Hi Daniel,
Congrats on your first system.
#1 => The RCA cable connected to the Sub out on the rear of the Sherwood goes to the Left RCA Sub in on the Energy Sub. Just to make the set up easier, once you make that connection, plug in the Sub to power, turn the power mode on the Sub to "on", the Low pass filter knob clockwise to about 120, and turn the volume level on the Sub to about 2 o'clock. (Once this is all working the power mode can be switched to auto.) The status indicator light on the lower front of the Sub should turn blue indicating it's functioning.
Here's the
Sherwood RD-6513 Manual and the
Energy ESW-C8 Manual (click on the links) Read through them and follow the adjusting of each speaker (including the Sub) on page 20.
#2 => Sorry, but connecting M-Audio AV 40 monitor speakers to your system isn't feasible as there are no "pre-outs" for the surround speakers on the Sherwood RD-6513.
Start with this and we'll see how it goes. Folks will chime in to assist. Tell us if the Sub indicator lights up.
(By the way, trim the length of the exposed speaker wire that goes into the connectors on the back of the Sherwood. They shouldn't have a lot of excess protruding . They should look more like the cable plugged into the Front Left positive connector.)
Please advise the make/ model of the 5 passive speakers.
I hope this was helpful.