The KZ ZSN are okay mixed usage wired in-ears that have a great design, but their audio reproduction is a bit disappointing. They look similar to the KZ AS10 and KZ ZS10, but they have a slightly more high-end feel thanks to a metal-finish backplate. However, they have a decent isolation performance but won’t be ideal for commuting. On the upside, like the other KZ headphones, the ZSN are very well-built and come with a nice braided, detachable cable that makes the headphones even more durable. The model we tested didn’t have in-line controls or a microphone, but KZ does offer a variant with both.
The KZ ZSN are very similar to the KZ ZS10 and KZ AS10, but their design is slightly smaller and they have a metal-finish backplate that gives a nice feel to the headphones. They are decently comfortable, but the in-ear fit might not be for everyone. The detachable braided cable is a nice addition and makes them more durable, but no extra cable comes in the box, which is slightly disappointing. On the upside, they are sturdy and feel like premium headphones.
The KZ ZSN are very stylish in-ears that would make you think their price range is higher than it actually is. They are fairly similar to the KZ AS10 and the KZ ZS10 due to their transparent casing that lets you see the electronic parts of the headphones. On top of that, this model has a metal-finish backplate, which gives it an even more high-end feel. Their braided cable is also a nice addition to their premium feeling. The buds are slightly bulkier than most in-ears, but are angled to give you a nice fit. They do protrude quite a bit out of your ears, too. If you prefer a full-transparent design without any solid backplates, take a look at the similarly performing KZ ZST.
The KZ ZSN are decently comfortable in-ear headphones. The earbuds are angled to suit the contour of your ear for a better fit. They are a bit bulky, which may not fit every listener, especially people with smaller ears, but they are thinner than the similar KZ ZS10 and KZ AS10, so some may find them a bit more comfortable. On the upside, they also come with different tip options to help you find a better fit and air-tight seal.
These headphones do not have an in-line remote with controls. However, there is a model variant with a one-button control scheme on the in-line remote.
The KZ ZSN headphones are very portable and will easily fit inside most pockets or in a bag. Their ear-hook design and the bulkier buds take slightly more space than most in-ears, but you shouldn’t have any problem carrying them around. However, they don’t come with a pouch or a case to protect them.
Like most KZ headphones, the ZSN are very well-built. These headphones are solid and even have a metallic-finish backplate, which the KZ AS10 and KZ ZS10 don’t have. The buds are dense and should survive a few accidental falls without too much damage. The cable is also detachable and replaceable, which makes them even more durable. You can also buy a Bluetooth adapter cable for these headphones to make them wireless.
The KZ ZSN are stable, and you should be able to jog with these without any problem thanks to the ear-hook design of the cable. They don’t move around in your ear and should be fine for most light sports. However, the cable might get stuck on something, yanking the headphones out of your ears or hurting you because of the ear-hook design.
The KZ ZSN are okay sounding closed-back in-ear headphones. They have a deep, powerful, and consistent bass and a well-balanced mid-range, but their treble performance is very uneven. It lacks detail and is overly sharp on some S and T sounds. Also, their bass is slightly boomy and muddy while their mid-range is a bit recessed and will, therefore, sound slightly hollow on vocals and lead instruments. Overall, these headphones will be better suited for bass-heavy genres, and the similar KZ ZS10 and KZ AS10 will be more neutral-sounding options.
The bass of the KZ ZSN is great. LFE (low-frequency extension) is at 13Hz, which is excellent. Low-bass is within 1dB of our neutral target, meaning these headphones produce just the right amount of thump and rumble, which is common to bass-heavy music and sound effects. Mid-bass, responsible for the body of bass guitars and the punch of kick drums, is fairly flat and within a dB of our curve. High-bass, responsible for warmth, is overemphasized by more than 3dB, making the bass of these headphones a bit boomy and muddy.
The mid-range is very good. The overall response is quite even and decently balanced. However, the broad 4dB recess centered around 800Hz pushes vocals and lead instruments towards the back of the mix by giving more emphasis to the bass and treble frequencies.
The treble performance of the KZ ZSN is sub-par. The response throughout the range is very uneven. There is a very deep 10dB dip centered around 6kHz, which will have a negative impact on some S and T sounds’ brightness and detail. On the other hand, the high peak around 10kHz results in these S and T sounds being overly sharp and piercing, especially on already bright tracks.
The frequency response consistency of the KZ ZSN is very good. If the user is able to achieve a proper fit and an air-tight seal using the assortment of tips that come with the headphones, then they should be able to get consistent bass delivery every time they use the headphones. However, there is a 5dB maximum deviation in the treble range under 10kHz.
The imaging is great. Their weighted group delay is at 0.17, which is excellent. The group delay graph also shows that the entire response is well below our audibility threshold. This ensures a tight bass and a transparent treble reproduction. Also, the L/R drivers of our test unit were very well-matched in frequency, amplitude, and phase response. This is important for accurate placement and localization of objects, such as footsteps and instruments, in the stereo field. However, these results are only valid for our unit and yours may perform differently.
The soundstage is poor. This is because creating an out-of-head and speaker-like soundstage is largely dependent on activating the resonances of the pinna (outer ear). The design of in-ears and earbuds is in such a way that fully bypasses the pinna and doesn't interact with it. Also, because these headphones have a closed-back enclosure, their soundstage won't be perceived to be as open as that of open-back earbuds like the Apple AirPods 2 2019, Google Pixel Buds, or the Bose SoundSport Free.
The harmonic distortion of the KZ ZSZ is okay. THD in the bass range is within very good limits, but it gets noticeably elevated in the mid and treble ranges. The sharp peaks shown on the graph could result in these frequencies sounding harsh and impure, which may become fatiguing after a while. On the upside, there is no big jump in THD at 100dB SPL, which could be due to the drivers’ flexibility under heavier loads or be caused by the noise floor of our test.
The KZ ZSN only block noise passively and won’t do much against the deep rumble of plane and bus engines. However, they’ll be decent against work environment noises. They fit differently than the KZ AS10 and KZ ZS10 and since their bud design is smaller, it seems to be less isolating. On the upside, the in-ear design doesn’t leak too much at higher volumes, so you should be able to block more ambient noise by raising your listening volume without bothering people surrounding you.
The isolation performance of the KZ ZSN is okay. In the bass range, where the rumble of airplane and bus engines sits, they achieved about 2dB of isolation, which is inadequate and won’t be great for public transit. In the mid-range, important for blocking out speech, they reduce outside noise by more than 14dB, which is good. In the treble range, occupied by sharp S and T sounds and A/C noise, they isolate by 31dB, which is quite good. The KZ ZS10 and KZ AS10 and have a better isolation performance overall.
The leakage performance of the ZSN is great. These in-ears do not leak in the bass and mid ranges, and their leakage is concentrated in a narrow range in the treble range. Therefore, their leakage will be thin and sharp-sounding. The overall level of the leakage is quiet too. With the music at 100dB SPL, the leakage at 1 foot away averages at 35dB SPL and peaks at 64dB SPL, which is over the noise floor of an average office.
The KZ ZSN headphones we tested didn't have an in-line microphone, but there is a variant with one. For wired headphones with a good in-line microphone, check out the Bose SoundTrue Ultra In-Ear, the 1More Triple Driver In-Ear, or the Apple EarPods.
The KZ ZSN headphones are passive headphones which means they do not have any active features and do not have a battery. You also can't customize their sound since there is no dedicated app or software support.
The KZ ZSN are wired headphones that can only be used passively. You’ll get audio support on any platform that has an appropriate 1/8” jack, but your range will be limited by their cable’s length. On the upside, their wired connection results in minimal latency when watching video content and for gaming, which is good. You can also buy a Bluetooth adapter cable for these headphones to make them wireless.
The KZ ZSN are okay mixed usage wired in-ears that set themselves apart by their great build quality, like the KZ ZS10 and KZ AS10. They offer good value, but some may feel like they are overly sharp and don’t passively isolate noise as well as other KZ headphones we've reviewed so far. See our recommendations for the best noise cancelling earbuds, the best wired headphones, and the best cheap earbuds.
The KZ ZSN and KZ ZST are very similar headphones with slight differences. The ZSN feel a bit more high-end thanks to the metal-like backplate on their earbuds. Some may find them overly sharp, but both headphones have very similar sound profiles. That said, the treble of the ZSN is more uneven. Other than that, they are practically identical and your choice will rely on which headphones you think look the best.
The KZ AS10 are slightly better headphones than the similar KZ ZSN. Their sound profile is more accurate, especially in the treble range. The AS10 have a different fit that isolate more ambient noise and will be a better option for commuting. Their fit also creates a more air-tight seal, which means they’ll leak less and will be better suited to listen to music at the office without disturbing colleagues. On the other hand, the ZSN have a more high-end look thanks to the metal-finish backplate on the earbuds, but that’s about it.
The KZ ZSN are better mixed usage and critical listening in-ears than the Apple EarPods. They are noticeably better built which more premium materials and a nice braided, detachable cable. The ZSN have poor treble, while the EarPods have poor bass performance. However, most people will find the EarPods to be slightly more comfortable due to their one-size-fits-all design. They also have a microphone, which is useful for calls.
The KZ ZSN are better critical listening in-ear headphones, but the Betron YSM1000 are going to be a bit more versatile for everyday casual use. The ZSN have a better audio reproduction and are noticeably better-built thanks to their detachable cable. On the other hand, the Betron have a microphone and their fit provides better isolation against ambient noise, which should be better for commuting.
The KZ ZSN are better headphones than the Symphonized NRG 3.0. They have a more comfortable fit, are better-built, and have a noticeably better sound quality. On the other hand, the NRG 3.0 have more lightweight and their in-ear fit has better isolation performance. They also have a microphone that our model of the KZ ZSN doesn’t have, but there is a model variant with one. Overall, the KZ ZSN should be a better choice for music, but the NRG 3.0 could be a better option for everyday casual use.