Reviewed by NoBordersAudiophile
:
-impressive technical performance
-smoothly yet crisply balanced warm U shape
-fast transient response that don’t go splashy
-well define and vibrant bass line
-clear non thin nor recessed mid range
-forwards non shouty vocal with wide enough centered presence
-good note weight (for piano, less so for acoustic kick drum)
-good resolution generous in micro details
-above average imaging for the price
-surprisingly good construction
-great sound value
:
–euphonic mellow mid bass punch (lack texture, definition, clear separation)
-lack clean air around instrument
-macro dynamic isn’t best articulated (greatly improve with short wide bore eartips)
-timbre has rare planar plasticky euphonic sheen (nitpick)
-attack lead is lacking bite and snap
-infamous KZ cable is detrimental to PRX sound
-need alot of amping to scale up
-need proper short wide bore eartips to not sound congested
TONALITY: 8/10
TECHNICALITIES: 8.5/10
TIMBRE: 7.5/10
SOUNDSTAGE: 8/10
IMAGING: 8.5/10
MUSICALITY (subjective): 7.8/10
CONSTRUCTION: 8.5/10
ACCESSORIES: 6/10
SOUND VALUE: 9.5/10
Intro
KZ is a well known ultra budget IEM maker from China. They have released more IEMs than their stars in the sky, and while in technical performance it’s often impressive, it’s less the case in tonal balance which at least they greatly improve with the time (harman target influence).
Today I will review their latest budget planar, the PRX.
Priced 50$ but easily findable for 30$, the PRX uses KZ patented 13.2mm silver plated planar driver using 14 n52 double sided magnet.
Let's see in this review if unlike PR1pro and PR2 the PRX will impress my ears both in musicality, tonal balance and technical performance.
CONSTRUCTIONS&ACCESSORIES
The PRX is well built, the shell is made of thick hard plastic with metal backplates that act like a semi-open back grill too. The QDC connector is an expected KZ burden, but it’s still possible to use any cable with these. Nozzles are angled and short, not long enough for deep fit. Comfort is OK, but not the most ergonomic in shape.
Cable included is vain, it’s the expected cheap silver plated cable that nobody wants to use. It’s sticky, fragile, and doesn't wake up the macro dynamic of IEMs properly. I would prefer to have the option of NO CABLE option since all these KZ cables begin to invade my place and I don't know what to do with it.
Boxing is minimalist, ecological footprint is minuscule here so it’s a plus…but there is no case for those caring about this. Only eartips included are nice, it’s KZ Starline, but it’s not very appropriate for the short nozzle PRX.
SOUND IMPRESSIONS
The tonality of PRX lean toward U shape to neutral with sub bass boost and notch of warmth, it’s no bass head but deliver fast slam plenty of rumble extension and vibrancy, clear and focused mids and fast highs with good micro details but not most sharpen even if quite crisp for a planar driver.
The bass offers warm mellow yet thick and weighty mid bass punch that isn’t very textured while sub bass is more tactile and clean, with few resonance releases. Attack transient is very fast and favors sustain over well defined attack lead which is lacking, this means kick drum isn’t abrasive in presence and bass line lacks a bit of bite.
The sub bass impact is wide and vibrant in slam, very impressive in how deep it can reach with proper ear tips. Due to fast transients, it can be well layered with digital punch or acoustic kick even if the underline presence of those are darkened.
Whatever volume you listen too, bass will not distort (unless their lack of power from amping source).
Even if mellow in punch, mid bass isn’t fully scooped here, it’s just that sub bass dominate it’s dynamic which feed wide slam than shorter kick drum hitting, it’s speedy but not super tight since their sustain euphony that make sustain-release slightly mushy-juicy, toms will not release long natural decay as it should.
Overall bass is the guilty pleasure part of PRX, which works better with slower beat heavy music than speedy one. This isn’t basshead level IEM but hefty slam and dense deep rumble do add energy and engagement to macro dynamic rendering. I’ve heard the worst bass performance from planar, it’s not as boomy, resonant, dry and thin as 7HZ Dioko or even my beloved Artti T10. This is thick, warmly thumpy and widely rumbly low end pleasure with impressive elasticity in infra bass for a planar (kinda feel like DD bass in fact).
The mid range is forwards in presence but not thin, it’s slightly warmed by bass impact and can go brighter when their no bass, but it will still stay well rounded in upper mids, unlike a lot of KZ, these aren’t prompt to sibilance, it’s not shouty for vocal and upper harmonic instrument release. Tones even if slightly dried by planar driver flavor are quite natural sounding, wide in presence and versatile in timbre for diverse instruments from piano to male and female vocal to violin to saxophone. The lower harmonic warmth feed well lower range female vocal which gain in breath vibrancy and density, i was surprise to enjoy vocal with a KZ IEM but it’s the case here, mid range is quite focused and not recessed, apart soprano vocalist nothing sound really thin, it’s slightly euphonic yet within an holographic open spatiality with impressive layering transient that permit listener to fully enjoy richness of whole mid range instrumentation.
This isn’t sharp or crisp mids even if never veiled by bass due to energetic presence push that is softened in spiky or noisy edges. For a planar, it’s near lush mid range, and even in a busy track the main instrument will be focused and clear, with its own presence layer, darken in definition.
The treble is sparkly on top but softens in attack bite and lead in lower and mid highs. Transient is super speedy and have short sustain with very long release, cymbals crash release is very textured and decay near infinite, which can stole air of other instrument and be a bit distracting, sharper percussions don’t go very snappy, they are fast and crunchy enough, well layered too, but attack lead is scooped. This is evident too with acoustic guitar which is more textured and sparkly than dynamic in attack, so string pulling is darken while shinny release is boosted, adding sense of definition and separation but not feeling completely right in term of transient fullness, still, this brilliance is very enjoyable and attack spike being smoothen it make it less fatiguing for long time listening.
I’ve tested Pr1pro and PR2 in the past and dislike them cause very treble in upper treble boost which is softer here but still extract a lot of micro details and sometime unwanted background noise artefact like resonance micro details and hissing of bad recording, something unbearable with other PR IEM but damped enough with PRX to not dominate the balance and just add extra openness yet with ‘’noisy air’’ around instruments.
So the highs are fast and exciting in release without going splashy, micro dynamic is great but darken with some euphony.
The Soundstage is wide and deep, but not very tall. You need proper eartips to open it up well, stock KZ Starline compress spatiality and this time make it tall and deep but not wide nor as well articulated in macro dynamic and layering, which is less holographic.
The imaging is above average for the price, layering is multi staged so you can dig in multiple spatial planes and stereophonic rendering is open enough so percussions or higher harmonic sound go left and right precisely. Space between instruments isn’t cleanest nor definition of presence sharpest, this makes positioning darker even if quite accurate.
Ok, out of critical listening impressions i want to let loose my enthusiasm about those, which is not always evident in cold hearted sound description. The KZ PRX is a crazy bargain for the price, especially at sale 30$ price, it’s among cheapest planar IEM on this planet and it’s not badly tuned, it’s very cohesive and smooth in balance with open holographic rendering. To get this level of technical performance is insane too, the macro dynamic is multi layered and these can deal with busy track effortlessly even if rendering is on the warmish side, transient isn’t sharpest but super speedy so vocal and mids instrument have their own presence energy and dynamism, percussions follow their pace, as if we were listening to an organically cohesive multi-BA IEM (ironically way superior to the one offered by KZ himself).
To disclaim everything, I did receive Rhapsody and AM16 with PRX and just have a crush on the latter, 2 others feel quite artificial and non cohesive in drivers balance while it’s the opposite for PRX. Very important thing to note (apart cable and eartips change) is that these are Very power hungry, among harder single planar IEM to drive i own, to wake up its dynamism and bass and upper treble it needs min of 200mW but 500mW and above is even better.
COMPARISONS
VS ARTTI T10 (1 planar-50-70$)
The T10 is more W shaped, bassier and brighter.
Bass is more boomy and slam has more resonance, punch isn’t as thick but more textured, sub bass is thinner but longer in decay, wider in slam, more spacious in layering too. Overall bass of PRX is leaner and juicier, with denser rumble, warmer tone that is more beneficial for cello timbre and tends to color mids more naturally.
Mids are more open, notably sharper and more energetic, upper mids are harsher-shoutier, less buttery and smoothen, their more air around instruments, definition feel clearer and cleaner, instrument attack has more bite and impact energy.
Treble is more crunchy with sharper transient, attack has more bite, presence of instrument is better define, percussions has more air around it, less euphony but their less sparkle and brilliance too, it’s more articulated in micro dynamic but for acoustic guitar it has more bite than brilliance release unlike PRX.
Soundstage is notably taller and deeper, while slightly wider with PRX.
Imaging is superior with T10, this is due to sharper instrument definition, cleaner separation and more articulated and vivid micro dynamics.
All in all, PRX feel more mid centric, smoother in balance, warmer and lusher in timbre, vocal are less shouty and more enjoyable, in fact PRX feel like the T10pro with more alive macro dynamic so in term of balance it’s superior to T10, while for technical performance it’s more subdued, not has good in soundstage-imaging-transient speed and macro-micro dynamic rendering.
VS LETSHUOER S08 (1 planar-100$)
The S08 are in fact quite similar in V to U shape lush balance but it’s a notch warmer, notably darker and a bit punchy, more mid centric and less boosted in sub bass than PRX.
Bass is thicker and more euphonic, warmer, heavier in punch and more shortened and compressed in sub bass. Bass lines are less clean and extended, both sub and mid bass kick is less well layered, less transparent too, bass is overall more boosted and dominant, adding more warmth and stealing more air around the instrument than cleaner sounding, more U shape PRX.
Mids are more intimate, thicker and lusher, not as wide and transparent, macro dynamic is more mush, stage is less open but vocals are less lean too, more focused and ultimately fuller and more natural in presence. Instrument attack is less snappy, clarity is inferior too.
Treble is notably darker and more rolled off on top, it’s less crisp and brilliant, less sharp in attack, percussions can get lost in the mix while it never happens with PRX.
Soundstage is wider and deeper with PRX, taller with S08.
Imaging is superior with PRX due to cleaner center stage and better layering, as well as more defined instrument presence in more spacious stages.
All in all, surprisingly the PRX is superior in technical performance from transient control to imaging-clarity-soundstage, but it’s less mid centric and warm even if as smooth, it’s not as thick sounding too but bass quality is superior, dig deeper. I'll say S08 is more musical while PRX is more technical. Fact PRX is 2 to 3 times cheaper than 100$ S08 tells alot about the intense sound benefit of the PRX.
CONCLUSION
The KZ PRX are exceptional IEM in terms of sound value and the tuning is smoothly balanced, way more so than other offerings in their PR planar series.
While it seem every new KZ IEM go aboard for some undeserved or bots feeded hype train, the PRX feel underrated since this ultra budget planar set a new milestone in term of technical meet musical sound value, i mean, check on ALI, you can find those for as low as 30$....in my country, it’s the price of 2 trio big mac and for once KZ offer an healthy tuning that don’t pierce they ears with upper mids violence or upper treble spike.
Simply put, the KZ PRX are a blessing for the audio enthusiast seeking to taste planar driver performance goodness at extremely affordable price, the fact it's both musical and technical is another plus and will already put the bar high for their next planar upgrade, findable in above 100$ price range with the like of Hidizs MP145 which seem logical upgrade of PRX.
The PRX make me conclude KZ excell with single driver setup, should it be dynamic or planar. The fact these don't have 5 tuning switch messing up with natural dynamism of sound is another plus too. If you seek for a warmish and bassy yet clear and holographic sounding IEM with speedy attack and effortless sound layering, the PRX is the cheapest and more likely greatest sub-100$ planar IEM to get.
35% off: https://keephifi.com/discount/prx-BLOG?redirect=%2Fproducts%2Fkz-prx
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PS: I want to thanks KZ for sending me PRX after I tell them i was curious about it. It make 2 years I haven't even touch a KZ IEM, while i don't think i will touch any multi-BA or hybrid, now i'm all curiosity about any single driver IEM they launch. This review earn me zero $, and was quite time consuming so it cost me $ in fact.
