Short answer: the Sennheiser CX 3.00, though neither ranks well in its class. It ranks #409 of 450 in-ear headphones by sound quality, rated 2.7/5, at $79.99; the KZ ZAS ranks #418, rated 2.4/5, at $75.99. With prices this close, go by the sound-quality ranking rather than the cost. Both are rated below 3.0/5 among the 450 in-ear headphones, so if sound quality matters, consider the Intuaura Reference 2019 instead, ranked #5 at $34.99.
The Sennheiser CX 3.00 is the better-sounding pick. Bass is boosted about 4 dB at 60 to 200 Hz and 2.5 dB below that in oratory1990’s measurement, so kick drums and bass lines hit with extra weight. Watch for: A sharp 8.6 dB peak near 7.6 kHz can make hi-hats and sibilants harsh, and presence between 3 and 6 kHz is down about 4.3 dB, with a 5.7 dB dip near 3.5 kHz that pushes vocals back.
Why pick the KZ ZAS: Bass is lifted about 2 to 3 dB from 20 to 200 Hz, so bass-heavy genres have plenty of weight, and listeners with a bassy or warm taste are the best match. Watch for: In hobbyist measurements on squig.link the presence range sits about 5.4 dB below target with a 7.5 dB dip near 3.4 kHz, which pushes vocals back and blurs detail.
Buy the Sennheiser CX 3.00. It is rated higher for sound quality, and the $4 saving on the KZ ZAS is not enough to make up the difference.
Looking for alternatives? See the complete Headphones rankings.
Specifications Side By Side
| Sennheiser CX 3.00 | KZ ZAS | |
|---|---|---|
| Price | $79.99 | $75.99 |
| Ranked | #409 of 450 in In-Ear Headphones | #418 of 450 in In-Ear Headphones |
| Form Factor | In-ear | In-ear |
| Harman Preference Score | 58 (measured by oratory1990, via AutoEQ) | 54 (measured by crinacle, via AutoEQ) |
| Deviation From Target | 3.19 dB standard deviation | 3.18 dB standard deviation |
| Tonal Tilt | -0.74 (negative is warmer, positive brighter) | -1.30 (negative is warmer, positive brighter) |
| Sub-bass Extension | Within 6 dB of target down to 20 Hz (+1.4 dB at 30 Hz) | Within 6 dB of target down to 20 Hz (+2.9 dB at 30 Hz) |
| Connection | Wired | Wired |
| Driver Type | Dynamic | Hybrid (1 dynamic + 7 balanced armature) |
| Impedance | 18 ohms | 24 ohms |
| Sensitivity | 118 dB SPL/V | 109 dB |
| Frequency Response | 17Hz - 21kHz (Manufacturer specified) | 10Hz - 40kHz (Manufacturer specified) |
| Back | Closed | Closed |
| Drivers | - | 1 x 10mm dynamic + 7 x balanced armature |
Related Headphone Comparisons
More worthwhile head-to-heads for Sennheiser CX 3.00:
- KZ AS10 vs Sennheiser CX 3.00
- Sennheiser CX 3.00 vs 1MORE Triple Driver
- Sennheiser CX 3.00 vs Questyle NHB12
- KZ ZAS vs CCA PLA13
- KZ ZAS vs Sennheiser IE 4
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
Sennheiser CX 3.00: $79.99 Amazon eBay
Pros: Bass is boosted about 4 dB at 60 to 200 Hz and 2.5 dB below that in oratory1990’s measurement, so kick drums and bass lines hit with extra weight. Treble from 6 to 10 kHz is lifted about 6 dB, which adds a bright edge to cymbals and gives it a V-shaped character some listeners enjoy. The 18 ohm impedance and 118 dB SPL/V sensitivity let a phone drive it easily.
Cons: A sharp 8.6 dB peak near 7.6 kHz can make hi-hats and sibilants harsh, and presence between 3 and 6 kHz is down about 4.3 dB, with a 5.7 dB dip near 3.5 kHz that pushes vocals back. A preference score of 58 and a 3.19 dB deviation mean the balance is far from the target. The Shure SE215 and FiiO FH3 are rated higher.
Full Sennheiser CX 3.00 review and specifications →
| Released | 2015 (11 years ago) |
|---|---|
| Back | Closed |
| Connection | Wired |
| Deviation From Target | 3.19 dB standard deviation |
| Driver Type | Dynamic |
| Form Factor | In-ear |
| Frequency Response | 17Hz - 21kHz (Manufacturer specified) |
| Harman Preference Score | 58 (measured by oratory1990, via AutoEQ) |
| Impedance | 18 ohms |
| Sensitivity | 118 dB SPL/V |
| Sub-bass Extension | Within 6 dB of target down to 20 Hz (+1.4 dB at 30 Hz) |
| Tonal Tilt | -0.74 (negative is warmer, positive brighter) |
EQ preset to match the Harman target
Set a preamp of -5.3 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 | -2.1 dB | 0.70 |
| Peak | 3,874 Hz | +7.0 dB | 0.66 |
| Peak | 7,101 Hz | -10.4 dB | 0.77 |
| Peak | 167 Hz | -3.4 dB | 1.15 |
| Peak | 4,954 Hz | +4.9 dB | 1.44 |
| High shelf | 10,000 Hz | +0.3 dB | 0.70 |
| Peak | 736 Hz | +1.5 dB | 1.33 |
| Peak | 1,412 Hz | -1.1 dB | 2.20 |
| Peak | 55 Hz | +0.4 dB | 1.63 |
| Peak | 314 Hz | -1.0 dB | 3.41 |
- Reviews, Comparisons and Sound Samples
- Head-to-Head Comparisons
KZ ZAS: $75.99 Amazon eBay
Pros: Bass is lifted about 2 to 3 dB from 20 to 200 Hz, so bass-heavy genres have plenty of weight, and listeners with a bassy or warm taste are the best match. It packs one 10 mm dynamic driver and seven balanced armatures per side. Sensitivity of 109 dB means any phone drives it easily.
Cons: In hobbyist measurements on squig.link the presence range sits about 5.4 dB below target with a 7.5 dB dip near 3.4 kHz, which pushes vocals back and blurs detail. A 5.5 dB peak near 11.9 kHz adds a thin, sizzly edge on top. The Final Audio E3000 carries a higher rating for less money.
Full KZ ZAS review and specifications →
| Released | 2021 (5 years ago) |
|---|---|
| Back | Closed |
| Connection | Wired |
| Deviation From Target | 3.18 dB standard deviation |
| Driver Type | Hybrid (1 dynamic + 7 balanced armature) |
| Drivers | 1 x 10mm dynamic + 7 x balanced armature |
| Form Factor | In-ear |
| Frequency Response | 10Hz - 40kHz (Manufacturer specified) |
| Harman Preference Score | 54 (measured by crinacle, via AutoEQ) |
| Impedance | 24 ohms |
| Sensitivity | 109 dB |
| Sub-bass Extension | Within 6 dB of target down to 20 Hz (+2.9 dB at 30 Hz) |
| Tonal Tilt | -1.30 (negative is warmer, positive brighter) |
EQ preset to match the Harman target
Set a preamp of -5.1 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 | -3.8 dB | 0.70 |
| Peak | 3,021 Hz | +20.0 dB | 0.67 |
| Peak | 177 Hz | -3.3 dB | 1.06 |
| Peak | 2,306 Hz | -20.0 dB | 0.65 |
| Peak | 801 Hz | +4.7 dB | 0.87 |
| High shelf | 10,000 Hz | +2.2 dB | 0.70 |
| Peak | 68 Hz | +0.7 dB | 1.83 |
| Peak | 5,877 Hz | -2.8 dB | 5.99 |
| Peak | 115 Hz | -0.5 dB | 2.49 |
| Peak | 5,429 Hz | +1.5 dB | 6.00 |
- Reviews, Comparisons and Sound Samples
- Head-to-Head Comparisons