step 2: Select the MP3 files to Enhance Click the Add File(s) icon to open the Add Files window.
Select the MP3 files you wish to normalize and click Open. Repeat the process to select files from different directories.
step 3: Set the target volume level. MP3Gain's Target "Normal" Volume field determines the target volume for your MP3 files. The default setting of 89.0dB is a good starting point. You can increase or decrease the target volume level later if desired.
step 4: Analyze your MP3 files. Click the Track Analysis icon and wait while the software analyzes the volume of your MP3 files. You can skip this step if you're not interested in knowing the current volume levels of the files
Step 5: Normalize your MP3 files. Click the Track Gain icon and wait while the software normalizes the volume of your MP3 files.
Listen to your MP3 files. If the files are too quiet or too loud, adjust the setting in the Target "Normal" Volume field and click Track Gain again.