[alsa-devel] 2 speakers are assigned to the same DAC, this can't support 4.0/2.1 channles

[hwang4]

On 2015年06月10日 12:59, Raymond Yau wrote:
>
> >
> >>
> >>> The alsa-info.txt for that Dell machine is at
> >>
> >> http://pastebin.ubuntu.com/11667982/
> >>
> >> The subwoofer is also at mono pin complex, are  there any low pass 
> filter
> >> for the subwoofer or vendor coeff need to be set ?
> >
> > I don't know it, I guess there is no hardware filter, it will work 
> with the software low pass filter in the pulseaudio.
> >>
>
> http://www.realtek.com.tw/products/productsView.aspx?Langid=1&PFid=27&Level=5&Conn=4&ProdID=166
>
> The ALC269 integrates five hardware equalizer bands composed of one 
> low-pass filter, one high-pass filter, and three band-pass filters to 
> compensate for mini-speaker frequency response
>
> Do you mean alc255 does not have tbr hardware equalizer ?
>
I don't have alc255 datasheet, but according to the alc269 feature 
description, it is highly possible that alc255 also has hardware equalizer.

And do you know how to control those equalizer filters with software or 
do you know where we can find the detailed document for this part?