So I have managed to get the audio split working with ReLive using VoiceMeeter for Call of Duty: Modern Warfare/Warzone 2019 with help from this Reddit post.
I have tried using OBS Studio to record (not stream) but the additional resource demand and final output quality was not as good as using ReLive!
This guide is using:
- Radeon ReLive v20.4.2
- Steel Series Arctis 5 (USB Chat Mix Dial version)
Install VoiceMeeter / VoiceMeeter Banana and Virtual Audio Cables.
Open Sound from Start Menu or right click the volume icon in the system tray Open Sound settings.

Select Sound Control Panel and set Playback to:
- Default Device: VoiceMeeter Output (VB-Audio VoiceMeeter VAIO)
- Default Communications Device: VoiceMeeter Aux Input (VB-Audio VoiceMeeter AUX VAIO)

Then Recording to:
- Default Device: VoiceMeeter Output (VB-Audio VoiceMeeter VAIO)
- Default Communications Device: Microphone (Arctis 5 Chat)

Open VoiceMeeter Banana and set the hardware input/outputs.

Hardware Input 1 = CABLE Output (VB-Audio Virtual Cables)
- A1 = send to Headphones
- B1 = send to Virtual input
Hardware Input 2 = Microphone( Arctis 5 Chat)
- A1 = send to Headphones (if you want to hear yourself otherwise unselect it)
- B2 = send to Virtual input
From here you can add Compression (Comp), Noise Gate (Gate), increase your db and Intellipan effects for your microphone.
VoiceMeeter VAIO
- A1 = send to Headphones
- B1 = send to Virtual input
VoiceMeeter AUX
- A2 = send to Headset Earphone (Arctis 5 Chat)
- B1 = send to Virtual input
Hardware Out:
- A1 = Headphones (Arctis 5 Game)
- A2 = Headset Earphone (Arctis 5 Chat)
You can add more final effects to each channel in the Master Section.
Within Call of Duty: Modern Warfare 2019 Audio set:
- Voice Chat Device: Default Communication Device

Then in Radeon ReLive set:
- Audio Capture Device: VoiceMeeter Aux Input (VB-Audio VoiceMeeter AUX VAIO)
- Separate Microphone Track: Enabled

I hope that helps!