So i tried connecting the sub a few different ways.
First i tried connecting the shield/drain wire to black, then the in wall red wire to the red on the RCA adapter on the AV receiver side. On the sub side i connected the in wall wires directly to the wire input on the sub without the RCA adapter. The sound output seemed very low even with the sub blasted to the max. The Audyssey settings all seemed off as well.
Then i tried connecting the RCA adapter on the receiver side with the black speaker wire in my wall, and the red to the red ( so I avoided connected to the shield bare wire ). Then I connected the RCA adapter to the sub in the same way. The output on the sub was way stronger and I had to lower the settings on the sub to 50%. However, i noticed EXACTLY what you said after pausing the scene i was testing with. After a few moments there was a hum/noise on the sub after awhile of no input from the AV Receiver. It was pretty noticeable even on the lower settings.
Then i tried connecting again to the shielded wire with RCA adapter on both the amp side and the sub side. And it was perfect. No noise or hum when there is no input on the AV receiver. I'm not sure if it was maybe just my connection but it seems the RCA input is much more powerful than just the speaker wire.
Once i got the sub situated the results on the audyssey tone tests came back as I had hoped but i had to change the Denon Setting of the LPF to "LFE+Mains" with a crossover at 120hz. In the past i noticed if i put this setting just to "LFE" i barely get any subwoofer at all. I'd have either too much woofer or too little and could never get it right. The individual speaker crossovers to 40hz cutoff for my front speakers and my in ceiling surrounds at 60hz cutoff. I'm still undecided whether i will bump the crosssovers up a little bit or not. I know the THX settings usually 80hz cutoff across all speakers. But overall, I'm very happy with the results. I may leave it with the Audyssey results. It sounds pretty well balanced to me as of now. Although at times i think I'd like a little bit more subwoofer. That's usually always the case tho.
Thank you very much
@noiseboy72 I wouldn't in a million years ever thought to connect to the "drain" shielded wire.
Now all I need to do is build a box to hide the sub and I need to try to get the right wall plates to connect the speaker wires so I don't have these ugly open wall plates with speaker wire coming out of them. I'm still not sure if i should put the RCA adapter near the sub inside the wall, and then put the wall plate as a RCA port, or put it as as two banana plugs then, connect them via RCA adapter near the sub and amp. I lean toward the former.
Eventually i'll need to put a hole behind my tv to make sure i can hide cables from my receiver to my TV. For now i can hide them behind the rather large S30 center speaker.