Working in conjunction with DirectSound 3D, QEM adds reverb, occlusion and obstruction effects to 3D sound streams. With this technology enabled, DS3D sound sources receive reverb to simulate acoustic reflections based on the listener's position relative to the source. Additionally, occlusion and obstruction filters are used to simulate the effects of obstacles in a virtual 3D environment. Does this sound familiar? Both QSound and Sensaura have algorithms that take advantage of EAX 1and 2 through DirectSound 3D.

It is unlikely that we'll see further titles released with A3D 2.0 support, so the lack of support on the Acoustic Edge isn't much to worry about. Although products featuring the QSound algorithms have not historically offered very convincing 3D sound, the Acoustic Edge coupled with QMSS does a good job of rendering sound in 3D space.

For those with 2-speaker solutions, QSound's QXpander feature does an excellent job of widening the sound stage, making a single pair of speakers much more enveloping. This sort of 3D “spacilization” has been around for a while, and while it is hardly a substitute for a four or six speaker solution, QXpander did have me looking over my shoulder a couple of times in two-speaker mode.

In order to make 6-channel analog sound possible, the Acoustic Edge, like the other 6-channel cards out there, makes use of dual AC97 codecs – the first providing channels one through four, while five and six are supplied by the second. These codecs also house the DAC and ADC; the quality of which help determine the card's input and output sound clarity. A pair of Sennheiser HD600 studio headphones was used for the subjective sound quality tests. Needless to say, the Acoustic Edge provided great 2D clearness with relatively little hiss, even at full volume.