• Status Closed
  • Percent Complete
  • Task Type Bugs
  • Category Drivers
  • Assigned To No-one
  • Operating System Sansa AMSv2
  • Severity Low
  • Priority Very Low
  • Reported Version Release 3.7.1
  • Due in Version Undecided
  • Due Date Undecided
  • Votes
  • Private
Attached to Project: Rockbox
Opened by clumsymoe - 2010-12-31
Last edited by saratoga - 2012-02-08

FS#11851 - clip+: sound messes up (popping) with certain songs

Strange audio playback problems on clip+ with particular files. Attached is a 1 min ish clip of one of the songs that was causing this problem, the other songs that have this problem are about the same (loudly mastered EDM). The problem only occurs in this song during the chorus, the other parts of the song use a different kick/bassline and the problem doesn’t exist there.

From my testing it occurs regardless of volume. It happened to me with no sound modifiers on, flat EQ and everything off. Didn’t try messing with them. Doesn’t happen on my X5L with 3.6 or on the clip with default firmware.

Closed by  saratoga
2012-02-08 20:33
Reason for closing:  Out of Date
Additional comments about closing:   Warning: Undefined array key "typography" in /home/rockbox/flyspray/plugins/dokuwiki/inc/parserutils.php on line 371 Warning: Undefined array key "camelcase" in /home/rockbox/flyspray/plugins/dokuwiki/inc/parserutils.php on line 407

Lots of fixes have gone in for playback and the dac driver since this was last tested. No one has confirmed that it still exists after 8 months. If someone can reproduce this, ask in IRC to have it reopened.

I listened 5 times through on the Clip+ without any issues. You mentioned a chorus, but this track is an instrumental. Any chance you uploaded the wrong file? If not, its probably just something specific to your player.

Well the chorus of the song, I guess. After clipping out this section of the song I put it on the clip to make sure it still caused problems. It’s defiantly the correct song.

Here’s a recording of playing the file in rockbox, then switching to the default firmware and playing it (I was a bit slow to match the volume on the default firmware).

The file output is clipped. Did you try to use Replaygain?
An easy test would be to set Rockbox Replaygain (Menu/Playback Settings/Replaygain) to on and use a pre-amplification of -1 dB.

Another user reported this for the clip+ as well. The user also reported that playback of a wav-file that was decoded on a PC showed the same behaviour. Maybe something misconfigured in the codec’s signal path?

Link to the thread:,27066.0.html

Edit: The popping noise is very prominent in the files that are linked in the forum thread. The noise does not seem to be connected to the amplitude or any clipping. It sounds like discontinous wave form (missing or doubled samples) in the audiostream. Maybe something related to pcm buffer / DMA transfer?

Does this still occur after the AGC fix went in today?

Anyone still have this issue? If not, I’m going to close it.

I haven’t listened to that song in a while, was that fix included in the latest version of rockbox? If so I can put that on my clip and test it sometime this weekend.

I’m not sure who put popping in the title, it’s defiantly not popping.

MikeS commented on 2012-01-20 21:49

Andree Buschmann changed the task title on 23 Jan.

ETA: 2011, that is.


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