KZ ZSX IEM Review

[MacClintock]

I am not an expert on acoustics, and am an electronics guy so let me put this it in a way that I understood myself - if I misrepresnt it I am sure more knowledable people can correct me.

Good to know! So my impression wasn't wrong.

An IEM is a device that has an output impedance that varies with frequency. An ear canal also has an input impedance that varies with frequency. When you couple these devices, the final FR depends on the interactions between the two variable impedance systems and is not a linear function of either. That is why the same IEM, measures same in some frequencies and different in some others in two different measurement rigs, and that is why it might procude a totall different FR in your ear canal, which has a different impedance/FR curve.

There is just a relevant point you did not take into account. I did not say that two IEMs that measure the same sound the same for EVERYBODY, but for a single person. If you combine the nonlinear output impedance e(x) with the nonlinear input impedance of a specific ear canal g(x) and the output impedance of two IEMs is identical (since it was measured) e(x) = f(x), doing a convolution with the input impedance will result in the same f(g(x)) = e(g(x).

 

[Chyżwar]

Measurements done by crinacle have no scientific basis, even if he had the largest database, he is a hobbyist, has no pertinent education and so on. They cannot be trustet neither on his 711 clone coupler nor on his new 5128. So please show me professional measurements to have a scientifically based argument.

IAtaman asked you: 'which measurements are you referring? 5128, 711, 711 'inspired' couplers you can buy on Ali Express? All of them?'

You answered: 'It doesn't matter. For sure the same IEM will measure differently at the 711 or the 5218 or on any other rig. But two IEMs that measure the same on the same rig, will sound identically for the same person, that is the claim.'

Now you inform us: 'They cannot be trustet neither on his 711 clone coupler nor on his new 5128.'


So which of your contradictory claims is true? If your claim only applies to certain measurement rigs, what methodology did you use to determine which ones? Which professional measurements confirm your claims about IEMs? Show us the test results, explain the research methodology.
Because everything you've given us so far is just your subjective talk about something you believe in. Now I would like to see the scientific basis.

 

[MacClintock]

IAtaman asked you: 'which measurements are you referring? 5128, 711, 711 'inspired' couplers you can buy on Ali Express? All of them?'

You answered: 'It doesn't matter. For sure the same IEM will measure differently at the 711 or the 5218 or on any other rig. But two IEMs that measure the same on the same rig, will sound identically for the same person, that is the claim.'

Now you inform us: 'They cannot be trustet neither on his 711 clone coupler nor on his new 5128.'


So which of your contradictory claims is true? If your claim only applies to certain measurement rigs, what methodology did you use to determine which ones? Which professional measurements confirm your claims about IEMs? Show us the test results, explain the research methodology.
Because everything you've given us so far is just your subjective talk about something you believe in. Now I would like to see the scientific basis.

There is no contradition, it can be any rig, as long as it is correctly calibrated, has the sufficient standards of quality and deviations and is used by a person competent to do so. Not all of these points are met by crinacle.

 

[audiosciencestudent]

What is their reputation?

I found this also : https://www.headphonesty.com/2022/03/kz-fake-multi-driver-iem-scandal/
They packed in multiple drivers and claimed it to be multi driver iem but actually some of the drivers were not even wired.
So it seems like a scam to claim higher number of drivers

Edit: Found 1 more https://www.facebook.com/groups/2386473901653225/posts/2822553261378618

 

[cistercian]

This one is a lot more sensitive.

I own a ton of KZ IEMs. I prize them primarily for their incredible sensitivity for use with crystal radio sets and also for listening to natural radio
with my home made VLF antennas. For music I much prefer my Sennheiser HD600 and HD560S. And several other Sennheiser cans.
BA transducers have a slightly (or severe depending on hearing) timbre coloration. I find them metallic and unnatural sounding.

But for raw sensitivity KZ really brings it. The AS16 is incredible and the much cheaper ZSN Pro X is also excellent. Amazing sensitivity but...
poor for music.

KZ took a hit when one of their series came with drivers that were plugged by resin. Which was lame of course. I avoided that model whose name I cant recall
now and thoroughly enjoy their other offerings for primarily scientific uses. I am listening to a storm complex off the east coast right now with a giant ferrite loopstick I built using a yamaha SC02 audio amp and a set of KZ ZS10 Pro X. Poor for music...great for tweaks and other sferics.

My loopstick is really huge. 46 and 1/16 inch long ferrite rod 1.02 inches in diameter with a coil 2.39 inches in diameter wound over it 40.5 inches long of #20 magnet wire. 2.44 lbs of it.1246 turns. An epic semi portable setup. The antenna weighs over 12 lbs!!!

 

[gabo4au]

One thing I would like to see in IEM reviews. And maybe this is just because I'm a musician who wears IEMs on a regular basis for playing live. One big key to playing live is getting a good seal and it has to stay there. Any slippage or falling out is totally unacceptable.

For this reason I generally always buy comply tips for my IEMs. They just stay in place and seal better than other things I've used. I will say that my Westone IEMs come with tips that are different from Comply's but seal very well as well and I generally don't replace them.

This brings me to another point and something I would like to see in reviews. IEMs have what I would call a "barrel" where the tip attaches. Maybe there is a standard word for it, if there is I don't know what it is.

These barrels are different sizes on IEM, again I'm not sure what they measure them in, but if you look at the Comply tips, they scale them by a "number." 100, 200, 300, 400, 500, etc..

The smallest barrels are the 100's and they progressively get larger the bigger the number. This is very important for seal! With the small tips, the 100s, there is more room to "compress" the tip and insert it into your ear. Especially if you have small ears. I don't have particularly small ears, but and IEM with a 100 tip definitely seals and stays put better than one with a 400 tip size.

For this reason, I will not buy an IEM with a large barrel size. I simply can't use it for live performance.

Most all the Shure tips are 100s, as are the Westones. Both of these companies cater to the professional musician market, so that may be why they have small barrels. I also have a pair of Klipsch that are 100s.

Odd the Sennheiser IEMs that come with their wireless in-ear monitoring system use size 400 tips. And nobody I play music with can get them to insert and seal very well. We all use Shure or Westone.

These barrel sizes may also have an impact on other consumers, so It would be nice if the size was listed in the reviews.

 

[markanini]

One thing I would like to see in IEM reviews. And maybe this is just because I'm a musician who wears IEMs on a regular basis for playing live. One big key to playing live is getting a good seal and it has to stay there. Any slippage or falling out is totally unacceptable.

For this reason I generally always buy comply tips for my IEMs. They just stay in place and seal better than other things I've used. I will say that my Westone IEMs come with tips that are different from Comply's but seal very well as well and I generally don't replace them.

This brings me to another point and something I would like to see in reviews. IEMs have what I would call a "barrel" where the tip attaches. Maybe there is a standard word for it, if there is I don't know what it is.

These barrels are different sizes on IEM, again I'm not sure what they measure them in, but if you look at the Comply tips, they scale them by a "number." 100, 200, 300, 400, 500, etc..

The smallest barrels are the 100's and they progressively get larger the bigger the number. This is very important for seal! With the small tips, the 100s, there is more room to "compress" the tip and insert it into your ear. Especially if you have small ears. I don't have particularly small ears, but and IEM with a 100 tip definitely seals and stays put better than one with a 400 tip size.

For this reason, I will not buy an IEM with a large barrel size. I simply can't use it for live performance.

Most all the Shure tips are 100s, as are the Westones. Both of these companies cater to the professional musician market, so that may be why they have small barrels. I also have a pair of Klipsch that are 100s.

Odd the Sennheiser IEMs that come with their wireless in-ear monitoring system use size 400 tips. And nobody I play music with can get them to insert and seal very well. We all use Shure or Westone.

These barrel sizes may also have an impact on other consumers, so It would be nice if the size was listed in the reviews.

I've had my best experience with Truthear Zero Red for monitoring, the fit is very secure for me with silicone tips none the less. Theres the issue as far as reviews go that fit security varies from person to person due to varying ear dimensions.

 

[gabo4au]

I've had my best experience with Truthear Zero Red for monitoring, the fit is very secure for me with silicone tips none the less. Theres the issue as far as reviews go that fit security varies from person to person due to varying ear dimensions.

Wow, you must have large ears canals! Those Truthear Zero Red's use a comply size 600 tip, so the barrel on those is huge. No way I could get that to seal enough to get me through a show. And I've never had a silicon tip I can keep in place, first thing I do is throw those things in the trash! hahaha But I am a drummer and not only move around a bit, but also sweat a fair amount during a show, so I understand I'm not the normal case for IEMs.

Yep, everyone's ears are different. But it would be nice in the reviews if it was noted as to how large or small the barrel size is. It's a big factor for me and maybe for some others as well. Maybe some people have never even noticed or thought about it, just can't keep "pair x" in their ears but "pair y" are solidly in place. Maybe they don't know that "x" is a 600 tip and "y" is a 100 tip!

 

[Phosphenetre]

I've had my best experience with Truthear Zero Red for monitoring, the fit is very secure for me with silicone tips none the less. Theres the issue as far as reviews go that fit security varies from person to person due to varying ear dimensions.

Same here. And none of the included tips for the Moondrop Chu 2 or 7 Hz Zero 2 produced a reliable seal for me with those respective IEMs. I was really excited for them both, especially the 7 Hz Zero 2, but simply couldn't get it to fit well consequently sound as designed. I'll find the time to dig up my SpinFit collection someday soon and try again, but given the shallow-fit design of the Zero 2, I have my doubts with respect to isolation as well, for stage use.

 

[markanini]

Wow, you must have large ears canals! Those Truthear Zero Red's use a comply size 600 tip, so the barrel on those is huge. No way I could get that to seal enough to get me through a show. And I've never had a silicon tip I can keep in place, first thing I do is throw those things in the trash! hahaha But I am a drummer and not only move around a bit, but also sweat a fair amount during a show, so I understand I'm not the normal case for IEMs.

Yep, everyone's ears are different. But it would be nice in the reviews if it was noted as to how large or small the barrel size is. It's a big factor for me and maybe for some others as well. Maybe some people have never even noticed or thought about it, just can't keep "pair x" in their ears but "pair y" are solidly in place. Maybe they don't know that "x" is a 600 tip and "y" is a 100 tip!

The Zero Red might not necessarily isolate well for drums, I play bass in my band and it's fine for me. For max isolation you would want an unvented IEM with foam tips, the selection of unvented IEMs is small, Kiwi Orchestra lite and Moondrop S8, and Etymotic off the top of my head.

 

[CedarX]

I often have seal problems with IEMs (lack of bass is the main symptom), but not so much with the IEM staying in place (secure fit), and isolation is not a main concern for me.
The tips included with every IEM rarely work for me!

IEMs have what I would call a "barrel" where the tip attaches. Maybe there is a standard word for it, if there is I don't know what it is.

With the small tips, the 100s, there is more room to "compress" the tip and insert it into your ear.

Foam tips (Comply) work for me as well. However, in order to compress them enough so the IEM stays in place, I need to be able to insert them deep enough. So, the nozzle (more common term than "barrel" I believe) diameter may be an important parameter (by the way, some nozzles are oval in shape), but the nozzle length relative to the IEM main body is at a minimum as important: IEMs with a very short nozzle such as the classic Blon BL3, just don't fit securely with foam tips for me.

On the other hand, I don't think the nozzle size is very critical when you use silicon tips, as long as you can install the tips onto the nozzle and they don't slip away.

I'll find the time to dig up my SpinFit collection someday soon and try again, but given the shallow-fit design of the Zero 2, I have my doubts with respect to isolation as well, for stage use.

Large size (L or XL) Spinfit tips work very well for me (good seal), but the seal is done in a different area of my ear canal, not as deep as with foam type. Although I am always concerned getting a secure fit, this has not been an issue with these large Spinfit tips. I think it is worth a try as an alternate way to get a good fit & seal for IEMs, and I actually prefer those rather than the Comply foam tips.

The last type of seal is the Etymotic's very deep insertion, whether using a foam tip or one of their multi-flange silicon tips. Seal and secure fit are perfect, and isolation is at a whole other level: it's like an ANC IEM !!! But one needs to be able to withstand that super deep insert (I do, but understand other won't).
What is interesting with the Etymotic's is that they are designed to work with a deep insertion: insertion depth affects the high FR response, so they are tuned accordingly. There is also a theory that, because the seal is done against the "bony part" of your ear canal, you also get better bass--so the Etymotic's are not as "bass-light" as one may think when looking at ety's FR graphs... Not sure if this is all true, but I have a pair of er4xr, and they do sound very good indeed.

 

[gabo4au]

I often have seal problems with IEMs (lack of bass is the main symptom), but not so much with the IEM staying in place (secure fit), and isolation is not a main concern for me.
The tips included with every IEM rarely work for me!





Foam tips (Comply) work for me as well. However, in order to compress them enough so the IEM stays in place, I need to be able to insert them deep enough. So, the nozzle (more common term than "barrel" I believe) diameter may be an important parameter (by the way, some nozzles are oval in shape), but the nozzle length relative to the IEM main body is at a minimum as important: IEMs with a very short nozzle such as the classic Blon BL3, just don't fit securely with foam tips for me.

On the other hand, I don't think the nozzle size is very critical when you use silicon tips, as long as you can install the tips onto the nozzle and they don't slip away.



Large size (L or XL) Spinfit tips work very well for me (good seal), but the seal is done in a different area of my ear canal, not as deep as with foam type. Although I am always concerned getting a secure fit, this has not been an issue with these large Spinfit tips. I think it is worth a try as an alternate way to get a good fit & seal for IEMs, and I actually prefer those rather than the Comply foam tips.

The last type of seal is the Etymotic's very deep insertion, whether using a foam tip or one of their multi-flange silicon tips. Seal and secure fit are perfect, and isolation is at a whole other level: it's like an ANC IEM !!! But one needs to be able to withstand that super deep insert (I do, but understand other won't).
What is interesting with the Etymotic's is that they are designed to work with a deep insertion: insertion depth affects the high FR response, so they are tuned accordingly. There is also a theory that, because the seal is done against the "bony part" of your ear canal, you also get better bass--so the Etymotic's are not as "bass-light" as one may think when looking at ety's FR graphs... Not sure if this is all true, but I have a pair of er4xr, and they do sound very good indeed.

Ah, thanks for the great reply! Now I know they call it the "nozzle!" This is really good discussion and should be part of the reviews on IEMs.

I have not tried the spinfit tip, actually never heard of them. So I'll try some of those. And I have never used the Etymotic IEMs either, but have used some of their plugs before. I generally have no problem with inserting something deep, so I want to try some of those as well.

The comments on venting is also important. I don't think either of my "go to" IEMs are vented. The Shure SE215s and my Westone UM Pro 50s.

 

[CedarX]

Getting a good fit—good seal, secure fit—is very important for IEM. I think there are useful tips (pun intended! ) that are not always well known or understood unfortunately.
In the end, it’s lot of trial & errors, what works for one individual may not work at all for another…
Cheers!

 

[Jimbob54]

Getting a good fit—good seal, secure fit—is very important for IEM. I think there are useful tips (pun intended! ) that are not always well known or understood unfortunately.
In the end, it’s lot of trial & errors, what works for one individual may not work at all for another…
Cheers!

And what works for you on IEM A might well not work for you with IEM B. Fickle beasts!

 

[phoenixsong]

And what works for you on IEM A might well not work for you with IEM B. Fickle beasts!

Can't agree with this enough! Also, tip sizing isn't standardized across the different tip brands, and even if their exact diameter is provided, not all tips of similar diameters seal identically due to different physical material properties and shapes. The resulting effect on seal and depth of insertion makes me believe that even people using similar sized tips of the same model on the same iem might perceive its effects differently. Together with this, the fact that different tips encourage resonance at different frequencies, combined with the different frequency and resonance responses of different iems and the *Fletcher-Munson curve, suggests that "ultimate rankings" of iem tips without consideration of the user and iem should be taken with a pinch of salt. I mean, without absolute isolation, even environmental noise of different loudness and frequencies would affect the perceived sound- but I digress.

To summarize, it's always key to consider variables and not blindly go "oh, Person A says these tips are awesome so they will magically work for me on my iems!" ASR is about pursuing the truth after all