The Anker Soundcore C40i adopts an open-ear fit, meaning the earbuds rest outside the ear canal rather than forming a seal inside it. They are fully wire-free, with no neckband or wingtips included, and each earbud houses a stereo speaker configuration. At 11.6 g, the overall build is notably light. Protection against moisture is covered by an IPX4 rating, classifying them as sweat resistant — suitable for exercise but not submersion. The design omits RGB lighting, a UV light, and any onboard display.
The Soundcore C40i uses a 14.3 mm driver unit and covers a frequency range of 20 Hz to 20,000 Hz. The earbuds do not include active noise cancellation or passive noise isolation, so ambient sound passes through freely — a characteristic consistent with their open-ear design. There is no support for spatial audio, Dolby Atmos, or Dirac Virtuo processing, and the driver does not use a neodymium magnet.
The Soundcore C40i delivers 7 hours of battery life per charge, with the included charging case providing an additional 14 hours for a combined total of 21 hours. A full charge takes 1.5 hours, and a battery level indicator is on board to keep track of remaining power. The battery is rechargeable, though wireless charging and solar charging are not supported.
The Soundcore C40i connects wirelessly over Bluetooth 5.4 with a maximum range of 10 m, and charges via USB Type-C. Fast pairing and NFC pairing are not supported, nor is Auracast. On the codec side, the earbuds do not offer LDAC, LDHC, AAC, or any variant of aptX — including aptX, aptX HD, aptX Adaptive, aptX Low Latency, aptX Lossless, or aptX Voice — and Bluetooth LE Audio is absent as well.
The Soundcore C40i supports multipoint connection to two devices simultaneously and can function as a headset for calls, backed by a mute function and voice prompts. Fast charging is available, and controls are handled through a panel placed on the device itself rather than an in-line remote. A travel bag is included in the box. The earbuds do not offer ambient sound mode, in-ear detection for auto-pause, a find-device feature, notification readout, a body temperature sensor, or a camera remote shutter function.
The Soundcore C40i is equipped with a 4-microphone array that includes noise-canceling microphone technology, aimed at reducing background noise during calls and voice interactions.
