** Description changed: - In Intrepid and Jaunty, audio sent through the Plantronics DA40 is - distorted if the per-application volume is above around 80%. - Unfortunately, all applications default to 100%. Audio sent directly to - the ALSA device is not distorted, so this is something happening in - pulseaudio. I attempted to test this under Karmic, but the volume - sliders behave very differently, with the pavucontrol sliders adjusting - the ALSA "Speaker" mixer, and I was unable to remove the distortion at - all. + [SRU Justification] + Impact: See below. But in short, distorted sound when on an analog-mono profile. Most soundcards support analog-stereo only, but for some hardware, this is a problem. + + Testcase: Using hardware that supports analog-mono profile, play back audio, source + material at sufficient volume. If this bug is fixed, there is no distortion. + + Regression potential: Can't think of any, and if so, it should only + affect downmixing to mono, which is unusual anyway. + + + In Intrepid and Jaunty, audio sent through the Plantronics DA40 is distorted if the per-application volume is above around 80%. Unfortunately, all applications default to 100%. Audio sent directly to the ALSA device is not distorted, so this is something happening in pulseaudio. I attempted to test this under Karmic, but the volume sliders behave very differently, with the pavucontrol sliders adjusting the ALSA "Speaker" mixer, and I was unable to remove the distortion at all. The DA40 is a mono device, so perhaps it's a problem with pulse downmixing stereo audio to mono without reducing the per-channel level, resulting in clipping. but I tested with a DA45, which is a similar mono adapter, and the problem didn't exist.
-- You received this bug notification because you are a member of Desktop Packages, which is subscribed to pulseaudio in Ubuntu. https://bugs.launchpad.net/bugs/416190 Title: Pulseaudio produces overdriven audio on mono downmix (e g to Plantronics DA40 adapter) Status in “pulseaudio” package in Ubuntu: Fix Released Status in “pulseaudio” source package in Precise: Fix Committed Bug description: [SRU Justification] Impact: See below. But in short, distorted sound when on an analog-mono profile. Most soundcards support analog-stereo only, but for some hardware, this is a problem. Testcase: Using hardware that supports analog-mono profile, play back audio, source material at sufficient volume. If this bug is fixed, there is no distortion. Regression potential: Can't think of any, and if so, it should only affect downmixing to mono, which is unusual anyway. In Intrepid and Jaunty, audio sent through the Plantronics DA40 is distorted if the per-application volume is above around 80%. Unfortunately, all applications default to 100%. Audio sent directly to the ALSA device is not distorted, so this is something happening in pulseaudio. I attempted to test this under Karmic, but the volume sliders behave very differently, with the pavucontrol sliders adjusting the ALSA "Speaker" mixer, and I was unable to remove the distortion at all. The DA40 is a mono device, so perhaps it's a problem with pulse downmixing stereo audio to mono without reducing the per-channel level, resulting in clipping. but I tested with a DA45, which is a similar mono adapter, and the problem didn't exist. To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/pulseaudio/+bug/416190/+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
