Greetings to all of you,

i´ve stumbled over a strange issue when encoding with lame. When encoding with 48kbit mono the encoded file has no issues, but encoding the same source into 48kbit stereo shows up some grave quality issues. Encoding with 96k stereo are good to go again. These are the conversion lines used:

C:\converter\lame_3_96_1>lame -b 48 -q 0 -m m --resample 44100 C:\qc\bonnier_2007_10_29\IC02.wav C:\qc\bonnier_2007_10_29\IC02_48k_mono.mp3

C:\converter\lame_3_96_1>lame -b 48 -q 0 -m s --resample 44100 C:\qc\bonnier_2007_10_29\IC02.wav C:\qc\bonnier_2007_10_29\IC02_48k_stereo.mp3

C:\converter\lame_3_96_1>lame -b 96 -q 0 -m s --resample 44100 C:\qc\bonnier_2007_10_29\IC02.wav C:\qc\bonnier_2007_10_29\IC02_96k_stereo.mp3

And there is the encoding result:
http://www.sendspace.com/file/e1ojk2

Can anyone let me know what i am doing wrong or confirm that there is a problem?

thanx for your help!

regards,
Radioflyer

The problem is that you are using -m s, which only allows 24 kbits per channel, instead of -m j, which allocates nearly all of the 48 kbits to the center channel and almost nothing to the side channel.

The stereo MP3 will sound worse because it has to encode twice as much audio using the same number of bits.

But -m j could help significantly.

Thanx for your support here... m -j did the job!