Headphones — Psb M4U 9

The M4U 9 is a closed-back Bluetooth headphone from PSB with all-digital active noise cancellation, finished in Jet Black. PSB announced it on 5 April 2023 at the AXPONA show in Schaumburg, Illinois, alongside the M4U TWM earbuds, with launch prices of USD 499, CAD 699, EUR 549 and GBP 449 and availability from June 2023.

Key specs that matter

The closed, circumaural design uses 40 mm dynamic drivers with graphene-infused diaphragms. Frequency response is 10 Hz to 23 kHz at the -10 dB points, 15 Hz to 23 kHz at -3 dB and 20 Hz to 23 kHz within 1.5 dB. Distortion at 1 kHz and 1 mW is 0.25 percent with ANC off and 0.5 percent with ANC on. Passive impedance is 32 ohm, maximum power handling is 30 mW, and the net weight is 362 g. Battery life reaches 25 hours in wireless active mode and 18 hours in ANC mode.

Engineering and use context

PSB says the graphene infusion adds damping, stiffness and efficiency to the drivers. Noise cancelling uses four digital MEMS microphones, and two further microphones serve cVc clear voice capture for calls. Bluetooth supports aptX Adaptive for low latency and up to 24-bit audio, as well as AAC, and NFC pairing is available. A three-position switch selects ANC with RoomFeel, Active with RoomFeel or Passive mode, the last working as a battery-free wired headphone. Physical controls cover volume, playback and mode selection, and the headphone folds for transport. Audiodo Personal Sound tests each ear to build a personalised hearing profile, and four EQ presets are provided. The PSB Headphones app for Android and iOS runs the hearing test and also allows EQ customisation and adjustment of ANC intensity, including RoomFeel, which PSB describes as recreating powered speakers in an optimised room. The larger, angled earpads are intended to fit a wider range of head and ear sizes. The spring steel headband is expandable with a fabric inner cover, the enclosures are ABS and polycarbonate, and gyro-suspended earpads tilted at 15 degrees come in fabric and leatherette. Ear cushions measure 84 x 114 x 17 mm outside, and the overall size is 200 x 200 x 90 mm.

Pairing

Wired listening works through USB-C or dual 3.5 mm inputs, so the cable can enter at the left or right earcup, with braided, tangle-free 2 m audio and USB cables supplied, and an EVA travel case of 180 x 220 x 98 mm is included, together with a 6.35 mm stereo adapter and a dual-input flight adapter. PSB covers the headphone with a two-year North American warranty.

Alternatives

PSB also makes the M4U 8 MKII, a wireless ANC over-ear model with aptX HD Bluetooth.