38 ASUS Xonar DX
6.7 AEC (Acoustic Echo Cancellation)
Xonar DX provides advanced Acoustic Echo Cancellation (AEC) for best voice
communication quality over your speakers. AEC technology can eliminate up-to-
40dB speaker echo return and suppress noises into your microphone for easier
conversation experience. AEC is an innovative feature to make Xonar DX the
best sound card choice for online chatting in VOIP applications (Skype, MSN,
Google, QQ, etc.) or online gaming. AEC provides the following benefits to you:
• Reduce the voice acoustic echoes like speakerphone devices when others talk
to you on line
• Minimize the playback sound echoes into your microphone during gaming or
music playback
• Effectively suppress background or system noises into your microphone
• 32-bit floating point algorithm providing precisely adaptive echo cancellation
performance up to 40dB
• Supports all VOIP applications and online games
To achieve the best performance of AEC function, the ideal system requirements
are as follows:
1. Speakers and microphone are low distortion (max. THD < 2%)
2. Flat frequency response between 300~4KHz
3. Use omni-direction electret microphone with >=40dB sensitivity
4. The microphone is more than 30cm far from PC’s speakers (fix the distance)
and do NOT turn your speakers too loud
5. Put your microphone 20~30cm away from you (fix the distance) and do NOT
speak too close or too loud into the microphone to avoid signal clipping and
distortion. Enable “microphone boost” on Xonar DX audio center mixer to get
proper input signal level.
6. It’s suggested to disable original AEC function residing in some of the soft-
phones or voice communication programs to get best performance from
Xonar DX audio card.
4 LFE Crossover
Frequency
Adjusts the cut-off frequency (50~250Hz) for LFE (low-
frequency effects) signals. Xonar DX will filter out the bass
signals below the crossover frequency from small speaker
channels and forward them to the subwoofer. The higher
the crossover frequency, the more bass signals will be
subtracted.
AEC function will be only suitable for bi-direction voice communication
applications. The speaker type will be set as 2 speakers and special voice
processing mode while AEC is applied (all audio effects will be suspended and
those controls on audio center will be frozen.). After you finish the voice-over-
IP applications, please remember to turn it off for normal high-fidelity audio
playback mode.