After buying another Sandisk Sansa Clip+ player for podcasts I was a little surprised its maximum volume was very limited, as opposed to the old instance of the player. Well, that may have been a newer firmware that limited the volume. The maximum was just not enough for listening to podcasts in public transportation.
Having done a search around the interwebs, it turns out the firmware applies that hard limit when your region is set to Europe. Nice, huh? To reset the config, go to Settings / System Settings / Reset Factory Settings / select Yes. Don’t worry all the files will be left intact, you’ll only need to restore the settings like Backlight, Power Saver, Sleep, etc. After the reset, select either North America or Rest of the world as your region. That’s all. There should be a new option in System Settings called Volume and set to High.
BTW, the same is true for Sandisk Sansa Clip Zip players.
Source: http://forums.sandisk.com/t5/Sansa-Clip-Sansa-Clip/Sansa-clip-8gb-too-quiet-even-with-latest-firmware/m-p/139258#M23624