Just a few years ago, there wasn't any great justification for purchasing a headset with a microphone unless your name was Cheryl and you worked in a call centre in Woking. Skype, Google Talk and the increasing number of games that include voice over IP, have stimulated a growth in the range of high quality headsets, combining headphones that are of a high enough quality to play games and listen to music with together with a decent microphone.
Sennheiser has a long track record of producing well priced high quality audio equipment. The PC155 is one in a range of headsets and is identical to the PC150 except for the nifty USB sound card adapter which accounts for the higher price. Icemat is a newcomer to audio gear with the Siberia being its first headset.
The Sennheisers have a more conventional microphone arrangement with it located on an arm attached to the left headphone and can be rotated into position when talking. The microphone arm is made of rubber so is less likely to snap, useful for a klutz like me. The Icemats have a detachable microphone on a lapel clip. This is potentially an excellent idea, enabling the headphones to be used on their own.
Both headsets have a single cable running from the â€˜phones into a volume control with the Icemat's being detachable. Small things differentiate the two products here: the Sennheiser's volume control is basic but functional, with its mic on/off switch and volume dial, whilst the Icemat with its reflective black box is stylish but overly minimalist with its lack of a visual indicator for the volume level.