How to cut 15 seconds of MP3 files from nested directories losslessly (linux/mp3splt)

Go to the folder where your MP3 files resides using cd command.
Then type the following in the terminal

find ./ -name '*.mp3' -type f -exec mp3splt {} 00.15 EOF \;

00.15 - 0 minutes and 15 seconds
EOF - end of file

For every "filename.mp3" file in the directory and all nested subdirectories, the command will create a new file with the following name "filename_00m_15s__XXm_XXs.mp3" and save it into the same directory where "filename.mp3" is located.