speakers and cables

Step one is to determine if the output of your amp is balanced or single end. If it is balanced the negative is not ground. If you don’t know the. The safest thing to do is connect the black to the chassis. If you have REL line subs then you need to combine the two positive wire to the right sub s x connect if to the right positive terminal. Then repeat this for the left. Black goes to chassis. This should work. 

I think I have a compromised system

I am also a member of that club.

it’s a glass with dirt on it, an extra layer of dirt won’t make a huge difference

That is absolutely one way to look at it. Of course, the other way to look at it is. . . .

And despite my limitations, I love listening to my rig,

And that’s a healthy attitude and one I try live by myself. If there is something I think that I can easily and affordably correct, I will give it a try. But sure, there are always compromises and certain sacrifices to be made in an imperfect world. I think that ’Y’ connectors out of a preamp MIGHT be a degree of a compromise that MIGHT sacrifice the siganl to a degree (to what degree I won’t venture, and "might" was an operative word), but what you get for that compromise is the ability to hook your subs up with RCAs and go straight to your speakers from the amp. That might be worth the compromise, and I guess the only way to know for sure would be to try both ways and compare. And I, personally, hate making audio comparisons, although some members seem to literally thrive on it.

As far as my analogy . . . that applies to the way I believe that my hearing works and not necessarily yours or anyone else’s. After I was thinking about it for a while, I actually thought of a better analogy for myself. Do you remember quite a long time ago hearing about when movie theaters were doing something to the effect of slipping in a quick frame of a cheese burger or something delicious every so many frames of the movie they were showing? The frame of the cheeseburger (or whatever it was) came and went so quickly that no one in the audience actually realized that they saw it. But, cheeseburger sales at the concessions counter increased dramatically. Or something like that--I don’t remember the exact details. But where I am going with that is that I believe my own hearing works kind of like that. I may not think I hear something that incrementally improves or degrades the performance of my system, but over time I start to realize that I am experiencing an increased level of comfort in my listening experiences (note the plural form) or, on the other hand, an increased level of listening fatigue and less desire to go back to my room and listen.

Just my own personal theory on my own personal hearing is all.

Not long ago I posted a question about power cords, and what one of the respondents replied with was mind blowing to me. Mind blowing in the differences he said he heard with different cords. That ability to hear (and identify what I hear) is wayyyyy beyond me.

@immatthewj

I think your ear can train your brain, and your brain can work with your ears to look for more details. But it truly only matters with discerning systems, "anyone" can hear the difference between a bluetooth pill and and car radio. We are in this hobby because we look for the perfect sound. So you can probably hear a lot more than you think :)

I remember your example from Colombo.

I also like Andrew Jones’s explanation that everything is determined to be flawed from the source to the speaker and what engineers do is fixing errors along the way. (Paraphrasing)

@sgordoxyz thank you, it is balanced

Update:

I implemented the @carlsbad2 method and it works nicely

Update:

I implemented the @carlsbad2 method and it works nicely

Which is picture #2 of the pictures you posted, correct?

Are you still going to try out a pair of "Y" splitters from Amazon just to see if you like RCAs to subs better? For what those splitters (probably?) cost, I would.

And, more importantly, how is the sound of (now having) TWO subs (count ’em!) sounding? Kickass?