Noise-cancelling technology was not new when Sennheiser’s PXC-250 portable headphone was released in 2005, but here was a cheap, practical, and stylish implementation of it. Sennheiser’s noise-cancelling technology is known as NoiseGardTM. The device works by two small microphones inside the earpieces sending any noise they detect to an amplifier, which then inverts the phase of the signal and mixes it with the amplified music source. As a result, a significant amount of steady-state noise (hums, buzzes, droning, and hissing) is eliminated. Ironically, because this load is lifted from your ears (and brain), you become significantly more sensitive to sounds that aren’t processed by the PXC-250, such as very low frequency vibration and high pitched rattling.
It’s easy to be pessimistic Because the history of hi-fi wonder toys isn’t exactly rosy – yet the PXC-250 impressed me. First and foremost, despite its exorbitant £90 price tag, it is excellently constructed despite weighing only 65g. The device is packaged in a soft but strong container that is large enough to hold an MP3 walkie and a few memory cards. For storage, the phones fold neatly into a compact, flat bundle, which can then be readily unfolded for use. They’re also really comfy to wear for extended periods of time. Still, don’t expect them to have the same Herculean strength as a regular pair of Sennheiser hi-fi cans due to their folding shape.
The processor is a compact, wand-like device that runs on a single AA battery and comes with a 1.8m captive connection and a single power on/off toggle. Put the headphones on your ears, turn them on, and you’ll notice that the PXC-250s filter out a lot of the steady-state noise around you, making listening an unnerving experience. They don’t entirely eliminate all rattling and hum, but they do eliminate a surprising amount of drone and general ‘whoosh.’ You can suddenly concentrate on the song and hear a lot of subtle treble and midband detail. The phones block out a lot of noise even when powered up with no music – just put them on, turn them on, and hear the environment vanish!
When you listen to music, you may detect some minor system imperfections, such as a slightly shaky midband and ‘broken’ piano notes, as well as a loss of bass punch and a general lack of immediacy. Still, sound quality is good overall – sweet and smooth, and not far behind the outstanding entry-level passive PX-100s. Whatever your feelings about signal purity, there’s no doubt that listening to slightly ‘processed’ music is more enjoyable than listening to pure, unadulterated audio with high levels of continual background loudness. Expect to pay £30 for a highly capable small headset for music creating on the go, which is well worth hunting out if a pair becomes available secondhand.