speakers and cables

Might not be the smartest guy in the room, I don't understand why this is so difficult. 

You have 1 amp, 2 subs and 2 speakers. 

You are going to be using line level inputs on the subs. You have L/R subs

Amp has L/R outputs

There are L/R speakers. 

Easy way is to go....

amp-LSub-Lspeaker 

Amp-Rsub-Rspeaker

You can do that a few ways run speaker wire to the sub, speaker wire from sub to speaker. Or you can bi-wire sub/speaker

The other way if you want speaker fist to not degrade the signal is...

amp-Lspaker-Lsub

You can us a spade from the speaker to the sub.

Keep it simple, don't overthink it, don't think you need to buy a bunch of things and have a tangled mess to hook up. Also use the crossovers and filters on the subs. I don't have subs on the 2ch stop, but have 2 big subs on my HT setup. Hooking them up was easy, getting the XO point, location and level set was the most difficult. Also when done, make sure the subs are in phase. That will kill this entire process. 

@immathewj @mswale @thecarpathian

I apologize if I confused or frustrated anyone. I know it's a simple issue for people who know what they are doing. I clearly don't.

In the process, I learned a few things though. The silver lining is that if I had a sub out or pre out on my component, I wouldn't have gone down in these rabbit holes and would not have learned anything. 

I also learned many ways to degrade a signal  

I think for the most part we're all guilty of making this sound way more difficult than it is.

The only way my way will work is if the output on sub1 sends the full signal to sub2, which it won’t. It’s low pass filter at the input I believe will stop the lows there and only pass on the higher signal through the high pass filter on its output to sub2 negating what having a second sub in the mix is for in the first place since no low Hz signal will be going to it.

Now you’ve got me going for my own supply of baby aspirin, @thecarpathian.

There’s only filters on your subs, not active.

Also use the crossovers and filters on the subs.

I apologize if I confused or frustrated anyone.

I am not at all frustrated, but I can understand how anyone could be confused after reading through all of this.

On edit:  but be sure to let us know how you feel about the sound when you put the 'Y' splitters in.

Also when done, make sure the subs are in phase. That will kill this entire process.

@mswale , if OP hooked up to both of his subs from amp + to + and - to -, and then he went from his subs to his speakers in the same manner (+ to + and - to -) is there any reason that his subs (or speakers) would be out of phase with each other? That is a serious question; OP did report that he felt that things sounded "thinner."

On edit:  if OP uses 'Y' splitters from preamp and goes out to his subs via RCAs, there is no way the subs could wind up out of phase?