:
Has the KZ sound true to form, and even more vivid version of that sound due to tuning and driver ability
Nice large stage, filled with lots of finite details and fun
Extra warm lower midrange girth and stature with 2 switches on
Great BA timbre almost being totally correct
Medium low weight at 8 grams each
AS24 PRO warmer in stock setting than original AS24
:
Slightly big, as you would expect with 12 drivers
Bass is still not everything like a DD bass, but some of the best BA bass to come out of the house of KZ
Little to no extra packaging case candy
Knowledge Zenith AS24 Pro Universal IEM
Redcarmoose Land October 26th, 2024
The AS24 to AS24 Pro:When I reviewed the original AS24 back in July of 2023 the original AS24 came with or without switches. I was surprised to find out I was the only one (around here) who ordered it without switches lol. The switchless model I was told kept the user from accessing a slightly warmer tone. So when I asked for the AS24 PRO model, I asked for switches. While yes, the switches really do something. I kinda found a home with only the AS24 Pro #1 and #2 switches turned on. But play around with all the switches, where as it comes (with all off) the 12 BA FLAGSHIP AS24 Pro has a deeper and less midrange centered playback as my old AS24. And later when I get into the side-by-sides I will compare the AS24 AND AS24 Pro directly. The point is though that both signatures work here, while of course the AS24 has less bass than the AS24 Pro I think always. In fact, trying both the AS24 and AS24 Pro models with the AS24 Pro model set to (all off) stock, I seemed to still note a hair more bass?
If you read my old AS24 review I talk about the model doing well for Classical while still being on the verge of being too analytical and low on bass for contemporary genres like Rock or Metal and HipHop. I mean sure it depends on what you are personally into which is the best way to go, though just remember the AS24 Pro is always going to lean on the side of more bass, especially with switch #1 and #2 up.
KZ talks about the extra high frequency reduction at 2 different levels with switch 3 and finally switch 4. With all 4 switches up I found the playback to hold extra vibrancy and while fun, I found (myself) a slightly more natural tone with just #1 and #2 switches up. The thing is every switch position is subtle enough to find a way to workout in the end. And really every switch position worked and was listable.
Build:
When you hold the AS24 and AS24 Pro next to each other they appear very much the same, same BAs in the same order, all except for the AS24Pro switches. The original switchless AS24 was clear and silver, and the older switched AS24 was brown and dark grey, same as the new AS24 Pro. I even question the metal looking ring around both of these models as when you place your teeth on real aluminum it is a different feel from the faceplate where I’m thinking even the chrome rings are plastic. The rest of the construction is 3D printed resin. And while the AS24 Pro weighs in at the same 8 grams as the AS24…..there is really no other differences except the switches, even the nozzle screens are identical. And while on the slightly larger size, I would call this almost medium large as there are larger IEMs to be found in IEM land. The qdc style 2Pins just mean the cables will stick-out farther if rolling cables. Looks like a single vent as shown in the pictures, to where an IEM like the KZ ZS10 Pro X actually looks like it has 5 small vents, of course a DD added needs to breath more.
Cable:
Package:
Comparisons:
Top row:
AS16 Pro and AS24
Bottom row:
KZ ZS10 Pro X and AS24 Pro
All comparisons done with the Sony WM1A with MrWalkman’s software, medium bore silicone ear-tips and the SIMGOT AUDIO LC7 modular cable in 4.4mm mode. As such this slightly lower midrange cable is slightly toned-down in the upper frequencies, that seems to complement every IEM used today. That said other cables could be a choice to enhance the upper midrange and treble, but here today all was well, as the WM1A is already very mid-forward just the way MrWalkman has tuned it to be. To summarize this cable, the LC7 doesn't really color the sound, except for adding lower midrange girth, and it does not excite the treble or upper midrange either. This personality, which was formulated possibly to go with the SIMGOT line of IEMs, does well also with full BA sets. All comparisons were done with the AS24 Pro with the #1 and #2 switch in the on position.
The KZ AS24 Pro attached with LC7 cable, with the ear-tips used for this review!
AS16 Pro:
While offering a slightly stripped-down rendition of what the AS24 Pro is doing……stuff is only slightly not as warm or as filled in with information. I hold a warm place in my heart for what the AS16 Pro is doing, as for me it was the first of this new wave of KZ creations I was to encounter in August of 2022. Coming in a choice of 2 colors the 8BA arrangement gave this reviewer a taste of what new KZ BA creations were to come. Those ideas came from a big stage doing the party tricks that 8 BAs can do at one time. I mean it is the space between instruments now that I look back on………holding a value here for folks willing to take a chance on KZ…….at only $56.00 then and now. But then something happened, something wonderful. I switched to more AS24 Pro vocal centric music and somehow everything came together finally truly hearing the basic differences between the AS16 Pro and the AS24 Pro. To where in reality the AS24 Pro was coming into its own. Bigger displays of stage, finer realization of instrumentation……..more harmonics. I was now hearing those extra 4 BAs. I was hearing KZ’s furthering of experience at build and it was something truly good! Some may say, well sure this is a given, but with the 2 switches on and the stage presence……..somehow it all came together here for this reviewer. Smoother yet also more refined and polished outcome. It was like I was doing this review, and I have spent a lot of time with this particular IEM, but all of a sudden someone flicked a switch into how the perception of sound was………and it was good! And…….yes, if you have only the AS16 Pro take a confident chance on finding both the KZ sound on this new AS24 Pro and an additional add of technicalities and a better tone…….a not so thin of tone, a warmer and more inviting tone, as a slight departure from the stark yet clear idea KZ were up and running with in 2022 with the AS16 pro! Yet looking back I realize that KZ had a sound, the AS16 Pro was the KZ sound then, and the KZ engineers have successfully added maturity to that sound, filled it in and filled it outward into the stage, they made something that is both more accessible and real sounding with the AS24 Pro.
KZ ZS10 Pro X:
Now this comparison was done as the very last item placed into this review. Why? First off this has been a favorite among KZs in my collection. But more than that I typically as a listener like Hybrids better, they just sound more real to me. Don’t get me wrong, a few all BA sets I own are all BA drivers and I still use them and at times use them for a whole day at a time, I’m not against all BA sets. It is just if I was to pick a favorite method to make IEMs it would still be Hybrids, even after all these years of saying that. The KZ ZS10 Pro X is a ridiculous price of $39.00! Lol $39.00…..now maybe you see why over 41,000 have clicked on my review……..It is a value if there ever was one in IEM land. But the second reason I saved this part to do last is because I wanted to make sure that I had a few days with the AS24 Pro before hearing the ZS10 Pro X again. I wanted to make sure I truly knew the AS24 Pro well and spent some time in-bed with it. Plus this on paper should be a difficult battle because KZ are moving forward and adding that needed bass to their all BA IEMs. This is the kind of thing that if you never knew you needed it, you may not, but once you get a taste of the full-on bass, there is an emotional time to try and go back.
The KZ ZS10 Pro X:
The first thing you notice is the 5 axis pure aluminum faceplate, we get plastic with all the rest today! The second thing you notice is the full-on bass. The timbre is super great, maybe even better than the AS24 Pro? Why? Partially covered-up maybe? This bass stuff with DD bass is real, as real as it gets. But sadly after spending all this time with the AS24 Pro I now start to hear the slight drawbacks encountered with only 4BAs and 1DD in the KZ ZS10 Pro X. Is there any way they can merge these two units into one? While the AS24 Pro does have more micro detail, the stage is even bigger in AS24 Pro land……there is a wider section though between instruments where sure that detail is left out with the ZS10 Pro X. But still it is apples to oranges. Sure the ZS10 Pro X is a little less in stage, but that stage is actually clearer and while maybe that original KZ sound is there, it is also overshadowed by lovable bass. What can I say I love my bass, deep analog textured DD bass. In many ways owning both solves some problems as if you ever get tired of the AS24 Pro you simply move to the ZS10 Pro X and you are still sedated by sound, it’s not the come down you may guess. I mean you’re probably expecting me to say the bass replay of the ZS10 Pro X is blurry or not detailed? No way, I’m not going to go there, I am going to proclaim the bass is actually faster and more fun than I can remember. What does this mean to the review? One, maybe this reviewer likes his bass, and is just being honest, able to dismiss all the extra detail you get from 12 BAs a side, and with the AS24 Pro you can seem to hear all 12. And because you can hear the price they are asking is worth it for the AS24 Pro, it is just again I wish they could join these two IEMs into one unit. Because if they could add the DD bass and the BA detail.......then you would really have something in your hands!
KZ ZS10 Pro X
1 10mm DD combined with 4 BAs a side
Two 50024s treble BA sound-makers
Two 30019s midrange BA producers
Music:
Here I’m taking various examples of music playback and finding just how the AS24 Pro acts. Of course the #1 and #2 switches are turned-on. I’m using the WM1A with MrWalkman’s firmware, the LC7 cable and medium silicone nozzle ear-tips.
Theatre of Tragedy
Assembly (Remastered)
Episode
44.1kHz - 24bit
This here is a song mixed with excessive treble vibrancy. In fact I was not sure what to expect as a song like this can come-off in many different ways depending on the IEM character. The money here is simply how all aspects of the set-up worked-out in the end. Why? Number one the DAP is more mid-centric than treble-centric. Number two the cable is not bright, but leans on the slightly toned-down version of treble. The ear-tips are not wide-bore, and finally the 2 extra warmth bass switches were activated to the AS24 Pro. In the end I was surprised and ended up doing this part of the review ahead of time, in front of other parts of the review only because of how good and unexpected the outcome was! This single tone of playback was indicative of just how careful the treble results formed into being. Just what I like, and just my cup of tea, just how this plays out to become. Where we all know there is a fine line between treble details and treble heat. Where sure playback is centered around the boost in upper frequencies here, yet that boost, that chance the producers took paid-off and was just tolerable, yet totally fun to experience. Sure we will try some more common mixes later but this way of life here showcases what extra attributes provided with the extra treble BAs. How this all goes down is in separation of visibility into the stage of just how the instruments were outlined and filled in. Beyond that how the instruments were created and formed with actual texture. Still as electronic pop that this genre contains we are left with a slight diminishment of bass tones, maybe less than you would guess. The added lower midrange of the LC7 cable helps out, but there is no way to deny this is rumble light, and faster and cleaner due to such personalities. Is this demeanor just because the AS24 Pro is an all BA IEM…….yes probably. But because of this lesser low-end balance we get forward treble and forward mids. Even from 00:00 the distorted guitar gets crispy fuzzy embellishments holding that guitar texture that is in reality not normal, but works here, because the whole song was meant to be balanced this way, only they are that much more forward and visible due to this IEM tuning and lack of DD bass. This is both unique and also on the careful side of correct. Is this the KZ tone, I would have to say yes it is. While because of all the drivers there is also a low end showcasing diminished reverberations, the kind that only exist in BA land. Yet the fast transients allow for noticeability in the attack. Where the bass is fully heard, just not felt nor rumbling.
Though it is the crunchy guitar that holds this tune's overall character, like turned to 11. Inside of that we can pick-out the cymbal strikes gaining air and fall-off……inside their own BA zone. At 00:13 we hear male vocals not behind nor forward. Yet what is enchanting in the synth arraignments gaining ground farther out to the stage than guessed they would be. Liv Kristine Espenæs makes the song for me when she makes her entrance at 00:54. The thing is her vocals are not forward nor recessed, fully heard and enough to be appreciated, but not forward as some vocal centric playback found in the IEM world.
There is a lot of action here, a lot of effects which the producers use to make this song standout among other styles of music at the time. And the AS24 Pro goes along with this creativity allowing the small extra stage embellishments; like male vocal effects stand out itemized. Plus the guitar is warm when you get down to it! They use a drum machine which has faint cymbals (brushes) at 01:18 and we hear them in their place fully known for the synthetic creation they hold, they are all too mechanical to be made by human hands.
Note timestamps only pertain to the digital file, not the video.
Hans Zimmer
Wonder Woman 1984 (sketches)
No Hero Is Born From Lies
44.1kHz - 24bit
So anyone who knows BAs and who knows Classical would be able to guess that this would be the KZ AS24 Pro in its element. And it sure is. The fast change-ups encountered here, the imaging of little Christmas toys into the stage, quick attacks and decays making room for even more attacks and decays.
KZ AS24 Pro
12 BA High-end Tunable In-Ear Monitor
- 4x31736 high-frequency/ultra-high-frequency BA array
- 2x29689 mid-frequency BA
- 1x 22955 low-frequency BA
- 1x 30019 high-frequency BA
- Four-stage toggle switch filter tuning
- High-precision sound channel structure
- DLP 3D PrintingTechnology
These little extra details are held inside of the stage, becoming endearing and welcome, to where sure I have heard this song more complete, even more bass with (more money) all BA IEMs, yet this idea of a playback, this KZ sound is on offer, and this is a lot of detail plus a lot of sound for the money. Anyone who knows, knows violins were made for this character of playback. Strings in general play along with all BA set-ups to make them sound like more money than they really are. In many ways my take on the AS24 Pro is a lot like my ideas about the original AS24, only here we are invited to partake of a warmer sound, a more filled-out sound and a more human sound, if that makes any sense? At 00:29 there is a nice extra embellishment of the bass, which in emphasis is a stark additive than what has occurred before and fast as the sound is, the AS24 Pro responds and responds with the money to showcase the magic found here. It is these extra bass frequencies that make the feeling of AS24 Pro complete and fun.
At 00:45 the main theme is introduced once more, to become slightly more vivid in nature, and due to the resolution, we feel that. At 00:50 we just heard 5 seconds of hanging chimes that were fully discernible. In fact any metallic sound is of their nature to reproduce right with BAs. At 01:01 there are flighty high pitched violins that ask for the brisk separation and subtle differences inside the stage to reveal. In fact even though those violins are not too forward, their additive is exciting. Again simply doing what BAs do best and not looking back. At 01:07 the horns take notice, and while they have existed in the song before, now they are showcased for inspection. At 02:34 there is the second installation of small taps……….nothing more than small percussion adds, that are in separation into the stage, but at the same time very small and not that loud, the KZ AS24 Pro lets those sounds be known and appreciated!
Finally at 02:36 the main theme takes hold and not asking for participation but demanding it! It is times like this that is make-it or break-it time, where it is either gain glory or go home, and guess which one we have on offer? Probably the fact that I can listen all day to this style of playback, and there are still details to be found, that is where the magic lies.
All BA sound is unique in that it offers a few very special ideas.
Plus:
1) Speedy attacks and transients
2) Focused pin-points of detail
3) BAs are small and fit in small areas
4) As a rule BAs don’t need to be always vented, but they are at times
5) Super quick decays (can be good or bad)
6) A special BA detail quality to the bass that DDs can't match
7) Detailed and accurate sound
8) Clarity boost over DDs
9) Typically use 1/2 the power of DDs
Minus:
1) Often promote BA timbre
2) Can be prone to distortion at times
3) Super quick decays (can be good or bad)
4) Can sound unnatural and steely
5) DDs displace more air, offering richer bass physicality
Conclusion:
In one sentence I can say there was KZ improvement. Where I’m from you don’t get 12 whole BAs a side for $115.99 (without switches) or tunable for $130.99…….you just don’t. And the thing that would normally make me run the other way would be glaring BA stridence or even off-timbre. Where here there is no DD to kind-of cover the off timbre. And sure at times there is a little……there is no denying that fact. But it’s so small it barely exists at all. In fact the more you listen the more you buy in to maybe this is exactly how the timbre is supposed to be, almost. The big difference here is that KZ has added secret sauce to the mix, and that sauce contains two elements. One, there are finite details which I don’t remember ever hearing before with a KZ model. Two, there is an added note weight and warmth that is subtle, but pulls-off better reverbs and is specifically showcased in the lower midrange. This added lower midrange then takes hold of tones and moves them into position to activate the whole personality……..as there is this added foundation that takes place. This foundation is there still if I switch the 2 switches back to the off position. It’s just how KZ tuned the AS24 Pro, but you can add to it by switching the two #1 and #2 to on. This double whammy of extra stage girth holds physicality so desperately needed with full BA sets. At times that density seems to travel up and even affect the higher notes. Whatever it is it adds realism, and that adds emotional involvement to listening sessions. This enhances the stage, adding distance between instruments and vocals, but more than that those drums hold drama. Any thinness has been replaced with correctness. And while no IEM is perfect, I seem to understand the KZ sound more now than with any other KZ installment? Meaning, sure all the KZs have a sound, a sound that now tells me they are from the same company. Only like a flower blooming that sound, that KZ sound is more vividly itself than ever before. Nope, KZ didn’t change a thing, they are carefully refining and adding detail to what was always their sound, at least what BA models I’ve heard?
Does this mean it is worth a new purchase? If the last KZ purchase you made was the AS16 Pro, then yes, it is a dramatic improvement into realizing the same sound. I have not heard the tunable AS24 model so I can’t say. But people who are way into KZ than I am say this new AS24 Pro is the best version yet, that it holds the best bass in a KZ all BA endeavor. That seems to offer more details than ever before for KZ. And where I can verify those details comes to light in the separation and creation of just another layer into the stage. When those extra subtle layers are added then you go forward.............and add the lower midrange girth……….well it becomes sounding even more correct. Then when you take in the fact that this is still $115.99 to $130.99…….well that is a lot of sound for the money no matter how you choose to look at it.
$115.99 to $130.99 (microphone option $1.00 more)
https://www.linsoul.com/products/kz-as24-pro
Disclaimer:
The KZ AS24 Pro has had full 10 days of continuous burn-in, though I had the IEM for a month.
Disclaimer:
I would like to thank Kaitlyn Wu of Linsoul for the love and KZ AS24 Pro review sample.
Disclaimer:
These are one person's ideas and concepts, your results may vary.
Linsoul website: https://www.linsoul.com/
Linsoul Aliexpress Store: https://ddaudio.aliexpress.com/store/2894006
Linsoul USA Amazon Store link: https://www.amazon.com/s?i=merchant-items&me=A267P2DT104U3C
Equipment Used:
Sony WM1A Walkman DAP MrWalkman Firmware 4.4mm balanced
Sony WM1Z Walkman DAP MrWalkman Firmware 4.4mm balanced
HiBy R3 II DAP 4.4mm balanced
HeartField R1 Ladder DAC/Dongle
Bonus Dongle:
The HeartField R1 Ladder DAC:
R2R DACs
From the 1990s, such resistor ladder DACs can do 16bit, even 18bit……still never (can they do) 24bit or 32bit. So no R2R DSD playback in correct resolution. The word is explained as such……
16-bit word results in 96dB
24-bit word results in 144dB
32-bit word 192dB
PCM DACs with a 16bit word:
The signal word header says what to do. Then the actual word shows the above 16 bit counts using on or off 2-4-6-16-32.
R2R DACs:
On and off 16 switches, each switch has to be joined to a precision resistor. These are precision resistors therefor even better than good resisters that have 1% accuracy.
Why different?
R2R resistors have greater accuracy are put into row of switches and resistors on a board.
R2R resistors have .0001 accuracy resistors, typically obtained and used in R2R DACs. These on and off signals are 44,000 times a second, more current higher voltage, less current lesser voltage thus a signal. Current to voltage converter is then used to make music by up and down voltage. Regular DACs Sigma Delta modulator 1 bit, 2 bit, and 3bit does DSD and is needed for conversion to PCM. Though there are DSD DACs which don’t do the PCM conversion and leave the signal in DSD. Here with R2R we see an analog volume knob, and the R1 does not get super loud, but is more about a smooth quality with a glow.
HeartField R1
R2R PORTABLE DAC & AMP
- R2R Technology
- Meticulous Sound Tuning
- Wide Range of Applications
- Only 19.8g Lightweight Design
The new R1 combined with the AS24 Pro:
Here we are gifted with just what the AS24 Pro was always waiting for. Yep, pure fun. In truth the HeartField R1 is way different sounding than any Dongle I have ever used. With the R1 analog volume control and overall demeanor we are taking a warm bath. As such what makes this experience so very different is the stage has the same images, but they are placed in different locations than the rest of the regular digital Dongle output. Not only different locations but holding warmer and mellow fluid textures than regularly found in Dongle Land. This new style of bass actually sounds like more, meaning it makes up for any loss of bass physicality to a point, adding what we always dreamed for the KZ AS24 Pro! There are many different analog volume settings for each and every TypeC device output. Meaning get the R1 your phone and depending which model the volume knob may be at 5 out of 10. But get the R1 the powerful 3.1 TypeC output from a mini-DAP like the HiBy R3 II and note all the volume loudness needed at even level 2 out of 10. A smoother set of trebles and midrange AS24 personality. More like sheets of sound than finite digital details. To where there becomes endearing imaging personalities about how somehow the stage just seems larger with what the R1 does, but more than that there is distance between music elements which seems to de-clutter the AS24 Pro sound. It is this warm inviting KZ AS24 PRO personality that extends listening times, gaining audio ground by showing you that a sound like old 1960s and 1970s audio gear can still be found in 2024 from a new style of Dongle/IEM combo! Cheers! 
