PSB M4U 9

With more than five decades spent manufacturing audio equipment, Canadian brand PSB has something of a legacy when it comes to sound reproduction. However, it wasn’t until 2012 that the brand entered the headphone market with the M4U 2 - its first pair of over-ear cans. 

It’s taken 12 years for PSB to launch the M4U 9 - the third iteration of its original headphones - and on paper they seem worth the wait. The headphones have been given a new design and boast improved technology for an elevated listening experience. 

The drivers are graphene-infused, making them lightweight, and they only require a small amount of power to drive them. Then there’s the active noise-cancelling (which utilises four microphones to tune out background noise) and PSB’s RoomFeel technology. The brand claims this emulates the experience of listening to music on a pair of loudspeakers, as opposed to the ‘in your head’ feeling using headphones can create.  

Just like the PSB M4U true wireless micro- planar earphones, these headphones also feature the ability to calibrate themselves to match the results of a short hearing assessment taken in the app. Called Audiodo Personal Sound technology, it ensures the sound should be perfectly tweaked to suit the wearer.  

Finally, they’ve had a design makeover and now feature larger, gyro-suspended, fabric and leatherette earpads tilted at 15 degrees for a better seal. But do the improvements really make for better sound? 

Sound Quality 

Overall, the PSB M4U 9 offers a pleasing sound that’s clear and bright with a detailed top end. The electronic tones of Illusion by Dua Lipa really shine when listening to the track through these headphones, but without overpowering the melodic vocal. Bass is clearly audible and rhythmically expressive, without becoming overpowering or muddied at higher volumes - it all makes for a very pleasant listening experience.  

It’s not just music that sounds good through these headphones, either. That Was Us, a podcast dedicated to reliving the TV drama This Is Us, sounds sharp. The headphones reproduce the lilting tones of Mandy Moore, Chris Sullivan and Stirling K Brown to the point where it sounds as though they are chatting right in front of me. It’s a similar experience when making calls through the headphones – conversations are clear and distortion-free, with only a handful of external noises picked up by the integrated microphones. 

Using the PSB Headphone app to take a three-minute hearing test in order to calibrate the audio from each earcup takes a pleasant listening experience and turns it into a great one. Before using the personal sound technology, Marry You by Bruno Mars is a little lacklustre, but switching to the bespoke sound profile really elevates the listening experience. The melodic vocals are the star of the show, but there’s plenty of gravitas given to the bass and the tinkling church bells in the track. 

However, what the personal sound technology can’t do is block out the creaking noise created by gyro-suspended earpads when tilting my head forwards or backwards. In the case of tracks with acapella sections or those without a thumping bassline, it causes a real distraction - which is annoying to say the least. 

While the headphones offer a sense of bass, they can’t achieve the depth and richness in the low notes that can be crucial to some tracks. This is evident when listening to Boom Boom Pow by the Black Eyed Peas. The bass is approaching hollow, and the relative lack of warmth and fullness makes for a rather underwhelming listen. 

Living with 

As headphones go, the PSB M4U 9s are big. So big in fact, they look comically large on my smaller-than-average head – almost like I’m parodying the cover of Born to Do It by Craig David. However, they feel surprisingly lightweight despite the hefty footprint. This larger size means a pretty big travel case as well, but they do come bundled with a plethora of accessories for every eventuality, including a 3.5mm cable, a 6.3mm stereo adapter, an aeroplane adapter, spare ear cups and a carabiner clip

If I’m honest, the headphones lack some of the premium feel I’d expect given the price. Compared with the AirPods Pro Max, which are only £50 more expensive, the M4U 9 doesn’t have the same quality feel, and comes across as on the plasticky side. 

There are physical buttons to adjust the volume, skip tracks and switch the active noise cancelling on or off on the edge of the right ear cup, and while this position doesn’t feel intuitive (my usual headphones have these controls in the centre of the ear cup) after ten minutes of wearing it feels completely natural and I’m not struggling to locate them. However, in my eyes, the lack of an automatic pause when the headphones are removed is a real oversight. That said, they do have some extremely useful features through the PSB app, including an equaliser with presets for different sound profiles (including tighter bass). 

When it comes to noise-cancelling, the PSB M4U 9s go some way to blocking out external sounds but they don’t manage to immerse me in the music completely. Instead, cars passing close by, aeroplanes overhead and dogs barking are faintly audible even when the ‘transparency’ feature, which makes the wearer aware of their surroundings, is turned off. 

The battery lasts up to 25 hours, although this drops to 18 hours when the active noise cancelling is switched on, and they charge using the bundled USB-C cable.

Conclusion

The PSB M4U 9s sound good, although the bass lacks some richness and depth. The design is on the large side for my taste and the suspended earcups create their own issues - but with good battery life, noise-cancelling that dulls most external sounds and the ability to personalise the sound, they are worth considering.

Listening Notes

Meghan Trainor To the Moon 

The strings and horns in this retro-inspired track are the stars of the show when listening on the PSB M4U 9s. That said, the soulful vocals and well-defined bass are given plenty of emphasis, making for an extremely pleasurable listen. 

George Michael and Mary J Blige As 

The characterful vocals of George Michael and Mary J Blige on this upbeat cover of Stevie Wonder’s track are perfectly reproduced, while the subtle percussion and rhythmic guitars are always prominent. It sounds as fresh as it did in the late 90s.

Sia I Forgive You

The haunting piano and Sia’s melodic vocals really shine in this emotional ballad. There’s plenty of sparkle at the top end, and as the song builds towards its crescendo the midrange isn’t overpowered. A spine-tingling listen.

If you are looking for a pair of over-ear headphones that sound good and offer the ability to personalise the sound to suit you, these are a good option. If you’re willing to splash the cash and aren’t looking for noise-cancelling that will completely immerse you in the music, or a particularly premium feel, then you should consider the M4U 9 headphones.