The JBL Live 770NC have a very bass-heavy tuning with a fairly excited treble response when used over Bluetooth with ANC on and without modifying the EQ. Hip-hop and EDM fans might enjoy the boomy (arguably bloated) sound of punchy kick drums and the deep rumble of sub-bass synths. The low-end’s exaggeration chiefly overwhelms the mid-range, so melodic parts, like lead synths, are comparatively harder to make out and sit low in the mix. You’ll hear excited focus on vocals and a bit of harshness on the high registers of guitar solos, while cymbals can sound piercing and shrill. The headphones sound virtually identical over Bluetooth as when they’re active and wired, but when wired and powered off, their bass is considerably reduced to a more neutral setting, and the low-treble is also more relaxed; take a look at this comparison.

If that’s not your preferred tuning, their companion app is equipped with an equalizer, and when it’s set to flat, the sound is the same as the default tuning. You can check out the EQ presets’ frequency responses, which are roughly variations on the theme of oodles of bass, except for the ‘Vocal’ preset, which has a more conservative bass curve. You can also create your own custom EQ.

A comparison of the default sound profile in Ambient Aware, with ANC off and ANC enabled, (shown here) reveals that Ambient Aware adds a bit more low-mid and bass content.

Lastly, if you’re using the microphone, the headphones’ frequency response changes, as you can see here. This mode emphasizes the frequencies speech occupies in the midrange but can leave audio sounding hollow and thin.