Originally Posted by bgbennyboy
There are two possible approaches to repacking:
1) Hack the original .xwb file - just changing the data and adjusting the block sizes.
2) Use the Microsoft's XACT tool (the tool that was originally used to build and compile the wavebanks) to make a new one. This might be a simpler approach. XACT comes with the free XNA Game Studio. Note that it only accepts wav/aif/aiff music/sounds so any re-recording shouldnt be encoded in a lossy format as you'd have to convert it back to wav again anyway.
Good stuff. Do you know of any way to get XACT on its own? Grabbing the entire studio would take a lot of time, I imagine.