DTS:X APO4 + DTS Interactive, easy read guide updated, here. I included 'Win CAudio', which will increase audio quality and reduce latency.
If you have already installed and are setup, disable the audio services and apply, shutdown the PC for 5 mins.
Admin console: net stop dtsapo4service & net stop audiosrv & net stop audioendpointbuilder
You only need to run 'Win CAudio' once per Windows install, not per pack.
Highest latency with the pack (just DTS, and E-APO upmixer) will be buffer latency.