Hi all, I'm very new to this and I've just been handed over a KEF 5.1 setup along with a Denon AVR-3805 amplifier by my uncle. All components were working when the setup was dismantled. I've paired all the speakers and they work perfectly. The KEF sub won't make a sound. I've got a Y connector to go in at the Left Input socket on the receiver and the red and white plugs at the amp end is in the Subwoofer sockets as written in the Denon manual. Images below. What am I doing wrong here? Is the powered sub supposed to be plugged elsewhere? I tried everything but nothing works. The sub has a green LED on at the back and I've toggled all the dials and switches at the back of the sub with music playing but no sound. I've factory reset the amp, the output mode is stereo (FL, FR and Sub). I can't even see the subwoofer setting option in the speaker setting menu.