Digital Silence DS-321D review
It's more common to see sound-isolating headphones than their noise-cancelling rivals. This is in many ways unsurprising – the circuitry and power supply necessary for active noise cancellation (ANC) makes earphones that use it more expensive and more power-hungry than their passive rivals. However, they’re also more effective at eliminating consistent background noise such as the hum of computers, engine noise or the rush of air, although not everyone can use them comfortably.
The DS-321D earphones are reasonably priced for a noise-cancelling set. They’re also particularly compact – the control and battery unit measures just 15x42x8mm and it has a sturdy metal clip that makes it easy to attach to your belt. It doesn’t require disposable batteries, but is instead charged via a supplied micro USB lead. The rechargeable battery should last for 14 hours of use and is significantly smaller than the AAA cell used by some competitors.
The active noise cancelling was really effective, eliminating the noise of the wind howling outside, as well as our air conditioning, servers and heating system. The cancellation circuitry didn't make much hiss, either, although we could hear it when we weren't playing music.
The earphones themselves produced a pleasingly detailed sound, but we were surprised how quiet they were, even with ANC disabled. The volume dropped further when we switched on noise cancelling. There was well-defined bass and the mid-tones sounded rich, together producing a powerful, emphatic sound – but only once we turned up the volume on our audio sources. Treble tones were also crisp without being too harsh.
This is a compact and reasonably priced set of earphones that’s particularly good if you wish to eliminate environmental noise. It comes with three sizes of silicone dome ear tip and is compatible with Comply's T-400 foam ear tips. The set also has a four-pole 3.5mm stereo plug, allowing its built-in microphone to work with mobile phones without affecting compatibility with MP3 players. The DS-321D doesn’t sound quite as good as some sets, but then it's half the price of many.