The Game Theater XP is a two piece system - the PCI card has the usual set of internal connections, but just two ports on the back plate. One of these is a multipin socket that connects the breakout box, while the other is a stereo 3.5mm input socket, into which you can plug a TV tuner card. Aside from this, all external connections are through the 'Rack'. This provides both digital and analog inputs and outputs, plus a nifty headphone socket with volume control. Four USB ports on the rack also turn it into a useful powered hub. The system certainly delivers on the entertainment front, with a host of environmental surround parameters that can be applied. The unit supports multichannel DVD playback, although it relies on a software DVD player to do the Dolby Digital decoding. Oddly, the digital output is stated to operate only at 48kHz, so if you are recording to an external audio CD recorder or MiniDisc deck, you'll have to rely on their internal systems (which may not be as good as the high quality software on your computer) for down-converting to 44.1kHz.

We ran into a performance oddity during the tests.The right analog output kept turning up after the left ran out of oomph, topping out nearly 2dB higher. Below that point the channels tracked each other to within 0.5dB. Even the right channel would not go as loud as the other sound cards. For this reason, rather than the 0.71 volts RMS level of the output test signals, we had to content ourselves with a mere 0.39 volts.This means that your speakers will need to be turned up higher to achieve the same volume as the other cards, with increased noise levels.

This difference between the channels on output was exhibited in the frequency response, with the right channel showing a high frequency rise of 0.3dB, which was almost completely absent from the left. The overall noise performance indicates that the breakout box does not automatically provide a better signal to noise ratio than having the whole thing on a PCI card, so look to the box as a convenience, not a performance booster.