Pros: Nice color palette, cool cable, solid construction, decent
Cons: Large housings, lacking in resolution in the midrange
KZ ZST Review: A Victory For Audiophiles On a Budget
KZ is a Chinese IEM company that specializes in making budget grade earphones, and is well known for their high-value offerings. While they have made pretty big waves in the Chi-Fi crowd, they remain relatively unknown to the broader Hi-Fi community. That’s a real shame considering they have some very compelling products, including the ZST Colorful that I am reviewing today.
You can find the KZ ZST on at Penon Audio, here, for $20.
Disclaimer: This review is based upon a sample unit provided to me by a manufacturer or distributor in exchange for my honest opinion and un-edited words. I do not profit in any way from the writing of the review. I would like to thank Penon Audio and KZ for sending me this review unit.
Preference and Bias: Before reading a review, it is worth mentioning that there is no way for a reviewer to objectively pass judgment on the enjoy-ability of a product: such a thing is inherently subjective. Therefore, I find it necessary for you to read and understand what I take a natural liking to and how that might affect my rating of a product.
My ideal sound signature would be an extended sub-bass with a leveled, but textured, mid-bass. The mids should be slightly less pronounced than the treble, but still ahead of the bass. I prefer a more bright upper range.
Source: The ZST was powered like so:
Nexus 6P -> earphones
Hidizs AP100 3.5mm out -> FiiO A5 3.5mm out -> earphones
HiFiMAN MegaMini -> earphones
PC optical out -> HiFiMe SPDIF 9018 Sabre DAC 3.5mm out -> earphones
All music was served as MP3 @320Kbps or as FLAC.
The ZST scales decently well with higher-end sources. It didn’t take too much amping to achieve high volumes.
The ZST has a warm-leaning sound signature, but doesn’t swing too far away from a balanced presentation. Bass presence is slightly boosted, as are vocals. Treble is present, but well balanced with the mids.
The high-hats of In One Ear were quite clear, and presented well. I expect nothing less from a hybrid IEM from KZ. Upper-treble decay is fast and precise, with no noticeable truncation.
The electronic synths in Midnight City were placed in the middle-back of the song, but never became inaudible. I’m impressed given how well the tonality of the synth was preserved despite its background positioning.
Outlands sounded reasonably open, with decent spacing and air. However, I found that violins were only of average clarity, something I still find to be quite a feat to my spoiled ears for a paltry $20. While I could certainly hear the foreground violins quite well, the background ones did not fair as well. They tended to fade in and out of audibility.
The mids of Flagpole Sitta were well defined and separated, but lacked some of the finer details present in some (much more expensive) IEMs. Guitar tonality was decent. Electric guitars lacked their usual intense power, but were still clear in the mix.
Jacked Up’s pianos had a softer edge to them, indicating a slower attack and decay in the mids. The guitar feedback sounded decently lifelike, but I found that separation was a little worse in this song. The ZST does tend to show its limits when presented with lots of mid-bound instruments, and more so when some of them live in the background.
Male and female vocals are presented equally well and naturally weighted. I really enjoy how they interact with my music, and really enjoy their presence overall.
Bass is present, with a slight boost. This really helps it express itself in rock and acoustic songs, such as Moth. The bass guitar, while more subtle in presentation, was still audible and dynamic.
The bass in Gold Dust had good impact and tonality to it. While it should certainly satisfy the average listener, I found my inner-basshead looking for more rumble. However, a quick boost to the 30Hz-100Hz range sorted that problem out quite nicely.
Sub-bass expression and dynamacism was quite good, with the ZST pushing pretty far down into lower frequencies. This made In For The Kill quite enjoyable, despite the ZST not being tuned for bassheads like myself.
Packaging / Unboxing
The ZST is packaged sparsely, but that’s not really a problem given the very low price these things sell for.
The ZST’s driver housings are made from two pieces of hard plastic. Its name is certainly not an overstatement, as the IEM oozes colors. The housings are quite large, similar in size to some of my 2x dynamic driver 2x balanced armature driver IEMs (despite having half the number of drivers). The housings are light, and feature a 2-pin detachable cable system. “ZST” is emblazoned on the back panel of the IEM tastefully, and looks like it won’t rub off any time soon. On the side of the IEM you can see “ZST HIFI-Armature” written.
The cable has a short 45-degree angle 2-pin connector on it which fits well into the housings of the ZST. The cable itself looks to be covered in a smoke-colored transparent plastic, underneath which are several colorful twisted wires (four to be precise).
The cable terminates in a rubber-coated 3.5mm jack and sports rubberized Y-splitters as well. While there is a version of the ZST that has a universal inline remote, I have the version that does not have it.
As I mentioned earlier, the housings of the ZST are large. So despite their ergonomic shape, they do pose a challenge to people like me who have smaller ears. I could wear them for about two hours without any issues, any longer and I could start to feel them pushing against my ears.
The ZST is complimented by a rather sparse offering of accessories. However, for $20, I feel that it does suffice. Inside the box you will find:
- 1x 2-pin cable
- 2x extra sets of silicone eartips
While a carrying pouch of some sort would certainly be appreciated, I can understand why it was omitted.
The ZST, while not a perfect IEM, is very, very good for the price. I could find no glaring flaws for it overall, and would wholeheartedly recommend it to someone looking for a cheap, slightly bass-boosted IEM on the cheap.
This review was originally featured on Resonance Reviews. Find us here.