Basically
there are two systems to gain a realistic sound ambience. There is surround sound on one
hand and 3d sound on the other. Surround sound uses a whole bunch of speakers to gain the
feeling for the listener that he was in the middle of the scene. The advantage of this
system towards normal stereo sound is quite obvious. The big disadvantage of surround is
that the necessary basic equipment is too expensive. It`s not interesting for the gaming
industry as far too few gamers can afford to get themselves a surround system. 3D sound
though offers a realistic ambience to the listener with only 2 speakers. This 3d feeling
is gained by frequency dependent amplitude and delay differences. This effect imitates the
human sense of hearing either by hardware or software. You only need a regular soundcard
to do the software encoding and some directx plugin like qsound tools to encode any wav
file within any audio editor that supports directx plugins. The hardware solution offers
realtime processing. Audio cards that support this just cost a few more bucks than regular
cards. Half-Life uses exactly this kind of encoding. People with onboard a3d/eax
(aureal 3d/environmental audio extensions) support can enjoy this feature. The following
audio cards have either a3d or eax support on board:
- Montego A3D (Turtle Beach)
- Monster Sound (Diamond Multimedia)
- Monster Sound M80 (Diamond Multimedia)
- Monster Sound MX200 (Diamond Multimedia)
- Storm 3D (Xitel)
- Storm VX (Xitel)
- Predator 3D (Shark Multimedia)
- NuSound 3D (Orchid)
- Audio Wave (Multiwave)
- Magic Wave (I/O Magic)
- Sb Live! (Creative Labs)
If you have one of these cards (or others that I forgot to mention
here that support a3d/eax too) you can experience the 3d feeling with just switching on
the a3d/eax support in Half-Life's sound setup.
The software support works via the directX interface. Direct sound 3D is slower than the
hardware solutions and makes the game choppy as it eats more cpu power. You can see this
lag in large outdoor areas or metalic rooms (whenever the 3d encoding is being used alot).
links:
Qsound
Dolby Digital
THX Surround
A3D
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