Subwoofer RCA output

[GregZ]

So I have this radio Android 8.1/9.0 System Rockchip 3368 PX-6 6-Core in my 07 G35 and when I originally installed the unit I was using factory speakers factory amp with LOC tapped into factory speakers for subwoofer. Sounded great but then i upgraded all my speakers in the car and switched to the RCA plug with the subwoofer out RCA(this was main reason I purchased this radio as it came with a subwoofer out rca) and installed 3 sets of RCAs. The set attached to the sub out rca is same I used with LOC tap. They work, the RCA y splitter is brand new, the other two sets of RCA'S work yet I get almost nothing from the subout rca. The sub had a very low hum when music was played but nothing fixed this. What do I do now??

[GregZ]

Sooo not one idea on what the issue is? I've bought and tried a Skar EQ to boost signal but sadly when you turn up the 12hz dial it does it for ALL speakers...Fail. So far the only that thing that works is hooking up my old LOC tapped into rear speaker wires and thats NOT how I wanted to get a signal to my sub amp. I tried getting a reading from the subout rca but wasn't even able to achieve that. Also ever since I installed the new speakers along with the new amp and went to the all RCA wire harness, when I use Carplay music will just randomly stop working then come back on. Once it just shut down completely all on it's own. Even before the install of new speakers with just the factory speakers and subs the unit will just decide on it's own to change the song or even go to a different app altogether. I love having the unit, looks sick and for the most part works well but the glitches start to wear on ya sadly though for the G35 installing any other type of radio looks crappy. I am by no means "shitting" on the product, as I said I love having it I would just like resolutions to these issues.