Query: My motherboard is MSI B360M PRO-VDH. I have connected Logitech R20 speakers to line-out port (green colored), & JBL flip 4 to line-in port (blue colored) via AUX cable. As a result, I am able to listen to music from both speakers simultaneously! Is it safe to use 2 audio ports together & play speakers in this way? Actually, my logitech subwoofer stopped working a long time ago and so I want to use JBL in place of the subwoofer.