2010/10/14 Valentine Sinitsyn valentine.sinitsyn@gmail.com
Hi David,
First of all, thank you for your work on subwoofer issues.
it seem that acer aspire 8943g has 5.1 speakers according to acer web site
with five built-in speakers and one subwoofer supporting low-frequency effects
https://bugtrack.alsa-project.org/alsa-bug/view.php?id=5083
alc670 is a 6 channels codec with [Audio Output] at nodes 0x02, 0x03 and 0x04
http://www.alsa-project.org/db/?f=d1c9aaa11903b6b1e2fd87b6d0466157ffdcb6ad
Seem that your Lenovo are not using ALC670,
Nope it doesn't. It is Lenovo Y550P with ALC272, and in my system, the subwoofer is connected at pin 0x17. I'm not at it at the moment, but I can send alsa-info.sh later if it is of any interest.
ALC272 is just a four channels codec ,
If you look at the block diagram (page 5) of alc272 datasheet , the mono-out (Port H) pin 0x17 has no volume control , and it is connected through 0x0f to [Audio Output] node 0x02.
This is quite different from STAC9200 which has a volume control for the mono-out widget
The beep-in and the beep generator can connected to 0x0f through [Audio Mixer] 0x0b this mean that the driver cannot assume that master-mono must be connected to a subwoofer.