Is 35’ and 50’ to long for RCA sub cables?

My short answer is, Yes.
Now if you could run XLR, then it wouldn't.
Bob

Well now noisy is it? If it's quiet and didn't loose signal strength, what's the issue. If your having a problem with RFI, or EFI  that's different..

Enjoy..

Yes you will lose sound quality for sure.

I’ve been told to run XLR (mic) cable and the. Just use the two conductors for RCA. Would that help even though my subs don’t have XLR inputs?

I’ve been told to run XLR (mic) cable and then just use the two conductors instead of all three for RCA. Would that help even though my subs don’t have XLR inputs?

Again is it noisy?

Again is it noisy?

Regards 

Regards

I’ve been told to run XLR (mic) cable and then just use the two conductors instead of all three for RCA. Would that help even though my subs don’t have XLR inputs?

No. You’re still putting a single ended signal down the cable. In order for common mode rejection to work, you need two signal wires, each out of phase to the other. 

Use RCA cables and see what It sounds like. More than likely it will be more than good enough for a sub.

I am running a 75 foot subwoofer cable to the home theater subs and no issues. Make sure they are shielded. I bought mine from Blue Jean cables. Also, Mediabridge makes a decent shielded subwoofer cable and you can  those virtually next day service with Amazon Prime. 

Why not go wireless?

@OP,
You are between a rock and a hard place.
I would take @audioquest4life 's rec and get a good shielded sub woofer cable in RCA. I know Audioquest makes some inexpensive sub cables that include a grounding wire-which should minimize any ground loop hum.
Bob

I ordered two sub cables from Mediabridge on Amazon. 
One cable was 50’ and the other was 35’ and both were perfect for the length. 
Hooked them up loosely to see if there was any issues and nothing, worked great and sounded great. No hum!

Now I have to get them all working in harmony together!!!

thanks