After unpacking, you’ll find the headsets, a USB adaptor and some instructions. The first thing you’ll probably notice is the length of the cable which measures in at three metres – more than enough! Sennheiser have cleverly included a cable management system in the form of an oval shaped accessory which you can clip to your clothing.

You also have an inline volume control and a mic on/off switch. At the end of the cable are two 3.5mm stereo jacks for both the headphones and microphone. The USB features sockets for each which allows you to use the headset with or without the USB soundcard. If you have an expensive soundcard, this will definitely please you.

The USB adapter that comes supplied with both headsets is a fantastic addition. This makes the headsets ideal for LAN parties and other events where you’re not using your own equipment. This ensures you still get great quality sound even when you’re not on a system with low quality audio hardware.

Both headsets are binaural. The PC166 has slightly larger cups than the PC156 which makes them a little more comfortable. The PC156 are more sitting on your ears rather than around them whereas the larger size of the PC166 means they can go around your ears. Both sets are very comfortable but we’d have to say the larger PC166 have the edge. Each of the cups are mounted on some sort of ball joint so they adjust to your head automatically. Both headsets can be adjusted vertically to match the size of your head, and the mechanism is not too loose and flimsy whilst at the same time not too stiff.

As you’d come to expect, both Sennheisers are very well made. The microphone rotates down smoothly to the correct position. It’s a shame that the microphone is not detachable as it restricts the uses for the headsets. For example, although they can be used for portable audio players you wouldn’t like to be seen on the bus or train with a microphone attached to your headphones. But then again, these are primarily for gaming uses.

Once you get to use the PC156/166 headsets, you immediately appreciate the clarity and the quality of the sound produced. Both headsets sound almost identical but the PC166 sounds a touch more dynamic when tested with a range of songs and different types of music. The balance is nice between the mid and high low range. Bass is excellent but that slight punch to it is missing. The overall sound is warm and bass is well defined.

As both headsets are aimed towards the gaming side of things, you’d expect them to immerse you into whatever your game of choice is. They do exactly that. In fact, whatever your application is, the headsets will immerse you. In the case of gaming, this allows you to quickly pinpoint the locations of enemies and direction of incoming fire and other hazards. This is where these headsets excel with their ability to produce accurate sounds with excellent clarity.

While audio performance is generally very good, it’s actually the microphone that really impressed us the most. Although the PC166 had the slight edge over the PC156, most likely due to noise cancelling, both the microphones combine superb clarity and in the case of the PC166; impressive noise cancelling to ensure you can be heard loud and clear by your team mates. Unlike microphones found on cheap headsets which are usually too quiet and muddy, the volume and clarity provided by these Sennheisers is superb. Whether you’re gaming or calling a friend with the Sennheisers, they will not fail to impress.

Now for the price. The PC156 and PC166 can be all yours for ~£52 from Overclockers.co.uk – of course that’s for one and they’re both priced the same. This price is excellent and indeed well worth it. At some places, the price is £70+ so it’s worth checking them out.