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View Full Version : Poor MP3 quality: What can be done about it?



strangelove
2008-10-18, 17:12
Hello,

I've got a Squeezebox Duet and I've noticed that the MP3s I play sound much worse than the uncompressed files I have. Now granted, MP3 is a compressed format. However these files sound much better on my Zune or computer so I can't figure out why they sound so bad through Squeezebox. As a test, I took some MP3s and uncompressed them to WAVs. The WAVs of the MP3s sounded much better when the two are compared back to back. This just doesn't make sense. Why does Squeezebox handle MP3s so poorly and what can I do about it?
Are there differnt MP3 decoder plugins I can use?

maggior
2008-10-18, 17:22
Check in your squeezecenter settings and ensure that you don't have transcoding enabled to a lower bit rate.

From the main squeezecenter window, click settings in the lower right hand corner. From there, click the player tab and select your player from the dropdown (if you have more than one player). Select "audio" from the drop down and ensure that "bit rate limiting" is set to none.

This wouldn't explain the fact that WAV sounds OK even though they are sourced from the original mp3 files since this would also result in a double encode, but it is worth checking.

JJZolx
2008-10-18, 18:34
It's a known problem with the Mp3 decoder. The workaround is to transcode the Mp3s to Flac at the server. That way they'll be decoded by LAME running on the PC instead of the Mp3 decoder on the Squeezebox.

http://forums.slimdevices.com/showthread.php?p=244199

http://bugs.slimdevices.com/show_bug.cgi?id=6231

andyg
2008-10-18, 19:36
Oh come on, that bug is not the issue here.

radish
2008-10-18, 22:02
Do you have replaygain switched on? Is it possible you have gain tags which are causing it to clip or something?

strangelove
2008-10-18, 22:51
I checked. I don't have bitrate limiting or replay gain activated. What does the LAME Quality Level option refer to? If the files are already MP3 it doesn't re-encode them does it?

JJZolx
2008-10-19, 01:46
I checked. I don't have bitrate limiting or replay gain activated. What does the LAME Quality Level option refer to? If the files are already MP3 it doesn't re-encode them does it?

No. Only if you have bitrate limiting set and the bitrate you've set is lower than the average bitrate at which the file has been encoded.

strangelove
2008-10-19, 14:07
So I changed the LAME quality setting from 9(worst) to 0(best) and now MP3s sound better and are indistinguishable from the WAVs. Doesn't make sense since I don't have bit rate limiting on, but there you go. It worked.

maggior
2008-10-19, 19:39
That is quite strange. If that is the case, this seems like a nasty bug to me.

What version of squeezecenter are you running? What OS? Have you upgraded?

strangelove
2008-10-20, 20:53
SqueezeCenter 7.2 with Windows XP SP2