For maximum colour quality
Goto LG
Monitor Settings>All Settings>Picture.Additional Settings>HDMI Ultra HD Deep Colour
Make sure it is enabled.
Then select the ISF Expert picture mode.
See this link for setting up Resolve for grading
For correct video monitoring…goto Settings/Master settings
Your Timeline Resolution needs to match your Video Monitoring format. See these examples of different resolutions.
Set System Audio to Scarlett 18i20 USB
Location of volume control on Scarlett 18i20 USB
Use the settings below to have your video output go to the main monitor for colour grading and your audio to the genelec speakers.
Preferences>Video and Audio
Goto Preferences>Video and Audio I/O
Use the following settings to setup Resolve for 5.1
Your timeline needs to be 5.1.
Make a new timeline and copy paste the picture from your graded timeline
In the Fairlight Page goto Menu>Fairlight>Bus Format and select 5.1
Your timeline will look like this. Return to the Edit Page
Right click in the track panel and select Convert to Linked Group. Your tracks will be renamed (L-R-C-LFE-Ls-Rs)
Add your 5.1 mix. In the in the correct order L-R-C-LFE-Ls-Rs.
With you 5.1 mix added, and with the settings above you should be able to monitor and export in 5.1.
Still unsure? Download this 5.1 test file. Add it to the end of your timeline. It should be clear if you have the tracks correctly assigned to the speakers.