1. One guy told me I can run cables from a sub into the speaker terminals along with my main speakers.
Some subs can be connected this way.
2. Another guy said just run cables from the sub into a Pre Out jack.
This is best. Your receiver has 2 pre-out jacks. Use either one.
3. Another said that I should probably ditch the plan and get something that would allow me to hook up two or even four subs.
You already can hook up four if you want. So your plan is fine.
4. Another said some things I still can't understand.
With audiophiles this is what we call situation normal.
I'm
a simple man, and mistakenly thought this was a relatively simple idea.
Yes. But audiophiles love to make everything as complex as possible.
My bad. But I'd still like to get something to enhance my listening
enjoyment, without having to buy a new power source and filling the
living room with subs, and without needing to understand what bass
management or DSP based EQ means.
One sub will do you just fine.
Forgive my naivety if you must; help
me if you can, remembering that the simpler the explanation, the better.
Any time.