Is the OnePlus Buds Pro 4 worth the upgrade from the Technics EAH-AZ40?
Verdict
Clear upgrade
Going from the Technics EAH-AZ40 to the OnePlus Buds Pro 4 buys you 16.0 points of HearWiki score - a clear step up that reviewers agree on rather than a marketing refresh. The gains are concentrated in value (7.0 to 9.0), sound (7.0 to 8.5) and battery (7.0 to 8.5). On paper: battery life 7.5 h to 13 h, codecs SBC, AAC to SBC, AAC, LHDC 5.0 and bluetooth 5.2 to 5.4. Worth checking: drivers per side goes 2 to 1 and case weight goes 30 g to 50.62 g. The two sit at effectively the same price. If your current pair is worn out or the gains line up with how you listen, this one is worth the money.
What actually changes
Sub-scores both products have, on the same 0-10 scale. Bars extend right for a gain, left for a loss.
- Sound7.08.5
- Battery7.08.5
- Calls7.07.5
- Value7.09.0
Spec differences
Only where the two genuinely differ - everything they share is omitted.
| Spec | EAH-AZ40 | Buds Pro 4 | Direction |
|---|---|---|---|
| Battery life | 7.5 h | 13 h | |
| Codecs | SBC, AAC | SBC, AAC, LHDC 5.0 | |
| Bluetooth | 5.2 | 5.4 | |
| Water resistance | IPX4 | IP55 | |
| Battery incl. case | 25 h | 45 h | |
| Full charge time | 120 min | 70 min | |
| Driver size | 6 mm | 11 mm | |
| Drivers per side | 2 | 1 | |
| Microphones | 1 | 3 | |
| Case weight | 30 g | 50.62 g | |
| Wireless charging | No | Yes | |
| Transparency mode | No | Yes | |
| Companion app | No | Yes | |
| Custom EQ | No | Yes | |
| Wear detection | No | Yes | |
| ANC type | none | adaptive | |
| Quick charge | 10 min = 90 min | 10 min = 11 hours playback | |
| Driver | 6mm | dual drivers; 11mm woofer + 6mm tweeter | |
| Frequency response | 20Hz-20kHz | 10Hz-40kHz |
About this verdict
Direction matters here: this page answers "EAH-AZ40 to Buds Pro 4". The other direction is a separate question with a different answer. Scores blend published review verdicts across true wireless and shift as new reviews land, so a marginal call today may not be one next quarter.