number of people.

 

[Doltonius]

It's not controversial partly because actual response in ear depends on the user's physiology, as does the HRTF. No target can be right for everybody. The Harman target is an evidence based average, so works well for people close to the average physiology. For a manufacturer that makes sense because it has the best chance of sounding good to the largest number of people.

The methodology at Harman deriving the IE targets is not good enough. The target responses that were compared to Harman were just too few and too bad. More recent Harman research shows that Soundguys' target (actually quite similar to JM1, with more treble), a tweaked DF target, and Harman IE are actually rather similar in preference. So Harman IE is not necessarily the one that is the "most average" or "most preferred". There should be a window of preference, which is Headphones.com's approach.

 

[CedarX]

More recent Harman research shows that Soundguys' target (actually quite similar to JM1, with more treble), a tweaked DF target, and Harman IE are actually rather similar in preference. So Harman IE is not necessarily the one that is the "most average" or "most preferred".

How does it prove that the Harman IE is not the “most average/preferred “?

 

[Doltonius]

How does it prove that the Harman IE is not the “most average/preferred “?

It ties in preference with soundguys' target in the new Harman preference research, and the tweaked DF is not far behind. So it is not "the most average/preferred", which means it is in its own league and beats the other targets, which I think is not the case according to the research, it does NOT beat soundguys' target. Though it could still be "one of the most average/preferred".

 

[CedarX]

It ties in preference with soundguys' target in the new Harman preference research, and the tweaked DF is not far behind. So it is not "the most average/preferred", which means it is in its own league and beats the other targets, which I think is not the case according to the research, it does NOT beat soundguys' target. Though it could still be "one of the most average/preferred".

I still don’t get your point, but it’s probably me… Anyway, the Harman target is still the best [Edit] one of the best science-based (preference from representative groups of users) things we have until some new research refines it.

 

[Doltonius]

I still don’t get your point, but it’s probably me… Anyway, the Harman target is still the best science-based (preference from representative groups of users) thing we have until some new research refines it.

There is new preference research by Sean Olive at Harman that suggests that other targets, namely, Soundguys' target, are equally well-preferred, if not more preferred, than the Harman IE target. This means, you cannot refer to Harman as "the best science-based thing". It is "one of the best science-based things", the other being Soundguys' target.

 

[WickedInsignia]

Seems a little like shifting the goalposts from "The methodology at Harman deriving the IE targets is not good enough" if the Harman IE target is actually "one of the best science-based things."
If an objectively definitive preference target emerges then let's all get behind that. Until then, who cares what's used if they're all neck-and-neck? Most here seem to acknowledge it's not an exact science.

 

[Doltonius]

Seems a little like shifting the goalposts from "The methodology at Harman deriving the IE targets is not good enough" if the Harman IE target is actually "one of the best science-based things."
If an objectively definitive preference target emerges then let's all get behind that. Until then, who cares what's used if they're all neck-and-neck? Most here seem to acknowledge it's not an exact science.

Many here believe that Harman compliance is the ultimate standard. Lots of people here slam more expensive IEMs just because they are not as similar to Harman as some of the cheap ones measured here. In light of the recent results, this mindset should change. Review strategies that compare the FR of an IEM with a single curve, be it Harman, soundguys, or whatever, are also flawed.

The methodology behind Harman's research is indeed not good enough. The total number of targets compared is still too few. Although it is a difficult issue: there are an infinite number of FR curves to consider, and even if we choose a granularity according to human audibility and make things finite, there are still way too many curves to experimentally compare. So this is why there are always theoretical motivations and heuristics in the development of the curves. This will likely be unavoidable.

 

[somebodyelse]

The methodology at Harman deriving the IE targets is not good enough. The target responses that were compared to Harman were just too few and too bad. More recent Harman research shows that Soundguys' target (actually quite similar to JM1, with more treble), a tweaked DF target, and Harman IE are actually rather similar in preference. So Harman IE is not necessarily the one that is the "most average" or "most preferred". There should be a window of preference, which is Headphones.com's approach.

That's fine - evidence based improvement is always welcome. It doesn't change the point that no target can be right for everybody. That's going to be true, whatever the target, until we start measuring each individual to determine what response is right for their physiology. Once you have that you can do some fine tuning for personal taste. There have been a few attempts to head in this direction using the ear-side mics to characterise the difference in resonance, some including 3D scans of ear and head/torso too. It's a step in the fight direction, but seems not to be all the way there yet.

 

[WickedInsignia]

Lots of people here slam more expensive IEMs just because they are not as similar to Harman as some of the cheap ones measured here.

Are you suggesting that the research is flawed because it reflects badly on expensive products?

Review strategies that compare the FR of an IEM with a single curve, be it Harman, soundguys, or whatever, are also flawed.

The targets you mentioned aren't drastically different to Harman and IEMs are usually slammed here for being way off the mark. A bunch of similar targets being similarly preferable doesn't negate that they're all a good basis for audio that will please most people.
Sure, there's more to audio than a target but we all know that. FR targets are the best objective guides we have right now. "Not good enough" implies a "better," which in this case doesn't exist.

 

[CedarX]

Many here believe that Harman compliance is the ultimate standard. Lots of people here slam more expensive IEMs just because they are not as similar to Harman as some of the cheap ones measured here. In light of the recent results, this mindset should change. Review strategies that compare the FR of an IEM with a single curve, be it Harman, soundguys, or whatever, are also flawed.

So if an OEM produces an IEM with any random FR measurement, I should now refrain to “slam” it and accept it “as good” as any other IEM? I would consider it if the OEM explains which user group they target and present supporting evidence as why their IEM is delivering for that group…
They never do…

If I change my mindset as you recommend, any IEM FR is acceptable. How is it helpful?

The review criteria may be imperfect, but I don’t think the strategy is flawed: even with these latest results, Harman is still a target that would be among the preferred ones for the largest group of users.

 

[markanini]

Why does anyone need to slam an IEM based on graph data when in-situ FR is this volatile?

 

[WickedInsignia]

Why does anyone need to slam an IEM based on graph data when in-situ FR is this volatile?

This sort of argument always comes across to me as audio nihilism. Effectively "everything is guesswork so why draw any conclusions at all."
Constants exist and they're not infinitely imprecise. It's not the exactitude many would wish for but I think that's well-acknowledged.
My issue is with people suggesting that because it's imprecise we should invalidate formal conclusions altogether. It reads as curtailment of objectivity to the benefit of those who are a little miffed that their favorite headphone rated poorly.