Replay gain and pre gain only seems to take effect when I restart the player. Is this a bug? Also, my pre gain only has positive values. Is this by design? I would actually like to lower the 89db target to 83db :(.
EDIT: I have firmware 02.03.31 installed on my device.
Not a bug. RG values tend to be negative; pre-gain is to compensate in case you have files w/o RG. Winamp does it by lowering dB levels of non-RG files.
If you are tech type, write MP3Tag script to mod RG field. If not, try asking on MP3Tag forums.
Keep mind that decibel scale is log, not linear. A 6dB drop is equiv to 75% power drop.