It seems I found the answer to my question/bugreport. My macbook pro 8.1 13-inch really has 3 speakers: left, right and so called (by Apple) "subwoofer" - standalone additional speaker, which is located on the right side (this is important!). It is a really new thing for me (after 2 years of using laptop). So alsamixer (and intel-hda driver) is absolutely correct naming one of the controls as "Bass speaker". Other items in alsamixer are: Master, Speaker, Headphone and PCM. Now the important thing: if I set to 0 right channel of Speaker in alsamixer, the left sounds like it was in Mac OS in the same mode (balance shifted to left speaker) - that is the right way how the balance should work! But balance slider in Ubuntu sound panel (let's call it slider U) works very strange: at first, when i start to move it to the left - alsamixer's Speaker right channel (slider A) goes down as it should be. But when slider U is approx. 5% till the end, slider A is already 0! At this point the sound is ok (coming from left speaker, but with bass as it should be). And if I continue to move slider U till the end, I see right PCM going down dramatically fast in alsamixer. And now the sound is incorrect (as stated in my bugreport).
So I can say that when in normal mode (balance set to 50/50) the sound is ok and identical to Mac OS. The questions are: 1) Why does ubuntu's sound panel (and pavucontrol too) treat subwoofer speaker as the right one? 2) Why does ubuntu's sound panel balance slider behave in such strange way (described above)? 2) Why is the subwoofer speaker included in right channel of PCM control (in alsamixer)? Overall, I am happy to solve this puzzle (the answer looks so simple if to look back). Please tell me, should I post a new report(s) or leave it as is? And sorry for my Russian English :) -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/1234252 Title: [MacBookPro8,1, CS4206] Left speaker low volume and absence of low freqs To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1234252/+subscriptions -- ubuntu-bugs mailing list [email protected] https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
