Hi all!
Configuration:
1) Kubuntu 10.04, Amarok 2.3.0;
2) Acoustic system Microlab 800 4.1;
3) Sound card integrated codec Realtek ALC888.

Problem: Amarok's equalizer does not redirect bass (low frequencies) to a subwoofer. As a result satellite speakers works in overload, sounds are distorted.

My question is: how this problem could be solved?
Thank you in advance

This is a lower level audio driver issue, rather than an Amarok issue. Amarok doesn't know any of the details of your speaker setup; it just outputs audio (which, as music, will be two-channel).

Since you're running 10.04, your audio system will be ALSA, so you need to look up instructions for defining an ALSA device which filters low frequency audio to the subwoofer channel (you may also wish to have it upmix to extra satellite channels if you have them, rather than just left and right; or if not searching for this may still help you locate the filtering instructions).

Once you have defined the filter in your .asoundrc, you can select that ALSA device as the output in your Phonon config (settings > configure Amarok > playback > configure Phonon).

After trying all available Multimedia configurations including Kmix settings I can say problem was not solved.
I could rephrase my question
How advanced users set up speaker configuration in linux and specifically in Kubuntu?

Sentynel wrote:you need to look up instructions for defining an ALSA device which filters low frequency audio to the subwoofer channel

Which leads rapidly to, for example:
http://alsa.opensrc.org/Low-pass_filter ... 28HOWTO%29

Note that you will need to add a hint for it to be shown in Phonon conf:

Code: Select all

pcm.upmix_20to51 {
    type plug
    slave.pcm lowpass_21to21
    slave.channels 3
    ttable {
        0.0     1       # left channel
        1.1     1       # right channel
        0.2     0.5     # mix left and right ...
        1.2     0.5     # ... channel for subwoofer
    }
    hint {
        show on
        description "Upmix channel"
    }
}

Thank you Sentynel!
I'll try it.
P.S. I never wrote drivers - it would be my 1-st experience

Moving topic as this is not Amarok specific.