[pulseaudio-discuss] Clevo P150HM, Realtek ALC892 and subwoofer

[Julian Sikorski]

W dniu 2011-06-19 11:28, Tanu Kaskinen pisze:
> On Sun, 2011-06-19 at 10:04 +0200, Julian Sikorski wrote:
>> Hi,
>>
>> I have recently got a Clevo P150HM laptop. It has 4 audio jacks (1 is
>> SPDIF hybrid) and 2.1 speakers. Under Windows, one needs to install THX
>> TruStudio Pro in order to make the subwoofer sound decent, as tested
>> here [1]. Under Linux (Fedora 15 x86_64), the bass level is
>> significantly worse. Is this even within the scope of PA, or should I
>> talk to ALSA developers?
>
> So the problem is simply that the subwoofer level is too low? If the
> sound card is capable of doing something for that, but ALSA doesn't
> expose the functionality to the userspace, then you should contact the
> ALSA developers. To find out whether ALSA already supports modifying the
> bass level, check the output of "amixer -c0" - does it show any controls
> that might be related to the bass level? You can also tweak the controls
> interactively with "alsamixer -c0".
>
> If the sound card does support bass level controlling, and the default
> setting is clearly wrong, then complain to the ALSA guys. If it's not
> clear that the default setting should be something else than it is, but
> you'd like to control the bass level (and you're not happy to do it with
> alsamixer), then it's in Pulseaudio's domain.
>
> If the sound card doesn't have any controls, and THX TruStudio Pro
> simply does some signal processing in software, then it's definitely not
> the ALSA developers' problem. The best place to do audio signal
> processing would be Pulseaudio, but we don't have very great facilities
> for that - module-ladspa-sink with an equalizer plugin might work, but
> there's no way to enable it only when using the built-in 2.1 speakers.
> Or is there, Colin and Arun? Wasn't one of you working on some kind of
> dynamic filter setup?
>
I tried alsamixer -c0 and there are no subwoofer controls available. It 
is kind of hard to test side-by-side due to the need to reboot, but in 
my subjective opinion under linux the test I linked to makes more, 
pardon me, farting noises.
The programme of THX TruStudio PRO which makes the most difference is 
the "Speaker" [1]. Anyway, the sound is much better than on Windows with 
"Speaker" enhancement off, which produces almost no bass at all.
I am not sure if this issue  is worth spending too much time on it, 
since the built-in speakers are quite low quality anyway - no match to 
my Sennheiser RS130 headphones at least.

Julian

[1] http://www.creative.com/oem/technology/thx.asp