PSB M4U 8 MKII Review

PSB is one of the latest speaker companies to branch into over-ear Bluetooth headphones. The M4U 8 MKII promises a mid-budget wireless headphone that aims for an audiophile sound, while also coming with notable features like ANC and sound personalization. Let’s see if it can offer something different compared to some of the market’s heavy hitters.

What You Get

  • M4U 8 MKII headphones
  • Airplane adaptor
  • Quarter-inch stereo adaptor
  • Gyro-action ear pads
  • 3.5mm cable
  • USB-C cable
  • Travel case

PSB M4U 8 MKII headband

Look & Feel

Even though the M4U doesn’t look as elegant as some of the other popular Bluetooth headphones in this price range, it makes up for it in practicality. The gyro ear cups definitely set it apart from many other wireless headphones, creating a better seal around your ears. It always angles itself just right, encompassing your ears with grace. You only start to feel the pressure while wearing the headphones for many hours, but the seal never loosens.

PSB M4U 8 MKII ear cups

Design & Functionality

The M4U uses a 40mm dynamic driver enclosed within an ABS + Polycarbonate housing. There are ways to adjust the output power within the PSB headphones app, and you can get the M4U to sound loud enough with marginal headroom. Noise-canceling also helps with this, but its strength is a bit lacking compared to some of the more popular Bluetooth headphones in this price range. It seems to mostly attenuate low-end sonic obstructions, but not mid-range high-end ones, which can be quite frustrating. Circling back to the sound though, the M4U sports a special technology called “RoomFeel,” which mimics the feel of high-quality loudspeakers, separating it from most other consumer wireless headphones. The sound becomes the M4U’s major feature, with everything else supporting it, including the in-app EQ and sound personalization test you can take. The test takes a few minutes and forms its own personalized sound spectrum based on the types of tones you can hear. Other wireless products have done this before like Denon’s PerL earbuds, but the M4U features more subtle sound changes to its specific tuning based on your results.


The M4U has a strong Bluetooth connection that never features any dropouts. It has fast paring too, connecting within seconds after holding down the dedicated Bluetooth button. The only CODECs it features are AAC and aptX HD.

Battery Life

Unfortunately, the M4U doesn’t have the best battery life. The most you can get out of its playback time is 25 hours, and that’s only with ANC turned off. This would have been acceptable for the price a few years ago, but recent wireless headphones have been pushing 50-60 hours for even less money.

PSB M4U 8 MKII side


One of the most impressive aspects of the M4U is its imaging depth. While the soundstage shows its limits, the left and right channel balance is communicated well. The soundstage definitely feels closed, but the imaging keeps everything from feeling too solidified. Everything feels like a real object with dimension, engulfing your headspace more significantly. It’s very immersive, even with its limited headspace. Its spatial accuracy is impressive for a Bluetooth headphone, as all the sound elements surround your head intimately and effectively.

Low End

PSB’s sound personalization and EQ affect the bass response quite a bit. With these features turned off, the bass still has some personality to it. Its tone is the right combination of thick and balanced. There’s tons of energy to the low frequencies, and its layers stack on each other in an organized fashion. It combines texture and clarity in a way that feels genuine to the track. Using EQ can add some extra lift to the sub-bass, but the sound personalization features make the most significant difference. Activating my personal sound filled out bass notes more effectively. It creates warmth and smooth vibrations that are very enticing.


There’s some surprising weight to the mids. While the frequency response isn’t as layered and organized as the bass, the mids have a clear showing. You get some nice details dispersed throughout the sound spectrum, and it results in some surprising transparency. If there are any considerable dips, the M4U never brings them into focus. Everything appears clear and well-defined for a Bluetooth headphone, giving vocals and notes good definition that you rarely need to EQ.


If you’re expecting a dropoff in the highs, the M4U will surprise you. I was not expecting how crisp the highs would appear in the mix. Even without EQ, treble has a significant presence in the sound signature, offering sparkle and sizzle to the top end of the region. It brings a respectable height and tail to the sound signature without sounding too bright or harsh.


The M4U gets everything it needs to right. That mostly has to do with the sound, which is the most important aspect of any pair of headphones after all. Its loudspeaker-inspired drivers reproduce some great sound, maybe some of the best you can hear over Bluetooth headphones in this price range. The level of transparency and depth it displays is rare to hear over Bluetooth, and that makes it its major selling point. Other features like ANC feel underdeveloped, only included because they felt like it was needed. The battery life is a bit disappointing too, especially with the swath of new headphones that feature huge playtimes. At the end of the day these are headphones, and the sound is going to be what everyone wants to buy them for. With its price, its shortcomings become so much more forgivable once you’re immersed in its sound.

Pros Cons
  • Imaging depth
  • Energetic bass
  • transparent mids
  • Crisp highs
  • Gyro ear cups
  • Fast pairing
  • Sound personalization features
  • Disappointing battery life
  • Weak ANC

The PSB M4U 8 MKII is available at Audio46.

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Alex S. is a sound designer and voice-over artist who has worked in film, commercials, and podcasts. He loves horror movies and emo music.