Help with connecting Sub-woofer

Hi All,
I am completely new to home theater and audio equipment. Just purchased a house with a media room which is pre-wired for speakers and trying to figure out how does the sub-woofer connect. Please help!

Let me describe the cables and the equipment:
1. Main wall plate in the closet: There is a wall plate in the closet where bunch of the wires are coming out from.
(i) 7 of these are 2-conductor speaker wires. I have already tested and labeled these for each speaker
(ii) There are 3 red/orangish 22AWG CMR wires with 4 conductors in each: Red, Black, Blue, Green
(iii) There are 4 coaxial like cable. Not too familiar with these but I believe these are cat-5e cables
(iv) there are 3 red wires which are slightly thicker than the other 3 red/orangish ones. i am not sure what these are but they are not coming out of anywhere else in that room
2. Wall Plate below projector Screen: This is the wall plate thats right below the proejctor screen next to an electrical outlet.
(i) it has 1 of the 7 speaker wires which goes to the center speaker
(ii) the only other wire here is 1 of the 3 red/orangish 22 AWG CMR wire with 4-conductors in it
3. Wall plate on left-wall: This wall plate is on the wall to the left of screen. It has only 1 yellow coaxial/cat-5e cable but it doesn't seem to pull out of the box and is not terminated else where in the house. Not yet sure where.

4. Receiver: The receiver I have is Sony STRDN850 7.2 channel. It has 2 outs for sub-woofer

5. Sub-woofer: I have a monoprice powered sub-woofer which has speaker-level ins and Line level inputs. it's called Premium 5.1-Ch. Home Theater System with Subwoofer on Monoprice website


My initial guess is that the sub-woofer is connected using the 4-conductor wire coming out of the wall below the screen but any research i have done so far, i haven't been able to figure out how to use that wire to connect to sub.

please tell me if this is enough information to help.