Here as promised, my impressions of the KZ ZSN Pro. It is interesting to compare it with the CCA CA4 which is very similar.
The ZSN Pro is one of the latest models in a new series of IEMs from KZ (Knowledge Zenith) featuring metal faceplates, revised drive units and a new type of connector. The ZSN Pro is an update to the original ZSN and like the earlier model, is a dual-driver hybrid (1DD + 1BA). The dynamic driver is a new 10mm dual magnet design which is claimed to be equivalent to a 14-15mm unit. It is the same as that used in the new KZS10 Pro and the CCA CA4 and has a field strength of 1 Tesla. The balanced armature is the familiar 30095 unit which has been extensively modified.
The packaging is the usual KZ small white box with an outline drawing of the IEMs on the front and some specifications printed on the back. Inside, the earphones are presented in a cut-out with the words “Hybrid Technology Earphone, Classic Upgrade” printed below. Under this cut-out you will find the detachable cable, a set of three Starline-type tips and documentation. A further set of soft silicone tips is pre-fitted on the IEMs.
The ZSN Pro has an alloy faceplate which has three embossed chevrons on its surface and looks futuristic in design. The shape is similar to that of the CCA C10. The body of the earphone is made of a clear acrylic through which the components can be seen. The words “ZSN Pro, Classic Upgrade” appear on the side of the earpieces. My particular example came in a fetching purple colour and looked very attractive.
The detachable cable is of a new design, following that used on the above-mentioned ZSN. It has a clear plastic female connector (known as “Type C”) with the pins being situated on the body of the IEMs. The cable itself is a braided copper-coloured type and has a very long section between the chunky Y-split and the earpieces and as a result is somewhat prone to tangling. The plug is a right-angled plastic 3.5mm type.
The earphones were left burning in for over 50 hours before testing and included tracks of white and pink noise, glide tones and other audio conditioning tracks. After this I used a Hifi Walker H2 DAP with a Fiio A5 amplifier for evaluation.
The ZSN Pro was tested using the supplied cable and the pre-fitted tips, which resulted in a very comfortable fit. The seal and isolation were above average. Sensitivity was fine, with adequate volume achieved on various devices, including a Moto G3 smartphone, but I found the sound balance preferable when run through the DAP via line out with a headphone amplifier.
The recent series of IEMs released by KZ’s sister company CCA have adopted a more neutral sound, excepting the latest CA4, which I found to have a more V or W-shaped profile. Conversely, the ZSN Pro, rather than exhibiting a strong V-shaped character in traditional KZ style, displayed a more balanced, shallow V-shaped response. In this respect I found it to have some of the qualities of both the CCA C10 and the more ambitious C16.
Bass
The bass was more mid-bass focused compared to the CCA CA4, which had a more sub-bass emphasis. As a result the overall balance was slightly warmer than neutral, and resembled that of the CCA C10. Sub-bass was present where it occurred in the recording, but was not overdone. In Rachmaninov’s “Symphonic Dance No.1” performed by the Minnesota Orchestra conducted by Eiji Oue, the bass drum had good impact and depth with a crisp initial strike. Decay was fairly quick resulting in a clean quality in this part of the spectrum. There was good weight to the orchestral climaxes. The deep synth bass underpinning Andrew Forrest’s “Unveiling Eternity” from his album “One” enhanced the atmosphere of the piece rather than dominating, producing a very natural balance. The appropriately mechanical sounds of the bass accompaniment in Pink Floyd’s “Welcome to the Machine” were suitably menacing, providing a perfect backdrop to the guitar chords and vocals.
Mids
The lower midrange had a warm character due to a little bass bleed which gave an attractive bloom to this area, again somewhat similar to that of the CCA C10. Generally, the midrange was a little recessed, but it did rise close to the boundary with the treble, giving good impact and immediacy. The bright energetic quality of E.J. Moeran’s “Serenade in G” performed by the Northern Sinfonia under Richard Hickox was a perfect example of this. Brass had appropriate shimmer and bite and percussion hit hard. The syncopated rhythms were beautifully articulated and produced a very attractive performance. Vocals were well delineated. Anne Murray’s voice in “You Needed Me” sounded great. Her clear diction and phrasing delivered all the emotion of the song, with the ambience of the recording venue nicely rendered. Supertramp’s “Know who you are” was another good example with Rick Davies’s light and expressive voice soaring over the accompaniment of guitars and strings to great effect. There was not as much detail from the ZSN Pro as the ZS7 or the CCA C16, but then I frequently had to remind myself of the price of these IEMs when hearing how well these acquitted themselves in this respect.
Treble
The high frequencies on these were well-extended with a brightness somewhat north of neutral, reminding me of CCA’s C16 (a far more costly model). The treble was generally smooth but there were some sharp peaks occasionally, especially at higher volumes, and with sibilance only occurring when actually present in the recording. This extension endowed the treble with air and sparkle. Andrew Heath’s “Headland” from his album “Soundings” is an ambient piece with numerous tinkly percussive elements which shone out nicely over the gentle synth background. The atmosphere of the piece was very well conveyed. “Wunjo” is the title track of Giles Reaves’s debut electronic album which is inspired by the Nordic runes. The quick, incisive and percussive synth accompaniment was clear and precise and drove the track along with a sense of urgency. The delicate acoustic guitars in Dan Fogelberg’s “Longer” had plenty of character and were spread attractively towards the boundary of the stereo image, forming a perfect foil for the poetic vocal line.
Soundstage
The ZSN Pro’s soundstage displayed good width and average height, but depth was a little shallow, resulting in the image being pushed slightly forward. Instrumental positioning was fairly good, though there was some flattening during climaxes. There was plenty of “air” in the stereo image which was stable and solid. The ambience of recording locations was well-presented and helped to create a believable, although reduced, space for the music. Benny Andersson’s “Piano” is a beautifully-recorded album of solo piano pieces with a fairly intimate acoustic. The ZSNs rendered this with a somewhat close perspective, which focused on the instrument rather than the recording space. Vangelis’s “Antarctic Echoes” also displayed a reduced soundstage and a little of the spacious quality of the piece was lost as a result. However, these criticisms only apply when compared to substantially more costly models.
Conclusion
The ZSN Pro presents an alternative sound picture to the recent CCA CA4 which employs the same drive units and cable and is a direct competitor. It is a question of balance. The ZSN Pro has a more neutral and arguably a more natural tuning, warmer mid-bass and lower mids, and a fairly energetic treble. The CA4 has a more lively, entertaining V or W shaped profile, more prominent sub-bass and a larger three-dimensional soundstage. The CA4 is the more immediately impressive of the two but the ZSN shows its merits after more extended listening. A worthwhile evolution of the KZ hybrid line possessing further refinement, the ZSN Pro represents great value with its well-balanced sound, comfortable fit and robust output.
Note: I would like to thank Gina from Senlee at Amazon.com for her excellent service and communication and for providing this review sample at no cost to me.
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