KZ ZSR Review: Balancing Your Budget

May 12, 2018 · 7 min read

KZ is a budget IEM brand based in China. Their aggressively valued products are often viewed as a staple of the Chi-Fi market, and as such, are fairly well known. While I’ve had my disagreements with choices they’ve made stylistically in the past, they seem to have differentiated themselves enough from their competitors for me to set aside my qualms. So, without further ado, here’s my thoughts on the ZSR!

You can find the ZSR for sale here, on AliExpress, for about $30! There’s a multitude of color options, as well as the option to add on a microphone. My version does not come with one.

About My Preferences: Heads up, I’m a person! As such, these words are my opinion, and they are tinged by my personal preferences. While I try to mitigate this as much as possible during my review process, I’d be lying if I said my biases are completely erased. So for you, my readers, keep this in mind:

  • My ideal sound signature would be an extended sub-bass with a leveled, but textured, mid-bass.
  • I have a mild treble sensitivity.

Source: The ZSR was powered like so:

HTC U11 -> USB-C adapter -> earphones


Hidizs AP100 3.5mm out -> FiiO A5 3.5mm out -> earphones


HiFiMAN SuperMini -> earphones


PC optical out -> HiFiMe SPDIF 9018 Sabre DAC 3.5mm out -> earphones

All music was served as MP3 @320Kbps or as FLAC.

Tech Specs

  • Sensitivity: 107dB
  • Resistance: 22Ω
  • Connectors: 3.5mm, 2-pin (0.78mm)

Sound Signature

Sonic Overview:

The ZSR is a V-shaped IEM. It makes use of both an elevated mid-bass and treble, though the treble is notably more prominent. The midrange is recessed but doesn’t take on a soft tonality that is often a result of such a tuning. Sub-bass is about 2dB less prominent than the mid-bass.

Treble: Songs used: In One Ear, Midnight City, Outlands, Satisfy, Little One

Treble is boosted by a considerable degree. This is an artifact of both the deliberate decisions made by KZ when they tuned the ZSR and a natural result of using the two BA drivers that they chose. Thankfully this boosting doesn’t do too much damage to cohesion. There are no blatant disconnects in the sound, nor are there particularly offensive peaks.

The ZSR’s treble retrieval in the treble is pretty substantial, especially for an IEM of this price point. It easily beats out my previous “under $40” staples in this regard. Furthermore, it does so without causing too much distortion or blurring in any particular set of frequencies.

Treble tonality is good, relative to its peers at this price. High-hats and cymbals sound distinct at all but the busiest parts of a song. Extension is very impressive as well, as there isn’t a noticeable degree of treble roll-off.

Sibilance is only a minor concern with the ZSR. The vast majority of my songs were easy to listen to, even at higher volumes. Satisfy didn’t fair too well though. The ZSR errs on the side of faithfulness to the recording, so take that in what way you will.

Midrange: Songs used: Flagpole Sitta, Jacked Up, I Am The Highway, Dreams, Too Close, Little Black Submarines, Do You Really Like Being Alone

The midrange arguably the strongest point of the ZSR. While it is recessed, it remains so while maintaining sonic integrity to a degree I can’t say I’ve heard many other IEMs reach at this price.

Instrumentals are a blast to listen to. The weighting of acoustic guitars is as satisfying as the crunch that accompanies electric ones. Strings and drums sound equally as good. Following from these traits is a very cohesive and pleasing tonal profile for acoustic instruments in the midrange.

Vocal intelligibility is above average, even when compared to more expensive IEMs. A small spike in the 1–2KHz range is responsible for that, as well as an accompanying spike from 4–5KHz. The ZSR favors male vocals though, not quite hitting that level of “sweetness” that I prefer in my female vocals.

Bass: Songs used: Moth, Gold Dust, In For The Kill (Skream Remix), War Pigs (Celldweller Remix)

The ZSR’s bass is not meant for “bassheads”. It’s meant for listeners who want a semi-visceral experience from the lower register but still demand sonic integrity from the rest of the sound spectrum. As such, the mid-bass hump is emphasized, but not to the point of being aggressive. The ZSR’s single dynamic driver does a good job balancing bass volume and bass quality, only failing to deliver good low-end performance in the most demanding of songs like In For The Kill.

All things considered, I still had lots of fun listening to my bassy songs through the ZSR, and all my drops were still punchy and weighted well. Just don’t expect your skull to shake once the bass drops.

Packaging / Unboxing


Construction Quality

The ZSR looks like polished black stones. “Left” and “Right” are printed stylishly on the shells denoting which side they should be used on. The finish is good and doesn’t seem like it will come off any time soon.

On the top of the shells, we’re greeted with recessed 2-pin connectors. The recession is clean and the connectors are firm. No complaints here.

The cable is of standard stock. It gets the job done and isn’t in any immediate risk of failure. It is made from twisted red and white inner strands coated with a translucent grey rubberized layer. There is some friction across the surface, but not enough to get caught on the edges of your clothes. Microphonics are about as negligible as one can really ask.

The ZSR’s cable is terminated with a 3.5mm jack, and like the rest of the cable’s components, it is housed in a matte black plastic. The stress relief is adequate.

It also features memory wire ear-hooks which definitely help keep it on my ears while I’m moving around.


As with all earphones, your comfort will vary according to your body’s unique aural anatomy. So while these are my impressions, there is a change that you may come to a different conclusion.

I had no problems wearing the ZSR for any duration. Whether it was during a bike ride for an hour or at work for three, I had no problems with the ZSR, even while using the eartips that came in the box.


Inside the box you’ll find:

  • 2x pairs extra silicone eartips.

The sparse offerings of the ZSR accessory wise would be pretty disappointing if it weren’t for the already-aggressive pricing of the device. The build is better than average for its price point, as is the sound. The corner had to be cut somewhere, and it appears that was with eartip offerings/cases. That’s fine by me though, since a good pair of eartips is quite literally $2, and a makeshift case can be fashioned from basic household materials if you are trying to be that frugal.


1: Brainwavz S0 ($50)

The S0 and the ZSR trade blows. While the ZSR offers much more detail retrieval in the upper-midrange and treble, the S0 counters with a more cohesive sound signature. The S0 is more sturdy, but that comes at an addition $20 in price. Furthermore, the S0 features a larger mid-bass hump than the ZSR and has a warmer midrange which really makes it a separate beast altogether, at least on a sound-signature level.

2: Alpha and Delta D3 (~$35)

The D3 feels like a more extremely tuned version of the ZSR. The ZSR’s midrange is noticeably more expressive, and offers more treble extension. The D3 touts a powerful and dynamic bass response that coexists well with its lower midrange. It also boasts class-leading construction, though it does cost more as a result.


The KZ ZSR, like many of its siblings, offers a very good price-to-performance ratio. It forsakes having a wide variety of often redundant eartips to eek out as much sonic fidelity as it could, and such a bet pays off. While it doesn’t offer the refinement you can get at higher price points, for $30 you’d be hard-pressed to find an IEM that offers a better overall value.

As always, happy listening!

Resonance Reviews

Resonance Reviews is a publication dedicated to bringing fair and rich reviews to the table while skipping the fluff that reviews usually have. We are dedicated to providing you the best in audio hardware reviews. Want to get in contact? Email us:


Written by


Tech enthusiast. Audiophile. PC builder. Reviewer. Writer.

Resonance Reviews

Resonance Reviews is a publication dedicated to bringing fair and rich reviews to the table while skipping the fluff that reviews usually have. We are dedicated to providing you the best in audio hardware reviews. Want to get in contact? Email us:

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