Moondrop Chu II IEM Review

[georgehifi]

Maybe the driver is not yet broken in properly?

That's what I "hoped" but some ****** here said can't happen with IEM's, even though they are a mechanical device with complient parts which change over time and with tempurature changes esspecially when that small.

Cheers George

 

[Blorg]

I have a proper Tektronix FR generator both are perfectly equal, they are just not "quite" weighty enough in the bottom end for me, which makes them less "meaty" in the prestation to what I like, which gives gut, body, and musicality to things like cello's etc etc

If 50Hz sounds audibly "perfectly equal" in level to 500Hz but you don't feel that's enough, you are used to ridiculously boosted bass levels.

But also, there is no conceivable way if you do that same test on your non-sealing earbuds you will get 50Hz at the same level as 500Hz. I just don't believe that's physically possible due to the inherent sub-bass roll-off of non-sealing earbuds, combined with the way human hearing works, for sub-bass to sound at an equal level it actually needs to be quite substantially boosted as our hearing is less sensitive in low sub-bass frequencies.

So this simply doesn't make any sense. Even with IEMs with a substantial sub-bass boost, due to loudness contour of human hearing, 50Hz pretty much always sounds lower than 500Hz. It sounds lower to me on the Chu 2, the point of this test is not so much they have to be exactly equal but that if you have a seal break the 50Hz will drop off dramatically. Yet you are saying it's perfectly equal on non-sealing earbuds? I went and tried this test myself with Fiio FF3 earbuds which are probably the bassiest that I have, and while 50Hz was audible, it was at a much lower level than 500Hz.

I don't think you are actually understanding what people are saying to you or trying any of this. How does your "proper Tektronix FR generator" make any difference to testing whether 50 and 500Hz sound the same? You think you need sophisticated lab equipment to compare a 50Hz to a 500Hz tone?

Did you actually go and compare a 50Hz tone to a 500Hz tone? Or are you missing the point and saying that the left and right sound "perfectly equal"?

Did you actually try pushing them in to see if the bass increases? You just repeat that you tried the different tips in the box. But maybe none of the stock tips sealed for you, that can happen. And we tell you this but you just repeat that you tried all the tips. You aren't listening.

Your replies indicate you aren't actually reading what people are saying to you but doing something else that isn't actually going to test what people are telling you to test.

I suspect the root issue is you are just used to a non-sealing earbud sound; these all have severely rolled-off sub-bass but many have quite bloated mid-bass levels, and warmer, fuller lower mids. So if you are used to this richer fuller sound, the Chu might sound bass light and thin. But this is how basically any "correct" sounding transducer is going to sound, it's the earbud with the mid-bass/lower-mid boost that is colouring the sound here.

I have quite a few earbuds as well as IEMs, and I have earbuds that are exactly like this, I know how they tend to sound with the physical limitations. And I could understand this, if you are used to this big mid-bass warm lower-mids bloat with rolled-off sub-bass, The Chu is more sub-bass focused with it coming down in the mid-bass and lower mids and that could sound thin or lacking in bass comparatively. See this graph, the Chu is much more "correct" here and has more sub-bass. But the FF3 does sound much warmer, fuller and richer, although to me, also bloated and unnaturally full and rich.

 

[Ktacos]

Curious why so many IEM's seem to have a peak around 13khz?

 

[georgehifi]

you are used to ridiculously boosted bass levels.

That's your opinion and you are entilted to it, my main system is regarded by many that hear it as close to perfect as possible, these Moondrop Chu II's IEM's as I've said to me are "slightly" down in "bass heft" and that reflects all the way up as I said to make cello's "guttural" lower notes sound a little on the lean side as well, which makes music not as enjoyable to me.

Cheers George

 

[Blorg]

Curious why so many IEM's seem to have a peak around 13khz?

Some of it is a coupler resonance, it's damped on the GRAS 45CA-10 High-Frequency (to 20kHz) Ear Simulator but it's still there. So you should expect a peak there, how large it is though can depend on the IEM, it's not just the coupler. As to why it's so common though, the coupler contributes. Beyond that I think it has to do with the mechanical resonance of the driver; it's more consistently visible in measurements of single DDs than hybrids.

https://www.grasacoustics.com/files/786-RA0401%20Whitepaper.pdf

Single DD

Hybrid/BA

You see a similar pattern in other people's measurements too, single DDs are more likely to have a larger spike there than hybrids or BAs. I'm not 100% sure on this but it's a theme I've noticed.

 

[Blorg]

That's your opinion and you are entilted to it, my main system is regarded by many that hear it as close to perfect as possible, these Moondrop Chu II's IEM's as I've said to me are "slightly" down in "bass heft" and that reflects all the way up as I said to make cello's "guttural" lower notes sound a little on the lean side as well, which makes music not as enjoyable to me.

Speakers and headphones don't sound the same, headphones and even more, IEMs, need a boost in the bass to sound similar to a neutral speaker in a reflective room, where the room amplifies the bass.

If you do have a good seal, it's likely because you are used to earbuds with more mid-bass. Earbuds can't do sub-bass so if they have a bass lift at all, it's always a mid-bass boost and then they roll off.

You say your earbuds sound neutral to you. But if they are actually boosted in the mid-bass, and you are just used to this mid-bass "heft" on the earbuds, that's going to be the norm you compare the Chu 2 against, and you're going to hear them more like this, because you're used to a broad boost in the mid-bass and lower mids. And from what you have said so far, it does seem this is pretty much exactly how you do hear them:

You could try to get used to the Chu, or you could look for something warmer if that's your preference, the sound signature of the Chu 2 or similar IEMs with more of a sub-bass focus can sound lacking in bass "heft" if you are used to a mid-bass boost. But there are plenty of warmer IEMs with boosted mid-bass as well.

It's not stuff like driver break-in (does not exist) or impedance issues with your source (the Chu2 has a totally flat impedance curve and FR will not be affected).

 

[georgehifi]

You say your earbuds sound neutral to you. But if they are actually boosted in the mid-bass, and you are just used to this mid-bass "heft" on the earbuds

This is what you say. I say they are not, and the enjoyment of all types of music prooves this.
I say no they sound as neutral and have body to the sound just as my full range system has and this gives music it's musicality. Take away that away with a "slightly" leaner bass and you take away "body" and "heft", and more importantly musicality.
Cheers George

 

[Blorg]

This is what you say. I say they are not, and the enjoyment of all types of music prooves this.
I say no they sound as neutral and have body to the sound just as my full range system has and this gives music it's musicality. Take away that away with a "slightly" leaner bass and you take away "body" and "heft", and more importantly musicality.

Right, so your earbuds have no mid-bass boost.

But relative to your earbuds, the Chu 2 has a "slightly leaner bass".

The Chu has a +10dB bass shelf.

So this +10dB bass shelf is "slightly leaner bass" than your earbuds.

How do we square this if your earbuds don't have more bass, somewhere, than the Chu 2? And it's not sub-bass if they're earbuds, earbuds can't do sub-bass.

You are saying your earbuds are not boosted in the mid-bass, but yet, they have more bass than an IEM with a +10dB bass shelf.

These are two contradictory positions, they can't both be right.

Subjectively, terms like "body" and "heft" usually refer to an emphasis on mid-bass and lower mids. Everything else you are saying points to your earbuds having a mid-bass/lower mid emphasis, which is very common on earbuds, if you try to add bass to earbuds that's what you get. They can do flat and rolled off, or they can do mid-bass and rolled off. And if you are used to that, the way the Chu bass shelf comes down, shaped with more sub-bass and less mid-bass emphasis, could indeed sound "lean", relatively.

 

[markanini]

This is what you say. I say they are not, and the enjoyment of all types of music prooves this.
I say no they sound as neutral and have body to the sound just as my full range system has and this gives music it's musicality. Take away that away with a "slightly" leaner bass and you take away "body" and "heft", and more importantly musicality.
Cheers George

One last question. Does moving around the shells in your ear cause any reduction in bass response? If no difference, you can be certain you are not getting proper seal, bass is compromised.

If yes, you are probably incorrectly referring to a warmer mid-range as bass. This causes confusion. It's akin to someone who is used to a boom box with the "bass" controls turned up. He gets a proper hifi system with full range speakers and complains about "bass". As the graph proves, earbuds have no real bass extension, and most bass lovers abandon earbuds for IEMs as soon as they can. Anyway stick with what you like, but I assume you tried an IEM for a reason. You could see your experience with Chu 2 as informative of your taste. If warmer mids is your taste there are other options in IEMs like 7Hz Zero 2.

 

[mc.god]

This is what you say. I say they are not, and the enjoyment of all types of music prooves this.
I say no they sound as neutral and have body to the sound just as my full range system has and this gives music it's musicality. Take away that away with a "slightly" leaner bass and you take away "body" and "heft", and more importantly musicality.
Cheers George

maybe this have enough body and heft if you are willing to try

 

[DanTheMan]

That's your opinion and you are entilted to it, my main system is regarded by many that hear it as close to perfect as possible, these Moondrop Chu II's IEM's as I've said to me are "slightly" down in "bass heft" and that reflects all the way up as I said to make cello's "guttural" lower notes sound a little on the lean side as well, which makes music not as enjoyable to me.

Cheers George

Try the QKZ X HBB. https://www.linsoul.com/products/qkz-x-hbb. They should do the trick. Some of the Blon models as well.

 

[MacClintock]

Some of it is a coupler resonance, it's damped on the GRAS 45CA-10 High-Frequency (to 20kHz) Ear Simulator but it's still there. So you should expect a peak there, how large it is though can depend on the IEM, it's not just the coupler. As to why it's so common though, the coupler contributes. Beyond that I think it has to do with the mechanical resonance of the driver; it's more consistently visible in measurements of single DDs than hybrids.

View attachment 376462

https://www.grasacoustics.com/files/786-RA0401%20Whitepaper.pdf

Single DD

Hybrid/BA

You see a similar pattern in other people's measurements too, single DDs are more likely to have a larger spike there than hybrids or BAs. I'm not 100% sure on this but it's a theme I've noticed.

Ok, but you have just kind of rephrased the problem instead of given a real, causal explanation. Single DDs really tend to have a peak there (the 711 coupler peak is around 8kHz, so it is not that), while IEMs using other driver types for the treble many times not. I would also like to know where this 13kHz resonance comes from.

 

[Blorg]

@georgehifi Blon Z300 could be a good pick. It has reduced pinna gain compared to the Chu2 which will reduce the brightness/sharpness and make the lower mids and mid bass sound fuller. The old BL-03 is even a touch more mid-bassier but the Z300 is better fit and sounds better to me. Tin T2 Plus is another option with less in sub-bass level but a more broad mid-bass to lower mids elevation (and also- less pinna, so less bright). If you want that signature, I think it sounds good.

 

[georgehifi]

It is what it is guys. Buy a pair and live with them.

Cheers George

 

[markanini]

It is what it is guys. Buy a pair and live with them.

Cheers George

If you want what you call bass on the Chu 2 you can stick a piece of spare earbud foam over the nozzles. If you like what that does the Chu 2 has screw on nozzles that help keep the foam you added fixed in place.

 

[georgehifi]

Thanks but no thanks, they "may" be great for video gamer fanatics, but the balance of the Chu II is just a bit too much on the "clinical/light" side for me for music, because of the lack of bass weight/heft which beside effecting double bass/organ etc etc, also refects in the way the lower mids sounds EG: as I said before the guteral weight that cellos have and the chestiness of male tenors/baritones.
If I can't get what is "just right" for myself I'd acually prefer "warm" over "clinical" any day with my IEM's or Earbuds.

Cheers George

 

[markanini]

Thanks but no thanks, the balance of the Chu II is just too bit too much on the "clinical/light" side for me, because of the lack of bass weight/heft which beside effecting double bass/organ etc etc, also refects in the way the lower mids sounds EG: as I said before the guteral weight that cellos have and the chestiness of male tenors/baritones.
If I can't get what is "just right" for myself I'd acually prefer "warm" over "clinical" any day with my IEM;s or Earbuds.

Cheers George

That's why I proposed a simple fix to the acoustic concern you expressed in the last pages. What you use is entirely up to you.

 

[georgehifi]

That's why I proposed a simple fix to the acoustic concern you expressed in the last pages.

Sorry that's not a fix but at best a bandaid solution, they should be right for music lovers from the get go.

Cheers George

 

[DanTheMan]

Chu II have significantly more bottom end than any earbuds. Unless you call 200 Hz a bottom end. Most probably you do have seal issues. I certainly had initially.

To be fair, several earbuds do get down under 80Hz, but none that I know of under 50 (There may be some however. I’d have to check all the measurements I’ve done). That’s really enough for a lot of music. I wouldn’t be overly pessimistic about the sound quality of earbuds. You can almost think of them as open back IEMs. Many people, Audiophiles included, are willing to sacrifice low end response for that open back sound. I believe open backs outsell closed backs in the audiophile space.

 

[DanTheMan]

This is what you say. I say they are not, and the enjoyment of all types of music prooves this.
I say no they sound as neutral and have body to the sound just as my full range system has and this gives music it's musicality. Take away that away with a "slightly" leaner bass and you take away "body" and "heft", and more importantly musicality.
Cheers George

I should have added before that you could also look at the Sony TWS, IER-M7, M9 and a lot of their old flagship models or the Creative Labs Aurvana TWS models. The HEAD Acoustics MDAQS likes these IEMs best and they measure more like the earbuds you treasure.