[alsa-devel] ALSA-USB driver issues with C-Media chipset

[Takashi Iwai]

At Fri, 20 Jul 2007 12:49:05 +0800,
Saurav SAHU wrote:
> 
> We have encountered some audio recording quality issues on the
> recent ALSA-USB drivers. These problems are faced on C-Media chipset
> based external USB audio devices. The recorded audio with 'arecord'
> is quite noisy, unclear and jerky. The version of ALSA I encountered
> are 1.0.12 and beyond. It seemed to work well previously on ALSA
> version 1.0.8. If I record with a Philips webcam mic (Philips
> chipset), the audio recording is very clear on across all ALSA
> versions. 
> 
> In case you have observed similar issues with C-Media drivers and
> aware of them, please let me know. 

To make it clear whether it's a driver problem of an alsa-lib problem,
try to record with -Dhw at first.  If you still have noises, try
44.1kHz (-r44100) with -Dhw.


Takashi