LSE? What does LSE stand for, and what company created it? Is it a new form of lossless audio or something, because I have never heard of it before. Nonetheless, keep in mind that if it is a LOSSY format (such as mp3, wma...), converting a lossy format to another lossy format will result in major quality loss. If LSE is a LOSSLESS format however, you can convert the lossy mp3 format to it and not lose any quality, but also keep in mind it won't improve the quality either.