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
