Rapture3D 2.5

Rapture3D includes an "OpenAL driver" used for rendering 3D multichannel audio efficiently. The game tells Rapture3D what sounds should be playing where and when, and Rapture3D gets on with the mathematics to make that happen. This can be used easily with a few OpenAL PC games already, and more if you're prepared to modify your system.
If you have a multichannel sound card, the hardware does all the work of controlling the sound boxes. The program uses different algorithms which you can use to improve the sound effects.