TechRadar review: JBL Live Flex 4 open-fit earbuds rival AirPods with smart case and ANC

The review said the Flex 4's lightweight, relaxed fit is suited to listening on the go, avoiding the irritation that tight in-ear seals can cause over time. It supports active noise cancellation and transparency modes, allowing users to block out surroundings or remain aware of them. TechRadar said ANC was surprisingly effective for open-fit earbuds, with True Adaptive Noise Cancelling 2.0 muffling cars passing by and colleagues typing in office and walking scenarios, though harsher sounds still seep in because of the open architecture.

The main feature is the smart charging case, TechRadar said. It has a touchscreen that lets users adjust ANC, EQ, playback and other settings without taking out a source device. The case also allows changes to speech for calls, toggles spatial audio, switches audio source, and includes tools such as a timer and flashlight. TechRadar described the case as possibly a gimmick, but responsive and feature-rich, making the earbuds competitive on features and usability. The JBL Headphones app adds more functionality, including custom wallpaper for the case and LDAC high-resolution codec support. TechRadar noted LDAC works with most Android phones but not iPhones.

Call quality is handled by a six-microphone system. TechRadar said calls were clear, and although the reviewer's voice was not always the most defined against background noise, speech was perfectly comprehensible, especially in recordings. Battery life is seven hours with ANC on, up to 10 hours with ANC off, and a maximum of 48 hours with the case. The earbuds support wireless charging. TechRadar said this is better than the new AirPods 5 with Wireless Charging at a similar price, though Apple's option is slightly cheaper.

On sound, TechRadar said the JBL Live Buds 4 and Live Beam 4 perform better than the Flex 4 because their tighter fit concentrates sound in the ear canals and gives low frequencies more impact. The Flex 4 still performed admirably, producing a relatively wide, spacious soundstage and pretty impactful bass for open-fit earbuds. With the default Studio EQ, balance across frequencies was decent, though the low end was a little lacking; TechRadar said a quick EQ tweak in the 32-250Hz range fixed that. Listening to Dave Brubeck's Take Five, the review described an expansive listen, with drums in the treble range beautifully weighted, keys and lead saxophone neatly separated, and double bass rich and full-bodied. LDAC added intricacies in the mid-range and finer detailing.

TechRadar's verdict said open-fit earbuds have limitations in sound quality and ANC generally, but the JBL Live Flex 4 still perform admirably. The review listed a smart, feature-rich case, surprisingly effective ANC for open-fit earbuds, a relaxed comfortable fit and strong overall sound quality as pros. It listed the sonic drawbacks of open-fit designs, spatial audio that could be better, and buds that are not the most premium-looking as cons.