HRTF-based 3D positional audio(C3DX) for 4 / 6 CH output.
l Professional digital interface, supporting 24-bit SPDIF IN/OUT (44.1K and 48K)
l Built-in 32ohm earphone buffer, ZV port, and PCtel HSP56 Modem interface.
l 32-bit PCI bus master.
l Comprehensive driver support: Microsoft DirectSound3D, EAX, Linux, BeOS, etc.
l Microphone echo and Karaoke ascending/descending key effects.
l Single chip design, digital power +3.3V, analog power +5V, 128 pins QFP.
l C3DX is the registered trademark of C Media AC97 Audio Device.

With high speed PCI V2.1 bus controller and legacy audio SB16 DSPemulator,CMI8738 is designed for PC add-in cards and all-in-one motherboards. No external CODEC is needed in CMI8738: CMI-8738 supports the legacy audio SB16, FM emulator/DLS wavetable music synthesis, and HRTF 3D positional audio functions. Above all CMI8738 supports C Media AC97 Audio Device PCtel HSP56 (1789) interface. Being compatible with A3D and DirectSound 3D, CMI8738 meets PC98 requirements, and supports professional digital audio interface such as 24-bit SPDIF IN (0.5V ~ 5V)and OUT(44.1K and 48K format).
CMI8738 uses HRTF 3D extension technology to enhance traditional HRTF 3D positional audio by substituting two-speaker system by four- speaker one(it supports additional 2CH 16-bit C Media AC97 Audio Device DAC to provide rear side audio). It greatly improves HRTF 3D positional audio quality and successfully removes the sweet spot limitations: users can enjoy genuine 3D audio gaming effects, and don't have to worry about the environmental confinement any more.
Being outstanding for its full audio functions, competitive price, and power management, CMI-8738 is the best choice for people seeking for optimum use of the PC applications.
C-Media licensed HRTF 3D library from Central Research Lab (CRL), U.K, who provides one of the world's best C Media AC97 Audio Device HRTF libraries (CRL also licensed its audio technology to YAMAHA, ESS, and other well-known sound chip makers).

HRTF 3D Positional 3D (C-Media 3D)
Only this sound processing technology can be called real 3D manifestation, as 3D usually refers to the three dimensions of X, Y and Z. This technology allows people to pin-point the location of sound in the real world (up/down, left/right, front/back)using only two speakers or a pair of headphones. This technology also supports interactive 3D applications to get a real-time placement of sounds via C Media AC97 Audio Device API (application programming interface) such as Microsoft DirectSound3DTM. We can also use this technology to simulate Multi-speaker Surround with two physical speakers to deliver five virtual" speakers in the air, surrounding the listener and creating home theater sound environment. This is the most economical and the easiest solution to people who would like to get high performance C Media AC97 Audio Device surround sound but dont want to spend money in adding extra speakers.