Echoing another user's suggestion of using Foobar2000. You can also do it by album so the quiet parts of the album remain quiet in relation to the other parts, as they were intended to be.
Create a playlist in Foobar2000.
Add whatever folders.
Select all.
Right-click and go to replaygain
I always choose "scan as albums (by tags)"
and then when it's done scanning click the button to adjust replaygain in the metadata.
Echoing another user's suggestion of using Foobar2000. You can also do it by album so the quiet parts of the album remain quiet in relation to the other parts, as they were intended to be.
Create a playlist in Foobar2000.
Add whatever folders.
Select all.
Right-click and go to replaygain
I always choose "scan as albums (by tags)"
and then when it's done scanning click the button to adjust replaygain in the metadata.