appearance of new frequencies in the mp3 output

Started by shameedsait September 8, 2006
Hi all, I low-pass filtered a wav file so that there was no component
above 16 kHz. But the mp3 file file I got after encoding the low-pass
filtered wav file using lame encoder had components well above 16 kHz
appearing intermittently. What could be the reason for this?
(windowing??? MDCT???)