i'm not an expert, but i did have sound problems installing Windows OS in EFI mode.
Did you try booting into the normal CD when installing linux? (If you did it by USB then it probably was EFI mode, since macbooks can only boot that way from them.) *There's usually two options when booting into CD, when you hold alt/option at startup Not that i've tried it, but it might be what is causing it. -- You received this bug notification because you are a member of Desktop Packages, which is subscribed to alsa-driver in Ubuntu. https://bugs.launchpad.net/bugs/1234252 Title: [MacBookPro8,1, CS4206] Left speaker low volume and absence of low freqs Status in “alsa-driver” package in Ubuntu: Confirmed Bug description: Ubuntu 13.04 fresh install or fully updated - no difference. While listening music through internal speakers I noticed that left speaker sounds differently from the right one. I would describe left speaker's sound as those from the headphones lying on the table: low volume level and mostly high frequences are heard. 1) Trying to check mixer levels in alsamixer, muting/unmuting, balance channels etc didnt help. 2) In alsamixer there is a mixer item called "Bass Speaker". If I mute it, other playback items (including Master) are muted too. If I make its level to 0, then sound from both speakers become identical: low volume and without bass frequences. Level of the Bass Speaker resets if I adjust volume level from Unity volume control tool. 3) Trying to set model parameter for intel_hda module to "mbp55" or "imac27" didnt help. 4) Sound from headphones is perfectly ok. ProblemType: Bug DistroRelease: Ubuntu 13.04 Package: alsa-base 1.0.25+dfsg-0ubuntu4 ProcVersionSignature: Ubuntu 3.8.0-19.29-generic 3.8.8 Uname: Linux 3.8.0-19-generic x86_64 NonfreeKernelModules: wl ApportVersion: 2.9.2-0ubuntu8 Architecture: amd64 AudioDevicesInUse: USER PID ACCESS COMMAND /dev/snd/controlC0: vkat 1970 F.... pulseaudio /dev/snd/pcmC0D0c: vkat 1970 F...m pulseaudio Date: Wed Oct 2 19:12:40 2013 InstallationDate: Installed on 2013-10-02 (0 days ago) InstallationMedia: Ubuntu 13.04 "Raring Ringtail" - Release amd64 (20130424) MarkForUpload: True PackageArchitecture: all SourcePackage: alsa-driver Symptom: audio Symptom_AlsaPlaybackTest: ALSA playback test through plughw:PCH failed Symptom_Card: Built-in Audio - HDA Intel PCH Symptom_Jack: Speaker, Internal Symptom_Type: High background noise, or volume is too low Title: [MacBookPro8,1, Cirrus Logic CS4206, Speaker, Internal] Background noise or low volume UpgradeStatus: No upgrade log present (probably fresh install) dmi.bios.date: 01/24/12 dmi.bios.vendor: Apple Inc. dmi.bios.version: MBP81.88Z.0047.B27.1201241646 dmi.board.asset.tag: Base Board Asset Tag# dmi.board.name: Mac-94245B3640C91C81 dmi.board.vendor: Apple Inc. dmi.board.version: MacBookPro8,1 dmi.chassis.type: 10 dmi.chassis.vendor: Apple Inc. dmi.chassis.version: Mac-94245B3640C91C81 dmi.modalias: dmi:bvnAppleInc.:bvrMBP81.88Z.0047.B27.1201241646:bd01/24/12:svnAppleInc.:pnMacBookPro8,1:pvr1.0:rvnAppleInc.:rnMac-94245B3640C91C81:rvrMacBookPro8,1:cvnAppleInc.:ct10:cvrMac-94245B3640C91C81: dmi.product.name: MacBookPro8,1 dmi.product.version: 1.0 dmi.sys.vendor: Apple Inc. To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/alsa-driver/+bug/1234252/+subscriptions -- Mailing list: https://launchpad.net/~desktop-packages Post to : desktop-packages@lists.launchpad.net Unsubscribe : https://launchpad.net/~desktop-packages More help : https://help.launchpad.net/ListHelp
