According to Apple’s adaptive EQ technology, the AirPods 4 produce a more or less neutral sound across the lows, mids and highs. However, as they have an open earbud design, deep sub-bass may be missing. Still, mids and highs are well detailed and clear. Sound quality assessment of sound was measured at a 3.6 out of 5 which is very common for this kind of earbuds.