Video from RCA, audio from HDMI at the same time

Hi guys! I was not satisfied with the sound quality from RCA on my RPi3, so i bought this: http://www.gearbest.com/cables-connector…17276.html (i know that i can use usb soundcards too, but i want to use this connector to my projector too, so it’s 2in1 for me)
I’m using Kodi on an old CRT tv, so the video must come from the RCA cable, but i want better audio from the HDMI-Jack adapter. My problem is when i plug the HDMI cable in my RPi, i can’t see anything on the TV.
“sdtv_mode=2” do nothing
“hdmi_ignore_hotplug=1” i can see the video, but no sound from HDMI
Is there any way to change my config.txt to fix this problem?