I think there's a simpler way to solve your issue. If you download Foobar2000 and the vgmstream plugin, you should be able to drop all the .fsb files into Foobar and then convert them all in one go, to .wav or .mp3.

That AWC file loads fine into Foobar with the vgmstream plugin.

You can then convert it to .wav if you choose.

If you use Interleaved DVI as the codec, stereo, sample rate 44100 and the interleave is 0x80, then it will play

It just seems to me like the files are all messed up. For example, some sounds tagged with a particular language are in another language, and some tagged with Wheatley and actually GLaDOS, or don't play at all. If the files are meant to be as they are, then lots of audio is missing, so it seems logi...

The main problem is that most of those files don't contain any audio. Some just have text / meta data, and others have textures. Do you know any dialogue that you can't find in these files?

You can just drop the .mus and .sdt files into Foobar and they will play with the vgmstream plugin. Some of the .sdt files are also .big files themselves and can be extracted the same way as the .big file you already did.

There shouldn't be any dummy files in MUSIC.GRP. There are 587 files in total. If you want an alternative extracting method, try my QuickBMS script attached, which will play in Foobar with the vgmstream plugin.

There aren't any filenames stored in that archive, so that's why the unpacker can't create them. Unless the filenames are stored elsewhere then there's no way to get them.

I've had a look at it. Haven't had much luck so far, but it seems as though the .SB4 follows the same format, although it might be a different audio type that for some reason vgmstream doesn't recognise. I'll keep trying though, see if I can make sense of it.

The whole file is split into various chunks. Offset 0 contains the start of the first set of chunks. Offset 4 contains the start of the audio data section (in Playstation ADPCM format) Offset 8 contains the start of the second chunk. I'm not sure what most of the chunk data is, but the "PPVA" chunk ...

Yeah, I can have a look if you post some of the example files.

You can drop that smaller .SB4 file onto Foobar and it will play the audio with vgmstream.

That file just contains standard raw PCM audio without any headers or other info. There will most likely be another file somewhere which contain sfilenames and offsets/sizes of the files in this .SS4 file. I've just remembered: in the PC version, the audio info and filenames are stored in .XML files...

Instead of using decfsb, just drop the encrypted fsb file into Foobar with Vgmstream installed. It plays the files perfectly.

While the other .wav files in the game are higher quality PCM audio, the sounds in common.xwb are only 11025/mono/XBOX ADPCM.

Not sure what you used to extract them, but my attached script will extract them correctly in a playable format, with the right filenames.