Audio Performance

Output Signal-to-Noise Ratio (A-Weighted):
124dB for Front-out,117dB for Headphone-out (600ohms) dB 
Input Signal-to-Noise Ratio (A-Weighted):
118 dB 
Output THD+N at 1kHz:
0.0003% (-110dB) for Front-out, 0.001% (-100dB) for Headphone-out 
Input THD+N at 1kHz:
0.0002% (-113dB) for Line-in 
Frequency Response (-3dB, 24-bit/192kHz input):
<10Hz to 90KHz 
Output/Input Full-Scale Voltage
2 Vrms (5.65 Vp-p) 

Bus Compatibility

PCI Express: 
-PCI Express Rev. specification compatible 
-Compatible with X1, X4, X8, X16 PCI Express slots 

Main Chipset

High Fidelity Headphone Amplifier:
Texas Instruments 6120A2*1 (120dB SNR, 100dB THD+N @ Vcc±12V, RL=600Ω, f=1kHz) Audio Processor:
ASUS AV100 High-Definition Sound Processor (Max. 192KHz/24bit) 
24-bit D-A Converter of Digital Sources:
Texas Instruments PCM1792A*1 for Front-Out (127dB SNR, Max. 192kHz/24bit) 
24-bit A-D Converter for Analog Inputs:
Cirrus-Logic CS5381* 1 (120dB SNR, Max. 192kHz/24bit) 

Sample Rate and Resolution

Analog Playback Sample Rate and Resolution:
44.1K/48K/96K/192KHz @ 16/24bit 
Analog Recording Sample Rate and Resolution:
44.1K/48K/96K/192KHz @ 16/24bit 
S/PDIF Digital Output:
44.1K/48K/96K/192KHz @ 16/24bit, Dolby Digital 
ASIO 2.0 Driver Support:
Supports 44.1K/48K/96K/192KHz @16/24bit with very low latency

I/O Ports

Analog Output Jack:
RCA jack *2 (Front R / Front L), 6.30mm jack*1 (Headphone out) 
Analog Input Jack:
6.30mm jack *1 (Shared by Line-In/Mic-In) 
Other line-level analog input (for CD-IN/TV Tuner):
Aux-In (4-pin header on the card) 
Digital S/PDIF Output:
High-bandwidth Coaxial/TOS-Link combo port supports 192KHz/24bit 
Front-Panel Header: 
Shared by Headphone out / 2 channels out / 
Microphone in 
S/PDIF Header: Connects to compatiable graphic cards for HDMI output

Driver Features

Operation System:
Windows Vista/XP(32/64bit)/MCE2005 
Dolby® Technologies:
Dolby® Digital Live 
Dolby Digital Live encodes any audio signal on PC in real-time to Dolby Digital (AC3) 5.1 surround sounds to your home theater environment through one single S/PDIF connection 

Dolby® Headphone 
Dolby Headphone technology allows users to listen to music, watch movies, or play games with the dramatic 5.1-channel surround or realistic 3D spacious effects through any set of stereo headphones. 

Dolby® Virtual Speaker 
Dolby Virtual Speaker technology simulates a highly realistic 5.1-speaker surround sound listening environment from as few as two speakers. 

Dolby® Pro-Logic II 
Dolby Pro-Logic II is the well-known technology to process any native stereo or 5.1-channel audio into up to 6.1 channel output, creating a seamless, natural surround soundfield. 
Smart Volume Normalizer™:
Smart Volume Normalizer™ 
Normalizes the volume of all audio sources into a constant level and also enhances your 3D sound listening range and advantages in gaming 
Xear 3D™ Virtual Speaker Shifter:
Virtual 7.1 speaker positioning 
Magic Voice™:
Xonar Essence STX provides VocalFX, the latest vocal effect technologies for gaming and VoIP, including: -VoiceEX: produces vivid environmental reverberation for your voice in EAX games -ChatEX: emulates different background environment effects when you chat online -Magic Voice: changes your voice pitch to different types (Monster/Cartoon…) for disguising your real voice or just for fun in online chatting 
Karaoke Functions:
Music Key-Shifting and Microphone Echo effects like professional Karaoke machine 
FlexBass™:
Professional Bass Management/Enhancement system 
3D Sound Engines/APIs:
Vista: DirectSound3D® GX 2.5, DirectSound® HW, DirectSound SW, A3D®1.0, OpenAL generic modes, 128 3D sounds processing capability 

XP: DirectSound2.5 SW, A3D®1.0, OpenAL generic modes, 128 3D sounds processing capability