KZ ZSN Pro – Should You Go Pro, Bro?

Pros:
– Improved driver with noticeably wider dynamics
– Wide soundstage
– Easy to drive from any source
– Excellent value

Cons:
– Mid bass bleed
– Male vocals somewhat recessed
– Cable can get tangled without chin slider
– Might be a side-grade depending on your current ownership

For more images, check my accompanying Audio Porn.

INTRODUCTION

Our old friends at Knowledge Zenith (KZ) made waves in late 2018 with the release of the ZSN. The ZSN was a major upgrade from Knowledge Zenith’s (KZ) very first hybrid IEM, the ZST.

But to understand where we are now (the ZSN Pro), we need to look at where we came from (the ZST and ZSN non-Pro).

The ZST was a single hybrid IEM, with 1xDynamic, 1xBalanced Armature per side. It had a medium-sized full acrylic resin shell, with a removable cable. It was a leap ahead of previous Knowledge Zenith (KZ) earphones, but it had serious flaws. The overall tuning was sloppy because there was no crossover. The treble was too sharp and sibilant for many people. So sharp, in fact, that I modified my BA drivers with a piece of acoustic foam (creating the ‘ZST Foam Mod’ on Head-Fi).

Fast forward to 2018, when Knowledge Zenith (KZ) announced a major upgrade to the original ZST (called the ZSN). The ZSN was based on the ZST shell, and maintained a single hybrid design – 1xDynamic, 1xBalanced Armature per side. However that’s pretty much where the similarities ended. Everything was redesigned and upgraded from the original ZST:

• Revised shell, using better quality resin material
• Aluminum IEM nozzle and rear faceplate
• Revised 2-pin jack (now known as the Para C plug)
• Upgraded cable (braided, thicker, no more memory wire)
• Upgraded dynamic drivers (titanium plated)
• The addition of a passive crossover circuit

The ZSN was a major hit, and Knowledge Zenith (KZ) sold loads of them. In my opinion it was one of the best values in ChiFi for 2018. I still enjoy my ZSN to this day, and even handmade carbon fiber back covers for it.

However, nothing is perfect, and ChiFi is always evolving. The biggest complaint some people had was the upper midrange could be harsh/sibilant at times, most noticeable with female vocals. Despite this minor flaw, I didn’t think the ZSN was so bad that it needed emergency attention (quite the contrary in fact). This is why it was a surprise when barely ~6 months later Knowledge Zenith (KZ) released the ZSN Pro.

So what’s different about the Pro version, and is it better than the original ZSN? Let’s dig deeper and find out.

SPECIFICATIONS

Drivers: 1xDynamic (10mm), 1xBalanced Armatures (1×30095) per side
Crossover: Yes
Impedance: 24 ohms
Weight: 29 g
Sensitivity: 112 dB
Frequency: 7-40,000 Hz
Cable: 0.75 mm 2-pin, removable, 3.5 mm 90-degree plug, mic and no-mic versions available
IEM colors: Black, cyan, purple
Price: $14 (at the time of this review)
Purchase link: ZSN Pro at Miss Audio

PACKAGING

The ZSN Pro comes in a small cardboard white box that is standard if you are familiar with Knowledge Zenith (KZ) earphones bought in the last few years. It’s nothing special, but it’s perfectly adequate and serves its purpose. You buy IEMs to listen to, not because they have a great box, right? The inner box has a clear plastic cover that shows off the ZSN Pro shells. And I know it sounds trivial, but I appreciate the small lip cut into the cover for easy removal. The IEM shells are mounted in an EVA foam layer, providing protection during shipping. The accessories (cable, spare eartips, and paperwork) are located underneath.

ACCESSORIES

The included eartips are all silicone type – 1 (pre-installed) pair of smooth silicone tips (black color, single flange, medium bore, M size), and 3 pairs of ‘Starline’ tips (black color, single flange, medium bore, SML sizes). Starline tips are one of my favorite tips, as the black ones are made of soft and flexible silicone, and they fit well enough for all day comfort.

The cable is a removable design, with 4-wires in a braided configuration. The ZSN Pro is available with and without an in-line microphone (mine being the no-microphone version). The microphone version has a single control button, providing music and phone call control (but no volume control). The plugs that attach to the IEMs are clear plastic, with L and R indicators (very difficult to read). The termination uses a 2-pin (0.75mm) design, with a new raised design not seen on any previous Knowledge Zenith (KZ) IEMs. This new 2-pin plug type is officially referred to as ‘Para C’ or ‘Paragraph C’.

In case you aren’t familiar with Knowledge Zenith’s (KZ) 2-pin nomenclature:

• ‘Para’ A is for ZS3, ZS3E, ZS4, ZS5, ZS6, ZS7 (and others)
• ‘Para’ B is for ZSR, ZST, ZS10, ED12, ES4, ES3, CCA C16 (and others)
• ‘Para C’ is for ZSN, ZSN Pro, CCA C10, ZS10 Pro (and others)

The cable itself is a good balance of being not too heavy/thick, but not too light/thin either. It’s brown in color, and has good strain reliefs at the Y-split and 3.5mm end. The 3.5mm end is a 90-degree L style plug. The cable also has pre-formed ear guides, which are secure yet flexible. This is a welcome departure from the annoying bendy memory wire Knowledge Zenith (KZ) has been using for years. Thank you Knowledge Zenith (KZ)!

It is one of the nicer ‘upgrade’ cables I’ve seen on a stock Knowledge Zenith (KZ)/CCA cable, and the pre-formed ear guides alone make the cable worth it. My only gripes with the cable are the lack of a chin slider and how low the Y-split is located, both of which can make the cable prone to tangling. I’d love to see a factory-applied chin slider at some point in the future, but for now you can add one of your own. A small rubber o-ring works well as a makeshift chin slider, which helps prevent tangles considerably.

BUILD

The Knowledge Zenith (KZ) ZSN Pro has an acrylic (polymer resin) shell that comes in 3 transparent colors – black, purple, and cyan. You can see the internals of the ZSN Pro through the shell, although the BA driver is located in the nozzle and can’t be readily seen. The back cover is made of a zinc-aluminum alloy, and has a matte finish (silver or black depending on the shell color selected). The cover has 3 raised zig zag lines, 1 small bass vent, and 1 mounting screw.

The ZSN Pro features a substantial and premium feel. The resin shell is very smooth, and there are no sharp edges. It’s very comfortable to wear, even for extended periods. The overall fit and finish is excellent, with no mismatched seams, gaps, or excess glue.

The shells have no channel indicators, and the only thing written on the side is “ZSN-PRO Classic Upgrade”. While it would have been nice to have channel identifiers on the IEM shells, here’s a handy guide showing the correct orientation of the shells and cable:

1. Hold up the IEM so that the ‘pointy’ part of the shell is facing down.
2. Now look at what direction the nozzle/eartip is pointing towards.
3. If the nozzle/eartip is pointing to the LEFT, then that’s the LEFT IEM shell.
4. If the nozzle/eartip is pointing to the RIGHT, then that’s the RIGHT IEM shell.

The ZSN Pro’s nozzle is 6mm wide, and is what I would consider an average/medium length. This allows either a shallow or deep insertion, depending on the eartip used. There is a retaining lip on the nozzle, allowing the eartip to stay securely on the IEM nozzle with little risk of falling off or staying behind in your ears while removing the earphone.

SOUND

The gear used for testing included: xduoo X3 (with Rockbox firmware), iPhone SE (with both headphone jack and Apple lightning adapter), and FiiO E12A Mont Blanc headphone amplifiers.

The ZSN Pro was easy to drive with any source, and I did not really notice any improvement when using an amplifier. This makes it ideal to use on-the-go with nothing other than your phone. 

Bass

The ZSN Pro uses a new double-magnet (tesla) titanium plated dynamic driver. KZ claims this improves the control as well as the dynamics of the driver. And I agree with this statement. The most obvious improvement with the ZSN Pro over the original ZSN is the sub bass. It both extends deeper and is more powerful than the original ZSN. If you listen to bass-oriented genres you’ll definitely appreciate the change. The low end has a satisfying rumble, which you’ll appreciate if you’re a basshead. There is some bleed into the midrange however.

Midrange

Overall, the ZSN Pro’s midrange is pleasing and warm. The midrange is recessed, and as a result male vocals aren’t as strong as they could be. However, this is no surprise given the ZSN Pro’s v-shaped sound signature. The upper midrange (~3kHz) have been somewhat dialed down and smoothed out compared to the non-Pro ZSN, which I feel was KZ’s attempt to address the complaints of midrange harshness some people had with original ZSN. While I definitely notice the difference this tuning change made, I never really had an issue with the midrange tuning of the original ZSN to begin with.

Treble

Treble on the ZSN Pro is pretty bright overall, with some airiness. Knowledge Zenith (KZ) actually added some additional treble to the ZSN Pro (vs the non-Pro ZSN), which does a nice job to balance the increased low end of the new double-magnet dynamic driver. If you’re extremely treble sensitive, you may have issue with the ZSN Pro. Otherwise, the increased treble adds extra clarity compared to the non-Pro ZSN. There is some minor sibilance, but I found it track dependent as opposed to being inherent in the drivers or tuning.

Isolation

The isolation is above average, which I attribute to the combination of the ZSN Pro’s heavier zinc alloy rear cover and single vent hole (vs 3 vents for the non-Pro ZSN).

Soundstage

The soundstage is average in depth and above average in width, both of which are improvements over the original ZSN. Imaging and instrument separation are both good, especially given the ZSN Pro’s price.

CONCLUSION

The Knowledge Zenith (KZ) ZSN Pro definitely makes some improvements on the original ZSN. However, the improvements are not massive, but rather subtle and incremental. Whether or not you should get it depends on if you already own the original ZSN or not. If you don’t own either, I’d recommend going with the ZSN Pro. It builds upon its predecessor, with an upgraded driver, improved dynamics, more treble clarity, wider soundstage, and better isolation. However, if you already own the original ZSN you may want to consider the ZSN Pro only if you’re one of the people that felt the upper midrange was too harsh, or if you wished the ZSN had a more elevated low end.

You find an INDEX of all our earphone reviews HERE.

DISCLAIMER

I would like to thank our friends at Miss Audio on Aliexpress for providing the Knowledge Zenith (KZ) ZSN Pro for my independent review.

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