4LFE Crossover Frequency

Adjusts the cut-off frequency (50~250Hz) for LFE (low- frequency effects) signals. Xonar D1 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.

6.7AEC (Acoustic Echo Cancellation)

Xonar D1 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 D1 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 D1 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 D1 audio card.

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.

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ASUS Xonar D1