Foobar2000 has a replay gain scanner system that can scan your files and add a replay gain tag to them which a music player can use to normalize the loudness.
Audacious allows you to open a folder and play all files inside and has replay gain support.
You have two problems (three if you count MP3’s).
Foobar2000 has a replay gain scanner system that can scan your files and add a replay gain tag to them which a music player can use to normalize the loudness.
Audacious allows you to open a folder and play all files inside and has replay gain support.