Due to lack of measurement equipment I cannot be sure, but I seem to experience a difference in perceived loudness between cd and mp3. CD seems to be louder than mp3 at the same level. I came to that conclusion when I walked out of my room playing an MP3 and noticed that I was terrorizing my fellow students with the noise while in my room it didn't sound that loud. I wonder what causes this. A few Hypotheses: 1) Limitation of the freqency extremes, either caused by the process of mp3 encoding or by the lousy output stages of my Soundblaster PCI 128. 2) Limitation of the dynamics, possibly caused by the above mentioned circumstances. 3) Lack of detail in mp3s causing the desire to turn up the volume in order to retrieve as much detail as I am used to on cd. Has anybody else experienced this effect or does anyone investigated the causes?