couldn't create xaudio2

Had the same issue on Windows 7. Fixed it by downloading https://www.nuget.org/packages/Microsoft.XAudio2.Redist and copying \build\native\release\bin\x64\xaudio2_9redist.dll from the downloaded package to C:\Windows\System32 and renaming to XAudio2_9.dll. The package can be opened with 7-Zip.