Short answer: the EarFun Air Pro 4. It ranks #309 of 450 in-ear headphones by sound quality, rated 3.9/5, at $62.99; the KZ ZAX ranks #326, rated 3.8/5, and costs $65.99, which makes this an easy call rather than a real tradeoff.
The case for the KZ ZAX: Across hobbyist measurements on squig.link sub-bass sits within 0.2 dB of target down to 20 Hz, and a 3.2 dB bass lift adds warmth and punch for pop and electronic music. The catch: A 9 dB peak near 11.2 kHz lifts the top octave about 6 dB above target, which can make cymbals and sibilants sound sizzly on bright recordings, and a 3.8 dB dip near 3.4 kHz slightly recesses vocals.
Buy the EarFun Air Pro 4. It is rated higher for sound quality than the KZ ZAX and costs less, so it is the default pick unless a specific strength of the other one matters more to you.
Want more options? Browse the full Headphones rankings.
Specifications Side By Side
| EarFun Air Pro 4 | KZ ZAX | |
|---|---|---|
| Price | $62.99 | $65.99 |
| Ranked | #309 of 450 in In-Ear Headphones | #326 of 450 in In-Ear Headphones |
| Form Factor | In-ear | In-ear |
| Back | Closed | Closed |
| Harman Preference Score | 72 (median of 5 squig.link measurements, calibrated to AutoEQ) | 71 (measured by crinacle, via AutoEQ) |
| Deviation From Target | 1.98 dB standard deviation | 2.29 dB standard deviation |
| Tonal Tilt | -0.73 (negative is warmer, positive brighter) | -0.43 (negative is warmer, positive brighter) |
| Sub-bass Extension | Within 6 dB of target down to 20 Hz (+2.3 dB at 30 Hz) | Within 6 dB of target down to 20 Hz (-0.7 dB at 30 Hz) |
| Connection | True wireless | Wired |
| Driver Type | Dynamic | Hybrid (1 dynamic + 7 balanced armature) |
| Drivers | 1 x 10mm dynamic | 1 x dynamic + 7 x balanced armature |
| Active Noise Cancelling | Yes | - |
| Battery Life | 11 hours (52 with case, Manufacturer specified) | - |
| Bluetooth Version | 5.4 | - |
| Bluetooth Codecs | SBC, AAC, aptX, aptX Lossless, LDAC | - |
| Built-in Microphone | Yes | - |
| IP Rating | IPX5 | - |
| Impedance | - | 24 ohms |
| Sensitivity | - | 113 dB |
| Frequency Response | - | 10Hz - 40kHz (Manufacturer specified) |
Related Headphone Comparisons
More top alternatives to EarFun Air Pro 4:
- Moondrop Lan 2 vs EarFun Air Pro 4
- EarFun Air Pro 4 vs Inawaken Dawn Mistwood
- KZ ZAX vs TFZ T2 Galaxy
- Inawaken Dawn Mistwood vs KZ ZAX
- KZ ZAX vs Pula Unicrom
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.
As an eBay Partner, we may be compensated if you make a purchase.
The Two Headphones In Full
EarFun Air Pro 4: $62.99 TWS Amazon eBay
Full EarFun Air Pro 4 review and specifications →
| Released | Aug 2024 (2 years ago) |
|---|---|
| Active Noise Cancelling | Yes |
| Back | Closed |
| Battery Life | 11 hours (52 with case, Manufacturer specified) |
| Bluetooth Codecs | SBC, AAC, aptX, aptX Lossless, LDAC |
| Bluetooth Version | 5.4 |
| Built-in Microphone | Yes |
| Connection | True wireless |
| Deviation From Target | 1.98 dB standard deviation |
| Driver Type | Dynamic |
| Drivers | 1 x 10mm dynamic |
| Form Factor | In-ear |
| Harman Preference Score | 72 (median of 5 squig.link measurements, calibrated to AutoEQ) |
| IP Rating | IPX5 |
| Sub-bass Extension | Within 6 dB of target down to 20 Hz (+2.3 dB at 30 Hz) |
| Tonal Tilt | -0.73 (negative is warmer, positive brighter) |
- Reviews, Comparisons and Sound Samples
- Head-to-Head Comparisons
KZ ZAX: $65.99 Amazon eBay
Pros: Across hobbyist measurements on squig.link sub-bass sits within 0.2 dB of target down to 20 Hz, and a 3.2 dB bass lift adds warmth and punch for pop and electronic music. Crinacle’s measurement gives it a preference score of 71. Its one dynamic and seven balanced armature hybrid runs at 24 ohms and 113 dB, so any phone or dongle drives it loud.
Cons: A 9 dB peak near 11.2 kHz lifts the top octave about 6 dB above target, which can make cymbals and sibilants sound sizzly on bright recordings, and a 3.8 dB dip near 3.4 kHz slightly recesses vocals. It costs more than the CCA C12 for the same rating, while the Tin HiFi T4 rates higher for a little more.
Full KZ ZAX review and specifications →
| Back | Closed |
|---|---|
| Connection | Wired |
| Deviation From Target | 2.29 dB standard deviation |
| Driver Type | Hybrid (1 dynamic + 7 balanced armature) |
| Drivers | 1 x dynamic + 7 x balanced armature |
| Form Factor | In-ear |
| Frequency Response | 10Hz - 40kHz (Manufacturer specified) |
| Harman Preference Score | 71 (measured by crinacle, via AutoEQ) |
| Impedance | 24 ohms |
| Sensitivity | 113 dB |
| Sub-bass Extension | Within 6 dB of target down to 20 Hz (-0.7 dB at 30 Hz) |
| Tonal Tilt | -0.43 (negative is warmer, positive brighter) |
EQ preset to match the Harman target
Set a preamp of -4.5 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 | +1.0 dB | 0.70 |
| Peak | 197 Hz | -3.9 dB | 0.41 |
| Peak | 639 Hz | +3.6 dB | 0.62 |
| Peak | 2,128 Hz | -6.0 dB | 1.80 |
| Peak | 4,125 Hz | +2.9 dB | 0.42 |
| High shelf | 10,000 Hz | +0.0 dB | 0.70 |
| Peak | 4,387 Hz | -3.1 dB | 5.67 |
| Peak | 9,739 Hz | -1.1 dB | 2.42 |
| Peak | 3,351 Hz | +1.7 dB | 4.33 |
| Peak | 6,468 Hz | +2.5 dB | 6.00 |
- Reviews, Comparisons and Sound Samples
- Head-to-Head Comparisons