M4U 4 – Audiophile Earphones

This product has been discontinued.

Warranty: 1 Year

Audiophile earphones for speaker-quality sound on the go.

The M4U 4 is PSB’s first-ever in-ear monitor and its designed unlike any other PSB earphone. Leveraging a unique two-way hybrid dual-driver design, perfected by legendary designer Paul Barton using dedicated drivers for high and low frequencies, M4U 4 in-ear headphones are infused with PSB’s scientifically developed RoomFeel™ technology to create a more spacious and natural sound. The M4U 4s are small and lightweight with an ergonomic profile and a snug around-the-ear cable design to ensure they are comfortable and secure while listening on the move. Also included is a fully detachable cable with a three-button remote and microphone that lets you answer a phone call and control music easier without ever reaching into your pocket.


Two drivers are better than one
Inside the M4U 4’s unique two-way driver design, the specially-constructed precision balanced armature driver used is individually calibrated to meet PSB’s testing benchmarks while utilizing a custom wave guide to link the driver’s internal sound tube to the woofer for a perfectly aligned driver integration. The moving coil dynamic woofer is no less unique, employing three individual chambers to smooth the response and create deep and accurate bass without being too boomy.

Designed for comfortable all-day listening
These small and lightweight in-ear headphones are portable and designed for sound enthusiasts who demand the most from their audio gear. The ergonomic low-profile design uses an around-the-ear cable and custom silicone and Comply™ Foam ear tips to provide you with a secure and comfortable fit–no matter how active you get when listening. They also come with a clip-on travel case that provides added protection and convenience when storing and travelling with the earphones.

Get connected and be in control
In the box, there are two fully detachable tangle-free cables so you can choose between a standard cable or one with an inline mic and three-button controls that let you adjust the volume, change songs, or answer incoming calls. ¼” (6mm) stereo and dual-input flight adapters are also included to give you the ability to hook up to your stereo at home and watch and enjoy movies while in the air. You can also clip the cables to clothing, or loop them behind your ears and out of the way.

The ultimate ear tip for audiophiles
In addition to the three sizes of soft silicone ear tips, the M4U 4 includes Comply™ Foam Tx-200 Series ear tips with an integrated wax guard for the most professional in-ear fit. Made with high-tech, super-soft memory foam that is heat sensitive and breathable, the Tx-200 ear tips mould to your ear canal to create an unparalleled seal and reduce ambient noises while improving directivity and enhancing the bass response.

  • Advanced two-way hybrid dual-driver design for deeper, more detailed sound
  • Small and lightweight with a secure around-the-ear cable design
  • Take calls and control your music easily with the three-button cable controls/mic
  • Fully detachable cables that connect to phones, stereos, and in-flight entertainment
  • Small, medium and large silicone ear tips for the perfect fit in any size of ear
  • Comply Foam™ Tx-200 premium ear tips also included for improved sound isolation

Frequency Response

LF Cutoff -10dB10-20,000Hz
LF Cutoff -3dB15-20,000Hz
Within ±1 1/2dB20-20,000Hz



Power Handling



Passive16 Ohms


TypeHybrid Dynamic & Balance Armature
Operating PrincipleVented
Size8mm Dynamic Single BA

Ear Coupling

Ear CouplingIn-Ear


Connection1/8" * (3.5mm) Stereo Jack


Driver EnclosureComply Foam Tx-200 & Silicon Eartips
Travel CaseEVA

Dimensions / Weights / Finish

Overall4 7/16 x 2 3/4 x 1” * (110 x 70 x 25mm) (Travel Case)
Weight0.9oz (25g) with cable
FinishBlack Diamond or Arctic White
Notes* Non-metric measurements are approximate.

** Some finishes may not be available in all models and/or all countries.

All specifications are subject to change without notice.


Push Function/Monitor Cable or Monitor Cable47” * (1.2m) Detachable Tangle-free
Push Function Cable or Apple Control47” * (1.2m) Detachable Tangle-free

Data sheets