It’s an irony that the most expensive phones in the entire round-up are also the smallest in form factor. With lightly padded speakers around 2.5cm in diameter and a headband under a centimetre wide, Sennheiser’s PXC 250-IIs are fully portable travel headphones, folding completely for ease of use.

The visual styling is delightful, with precision joints and nice details, such as the integration of small foam pads on the otherwise plain headband.

The Sennheiser 250-IIs are also the only active noise-reducing headphones in the group, with an integral volume knob that’s much easier to use than the small buttons on the firm’s other entry in this set of reviews.

We’d better get to the sound of these phones now, because there’s quite a lot to say. Until you activate NoiseGard (the set’s integrated noise-cancelling feature), these are fairly unremarkable headphones. The bass is flimsy and barely there, whereas the middle frequencies are overbearing.

Flick on NoiseGard, however, and the headphones suddenly match some of the better studio phones in the round-up, with a satisfying balance and an instant sense of virtual space, with acoustic music sounding particularly close. All this is achieved not by boosting the frequencies of music coming in, but by filtering out ambient noise.

Trying them in a noisy environment with TV in the background, we were aware that the noise cancellation wasn’t as effective as in some studio-sized phones we’ve tried, but the results were still game-changing.

Sennheiser PXC 250-IIThe PXC 250-IIs are the most portable (and priciest) headphones we tested

Buying Advice: If portability were our main concern, these would be the phones we’d choose. They’re very lightweight and unobtrusive, with delightful styling. And the sound they generate is terrific, too: that’s in no small part thanks to the active noise-cancelling feature. The price tag is likely to be off-putting, though.

Test Centre: Group test: what are the best headphones?

OUR VERDICT

If portability were our main concern, these would be the phones we’d choose. They’re very lightweight and unobtrusive, with delightful styling. And the sound they generate is terrific, too: that’s in no small part thanks to the active noise-cancelling feature. The price tag is likely to be off-putting, though.

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