I'm trying to integrate multiple sound effects (46 files), and multiple background music files (7 files) into an iOS game I'm currently developing. The volume levels of my downloaded audio assets are not well proportionate. Having absolutely no prior experience with sound design, google pointed me to normalization through sox.
I learned sox's norm effect performs normalization but wouldn't give the desired results since it's based on peak level normalization rather than average RMS level (all those are new ambiguous terms to me). There also seems to be quite a few other volume level manipulation effects such as compand, loudness, gain and others ... but I'm not quite sure which one suits my need best. My audio files are either wav or mp3, some are stereo (2 channels) others are mono channel, and I'd like to convert all the files to wav, mono channel before I "normalize" their volume.
My question is what would be a good sox command (or command sequence) to achieve what I described above? an example applied to a single file would be perfect... I can then write a script to replicate it on all my files.
PS: I don't expect an automated magic formula that would perfectly adjust all my audio files volume, I'm just hoping for acceptable automated conversion of most files, and if some remain disproportionate, I can tweak them individually. I'm also open to other MacOS or linux tools suggestions.