Short answer: the KZ ZSN Pro X. It ranks #243 of 450 in-ear headphones by sound quality, rated 4.0/5, at $23.99; the 7Hz x Crinacle Zero 2 ranks #275, rated 3.9/5, and costs $24.99, so there is not much of a tradeoff to weigh.
The case for the KZ ZSN Pro X: The hybrid design with a 10mm dynamic driver and a balanced armature gives bass about 3.6 dB above target at 60 to 200 Hz, which adds punch and warmth for pop and hip hop. Watch for: A 7.2 dB peak near 8.1 kHz and an air band about 5.8 dB above target can make cymbals and s sounds sharp or hissy at higher volume.
The case for the 7Hz x Crinacle Zero 2: Crinacle’s measurement gives it a preference score of 73, and an average deviation of just 2 dB from the Harman target is unusually even for a budget single dynamic driver. Watch for: Hobbyist measurements show the presence region about 3 dB shy of target with a 4.7 dB dip near 5.9 kHz, which can make guitars and vocal consonants sound a little veiled.
Buy the KZ ZSN Pro X. It is rated higher for sound quality than the 7Hz x Crinacle Zero 2 and costs less, which makes it the one to get unless you need something the other one does better.
Still deciding? The full Headphones rankings cover every ranked option.
Specifications Side By Side
| KZ ZSN Pro X | 7Hz x Crinacle Zero 2 | |
|---|---|---|
| Price | $23.99 | $24.99 |
| Ranked | #243 of 450 in In-Ear Headphones | #275 of 450 in In-Ear Headphones |
| Form Factor | In-ear | In-ear |
| Harman Preference Score | 74 (measured by oratory1990, via AutoEQ) | 73 (measured by crinacle, via AutoEQ) |
| Deviation From Target | 2.09 dB standard deviation | 1.99 dB standard deviation |
| Tonal Tilt | -0.17 (negative is warmer, positive brighter) | -0.71 (negative is warmer, positive brighter) |
| Sub-bass Extension | Within 6 dB of target down to 20 Hz (-0.1 dB at 30 Hz) | Within 6 dB of target down to 20 Hz (+1.1 dB at 30 Hz) |
| Connection | Wired | Wired |
| Driver Type | Hybrid (1 dynamic + 1 balanced armature) | Dynamic |
| Drivers | 1 x 10mm dynamic + 1 x balanced armature | 1 x 10mm dynamic |
| Impedance | 25 ohms | 32 ohms |
| Sensitivity | 112 dB/mW | 108 dB SPL/V |
| Frequency Response | 7Hz - 40kHz (Manufacturer specified) | 10Hz - 20kHz (Manufacturer specified) |
| Back | Closed | Closed |
Related Headphone Comparisons
More worthwhile head-to-heads for KZ ZSN Pro X:
- 7Hz Salnotes Zero vs KZ ZSN Pro X
- KZ ZSN Pro 2 vs KZ ZSN Pro X
- KZ ZSN Pro X vs Letshuoer D02
- KZ ZSN Pro X vs KZ ZSN Pro
- 7Hz x Crinacle Zero 2 vs KZ ZSN Pro
Prices on this page were last checked October 11, 2026 at 4:59 PM UTC. Product prices and availability are accurate as of that date/time and are subject to change; the price and availability shown on Amazon at the time of purchase will apply to the purchase of this product.
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The Two Headphones In Full
KZ ZSN Pro X: $23.99 Amazon eBay
Pros: The hybrid design with a 10mm dynamic driver and a balanced armature gives bass about 3.6 dB above target at 60 to 200 Hz, which adds punch and warmth for pop and hip hop. A preference score of 74 at an inexpensive price is strong, and the 25 ohm impedance with 112 dB/mW sensitivity makes it easy to drive from a phone. It also suits a warm or v-shaped taste.
Cons: A 7.2 dB peak near 8.1 kHz and an air band about 5.8 dB above target can make cymbals and s sounds sharp or hissy at higher volume. The 3 to 4 kHz region dips about 2.9 dB, so vocals can sound a little distant. It has no wireless features or noise cancelling.
Full KZ ZSN Pro X review and specifications →
| Released | Jul 2020 (6 years ago) |
|---|---|
| Back | Closed |
| Connection | Wired |
| Deviation From Target | 2.09 dB standard deviation |
| Driver Type | Hybrid (1 dynamic + 1 balanced armature) |
| Drivers | 1 x 10mm dynamic + 1 x balanced armature |
| Form Factor | In-ear |
| Frequency Response | 7Hz - 40kHz (Manufacturer specified) |
| Harman Preference Score | 74 (measured by oratory1990, via AutoEQ) |
| Impedance | 25 ohms |
| Sensitivity | 112 dB/mW |
| Sub-bass Extension | Within 6 dB of target down to 20 Hz (-0.1 dB at 30 Hz) |
| Tonal Tilt | -0.17 (negative is warmer, positive brighter) |
EQ preset to match the Harman target
Set a preamp of -3.8 dB, then add these filters in any parametric equalizer (Wavelet, Equalizer APO, Peace, or a player with parametric EQ). Calculated by AutoEQ from its measured frequency response.
| Filter | Frequency | Gain | Q |
|---|---|---|---|
| Low shelf | 105 Hz | +0.8 dB | 0.70 |
| Peak | 928 Hz | +5.3 dB | 0.66 |
| Peak | 166 Hz | -3.4 dB | 0.67 |
| Peak | 2,193 Hz | -4.4 dB | 0.61 |
| Peak | 3,392 Hz | +6.1 dB | 2.82 |
| High shelf | 10,000 Hz | -4.4 dB | 0.70 |
| Peak | 6,459 Hz | +3.5 dB | 5.25 |
| Peak | 4,968 Hz | -3.5 dB | 5.59 |
| Peak | 4,039 Hz | +1.3 dB | 6.00 |
| Peak | 5,964 Hz | +0.9 dB | 5.91 |
- Reviews, Comparisons and Sound Samples
- Head-to-Head Comparisons
7Hz x Crinacle Zero 2: $24.99 Amazon AliExpress eBay
Older model: the 7Hz Salnotes Zero (ranked higher, rated 4.8/5). See every 7Hz Zero generation.
Pros: Crinacle’s measurement gives it a preference score of 73, and an average deviation of just 2 dB from the Harman target is unusually even for a budget single dynamic driver. Across four hobbyist measurements on squig.link, bass sits about 1.8 dB above target and sub-bass reaches flat to 20 Hz, so kick drums and synth lines have a gentle, full weight without swamping vocals. The mildly warm balance suits listeners who like a relaxed, bassy tilt over a bright one.
Cons: Hobbyist measurements show the presence region about 3 dB shy of target with a 4.7 dB dip near 5.9 kHz, which can make guitars and vocal consonants sound a little veiled. A 4.2 dB lift near 11.9 kHz adds some sparkle on top that can draw attention to cymbals. The KZ ZSN Pro X rates slightly higher at a similar price.
Full 7Hz x Crinacle Zero 2 review and specifications →
| Released | Nov 2023 (2 years ago) |
|---|---|
| Back | Closed |
| Connection | Wired |
| Deviation From Target | 1.99 dB standard deviation |
| Driver Type | Dynamic |
| Drivers | 1 x 10mm dynamic |
| Form Factor | In-ear |
| Frequency Response | 10Hz - 20kHz (Manufacturer specified) |
| Harman Preference Score | 73 (measured by crinacle, via AutoEQ) |
| Impedance | 32 ohms |
| Sensitivity | 108 dB SPL/V |
| Sub-bass Extension | Within 6 dB of target down to 20 Hz (+1.1 dB at 30 Hz) |
| Tonal Tilt | -0.71 (negative is warmer, positive brighter) |
EQ preset to match the Harman target
Set a preamp of -4.4 dB, then add these filters in any parametric equalizer (Wavelet, Equalizer APO, Peace, or a player with parametric EQ). Calculated by AutoEQ from its measured frequency response.
| Filter | Frequency | Gain | Q |
|---|---|---|---|
| Low shelf | 105 Hz | -1.1 dB | 0.70 |
| Peak | 6,290 Hz | +4.3 dB | 0.72 |
| Peak | 182 Hz | -2.3 dB | 1.03 |
| Peak | 1,916 Hz | -1.7 dB | 0.50 |
| Peak | 855 Hz | +1.8 dB | 1.59 |
| High shelf | 10,000 Hz | +0.9 dB | 0.70 |
| Peak | 67 Hz | +0.4 dB | 2.53 |
| Peak | 7,224 Hz | -1.2 dB | 5.84 |
| Peak | 5,811 Hz | +0.8 dB | 5.07 |
| Peak | 3,871 Hz | -0.3 dB | 2.41 |
- Reviews, Comparisons and Sound Samples
- Head-to-Head Comparisons