Sony LinkBuds Fit (WF-LS910N) / Sony ULT WEAR (WH-ULT900N)

Sony LinkBuds Fit (WF-LS910N): LinkBuds Fit WF-LS910N in-ear true wireless earbuds; black, white, green and pink. The open-design LinkBuds Open (WF-L910) and the older LinkBuds S (WF-LS900N) are separate models.

Sony ULT WEAR (WH-ULT900N): WH-ULT900N (printed code YY2981) closed over-ear wireless headphones; Black, Off-White, Forest Gray. ULT FIELD speakers and the WH-1000X series are separate products.

SpecificationSony LinkBuds Fit (WF-LS910N)Sony ULT WEAR (WH-ULT900N)
Release year20242024
Driver and frequency8.4 mm driver; closed type; 20–20,000 Hz over Bluetooth (44.1 kHz), 20–40,000 Hz with LDAC (96 kHz, 990 kbps) Sony—
Noise cancellingActive noise cancelling; Personal NC Optimiser; Ambient Sound Mode and Auto Ambient Sound

Personal NC Optimiser tunes cancellation to the ear shape and how the buds are worn. Auto Ambient Sound changes how much outside sound is let in depending on the surroundings.

Sony		Digital active noise cancelling with Integrated Processor V1 and Dual Noise Sensor; Ambient Sound mode

Two mics on each cup sample outside noise and the processor generates an inverse signal; Ambient Sound mode lets you hear announcements and speech without removing the headphones.

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Bluetooth and codecsBluetooth 5.3; SBC, AAC, LDAC, LC3; A2DP, AVRCP, HFP, HSP, TMAP, CSIP, MCP, VCP, CCP

LC3 and profiles such as TMAP/CSIP are for Bluetooth LE Audio, enabling lower-power audio on compatible phones. LDAC is used on Android for high-bitrate streaming; iPhones use AAC.

Sony		Bluetooth 5.2; A2DP, AVRCP, HFP, HSP; SBC, AAC, LDAC; about 10 m range

LDAC carries audio at a higher bitrate from Android devices; iPhones do not support LDAC and use AAC.

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Multipoint and processingMultipoint connection (two devices); DSEE Extreme

DSEE Extreme tries to restore high-frequency detail lost in compressed music files.

Sony		—
BatteryEarbuds: up to 5.5 hours of music with ANC on and 8 hours off; up to 4 hours of calls; earbud charge about 2 hours, case charge about 3 hours (USB) SonyMusic up to 30 hours ANC on, 50 hours off; calls up to 30 hours ANC on, 40 hours off; about 3.5 hours to charge over USB Sony
FitNewly designed Fitting Supporters and ear tips

The soft supporter fin rests against the ear’s ridge to help keep the bud in place while moving.

Sony		—
Weight and durabilityAbout 4.9 g each (with M tips); case about 41 g, 47.2 × 47.2 × 32.6 mm; IPX4

IPX4 means resistance to splashing water from any direction; it is not for submersion or swimming.

Sony		—
Driver and ULT button—40 mm dome-type closed dynamic driver with neodymium magnet; ULT button for bass-heavy sound mode

The ULT button switches to a strong bass setting with one press; the app equaliser can tune the sound further.

Sony
Frequency response—5–20,000 Hz (JEITA, wired); 20–20,000 Hz over Bluetooth (44.1 kHz sampling) Sony
Multipoint and sensor—Two Bluetooth devices at once; wear sensor (pauses music when removed)

You can switch between a phone and a computer without re-pairing.

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Wired use—Detachable single-sided cable of about 1.2 m, gold-plated L-shaped 3.5 mm plug; passive operation supported

When the battery is flat you can keep listening over the cable; audio over USB-C is not listed.

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Microphone and processing—Electret condenser, omnidirectional microphone; DSEE

DSEE tries to restore high frequencies lost in compressed music.

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Impedance and sensitivity—314 Ω on, 32 Ω off (1 kHz); 110 dB/mW on, 100 dB/mW off (wired) Sony
Weight and colours—About 255 g; Black, Off-White, Forest Gray Sony
In the box—Connection cable, USB cable, reference guide, warranty card Sony
Service program—Free repair until 31 January 2027 for cracks in the rotating shaft between headband and housing on specific serial numbers

The serial number is printed inside the left hanger; Sony provides affected ranges and a checker per colour. The crack can cause the housing to detach. Ranges listed in Canada: Black 1000001–1164062, Off-White 2000001–2040144, Forest Gray 3000001–3026514.

Sony