Sony ULT WEAR (WH-ULT900N) / Sennheiser MOMENTUM 4 Wireless

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.

Sennheiser MOMENTUM 4 Wireless: MOMENTUM 4 Wireless over-ear wireless headphones; Black (509266), White (509267), Graphite (700383) and later Brown, Teal, Copper and Denim colours. MOMENTUM True Wireless in-ear models and MOMENTUM 3 Wireless are separate products.

SpecificationSony ULT WEAR (WH-ULT900N)Sennheiser MOMENTUM 4 Wireless
Release year20242022
Noise cancellingDigital 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.

Sony		—
Driver and ULT button40 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 response5–20,000 Hz (JEITA, wired); 20–20,000 Hz over Bluetooth (44.1 kHz sampling) Sony—
Bluetooth and codecsBluetooth 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.

Sony		Bluetooth 5.2, Class 1; A2DP, AVRCP, HFP; SBC, AAC, aptX and aptX Adaptive

aptX Adaptive works only with Android phones that support it; iPhones use AAC. Multipoint connections are managed in the app.

Sennheiser
Multipoint and sensorTwo Bluetooth devices at once; wear sensor (pauses music when removed)

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

Sony		—
BatteryMusic 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—
Wired useDetachable 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.

Sony		Hi-res digital audio over USB-C; 3.5 mm / 2.5 mm analogue cable

When listening over USB-C, the headphones decode digital audio internally; the analogue cable works even with a flat battery.

Sennheiser
Microphone and processingElectret condenser, omnidirectional microphone; DSEE

DSEE tries to restore high frequencies lost in compressed music.

Sony		—
Impedance and sensitivity314 Ω on, 32 Ω off (1 kHz); 110 dB/mW on, 100 dB/mW off (wired) Sony—
Weight and coloursAbout 255 g; Black, Off-White, Forest Gray Sony—
In the boxConnection cable, USB cable, reference guide, warranty card SonyCarry case; USB-C charging cable; audio cable with 3.5 mm and 2.5 mm jacks; airplane adapter Sennheiser
Service programFree 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		—
Type—Around-ear, closed-back, wireless; active noise cancelling

The ear pads fully surround the ear; Sennheiser cites a lightweight design, padded headband and deep cushioned earpads for long-wear comfort.

Sennheiser
Driver and frequency response—42 mm dynamic driver; 6 Hz–22 kHz; 106 dB SPL (1 kHz / 0 dB FS)

The frequency range describes measurement limits; the sound you hear is also shaped by the in-app equaliser and sound personalisation.

Sennheiser
Impedance—Active 470 Ω, passive 60 Ω Sennheiser
Noise cancelling and microphones—Adaptive hybrid ANC; 4 microphones in total (2 per side, MEMS, beamforming; 50 Hz–10 kHz); anti-wind mode; transparency mode

Hybrid ANC uses both outer and inner microphones; adaptive mode changes the level of cancellation to match ambient noise.

Sennheiser
Battery and charging—700 mAh lithium-ion; up to 60 hours with noise cancelling on; full charge in about 2 hours; up to 4 hours from 5 minutes of charging; USB-C 5 V 800 mA

Sennheiser says the 60 hours was measured with an iPhone at medium volume; higher volume and aptX Adaptive can shorten it.

Sennheiser
Controls and app—Touch surface on the right cup; Smart Pause wear detection; Auto On/Off; 5-band equaliser and Sound Personalization in the Smart Control app

Smart Pause stops playback when the headphones are taken off and resumes when they are put back on; Auto On/Off shuts them down to save power when not in use.

Sennheiser
Water resistance—No IP rating listed

With no certification against sweat or rain, care is needed when it gets wet during exercise.

Sennheiser