KZ ZS12 PRO 2

Let's get started. Firstly, let me thank @KEEPHIFI for providing me this set for review. So when approached about this set, I was a bit excited. Now granted, with the release schedule KZ used to have, it's admittedly a bit hard to get pumped for a specific release, but in this case, I was, because two sets specifically reintroduced me to the KZ landscape. My KZ experience started in 2017 with the KZ ZS5, which was one of my first hybrids ever, as this was the first affordable hybrid on the market (along with the S*F*R* brand, but that can't be mentioned here). Following my disappointment in this set, I did not indulge in KZ until many years later, with the KZ DQ6, which was the first KZ I fell in love with, and this 3DD set was a BANGER, but the QC was less than desirable, as the pin well cracked, and so I got intermittent sound cut outs, so into the cherrywood box it went, and out went any KZ purchases for another couple of years, until I picked up the KZ ZS10 Pro 2 and the KZ ZS12 Pro X at approximately the same time. I was impressed immediately by both. While each exhibited some BA sheen, as well as crispness and air that bordered on crispy, I placed a 300 mesh on both, and away I went! The bass performance and stage of the ZS10 Pro 2 was so impressive, that I had a reaction moment one night listening to Bob Marley - Natty Dread, that nearly brought me to tears, but QC issues reared it head once again. and while tip rolling, the mesh came off on the left shell, and well, I wasn't able to fix it, so into the cherrywood this went. The ZS12 Pro X was the first KZ set to break into my top 12 first rotation box, so the best of the best in my collection, and to this day, one of only two KZ to earn this distinction (KZ AM16 Balanced is the other). While very bright, it had a balanced tuning that was a bit more "refined" than the others, and I considered the Pro X the best hybrid KZ had to offer. It got 1100 switch position, and it stayed in the 1st rota until it lost favor, and slid out, never to return, but overall, still quite the achievement. It's all metal build was also quite impressive, and beautifully elegant. So the opportunity to hear the follow up ZS12 Pro 2 was exciting for me! Would this set improve over the legendary ZS12 Pro X? Would it solve the problems that showed itself on the OG set? The ZS12 Pro 2 landed, so I immediately put them to the test, and put it through the paces, to see how this stacked up to it's predecessor? Here's what I heard, so buckle your seatbelts and prepare for a 100% unbiased impression with heartfelt observations and thoughts. Now on to the FUN stuff!

The unboxing experience is pure KZ. Tiny, white, non-descript box, that inside contains a plastic protective sheet, the IEMs in a plastic protective holder, the standard silver KZ cable, and 3 pairs of KZ Starlines in miniscule, S, and M size, plus a warranty card. That's it. End of unboxing. I never use the KZ stock cable, as it's just...meh. Also, Starlines are useless for me, as they are the tiniest tips ever, so not useable for big ear holes like mine, so I settled for cable rolling to the ISN H20 stock cable, which is a fantastic stock cable, and also a great colorway match for this set, and some JVC Spiral Dot tips. Now, we're set to rock n roll! The shells aren't metal like the previous version, but a metal faceplate with the gold screw, like the ZS12 Pro X, and a resin/plastic shell. Regardless, it's small, it's comfortable to wear, and I got an excellent fit, considering it's packing 6 drivers per side (5BA + 1DD). Now let's move on to what most of you are here for...the sound impressions!! But first, let's look over the published specs and the frequency response graph, then we get down to the nitty gritty.

THE SPECS :

KZ ZS12 Pro 2

TECHNICAL INFORMATION :

Frequency Response Graph courtesy of KeepHiFi & KZ. All rights reserved.

KZ ZS12 Pro 2 : $60.00

Available for purchase at this location.

The Gear :

What did I use for my listening sessions for my review??

For the KZ ZS12 Pro 2, I used a wide swath of sources, which mostly leaned warm, with a couple brighter sources, to test the resolving capacity as well as the crispiness/sharpness factor (Muse M6 Double in solid state mode, FiiO JM21 (untethered), and Hiby R3 II (untethered)), and several tube amps and daps. These include the Shanling M8T (classic tube mode, medium gain, F2 filter), Cayin Ru9 (tethered to FiiO JM21) in classic tube mode, high gain, and F1 filter, iBasso Nunchaku (tethered to Hiby R3 II), Sony NW-ZX100, and FiiO M21.

Music playlist for these impressions?

Ezra Collective - Dance, No One's Watching
Robert Glasper - Canvas
George Duke - A Brazilian Love Affair
Aki Rissanen Aleatoric - Aleatoric
Mareike Wiening - Reveal
Paul Booth - 44
Bob Marley & the Wailers - Survival
Belnejoum - Dark Tales Of Zarathustra
Cryptosis - Celestial Death
And Oceans - The Regeneration Itinerary
Alghol - The Ossuary Key
Cinder - Break Your Silence
Karate - 595
Shuffled Alt Rock, Hard Rock, and Pop Music playlist

SOUND IMPRESSIONS :

Dynamics : 4
Resolution : 4
Crispness : 4.5
Air : 4
Details : 4
Instrument Separation : 4
Imaging : 3.5
Tonality/Timbre : 3.5
Low End Impact : 4
Low End Rumble : 4
Note Resolution Midrange : 4
Note Resolution Bass : 4.5
Bass elasticity/nimbleness : 4
Sibilance Presence : 2.5 (low, weighted at 3)
Soundstage : 4 (dimensional, with equal width and height with solid depth)

Overall score : 4/5

SOUND CHARACTERISTICS :

So what's the KZ ZS12 Pro 2 sound like? Well, let me get the cat out of the bag right off the top, and then explain why I think this is, but in my humble opinion, the ZS12 Pro 2 is the BEST hybrid KZ IEM this company has ever released! It starts with the bass, which was greatly improved form the ZS12 Pro X. One of the knocks on the X, and not just from me, but from many, was the bass was a bit linear, and lacked body and sub bass presence. Well, rest assured, KZ made sure this would not be the case with the Pro 2, as the bass not only delivers satisfyingly rumble, but it also punches deep, so it slaps down to the floor with authority (for a KZ). Couple that with a very note resolute bass, that you hear individual bass notes clean and clear, and the bass is impressive. Now, is it all wine and roses? Nope. The mid bass, though it does have some energy, isn't very punchy or impactful. It's got more speed and elasticity going for it, so with the note resolution, and elasticity, presents a rumbly and nimble bass, that can keep up with bass heavy tracks in hip hop, reggae, and acid jazz. So while listening to Marley, Beenie Man, Brand New Heavies, or Dr Dre or Beastie Boys, the bass was nuanced as well as heavy. Just don't expect the mid bass to slap you in the face with impact or energy, because it's there, but not in any real focus. It provides some warmth in the lower midrange, so that note weight is good, and certainly more weight and warmth that the X, but this still leans more on nimble and transparent than forceful and punchy.

Midrange is transparent, with slight warmth (not a lot though), spaciousness, and incisive. There's a crispness that's pervasive, and front and center with the midrange. It's not that it's forward, as it might be just a smidge recessed, but the incisiveness and crispness really brings those instruments living within that realm into focus. The drawback here is that some sibilance can be detected in voices, and especially in recordings where it's more pronounced or baked in, so be forewarned. Detail retrieval and separation, in turn, pops and shines. There's no veil, smear, or muddiness to be found, though honestly, the midrange isn't very musical as a result, and the notes do suffer from a lack of refinement or smoothness. Space is directed by width and height. So that it's a wide and tall scene, while depth is a bit lacking, or more like not focused as much as the width and height. Vocals has a breathiness to them, but lack a bit of emotiveness and heft. It's micro over macro in terms of vocal presentation, but guitars and keys especially have bite and crispness that really highlights classic rock, metal, and reggae tracks. Acid jazz music, like Ezra Collective, Alfa Mist, Brand New Heavies, or Yussef Kamaal are translucent, bouncy, and immersive, so that you really get drawn into the transitions in the musical passages, both in detail and precision, as the bass keeps the beat, and keeps it engaging. The midrange tuning, along with the bass, keeps it moving. Gets you moving, and you are locked in. This is something not present with the X, and not usually found in any KZ hybrid, so this is why I stated these are the best KZ hybrid in my opinion.

Treble is going to be controversial. It's going to be divisive. No two ways around it. It's very similar in texture, air, and extension with the X, and there were many who said the X's treble was a bit too much for them. Well, if so, this will also fall in the same camp of detriment, as even though it's slightly better textured, slightly smoother, and less strident, there's still that BA sheen that's heard, that's due to KZ's budget BA's. There's really no way around it, and almost every single KZ hybrid set that utilizes BA's, features this sheen. The BA timbre does cause some unnaturalness to be present, but I negated a lot of this problem by using warm sources, and tube sources. For example, in classic tube mode through the Cayin Ru9, the timbre was smoother and more natural, while retaining that shimmer and air that will appease many a treble connoisseur, and delight treble heads. The treble is so clean, so clear, so airy, and crisp, that sometimes it seems the shimmer goes on for days with cymbal strikes, the trumpet bellow, or the ring of bells. It's wonderfully textured, but again. just be warned, that it will be a bit much for sensitives, and without the harmonic warmth of vaacuum tubes or r2r, the tonality might feel a bit off or unnatural. Tubes go a long ways in correcting that issue though.

COMPARISON :

KZ ZAX ($60.00) : So the comparison section features the two KZ sets I previously felt were the best hybrids in the KZ stable, and we start with the ZAX. ZAX is a 7BA + 1DD hybrid that is a favorite of the KZ and IEM community, for it's amazing price to performance and fun signature. Well, the ZS12 Pro 2 is a more balanced, refined (especially on the edges), and airy take, with deep sub bass rumble, and a more polite mid bass energy and presence, that's elastic and resolving, with warm, but transparent midrange. The ZAX is BOLD and unapologetic. It's got intrusive and bold mid bass, where you do get some bleed, and the response in the bass is slower and more heavy handed, with less emphasis on note resolution and more on energy and rumble. The rumble is equal to the mid bass energy, so you get a FULLNESS that's every present. The bass attacks you! The midrange is warm as well, but with much more note weight, but it loses out in elegance and refinement, as it's more artificially colored due to the mid bass, and this affects the resolution and detail retrieval in the midrange, so while vocals are heartier and more emotive, you lose macro and micro detail, as well as vocal intimacy, in exchange for warm, thick and bold, again, in exchange for breathiness and intimacy. Treble is almost a doppelganger in terms of air, extension, crispness, and energy. The difference is that the shimmer and air is a touch more controlled, with an evenness in the ZS12 Pro 2 that's lacking just a touch in the ZAX. It's a more refined approach, with the edges smoothed over a bit, but let's not confuse this for smooth treble, because that does not exist with the ZS12 Pro 2 or the ZAX. As far as soundstage, the ZS12 Pro 2 is once again more refined, more dimensional, and more linear and clean, while the ZAX is fuller, wider, and more BOLD. The ZS12 Pro 2 will give you the deeper, more resolute stage, with more accurate imaging, and the ZAX is more IMAX grandiosity and boom. Advantage : KZ ZS12 Pro 2.

KZ ZS12 Pro X ($55.00) : The predecessor of the ZS12 Pro 2, the X possesses the same 5BA+1DD as the Pro 2. Widely considered the best sounding KZ hybrid, it was the first KZ set to break my top 12, so at one time, I guess I agreed with the consensus? Well, as of 2025, this would no longer be the case. The Pro 2 improved on all the areas of weakness that were exhibited in the X, with even the treble, which are still quite similar, improved in texture and stridency. The X has a thinner, more drier midrange, while hav ing a more linear bass approach, so the rumble is less, the mid bass energy a touch more restrained, and the treble, though equally as airy and shimmery, has more stridency issues and lacks the control of the Pro 2. Soundstage was also improved, as the X suffered from a more intimate staging and less precise imaging. Detail retrieval and separation are pretty much the same, with the X's drier midrange maybe providing the illusion of more transparency and more technicalities, but there's a more refined take through the Pro 2, with greater sense of space, dimensionality, and refinement. The X is still a price to performance beast when it comes to listening to classical music, instrumental jazz, or acoustic music, as it's got enough bass to keep that style of music honest, while having a high level of incisiveness and transparency. Through tubes, it gets even better, so if you are into that kind of music, and you don't feel like you need that much bass presence, and you want a more "technical" approach, plus a gorgeous all metal shell, then the X would satisfy you, and provide strong performance, but if you seek improvements and don't mind a bit of rumble and warmth, while upping the refinement ante, then the ZS12 Pro 2 is the logical response. Advantage : KZ ZS12 Pro 2.

CONCLUSION :

So my excitement in receiving this set was warranted. For someone who loves airy treble, it's check! For someone who loves incisive midrange and technicalities, it's check! For the soundstage lover in me, it's again a check! For the bass lover, who likes to hear note resolution, rumble, and have elastic bass for metal? Check, check, check, check! This set hit the spot. It's without a doubt, in my mind, the best hybrid KZ has ever released, and it's better than the ZS12 Pro X, ZAX, ZS10 Pro 2, ZA12, ZAS, and ZSX. It's the BOSS King, and it's an all-rounder, that is equally at home with reggae, hip hop, acid jazz as it is metal, rock, or classic rock. It's also spacious, and immersive, so it has the ability to draw the listener into the music, and do it with a price to performance that is hard to beat. So if you listen to Snoop Dogg, Cradle of Filth, Zacc Harris, Stanley Cowell, Obituary, or Bounty Killer, the ZS12 Pro 2 won't leave you for wanting (ok, maybe a touch more mid bass punch), and does a great job canvassing a wide range of genres, and it won't break your bank, to get high performance and resolution out of your music. So yes, this is an easy rec, and I look forward to others sharing their experience with the latest, and in my opinion, greatest KZ hybrid release.

RECOMMENDATION LEVEL : BUDGET HYBRID ALL-ROUNDER BOSS LEVEL - VERY HIGH 8/10.

Thank you so much for reading and remember to be water with your audio luv! When you do...AUDITORY ZEN UNLOCKED!