The GSP line from Sennheiser welcomes a new addition in the form of the GSP 550. This new headset borrows the design from the GSP 500, adds in a fresh coat of paint as well as 7.1 Dolby surround sound. Not only do we get these new features, the GSP 550 also retains all the highlights from the 500, these include the semi-open back design, adjustable headband, broadcast quality microphone and the impressive frequency response of 10-30,000Hz.