I'm thinking that this is one option.

T

 

This is my current setup. Sorry, for the horrible drawing

 

A picture says 1000 words...lol

 

Having a tough time with the pic. It's just not focused, but make it look like Ts pic and you're good to go!

 

If you've got it hooked up exactly like your drawing then no wonder your having issues.
When you attach a set of Y's to your cables you now have 2 reds and 2 whites. The front channel of the amp MUST HAVE 1 red and 1 white. Same goes for the rear

 

Let me go back and verify, I'm going off memory.

 

Most people can relate RCA colors to red and white. When you introduce a set of Y splitters, now you have 2 reds and 2 whites at the end of the RCA. You take one red and one white for each channel. Your drawing suggests that you have 2 reds on one channel and 2 whites on one channel on both amps. That won't fly and stands to reason why your setup sounds like crap.

 

Using colors only, this is how the front should be connected.
Red is red and black is white in the diagram.

Edit: The front outputs will include the faring and tourpak speakers.
The rear outputs are reserved for the JL amp/Pioneer Pro's.
Use T's diagram to wire the JL amp.

 

I would not split about a way that allows you to keep front and rear in this setup. You need the 998 xovers for the 4180. So if you keep the front inputs to the 4180 you will have the tour pack and fairing, which can use the same xover frequency and then the rear output to the JL to have a lower freq for the Pioneer Pro.

 

You are correct. I should have been more clear on that.