Version:           rev 925961 (using Devel)
Compiler:          g++ (Ubuntu 4.3.2-1ubuntu12) 4.3.2
 
OS:                Linux
Installed from:    Compiled sources

MP3 files generated by the audiocd kioslave are unlistenable as they sound like they have a very high background noise level with lots of white noise.  The files are very loud compared to those generated by kaudiocreator.

(Note that this sounds like a different problem to bug 171065 as you can hear the music at the beginning of the track but it degrades to total noise later on.)

Debugging info:
kio_audiocd(2882) kdemain: Starting  2882 
kio_audiocd(2884) kdemain: Starting  2884 
kio_audiocd(2882) AudioCD::AudioCDProtocol::initRequest: dir= ""  file= ""  req_track= -1  which_dir= 2  full CD?= false 

kio_audiocd(2884) AudioCD::AudioCDProtocol::initRequest: dir= ""  file= ""  req_track= -1  which_dir= 2  full CD?= false 

kio_audiocd(2882) AudioCD::AudioCDProtocol::initRequest: dir= "MP3"  file= ""  req_track= -1  which_dir= 4  full CD?= false 

kio_audiocd(2884) AudioCD::AudioCDProtocol::initRequest: dir= "MP3/"  file= "Artist - 01 - Track  1.mp3"  req_track= 0  which_dir= 0  full CD?= false 

kio_audiocd(2882) AudioCD::AudioCDProtocol::initRequest: dir= "MP3/"  file= "Artist - 01 - Track  1.mp3"  req_track= 0  which_dir= 0  full CD?= false 

kio_audiocd(2882) EncoderLame::receivedStderr: Lame stderr:  Assuming raw pcm input file : Forcing byte-swapping
LAME 3.98 64bits (http://www.mp3dev.org/)
Using polyphase lowpass filter, transition band: 18671 Hz - 19205 Hz
Encoding <stdin> to /tmp/kde-devel-kde4/kde-kde-devel/kio_audiocdJH2882.mp3
Encoding as 44.1 kHz stereo MPEG-1 Layer III VBR(q=2)
 
kio_audiocd(2882) EncoderLame::processExited: Lame Encoding process exited with:  0 
kio_audiocd(2884) kdemain: Done 
kio_audiocd(2882) kdemain: Done 



Lame version:
LAME 64bits version 3.98 (http://www.mp3dev.org/)

Below is some info generated from the mp3gain utility for an MP3 generated by the kioslave and one from kaudiocreator:

kioslave (sounds bad):
Recommended "Track" dB change: -11.870000                                    
Recommended "Track" mp3 gain change: -8                                      
Max PCM sample at current gain: 71388.495585                                 
Max mp3 global gain field: 197                                               
Min mp3 global gain field: 155                                               

kaudiocreator (sounds good):
Recommended "Track" dB change: -8.700000
Recommended "Track" mp3 gain change: -6
Max PCM sample at current gain: 35991.263142
Max mp3 global gain field: 193
Min mp3 global gain field: 135

(command used $ mp3gain -s s <file.mp3>)

The "Max PCM sample at current gain" value for the kioslave generated file is very high compared to other mp3s in my collection which tend to be around 29-38k range (also generated in kaudiocreator) - e.g. twice the value.  The "Min mp3 global gain field" is also a bit higher than for the other files but not by anywhere near the same proportion.

I'm not sure if this is any help diagnosing the problem, or what additional details would be useful - if you need any more details let me know.