Set the number of CPU’s to 1 in Settings/System/Processor.
Set the Execution Cap to 100% in Settings/System/Processor.
Set the Paravirtualization Interface to Minimal in Settings/System/Acceleration.
Set the Host Audio Driver to PulseAudio in Settings/Audio.
Set the Audio Controller to Intel HD Audio in Settings/Audio.
When your VM is up,
Edit 20180312: Check the checkbox [x] Disable all enhancements in
Control Panel \_ Sound \_ Speakers \_ Properties \_ Enhancements