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I'm trying to setup a pulseaudio based WLAN audio stream and while debugging quality problems, I noticed that even playing a local WAV file using paplay results in a playback with quality problems in the form of sporadic stuttering and a continuous background noise.

I tried it with both, a Raspberry Model B+ and a Raspberry 2, using multiple Raspbian versions (2013-09-25-wheezy-raspbian, 2015-05-05-raspbian-wheezy and 2015-09-24-raspbian-jessie) and various Pulseaudio versions - almost everything from 2.0 to a 7.1 freshly compiled from source.

After days of tinkering I'm only left with the impression that Pulseaudio must be somehow fundamentelly flawed on the Pi. Using MPD on the Raspberry or paplay on my Ubuntu based notebook results in crystal clear playback using the same WAV file.

I also find it very discouraging to notice that the sound quality and the stability of the remote sink seems to get worse with every more recent version of pulseaudio.

Any thoughts on this? Has anyone the same problem or could be so kind to try the steps below to reproduce the problem?


Steps to reproduce (in case of a fresh raspbian install):

apt-get install pulseaudio
reboot
wget https://archive.org/download/onclassical-quality-wav-audio-files-of-classical-music/onclassical_demo_demicheli_geminiani_pieces_allegro-in-f-major_small-version.wav -O test.wav
paplay test.wav
  • As far as I remember ALSA works well (for WAV I think you can use aplay, might be wrong). Sometimes, probably due to codecs, you need to use a different programs for different formats, so you could try MP3 etc – Wilf Dec 7 '15 at 21:51
  • @Wilf Thank's for the suggestion. aplay indeed plays the WAW smooth, but still with noticeable static noise on the PI. – s1lv3r Dec 7 '15 at 22:52
  • The default audio out on the Pi models uses PWM for audio, so is not really for hi quality audio. If you want btter quality you can use a variety of USB Sound Cards, as well as addon boards like the HiFIberry – Wilf Dec 7 '15 at 23:04
  • @Wilf Bought a HifiBerry DAC+. Works like a charm now. :-) Just couldn't believe the onboard audio is that bad - I'm not a audiophile or something, but it turns out the onboard audio is useless for everything but basic voice tasks ...- nevertheless feel free to post an answer and I'll accept it as solution. – s1lv3r Dec 15 '15 at 23:48
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The default audio out on the Pi models uses PWM for audio, so is not really for hi quality audio.but is enough to make it audible - for example see the tests done here

Onboard audio: enter image description here HiFiberry DAC: enter image description here

If you want better quality you can use a variety of USB Sound Cards, or addon boards like the HiFiBerry.

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