Knowledge Zenith (KZ) impressions thread
Jul 3, 2021 at 8:50 AM Post #55,936 of 63,672
Should I jump on the AST hype train? Already have AS12.
I have both, technicalities wise it’s an upgrade. Tuning wise they sound day and night. AS12 is KZ V-shape house sound, AST is dark warm signature. If you like bright and impactful, you may need to reconsider AST, it may disappoint you.

Imagine AS12 is sparrow’s chirps and AST is night owl’s hooting.

Basically that describes the characteristics.
 
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Jul 3, 2021 at 8:55 AM Post #55,937 of 63,672
The only one I know is the Variations. Moondrop also tuning their IEMs to harman target which KZ also trying to do, so they will be pretty similar frequency curve. I have the Aria and it can stand against CCA CKX even with just a single DD.
The recent release of moondrop tuning is diverting from Harman IMO. Harman has 2.5khz pinna gain peak vs Moondrop started to target 3khz as new peak after RSV>Dusk>Aria>Sparks>Variations. Also the bass shelf is diverting from Harman as well, they slimmed out 150hz volume to make it more sub-bass focused.
 
Jul 3, 2021 at 1:23 PM Post #55,938 of 63,672
Ok ... so I received the ZAX in the mail today. After an afternoon of listening my initial impression is that these are stupid good for 45 euros :smile::smile::smile::smile: I can see why people are in love with the similar CKX that has a touch darker treble. I will be ordering the CKX because I think both sets are destined to be classics, and I think my wife would love them as well, especially with her smaller ears. I can't believe it's taken me so long to catch up to last year, but here I am.

I was happy to see a full compliment of starlines in ZAX box, and the pretty silver plated cable with clear plastic touches is a nice improvement over KZs famous brown jobber. Along with the starline tips I'm using the copper cable from the C12s to burn them in and they are a touch dark. I found another online review (outside the head-fi fam) who claimed to prefer lots of treble and thought his set were dark, too, so I don't think I'm crazy. I'll try the silver plated cable tomorrow as opinions and burn in have only just begun.

Any and all bass issues my C12 had on fast metal are gone OOTB. The double magnet thing seems to work, but from what I've read online about other tech I think that KZ are probably a step behind the beryllium and carbon nanotube DDs that are collecting fans among the other chifi marques. Quantitatively there is more bass (> 60hz) to my ears over the C12. I'm holding any qualitative thoughts about bass until they burn in as the C12 are quite potent here with a touch of EQ. For synthwave, trip-hop, and most jazz I've tried to date the C12 is just pitch perfect.

Subbass is too early to tell. It's not disappointing by any means, but the C12's exercised 7mm is holding its own here relative to ZAX's 10mm with no burn-in. I'm not hearing that big of a difference in electronic or synthwave music for the moment below 60hz.

I was dying to know how these fared for classical and orchestral pieces. Initial observation is that contrabass and cello strings are audibly and markedly improved right out of the box. Violin and horns are about equal in tone and timbre wise to my ears relative to the C12. I think the mid-bass and mids-to-bass transitions are better tuned over the C12. Plus, we've got 4 more drivers to play with, so no surprise here. The more problematic (busy) orchestra pieces that were tripping up the C12 get a passing grade. Still not as detailed and layered as they could be, but its passable when things get busy.

The big difference in classical works is from the enhanced soundstage, which I would deem "very good" at any price. There is definitely a much wider soundstage than the C12 can muster and this is the biggest and happiest improvement. I'd put ZAX easily on par with the bumper crop of $100-$250 studio closed-back headphones for soundstage and positioning, which is how my ears are trained after decades of use, starting with Sony V6. Open backs are a different story, obviously. When I want crazy soundstage I reach for my Grados.

Treble in jazz is close to being a wash to my ears. With the C12s, players like Miles Davis, Charlie Parker, and Stan Getz in his pre-samba days are freaking lit. Using the same EQ presets with the ZAX reveals more width and maybe juuuuuuuuust barely a touch more of what reviewers call sparkle (12 kHz and up). I still think the C12 is a very good choice for jazz with that set being a bit more analytical, and the ZAX being a touch more musical and maybe less revealing. A paradox, I know.

My only slight disappointment is that when I ordered them I thought that the ZAX might be a bit more open given the shell design. These provide about half the isolation of the C12 which is one of the reasons I ordered them over the CKX (another big one was reports of the increased treble, which is good for me). I need to be able to hear what's going on in the house and my office. Pausing the music is enough to have a quick conversation without removing the IEM, so that's Mission Accomplished for my personal requirements. They do leak a bit at high moderate to loud volumes. but this isn't an issue for me. In a busy office I would choose these over a more isolated pair if you have to regularly deal with interruptions.

Fit and finish: I managed to find a cyan resin shell with black faceplate and find these to be a great looking set with a premium feel that belies their asking price. The shell shape is about 95% the same as my C12, and the driver positioning internally looks very similar to the C12, too. Fit is very similar with the ZAX being overall smaller and smoother from its curved faceplate.

Based on what I've heard today I really like these but will not be ditching the C12 anytime soon. I A/B tested them by putting one each on the brown cable and mixing FLAC tracks into mono with combined L+R. The ZAX is more efficient yielding 5-10dB more volume than the C12, so I had to compensate in the balance. Moving left to right during different passages on my reference tracks didn't yield as big of a difference as I thought there would be, but switching between full sets the bump in SQ is more apparent. Maybe the moondrop aria or starfield is as good for some folks' ears as these, but I don't see them keeping up with the ZAX in resolution or soundstage. I'll never know and that's fine with me.

I will report back in a couple of weeks to see if anything's changed opinion wise. I think I'm going to target one of the EST hybrids from Mangird or Tri in a couple of months in a higher price tier rather than go down the ASX/AST rabbit hole. I canceled the CSNs; I sadly don't have enough time to devote to comparisons for comparison's sake. I will stay tuned for KZ and CCA's next releases and maybe jump on a blind purchase for one of their future ears. cheers
 
Jul 3, 2021 at 8:52 PM Post #55,939 of 63,672
Ok ... so I received the ZAX in the mail today. After an afternoon of listening my initial impression is that these are stupid good for 45 euros :smile::smile::smile::smile: I can see why people are in love with the similar CKX that has a touch darker treble. I will be ordering the CKX because I think both sets are destined to be classics, and I think my wife would love them as well, especially with her smaller ears. I can't believe it's taken me so long to catch up to last year, but here I am.

I was happy to see a full compliment of starlines in ZAX box, and the pretty silver plated cable with clear plastic touches is a nice improvement over KZs famous brown jobber. Along with the starline tips I'm using the copper cable from the C12s to burn them in and they are a touch dark. I found another online review (outside the head-fi fam) who claimed to prefer lots of treble and thought his set were dark, too, so I don't think I'm crazy. I'll try the silver plated cable tomorrow as opinions and burn in have only just begun.

Any and all bass issues my C12 had on fast metal are gone OOTB. The double magnet thing seems to work, but from what I've read online about other tech I think that KZ are probably a step behind the beryllium and carbon nanotube DDs that are collecting fans among the other chifi marques. Quantitatively there is more bass (> 60hz) to my ears over the C12. I'm holding any qualitative thoughts about bass until they burn in as the C12 are quite potent here with a touch of EQ. For synthwave, trip-hop, and most jazz I've tried to date the C12 is just pitch perfect.

Subbass is too early to tell. It's not disappointing by any means, but the C12's exercised 7mm is holding its own here relative to ZAX's 10mm with no burn-in. I'm not hearing that big of a difference in electronic or synthwave music for the moment below 60hz.

I was dying to know how these fared for classical and orchestral pieces. Initial observation is that contrabass and cello strings are audibly and markedly improved right out of the box. Violin and horns are about equal in tone and timbre wise to my ears relative to the C12. I think the mid-bass and mids-to-bass transitions are better tuned over the C12. Plus, we've got 4 more drivers to play with, so no surprise here. The more problematic (busy) orchestra pieces that were tripping up the C12 get a passing grade. Still not as detailed and layered as they could be, but its passable when things get busy.

The big difference in classical works is from the enhanced soundstage, which I would deem "very good" at any price. There is definitely a much wider soundstage than the C12 can muster and this is the biggest and happiest improvement. I'd put ZAX easily on par with the bumper crop of $100-$250 studio closed-back headphones for soundstage and positioning, which is how my ears are trained after decades of use, starting with Sony V6. Open backs are a different story, obviously. When I want crazy soundstage I reach for my Grados.

Treble in jazz is close to being a wash to my ears. With the C12s, players like Miles Davis, Charlie Parker, and Stan Getz in his pre-samba days are freaking lit. Using the same EQ presets with the ZAX reveals more width and maybe juuuuuuuuust barely a touch more of what reviewers call sparkle (12 kHz and up). I still think the C12 is a very good choice for jazz with that set being a bit more analytical, and the ZAX being a touch more musical and maybe less revealing. A paradox, I know.

My only slight disappointment is that when I ordered them I thought that the ZAX might be a bit more open given the shell design. These provide about half the isolation of the C12 which is one of the reasons I ordered them over the CKX (another big one was reports of the increased treble, which is good for me). I need to be able to hear what's going on in the house and my office. Pausing the music is enough to have a quick conversation without removing the IEM, so that's Mission Accomplished for my personal requirements. They do leak a bit at high moderate to loud volumes. but this isn't an issue for me. In a busy office I would choose these over a more isolated pair if you have to regularly deal with interruptions.

Fit and finish: I managed to find a cyan resin shell with black faceplate and find these to be a great looking set with a premium feel that belies their asking price. The shell shape is about 95% the same as my C12, and the driver positioning internally looks very similar to the C12, too. Fit is very similar with the ZAX being overall smaller and smoother from its curved faceplate.

Based on what I've heard today I really like these but will not be ditching the C12 anytime soon. I A/B tested them by putting one each on the brown cable and mixing FLAC tracks into mono with combined L+R. The ZAX is more efficient yielding 5-10dB more volume than the C12, so I had to compensate in the balance. Moving left to right during different passages on my reference tracks didn't yield as big of a difference as I thought there would be, but switching between full sets the bump in SQ is more apparent. Maybe the moondrop aria or starfield is as good for some folks' ears as these, but I don't see them keeping up with the ZAX in resolution or soundstage. I'll never know and that's fine with me.

I will report back in a couple of weeks to see if anything's changed opinion wise. I think I'm going to target one of the EST hybrids from Mangird or Tri in a couple of months in a higher price tier rather than go down the ASX/AST rabbit hole. I canceled the CSNs; I sadly don't have enough time to devote to comparisons for comparison's sake. I will stay tuned for KZ and CCA's next releases and maybe jump on a blind purchase for one of their future ears. cheers
Welcome to KZ club👍 I heard KZ had EST project which is suspended. It will be interesting one if KZ could develop EST drivers with Shenzhen OEMs.
 
Jul 3, 2021 at 9:03 PM Post #55,940 of 63,672
Welcome to KZ club👍 I heard KZ had EST project which is suspended. It will be interesting one if KZ could develop EST drivers with Shenzhen OEMs.
I would be very interested to see KZ or their daughter/sister company CCA take on tuning an EST hybrid or tribrid IEM. Hopefully they'll try to target a sub-$300 pricepoint for it. I'd love to see them hit $250, but it may not be possible, as I know the Sonion EST drivers are notoriously expensive because they're quite delicate and challenging to manufacture. Electret drivers are also notoriously difficult to tune the fundamental harmonic resonances down in, so KZ would have a rather extreme challenge on their hands. Given their FR graphs as of late, maybe they should toss the project to CCA and let their engineers sink their teeth into it before bringing their designs back to KZ proper.
 
Jul 3, 2021 at 9:31 PM Post #55,941 of 63,672
I would be very interested to see KZ or their daughter/sister company CCA take on tuning an EST hybrid or tribrid IEM. Hopefully they'll try to target a sub-$300 pricepoint for it. I'd love to see them hit $250, but it may not be possible, as I know the Sonion EST drivers are notoriously expensive because they're quite delicate and challenging to manufacture. Electret drivers are also notoriously difficult to tune the fundamental harmonic resonances down in, so KZ would have a rather extreme challenge on their hands. Given their FR graphs as of late, maybe they should toss the project to CCA and let their engineers sink their teeth into it before bringing their designs back to KZ proper.
KZ used to be able to make thing with a fraction of a price, my hope is 30% of $5-600. 150-200🙌
 
Jul 3, 2021 at 10:32 PM Post #55,942 of 63,672
I have both, technicalities wise it’s an upgrade. Tuning wise they sound day and night. AS12 is KZ V-shape house sound, AST is dark warm signature. If you like bright and impactful, you may need to reconsider AST, it may disappoint you.

Imagine AS12 is sparrow’s chirps and AST is night owl’s hooting.

Basically that describes the characteristics.

Great information, thanks. I read your discussion about AST being sensitive to source impedance. Do they still sound "dark" with optimal source (i.e. close to zero impedance)? Also, how much of a technicalities upgrade it is?
 
Jul 3, 2021 at 11:34 PM Post #55,943 of 63,672
KZ used to be able to make thing with a fraction of a price, my hope is 30% of $5-600. 150-200🙌
If they're using a dual-chamber electret like Sonion makes, or their newer model with two of the dual-chamber electret drivers run from the same transformer pack, then I doubt they'd be able to keep to that price point. If they used single electret driver like Shuoer did in the tape or BGVP did in the Zero, then maybe they'd be able to meet that price point without the crazy tuning issues that both of those units are plagued with in their attempts to keep driver count at a minimum. Poor crossover choices and oddly tuned DD selection leads to scooped out mids and peaky treble. Electret or "electrostatic" drivers should be relegate only to mid and upper treble, due to their extremely light membranes often lacking impactfulness in the lower treble where a BA driver would be better suited. I'd love to see them actually do something like that. A compact set like the CKX with a DD, a trio of BA drivers for the mid-bass to mids transition, a full-range crossed over for mids, and a low to mid-treble driver topped off with a single electret properly tuned to handle just the mid to upper treble extension. That would be an absolutely glorious product at a $250 price point or below. We've seen that the guys at CCA can tune well with the CKX, so I'd love to see them make a "pro" version with some EST treble extension. Maybe ditch the 30095 from the nozzle and replace it with an electret mounted elsewhere. If they were to consider going that far, I'd like to see them go ahead and use a 3D printed insert to add sound tubes and driver mounting points. Sound tubes really are important.
 
Jul 4, 2021 at 12:17 AM Post #55,944 of 63,672
Ok ... so I received the ZAX in the mail today. After an afternoon of listening my initial impression is that these are stupid good for 45 euros :smile::smile::smile::smile: I can see why people are in love with the similar CKX that has a touch darker treble. I will be ordering the CKX because I think both sets are destined to be classics, and I think my wife would love them as well, especially with her smaller ears. I can't believe it's taken me so long to catch up to last year, but here I am.

I was happy to see a full compliment of starlines in ZAX box, and the pretty silver plated cable with clear plastic touches is a nice improvement over KZs famous brown jobber. Along with the starline tips I'm using the copper cable from the C12s to burn them in and they are a touch dark. I found another online review (outside the head-fi fam) who claimed to prefer lots of treble and thought his set were dark, too, so I don't think I'm crazy. I'll try the silver plated cable tomorrow as opinions and burn in have only just begun.

Any and all bass issues my C12 had on fast metal are gone OOTB. The double magnet thing seems to work, but from what I've read online about other tech I think that KZ are probably a step behind the beryllium and carbon nanotube DDs that are collecting fans among the other chifi marques. Quantitatively there is more bass (> 60hz) to my ears over the C12. I'm holding any qualitative thoughts about bass until they burn in as the C12 are quite potent here with a touch of EQ. For synthwave, trip-hop, and most jazz I've tried to date the C12 is just pitch perfect.

Subbass is too early to tell. It's not disappointing by any means, but the C12's exercised 7mm is holding its own here relative to ZAX's 10mm with no burn-in. I'm not hearing that big of a difference in electronic or synthwave music for the moment below 60hz.

I was dying to know how these fared for classical and orchestral pieces. Initial observation is that contrabass and cello strings are audibly and markedly improved right out of the box. Violin and horns are about equal in tone and timbre wise to my ears relative to the C12. I think the mid-bass and mids-to-bass transitions are better tuned over the C12. Plus, we've got 4 more drivers to play with, so no surprise here. The more problematic (busy) orchestra pieces that were tripping up the C12 get a passing grade. Still not as detailed and layered as they could be, but its passable when things get busy.

The big difference in classical works is from the enhanced soundstage, which I would deem "very good" at any price. There is definitely a much wider soundstage than the C12 can muster and this is the biggest and happiest improvement. I'd put ZAX easily on par with the bumper crop of $100-$250 studio closed-back headphones for soundstage and positioning, which is how my ears are trained after decades of use, starting with Sony V6. Open backs are a different story, obviously. When I want crazy soundstage I reach for my Grados.

Treble in jazz is close to being a wash to my ears. With the C12s, players like Miles Davis, Charlie Parker, and Stan Getz in his pre-samba days are freaking lit. Using the same EQ presets with the ZAX reveals more width and maybe juuuuuuuuust barely a touch more of what reviewers call sparkle (12 kHz and up). I still think the C12 is a very good choice for jazz with that set being a bit more analytical, and the ZAX being a touch more musical and maybe less revealing. A paradox, I know.

My only slight disappointment is that when I ordered them I thought that the ZAX might be a bit more open given the shell design. These provide about half the isolation of the C12 which is one of the reasons I ordered them over the CKX (another big one was reports of the increased treble, which is good for me). I need to be able to hear what's going on in the house and my office. Pausing the music is enough to have a quick conversation without removing the IEM, so that's Mission Accomplished for my personal requirements. They do leak a bit at high moderate to loud volumes. but this isn't an issue for me. In a busy office I would choose these over a more isolated pair if you have to regularly deal with interruptions.

Fit and finish: I managed to find a cyan resin shell with black faceplate and find these to be a great looking set with a premium feel that belies their asking price. The shell shape is about 95% the same as my C12, and the driver positioning internally looks very similar to the C12, too. Fit is very similar with the ZAX being overall smaller and smoother from its curved faceplate.

Based on what I've heard today I really like these but will not be ditching the C12 anytime soon. I A/B tested them by putting one each on the brown cable and mixing FLAC tracks into mono with combined L+R. The ZAX is more efficient yielding 5-10dB more volume than the C12, so I had to compensate in the balance. Moving left to right during different passages on my reference tracks didn't yield as big of a difference as I thought there would be, but switching between full sets the bump in SQ is more apparent. Maybe the moondrop aria or starfield is as good for some folks' ears as these, but I don't see them keeping up with the ZAX in resolution or soundstage. I'll never know and that's fine with me.

I will report back in a couple of weeks to see if anything's changed opinion wise. I think I'm going to target one of the EST hybrids from Mangird or Tri in a couple of months in a higher price tier rather than go down the ASX/AST rabbit hole. I canceled the CSNs; I sadly don't have enough time to devote to comparisons for comparison's sake. I will stay tuned for KZ and CCA's next releases and maybe jump on a blind purchase for one of their future ears. cheers
I was very pleasantly surprised by my CCA CKX. I did have to EQ out a tiny bit of the peaks from the treble since I'm sensitive to it, and I added a bit more gain from 14-20kHz, since they drop off quite dramatically there, and they just sound so good for their pricepoint. They're also just so small for having so many drivers crammed into them that it just doesn't seem possible. I definitely rec them for people just getting into IEMs without any definite preferences for sound signature because they aren't too extreme in any way, but have a fairly comfortable club/house tuning.
 
Jul 4, 2021 at 5:20 AM Post #55,945 of 63,672
Interesting thoughts above here ^ re: driver tech. One thing I'd read about the new KZ ZAS was that the 50024 units are using composite. I've not found any more details more than that, but it seems like they are doubling down on BA technology and aren't finished with it. KZ have bucked the other driver trends which leads me to believe that they've made significant investments in BA fabrication and are reluctant to follow the ChiFi herd. Developing proprietary tech helps a firm stay competitively differentiated and to leverage existing assets. We may not see them hop into EST territory.

With a new tuning and a new premium shell design, the ZAS is a clear iteration on the ZAX. The ZAX also has 50024s in basically the same configuration, including the 30019 treble unit but there's no mention about the ZAX BA units being composite or iron. I haven't looked on AST/ASX driver particulars, but maybe one or both of that platform was serving as an invisible mule for newer tech that wasn't advertised. We will just have to keep on the lookout for early scoops!
 
Jul 4, 2021 at 6:21 AM Post #55,946 of 63,672
Interesting thoughts above here ^ re: driver tech. One thing I'd read about the new KZ ZAS was that the 50024 units are using composite. I've not found any more details more than that, but it seems like they are doubling down on BA technology and aren't finished with it. KZ have bucked the other driver trends which leads me to believe that they've made significant investments in BA fabrication and are reluctant to follow the ChiFi herd. Developing proprietary tech helps a firm stay competitively differentiated and to leverage existing assets. We may not see them hop into EST territory.

With a new tuning and a new premium shell design, the ZAS is a clear iteration on the ZAX. The ZAX also has 50024s in basically the same configuration, including the 30019 treble unit but there's no mention about the ZAX BA units being composite or iron. I haven't looked on AST/ASX driver particulars, but maybe one or both of that platform was serving as an invisible mule for newer tech that wasn't advertised. We will just have to keep on the lookout for early scoops!
Some dude claimed he already got ZAS and he said its closer to CSN than ZAX.
Which i guess the Xun Driver could cause that, but it seems the new BAs is not performing well in ZAS. well the black BAs is not performing that great in ASX and AST either.
Forgot which page the first impression post was on.
 
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Jul 4, 2021 at 8:47 AM Post #55,947 of 63,672
The recent release of moondrop tuning is diverting from Harman IMO. Harman has 2.5khz pinna gain peak vs Moondrop started to target 3khz as new peak after RSV>Dusk>Aria>Sparks>Variations. Also the bass shelf is diverting from Harman as well, they slimmed out 150hz volume to make it more sub-bass focused.
That seems to be more ideal to my ears based on the iems i like.
 
Jul 4, 2021 at 9:01 AM Post #55,948 of 63,672
Interesting thoughts above here ^ re: driver tech. One thing I'd read about the new KZ ZAS was that the 50024 units are using composite. I've not found any more details more than that, but it seems like they are doubling down on BA technology and aren't finished with it. KZ have bucked the other driver trends which leads me to believe that they've made significant investments in BA fabrication and are reluctant to follow the ChiFi herd. Developing proprietary tech helps a firm stay competitively differentiated and to leverage existing assets. We may not see them hop into EST territory.

With a new tuning and a new premium shell design, the ZAS is a clear iteration on the ZAX. The ZAX also has 50024s in basically the same configuration, including the 30019 treble unit but there's no mention about the ZAX BA units being composite or iron. I haven't looked on AST/ASX driver particulars, but maybe one or both of that platform was serving as an invisible mule for newer tech that wasn't advertised. We will just have to keep on the lookout for early scoops!
For most budget chifi the DDs usually play a very large role and the BAs are mostly for fine tuning. The ZAS sounds like the CSN especially at the treble end and nothing like the ZAX..
 
Jul 4, 2021 at 9:49 AM Post #55,949 of 63,672
For most budget chifi the DDs usually play a very large role and the BAs are mostly for fine tuning. The ZAS sounds like the CSN especially at the treble end and nothing like the ZAX..

To be fair, a lot of the high end stuff isn't so different. Campfire Audio tout their 10mm "ADLC" driver. The Dorado 2020 is a vee shaped $1000 pair and only has a single BA. Their yellow entry level IEM at $250 also has a single 10mm DD.

That's an interesting observation about the KZ trio. Isn't the ZAX also the same Xun driver as CSN and ZAS? It's described as 10mm double magnet driver. Was it tuned up a bit before getting marketed as the Xun?

cheers

edit: small correction - $1099 per pair. Based on the reviews, it seems campfire went the distance to tune these for wide appeal to rock and 80s pop. I just can't imagine a $1040 improvement to sound for pop music over our beloved KZ sets.
 
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Jul 4, 2021 at 10:54 AM Post #55,950 of 63,672
Does Linsoul own KZ..? Some guy on youtube told me they do, matter-of-factly. I can't find any such "proof" of this.
 

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