Instructions how to enable 3D spatial audio for 'Unreal Tournament 1999' aka UT99.
Intended to be used with headphones (stereo). Works with any sound card.
The difference should be clearly noticeable as sound becomes out-of-head.
Non-native to game solutions to create 3D spatial audio for headphones is done using only 5.1/7.1 channel output and have no elevation. Having 3D spatial sound directly from audio engine has elevation and is more accurate.
Patched UT99 supports OpenAL Soft which allows to enable 3D spatial audio with custom HRTF.
Important to use UT v469d build or later since there are bug fixes related to audio. Get latest patch here.
Instructions and a way to find best sounding HRTF are included in 'Readme.txt' inside UT99-OpenAL-XXXX archive.