The PSB M4U 8 comes with a hard case, 1/4'' stereo adapter plug, an audio cable, an airline adapter, and a USB cable for charging the internal battery.

The headphones, comprised largely of plastic, feature a hinged design for compact folding. This easy-travelling design complements the comfortable fit, achieved with the help of some deep pleather earpads.

Connectivity remains a cinch, and the active noise cancellation is actually quite good.

Specs

Frequency Range: 10-20,000 Hz
Impedance: 32 ohms
Sound Pressure Level (SPL): NA
Total Harmonic Distortion (THD): NA

PSB delivers specs that illustrate a fairly standard frequency range and a fairly low nominal impedance - allowing these headphones to work well with low-output devices like cell phones, computers, and personal audio players. While SPL and THD aren't supplied by the manufacturer, the Sound Pressure Level is probably close to the standard 100 dB mark. Total Harmonic Distortion is probably low for a consumer model, and I'd guess that it is somewhere around <0.3%.

Low End

In the low end, the M4U 8 offers a booming bass that can seem to verge on muddy at times. However, the lows still sound worlds above what I was expecting. Despite the consumer-oriented target of this headphone, there's still more than a little amount of detail at play here - definitely lending itself to some critical listening.

Mids

The mids are detailed with a solid sense of fidelity. Admittedly, there's a shadow of compression in the upper mids, but the sound is by-and-large rich and contrasting. Make no mistake, for the price, this midrange remains mostly spot-on.

High End

Subdued in the highs with some clipping, the M4U 8 delivers a middling listening experience here. Those listeners who prefer a less intense high end may rejoice at the slightly relaxed feel, but fans of raw detail will doubtlessly be left wanting for more. Personally, I would prefer more detail here and while the high end is far from horrible-sounding, there's so much more detail missing from my test tracks.

Soundstage

With good placement and some sense of depth, the soundstage is about what one would expect in a noise-cancelling, bluetooth-enabled headphone. Music still has a certain grandeur to it (no doubt helped along by the decent low end), but the PSB M4U 8 still falls just short of delivering realistic soundstage.

Other Observations

Connectivity is remarkably easy... easier than the other PSB models I've tried in the past. Add to this the next-level noise cancellation and I can highly recommend this headphone for a daily commute.

The low end is growing on me, even though I still maintain that it can sound muddy at times. It will handle most test tracks I stack up against it, and only the trickiest of tracks really display the muddiness. Suffice to say, if you're a fan of powerful bass, you may also fall in love with this low end.

Recommendations

For folks searching for the cheapest bluetooth noise-cancelling headphone out there, the PSB M4U 8 will quickly be cast aside for something more economical. But more's the pity, because this headphone remains a strong performer where connectivity and isolation are needed. Really, you'll be hard-pressed to find these features in a better sounding headphone, regardless of the sound you crave. In essence, the M4U 8 offers a surprisingly fantastic sound for a consumer-oriented headphone.

Final Analysis

With an ample low end and strong mids, the PSB M4U 8 boasts a robust sound that doesn't skimp on the details. Despite its slightly relaxed high end, the ease of connectivity and high-quality noise cancellation make this headphone a no-brainer for any discerning commuter.

Carroll Moore is a Tech lover and audiophile headphone enthusiast, photographer and writer for the likes of Audio46.