Hey man, don’t feel like your butchering it. It’s probably ME! Some of us(probably mostly me) forget that the terminology we use, is turned into shorthand after many years of communicating about it. Sorry for not thinking about that a little more. You’re doing fine, and if you need to ask again, go for it. That’s how we learn. I guess I feel like I’d rather assume you know certain thing and find out you don’t than talk down to you like some mr know it all.
So the crossover, or XO, is the point at which the avr transitions from sending content from the speaker to the subwoofer. The “woofer” in almost all speakers is passive, and powered by the avr, which you’ve picked up on. The subwoofer is powered by itself but content is still sent from the avr, which due to its design is only bass and midbass.
Think of the frequency range being divided into two parts. High and low. Speakers are responsible for the high, and subs are responsible for the low.
Imaging a piano being played through your system starting at the very top twinkly keys and working your way down to the left. When you get to the last 1/3(example) that’s where the avr would start sending content to the sub. This XO is not a brick wall, but slopes down above and below that point.
Maybe this will help
(disregard the LFE section in the pic, just for now)
You’re basically right on the pre amp. Instead of connecting your speakers directly to the avr, you’d connect them to the amp with speaker cable, which in turn is connected to the avr by rca. The avr sends the signal to the amp, but volume is still controlled by the avr. This is because the way volume works is not how most people think. The volume knob is actually used to attenuate, or choke power. Like a dam in a river. The avr is loaded with power(water in the river) but the gates(volume knob) are used to let more out, until finally when the gates are wide open it’s the same as volume being all the way turned up. Please disregard that last bit if I made things more confusing. I’m still on my first coffee! Lol
Other important avr features, to me at least would be Audyssey room correction. This is basically an equalizer that’s semi-automatic. You place the included mic where your ears go and it plays tones and measures(internally) how those tones interact with the room. Then it adjusts the delays, due to different speaker distances and equalizes the signal for a flat response. Flat response means if you run a sweep tone from 20hz up to 20khz the sound would stay even, and not have any frequency ranges that are louder, or quieter than others. Thats basically to maintain a balanced sound. I assume that’s the earc you asked about. The RC in that would probably stand for “room correction”.
I have tried some “game mode” lag compensations and haven’t found any of them useful personally. Wouldn’t worry about that one. I wouldn’t be too concerned about power ratings as most competent AVR’s should have enough. As long as you don’t have super power hungry speakers, or powering a block party.
Ok. That’s all’s I gots for now. I hope I’m not making things more confusing. Just trying to help. Sometimes I actually can!
Btw, if you’re preference is really to keep the layout how it is. Then I would also move the couch ahead a couple feet, and then put surround speakers on stands in their proper locations. Plenty of available, IW/IC(in wall, in ceiling) speakers to do Atmos with. Shady listed the usual suspects for speakers, and they all have something good to choose.