Wanting to have all files at same volume.

Hi all, new to the board so a big hi to you all. I’ve just installed the 2.1.1 version as it was recommended to me.
Here’s my problem. I have a lot of MP3 files but I do notice that some playback louder than others. Is there a way of producing an ‘across the board’ playback level for all my MP3 files.
If anyone can point me to a solution, I’d be very grateful.
Thanks in advance.

Use “Replay Gain” or “Sound Check

Much appreciated Steve, many thanks.