Short answer: the KZ ASX, though neither ranks well in its class. Both are rated 2.0/5 for sound quality (#431 and #432 of 450 in-ear headphones), and the KZ ASX costs $131.99 against $149.99 for the Etymotic ER2SE, and with sound quality even, the cheaper one is the better buy. Both are rated below 3.0/5 among the 450 in-ear headphones, and the Truthear Nova, ranked #2 at $169.99, is a better place to start if sound quality matters.
Why pick the Etymotic ER2SE: Listeners who want a flat, diffuse field style sound get midrange that stays within about 1 dB of target from 200 Hz to 3 kHz, with no peak larger than 2.1 dB across the upper range. Watch for: In oratory1990’s measurement sub-bass is about 10 dB below target and falls 6 dB short by 71 Hz, so pop, hip hop and electronic music sound thin.
Why pick the KZ ASX: Ten balanced armature drivers per side run easily from a phone thanks to 20 ohm impedance and 106 dB/mW sensitivity. The catch: A deep 13.2 dB dip near 7.3 kHz and treble about 5.9 dB below target leave cymbals and detail dull, while a 5.1 dB peak near 1.7 kHz can make vocals sound pushy and nasal.
Buy the KZ ASX. Both are rated the same for sound quality, and it costs $18 less than the Etymotic ER2SE.
Looking for alternatives? See the complete Headphones rankings.
Specifications Side By Side
| Etymotic ER2SE | KZ ASX | |
|---|---|---|
| Price | $149.99 | $131.99 |
| Ranked | #432 of 450 in In-Ear Headphones | #431 of 450 in In-Ear Headphones |
| Form Factor | In-ear | In-ear |
| Back | Closed | Closed |
| Harman Preference Score | 49 (measured by oratory1990, via AutoEQ) | 49 (measured by crinacle, via AutoEQ) |
| Deviation From Target | 3.93 dB standard deviation | 3.75 dB standard deviation |
| Tonal Tilt | +1.16 (negative is warmer, positive brighter) | -1.04 (negative is warmer, positive brighter) |
| Sub-bass Extension | Falls 6 dB below target at 71 Hz (-9.6 dB at 30 Hz) | Within 6 dB of target down to 20 Hz (+1.5 dB at 30 Hz) |
| Connection | Wired | Wired |
| Driver Type | Dynamic | Balanced armature |
| Impedance | 15 ohms | 20 ohms |
| Frequency Response | 20Hz - 16kHz (Manufacturer specified) | - |
| Built-in Microphone | No | - |
| Drivers | 1 x dynamic | 10 x balanced armature |
| Sensitivity | 96 dB/mW | 106 dB/mW |
Related Headphone Comparisons
How KZ ASX compares with other leading options:
- 1MORE Penta Driver vs KZ ASX
- Etymotic ER3SE vs KZ ASX
- KZ ASX vs 1MORE Quad Driver
- 1MORE Penta Driver vs Etymotic ER2SE
- Etymotic ER2SE vs Etymotic ER3SE
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
Etymotic ER2SE: $149.99 B&H Photo Video eBay
Pros: Listeners who want a flat, diffuse field style sound get midrange that stays within about 1 dB of target from 200 Hz to 3 kHz, with no peak larger than 2.1 dB across the upper range. That keeps voices and acoustic instruments uncolored and free of harshness. The 15 ohm dynamic driver is an easy load for a phone.
Cons: In oratory1990’s measurement sub-bass is about 10 dB below target and falls 6 dB short by 71 Hz, so pop, hip hop and electronic music sound thin. Treble also runs about 6 dB low from 6 to 10 kHz with a 9.5 dB dip near 11.8 kHz, which dulls air and sparkle.
Full Etymotic ER2SE review and specifications →
| Released | 2019 (7 years ago) |
|---|---|
| Back | Closed |
| Built-in Microphone | No |
| Connection | Wired |
| Deviation From Target | 3.93 dB standard deviation |
| Driver Type | Dynamic |
| Drivers | 1 x dynamic |
| Form Factor | In-ear |
| Frequency Response | 20Hz - 16kHz (Manufacturer specified) |
| Harman Preference Score | 49 (measured by oratory1990, via AutoEQ) |
| Impedance | 15 ohms |
| Sensitivity | 96 dB/mW |
| Sub-bass Extension | Falls 6 dB below target at 71 Hz (-9.6 dB at 30 Hz) |
| Tonal Tilt | +1.16 (negative is warmer, positive brighter) |
EQ preset to match the Harman target
Set a preamp of -6.3 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 | +6.3 dB | 0.70 |
| Peak | 7,641 Hz | +7.2 dB | 0.59 |
| Peak | 1,757 Hz | -6.3 dB | 0.29 |
| Peak | 803 Hz | +5.2 dB | 0.92 |
| Peak | 3,742 Hz | +1.8 dB | 2.11 |
| High shelf | 10,000 Hz | -1.4 dB | 0.70 |
| Peak | 74 Hz | +0.6 dB | 2.33 |
| Peak | 185 Hz | -0.4 dB | 1.52 |
| Peak | 1,404 Hz | -0.4 dB | 3.73 |
| Peak | 399 Hz | +0.3 dB | 2.15 |
- Reviews, Comparisons and Sound Samples
- Head-to-Head Comparisons
KZ ASX: $131.99 Amazon eBay
Pros: Ten balanced armature drivers per side run easily from a phone thanks to 20 ohm impedance and 106 dB/mW sensitivity. Bass sits about 4.1 dB above target in the squig.link median, so listeners who want a bassy, warm signature get extra punch.
Cons: A deep 13.2 dB dip near 7.3 kHz and treble about 5.9 dB below target leave cymbals and detail dull, while a 5.1 dB peak near 1.7 kHz can make vocals sound pushy and nasal. The Zero Audio Duoza ZH-DWX10 rates slightly higher for less money.
Full KZ ASX review and specifications →
| Released | 2020 (6 years ago) |
|---|---|
| Back | Closed |
| Connection | Wired |
| Deviation From Target | 3.75 dB standard deviation |
| Driver Type | Balanced armature |
| Drivers | 10 x balanced armature |
| Form Factor | In-ear |
| Harman Preference Score | 49 (measured by crinacle, via AutoEQ) |
| Impedance | 20 ohms |
| Sensitivity | 106 dB/mW |
| Sub-bass Extension | Within 6 dB of target down to 20 Hz (+1.5 dB at 30 Hz) |
| Tonal Tilt | -1.04 (negative is warmer, positive brighter) |
EQ preset to match the Harman target
Set a preamp of -8.1 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 | -0.7 dB | 0.70 |
| Peak | 8,524 Hz | +7.0 dB | 2.10 |
| Peak | 170 Hz | -4.8 dB | 0.68 |
| Peak | 1,663 Hz | -7.0 dB | 1.97 |
| Peak | 715 Hz | +5.0 dB | 0.94 |
| High shelf | 10,000 Hz | +3.8 dB | 0.70 |
| Peak | 3,831 Hz | +2.7 dB | 2.15 |
| Peak | 5,171 Hz | -5.9 dB | 4.41 |
| Peak | 2,135 Hz | -1.9 dB | 5.06 |
| Peak | 2,688 Hz | +1.2 dB | 3.43 |
- Reviews, Comparisons and Sound Samples
- Head-to-Head Comparisons