This is a safe tweak, and should contain absolutely nothing to cause a crash. Seriously. If you are having crashes it's likely from another source. DirectX 10 is the largest culprit in Windows 7, 8, and 10 - try disabling it using step 1 of this guide. Or, if you really want to use DX10 and are on Windows 7, try this guide.
Having said all that, I hold no responsibility for anything going wrong because of this fix etc etc.
This tweak does not fix issues such as missing audio or sounds suddenly cutting out.
Download the fix from one of the following mirrors:
Installing the mod is easy. Simply extract the downloaded file into “Bioshock 2\SP\Content\System” *, and you're all done!
Your System folder structure should now look like the following:
To uninstall, simply delete SoundMixStates.ini.
* If you cannot find your Bioshock 2 installation directory, use the following steps. Right-click the game in your Steam Library and choose ‘Properties’. In the new window choose the ‘Local Files’ tab, then click the topmost button titled ‘Browse Local Files’. The location of Bioshock 2 will now open.
People found you could restore the original mix by replacing ConfigINI.IBF with the original retail version. This worked to an extent, but as the replacement file was pre-DLC it didn't work very well with Minerva's Den and the Protector Trials.
ConfigINI.IBF contains a bunch of packed .ini files, but the only relevant to this is SoundMixStates.ini. We do some tomfoolery to extract a retail version and a latest version (1.5.0.019), compare the two to find DLC entries, then add them back into to the retail version.
There looks to be potential here to improve the mix, things like increasing the volume of certain guns. It would require much experimentation & investigation to discover unlisted object names, and would need plenty of time tweaking numbers just to get a start (the mix maxes out at 0.0db, so before you can make particular entries louder you'd have to change all the other numerous entries to be softer). But I welcome anyone to have a go!
It's interesting to note that SoundMixStates.ini went completely untouched until patch 1.4, and then the mix was suddenly modified. If anyone knows the internal reasoning, I'd be very intrigued to know why it was changed. As the 360 version went unchanged and hence doesn't have these bugs, I imagine someone porting the DLC to PC simply chose the wrong codebase on accident.
For anyone interested, here is a zip containing all the untouched .ini files extracted from ConfigINI.IBF. These can be used to change a lot of the variables for the game, including damage and loot tables. Difficulty mods have previously been made for Bioshock 1 using these methods.